NCCER Boilermaker cheat sheet

Lockout/tagout requires isolating every energy source, applying a personal lock, and verifying zero energy before work starts.

Entry atmosphere: oxygen must read between 19.5% and 23.5%; permit-required confined spaces need a permit, attendant, and atmospheric testing.

Trench spoil, tools, and materials stay at least 2 ft (0.6 m) from the edge; trenches 5 ft deep or more need sloping, shoring, or a trench box.

Scaffold guardrail systems are required at 10 ft (3 m) above a lower level; toprail 38-45 in high, midrail about halfway to the platform.

Ladder setup follows the 4-to-1 rule: base 1 ft out from the wall for every 4 ft of working height.

A grinding wheel's marked maximum RPM must equal or exceed the grinder spindle RPM; the guard stays on and the tool rest sits within 1/8 in of the wheel.

A fire watch is kept during hot work and at least 30 minutes after work ends, longer where combustibles may smolder.

Hearing conservation programs start at 85 dBA time-weighted average over 8 hours; hearing protection is mandatory at 90 dBA TWA.

Hand tool rules: match wrench size to the fastener, never use a cheater pipe, and replace any hammer handle that is cracked or loose.

Neutral flame: one clear inner cone, used for cutting steel and welding mild steel. Oxidizing (excess oxygen) gives a short sharp cone; carburizing (excess acetylene) gives a feathered three-part flame.

Acetylene working pressure never exceeds 15 psi (103 kPa); acetylene is never used with copper tubing or silver-brazed fittings.

Oxygen hose is green with right-hand threads; fuel gas hose is red with left-hand threads; keep oil and grease away from all oxygen equipment.

Cutting oxygen purity should be 99.5% or higher; low purity widens the kerf, produces slag, and slows the cut.

Cutting tip size and cutting oxygen pressure increase with plate thickness; the preheat holes are sized for the thickness range stamped on the tip.

Oxyfuel cutting is an oxidation process, so it cuts mild steel well but not cast iron, stainless steel, aluminum, or copper alloys without a powder or flux aid.

E7018: 70 ksi minimum tensile, all-position, low-hydrogen iron-powder coating; rods go into a 250 °F (120 °C) holding oven once the container is opened.

Standard single-V groove: 37.5° bevel per plate = 75° included angle, with root face and root opening set by the WPS.

SMAW current rule of thumb: about 1 amp per 0.001 in of electrode diameter, so a 1/8 in electrode runs roughly 125-140 A.

Third-angle projection: top view above the front view, right-side view to the right of the front view.

Line conventions: visible outlines heavy and solid, hidden edges short dashes, center lines long-short-long, dimension lines thin with arrowheads.

Scale of 1/4 in = 1 ft-0 in: multiply a measured print length by 48 to get actual inches.

Circumference C = πD = 3.1416 × D; the flat pattern for a rolled shell uses the mean diameter (OD minus one plate thickness).

Bend allowance BA = 0.01745 × A × (R + 0.5T), where A is bend angle in degrees, R the inside radius, and T the plate thickness.

A 3-4-5 triangle (or any multiple) establishes a true 90° corner in layout; the diagonals of a laid-out rectangle must measure equal.

Layout media: soapstone for rough or hot work, layout dye with a scribe for precise lines, center punch for hole locations.

Numerical dimensions and notes on the print govern; a scaled measurement is never substituted for a stated dimension.

Round-to-rectangular transitions are laid out by triangulation, developing the true length of each element before marking the plate.

Working load limit = minimum breaking strength ÷ design factor: 5:1 for wire rope and synthetic web, 4:1 for alloy chain.

Two-leg sling tension per leg = W ÷ (2 sin θ), where θ is the leg angle measured from horizontal.

Sling angle factors (share of load per leg): 60° = 0.577, 45° = 0.707, 30° = 1.000, so flatter slings carry greater tension.

The sling angle is always measured from horizontal, never from vertical; rigging flatter than 30° from horizontal is avoided.

Hooks come out of service at a 15% increase in throat opening, 10% wear, or any crack, twist, or bend.

Shackles are loaded along the bow-to-pin centerline; side loading and a screw pin that is not fully seated reduce capacity.

The hook is positioned directly above the load's center of gravity; tag lines control rotation and no one stands under a suspended load.

Wire rope is removed for kinks, bird-caging, heat damage, or six or more randomly distributed broken wires in one lay on a running rope.

Sharp corners are padded with softeners before choking a sling; edge protection preserves the sling's rated capacity.

Fire-tube boilers have hot gases inside tubes surrounded by water (large storage, lower pressure); water-tube boilers have water inside tubes with gases outside (higher pressure, faster response).

ASME Section I covers power boilers, Section IV heating boilers, Section VIII pressure vessels, and Section IX welding qualification.

Hydrostatic test of new construction is 1.5 × MAWP, held while all joints are inspected; safety valves are removed or gagged during the test.

Safety and relief valves are set at or below the MAWP, and the lowest-set device governs the maximum allowable pressure of the system.

Common vessel heads: hemispherical (strongest, costliest), 2:1 elliptical (most common), torispherical, and flat heads for low pressure.

Counterflow exchangers give the highest effectiveness; shell-side baffles support the tubes and direct flow across the tube bundle.

The economizer preheats feedwater with flue gas, the air preheater warms combustion air, and the superheater raises steam above saturation temperature.

Bottom blowdown from the mud drum controls dissolved and suspended solids; continuous blowdown is taken from the steam drum water line.

Tube-to-tubesheet joints are made by roller expansion and/or seal welding; rolled joints rely on a measured tube wall reduction for a leak-tight fit.