OH Boiler Operator cheat sheet

ASME Section I governs power boilers; ASME Section IV governs heating boilers.

Maximum allowable working pressure is the highest pressure allowed by the weakest component and is stamped on the boiler nameplate.

Safety valve set pressure must not exceed the maximum allowable working pressure, and valve capacity must equal or exceed the boiler's maximum steaming capacity.

Firetube boilers pass hot combustion gases through tubes surrounded by water; watertube boilers pass water through tubes surrounded by hot gases.

Staybolts tie flat tube sheets and plates together to support pressure loads; a broken or leaking staybolt is a structural defect.

The water column connects the boiler steam and water spaces to the gauge glass and supports the low-water cutoff and try cocks.

A pressure gauge range is commonly about twice the operating pressure, placing the normal operating point near the middle of the dial.

Hydrostatic test pressure for new or repaired power boilers is 1.5 times maximum allowable working pressure with safety valves isolated or removed.

Blowdown valves are fitted at the lowest practical point to remove sludge and control dissolved solids.

Normal water level is at the center of the gauge glass, keeping the fireside surfaces covered and leaving steam space above.

If no water is visible in the gauge glass, shut off fuel, stop firing, and do not feed water into an overheated boiler.

Test the low-water fuel cutoff by lowering the water level or opening its test valve; the burner must stop before water leaves the visible glass.

Bottom blowdown removes sludge; use short, frequent blows with the boiler under normal load and never blow down when water is low.

Two-valve blowdown sequence: open the boiler-side valve first, then the downstream valve; close the downstream valve first, then the boiler-side valve.

Blow down the gauge glass to verify that water connections are clear, then close the drain and watch the water level return promptly.

Foaming and carryover are caused by high dissolved solids, high alkalinity, oil or organic contamination, or sudden steam demand.

Continuous blowdown from the steam drum controls dissolved solids; bottom blowdown removes sludge and sediment.

Water hammer is caused by trapped condensate or rapid valve movement; drain and trap steam lines before admitting steam.

Complete combustion requires fuel, oxygen, ignition, turbulence, time, and sufficient temperature.

Stoichiometric air is the exact amount of air needed for complete combustion; practical firing uses excess air.

Excess oxygen in flue gas indicates excess air; carbon monoxide indicates incomplete combustion.

Natural gas contains roughly 1,000 Btu per cubic foot; No. 2 fuel oil contains about 140,000 Btu per gallon.

Draft systems include natural, forced, induced, and balanced; induced draft keeps the furnace slightly negative.

Pre-lightoff purge removes combustible gases from the furnace, typically requiring at least four furnace air changes.

A flame safeguard closes the fuel valve on flame failure and requires a purge before restart.

Fuel oil must be atomized; viscosity is controlled by heating the oil to the proper temperature.

One boiler horsepower equals 33,475 Btu per hour, or about 9.81 kW.

Daily checks include gauge glass condition, low-water cutoff test, flame signal, draft, and abnormal noise or leaks.

Internal inspection examines fireside and waterside surfaces for scale, corrosion, cracks, and tube wear.

Hydrostatic testing at 1.5 times maximum allowable working pressure verifies pressure tightness with safety valves isolated.

Ultrasonic thickness testing measures wall loss from corrosion or erosion without cutting the boiler.

Safety valve pop testing verifies opening pressure and reseating; only qualified personnel perform it.

Lockout/tagout isolates energy before repair; verify zero energy and close fuel, steam, and water valves.

Refractory cracks or spalling can cause hot spots and efficiency loss; inspect furnace walls and baffles.

Water treatment tests include hardness, alkalinity, pH, conductivity or TDS, and oxygen scavenger residual.

Burner maintenance includes cleaning electrodes, flame scanner, nozzles, and checking linkage adjustment.

The safety valve is the final overpressure protection; never plug, wire, or use it for routine pressure control.

The low-water fuel cutoff automatically stops fuel firing on low water; it must be tested regularly and never bypassed.

A high-pressure limit switch cuts off fuel at a set pressure below the safety valve setpoint.

On flame failure, fuel valves close and the burner locks out; purge the furnace before restarting.

If the gauge glass breaks, close the upper and lower gauge-glass valves, then use try cocks to check water level; do not stand directly in front of the glass.

For a fuel leak, stop firing, shut off fuel at the source, ventilate, eliminate ignition sources, and evacuate if the leak is large.

Confined space entry requires a permit, atmospheric testing, ventilation, an attendant, and a rescue plan.

For a runaway burner or uncontrolled pressure rise, trip the fuel, isolate the boiler, and vent safely.

Steam and scald hazards are controlled by draining lines, wearing PPE, and opening valves slowly.

Ohio boiler rules are administered by the Division of Industrial Compliance, Bureau of Boiler and Pressure Vessel Compliance.

ASME Code construction requirements are adopted by reference; inspectors verify the nameplate and certificate.

The operator must maintain required logs and make them available to inspectors.

Do not operate a boiler beyond its maximum allowable working pressure or with safety devices out of service.

Report accidents, explosions, or dangerous conditions to the jurisdiction as required.

Boiler inspections may be required before operation and after repairs; operators must provide access.

Operator responsibilities include water treatment, blowdown, fuel-air adjustment, and emergency shutdown.

Required fittings include safety valves, gauge glass, pressure gauge, low-water cutoff, and blowdown valves.

Only authorized persons may adjust safety valves or combustion controls.