Power Eng 4th Class 4A cheat sheet

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.

Sensible heat: Q = m·c·ΔT; latent heat of vaporization of water at atmospheric pressure ≈ 2257 kJ/kg.

Superheat = actual steam temperature minus saturation temperature at the same absolute pressure.

Thermal efficiency of a Rankine cycle = (h1 − h2)/(h1 − hf); turbine work minus pump work divided by heat added.

Steam tables: enthalpy of saturated liquid hf, saturated vapor hg, latent heat hfg = hg − hf; hfg falls to zero at critical point (22.06 MPa, 374 °C).

First law for steady flow: Q − W = m·(h2 − h1 + (V2² − V1²)/2 + g(z2 − z1)); kinetic and potential terms often negligible.

Stress = force ÷ cross-sectional area; strain = change in length ÷ original length; Young's modulus = stress ÷ strain in the elastic range.

Thermal expansion: ΔL = α·L·ΔT; a 100 m steel pipe (α ≈ 12×10⁻⁶/°C) grows about 12 mm per 10 °C rise.

Boiler horsepower = 33 475 kJ/h ≈ 9.81 kW; 1 kW = 1 kJ/s; 1 bar = 100 kPa = 0.1 MPa.

Heating surface is measured on the fire side; economizer and superheater surface are included, but waterwall tubes are counted by their exposed fire-side area.

Factor of evaporation = (h_steam − h_feedwater) ÷ 2257 kJ/kg; equivalent evaporation = actual evaporation × factor.

Boiler efficiency (indirect/heat loss method): 100% − stack loss − moisture loss − unburned carbon loss − radiation and convection loss.

Safety valve set pressures: the lowest-set valve is at or below MAWP; no valve may be set above MAWP, and the highest set pressure is typically ≤ 110% of MAWP.

Superheater and reheater outlet safety valves are set lower than drum safety valves so the superheater valves open first.

Water column and gauge glass must be blown down and proven; low-water fuel cutoff must be tested at each shift and after repairs.

A firetube boiler has products of combustion inside tubes surrounded by water; a watertube boiler has water in tubes surrounded by hot gas.

Steam drum internals: baffles and separators remove moisture; carryover causes high conductivity in the steam and superheater fouling.

Stoichiometric air for natural gas ≈ 9.5 m³ air/m³ gas (about 2 m³ per 1000 kJ); for fuel oil ≈ 14 kg air/kg oil.

Optimum excess air for natural gas ≈ 5–10%; for oil ≈ 10–15%; for coal ≈ 15–25%. Excess O₂ in flue gas ≈ 3% corresponds to roughly 15% excess air.

Draft: natural draft = stack height × (air density − gas density) × g; forced draft fans supply air, induced draft fans remove gas.

Flame scanners must prove flame within the trial-for-ignition period; typical pilot trial for ignition ≤ 10 s for gas, ≤ 15 s for oil.

Furnace purge: airflow at ≥ 25% of full-load airflow for at least 5 minutes before any ignition attempt.

Air-fuel ratio control on a jackshaft or parallel positioning system must be tuned with a flue gas analyzer at low, mid, and high fire.

Soot blowers reduce stack temperature by cleaning convection surfaces; a rising stack temperature at fixed load signals fouling.

Pulverizer fineness typically 70–80% passing a 200-mesh sieve; primary air transports coal and controls mill outlet temperature.

Centrifugal pump affinity laws: Q ∝ N, H ∝ N², P ∝ N³; Q ∝ D, H ∝ D², P ∝ D³.

NPSH available = (p_suction − p_vapour)/(ρ·g) + static head − friction loss; NPSH required comes from the pump curve.

Best efficiency point (BEP): operate between 70% and 120% of BEP flow to avoid recirculation, cavitation, and shaft deflection.

Specific speed Ns = N·√Q ÷ H^0.75; low Ns favors radial impellers, high Ns favors mixed-flow and axial designs.

Positive displacement pumps deliver nearly constant flow against varying pressure; a relief valve on the discharge is mandatory.

Reciprocating compressor: clearance volume reduces volumetric efficiency; multi-stage with intercooling reduces power and discharge temperature.

Steam turbine stage efficiency improves with superheat; condensers lower exhaust pressure and increase available enthalpy drop.

Diesel engine starting: pre-lube, barring, and air start pressure typically 1.7–3 MPa; overspeed trip tested before running.

ASME B31.1 is the Power Piping Code; B31.3 covers process piping; B16.5 covers pipe flanges and flanged fittings.

Pipe schedule number = 1000 × P/S, where P is internal design pressure and S is allowable stress; higher schedule = thicker wall.

Gate valves are for isolation, globe valves for throttling, and check valves permit flow in one direction only.

Safety valve: pop action with huddling chamber; relief valve: gradual opening proportional to overpressure; pilot-operated valves use system pressure to actuate.

Blowdown valves are installed between the boiler and the safety valve; the safety valve must never be used as a blowdown or isolating valve.

Steam traps: thermostatic (temperature), thermodynamic (velocity/pressure), and float-and-thermostatic (condensate level); trap failure causes water hammer.

Expansion loops and anchors absorb thermal growth; guides allow axial movement and prevent buckling.

Flange bolting is tightened in a star pattern in stages to compress the gasket evenly and avoid leakage.

A transmitter outputs 4–20 mA DC over its calibrated span; 4 mA is live zero so a broken wire reads below zero and is detectable.

PID control: proportional output = Kp·error; integral removes offset; derivative anticipates rate of change and amplifies noise.

Three-element drum level control uses drum level, steam flow, and feedwater flow to reject false level readings from swell and shrink.

Low-water fuel cutoff must be wired to lock out the burner and require manual reset; it is not a substitute for the gauge glass.

Flame safeguard program: prepurge, pilot trial for ignition, main flame trial, run period, and post-purge; any failure goes to lockout.

High steam pressure and high water temperature limit switches must be independent of the operating controller and tested periodically.

Calibration: zero and span adjustment against a traceable standard; record as-found and as-left values.

Thermocouples (mV output) and RTDs (resistance change) are common temperature sensors; RTDs are more stable and accurate at low temperatures.

Scale is mainly calcium and magnesium salts; hardness is removed by softening (ion exchange) or demineralization.

Internal treatment: phosphate or chelant for scale control, sulfite or hydrazine for oxygen scavenging, amines for condensate pH control.

Oxygen pitting is prevented by deaeration plus chemical scavenger; sulfite residual typically 20–40 mg/L in the boiler water.

Blowdown controls dissolved solids: conductivity is the usual indicator; maintain within the boiler manufacturer's limit.

pH target for boiler water is typically 10.5–11.5; condensate pH 8.5–9.5 to protect carbon steel return lines.

Foaming and carryover are caused by high alkalinity, high dissolved solids, or oil contamination; silica can carry over into steam and deposit on turbine blades.

Caustic embrittlement (stress corrosion cracking) occurs in riveted or stressed areas at high caustic concentration; nitrate or coordinated phosphate treatment mitigates it.

Feedwater heaters raise efficiency by bleeding extraction steam; they also remove some dissolved gases.

Combustion requires fuel, oxygen, heat, and an ignition source; the three T's are time, temperature, and turbulence.

Higher heating value (HHV) includes latent heat of water vapour; lower heating value (LHV) excludes it; natural gas HHV ≈ 37–39 MJ/m³.

Flue gas CO₂ and O₂ are inversely related; rising O₂ with falling CO₂ indicates excess air.

NOx control: low-NOx burners, flue gas recirculation, overfire air, and selective catalytic reduction (SCR) with ammonia or urea.

Particulate control: mechanical collectors, fabric filters (baghouses), and electrostatic precipitators; ESP efficiency depends on resistivity and field strength.

SO₂ control: wet limestone scrubbers, spray dryers, and dry sorbent injection.

Opacity monitors measure visible emissions; a sudden rise often indicates incomplete combustion or soot blowing.

Fuel oil viscosity must be reduced by heating for atomization; natural gas is measured by volume corrected to standard conditions.

Ohm's law: V = I·R; power P = V·I = I²R = V²/R; single-phase kW = V·I·pf ÷ 1000.

Three-phase power: kW = √3·V·I·pf ÷ 1000; apparent power kVA = √3·V·I ÷ 1000.

Motor synchronous speed = 120·f ÷ poles; a 4-pole motor on 60 Hz runs at 1800 rpm, with slip typically 2–4%.

Motor protection: overload heaters or electronic overloads, short-circuit fuses or breakers, and ground-fault protection.

Locked-rotor current is typically 5–8 times full-load current; reduced-voltage starters limit inrush.

Transformer: voltage ratio equals turns ratio; current ratio is inverse; kVA rating is set by winding temperature rise.

Emergency generator and battery systems supply control power, lube oil pumps, and emergency lighting on loss of normal supply.

Grounding: equipment bonding protects personnel; a ground fault on an ungrounded system is detected by a ground detector, not by tripping.

ASME Boiler and Pressure Vessel Code Section I covers power boilers; Section IV covers heating boilers; Section VIII covers pressure vessels.

ASME Section VI covers care and operation of heating boilers; Section VII covers care and operation of power boilers.

Jurisdictional inspection: internal and external inspections at intervals set by the authority having jurisdiction; certificates of inspection are posted.

Confined space entry requires permit, atmospheric testing (O₂ 19.5–23.5%, LEL below 10%, H₂S and CO below limits), attendant, and rescue plan.

Lockout/tagout: isolate energy, apply lock and tag, verify zero energy before work; only the person who applied the lock removes it.

Hot work permit requires fire watch, combustible clearance, and gas testing before and during welding or cutting.

Boiler room ventilation must supply combustion air and limit ambient temperature; gas-fired burners need permanent openings sized to the appliance input.

Incident reporting: any explosion, rupture, or serious injury is reported to the authority having jurisdiction immediately; records of operator training and log entries are retained.