NCCER Sprinkler Fitter cheat sheet

OSHA fall protection triggers: 6 ft in construction, 4 ft in general industry, and 10 ft on scaffolds; a guardrail top rail sits 42 in ±3 in with a midrail at 21 in.

Extension ladders are set at a 4:1 slope (1 ft out for every 4 ft up) and extend at least 3 ft above the landing surface.

Any trench 5 ft or deeper needs a protective system (slope, shore, or shield) unless a competent person documents stable rock; spoil and equipment stay at least 2 ft back from the edge.

Permit-required confined space entry requires oxygen between 19.5% and 23.5%, plus atmosphere testing and a designated attendant outside the space.

Lockout/tagout: isolate, block, or bleed every energy source and verify zero energy before servicing pipe, valves, or equipment.

Hot work (brazing, cutting, grinding) requires a permit, removal or protection of combustibles within 35 ft, and a fire watch that continues after the work stops.

Cutting or coring concrete and masonry releases respirable crystalline silica; use wet methods or dust collection plus a respirator.

Wear eye protection, gloves, and sleeves when handling threaded pipe; hearing protection is required at an 85 dBA time-weighted average.

Use two pipe wrenches - one to turn the pipe, one as a back-up on the fitting or valve - so turning force is not transferred into hangers or equipment connections.

NPT threads have a 1-in-16 taper (3/4 in per foot); 1 in pipe has 8 threads per inch and 2 in pipe has 11.5 threads per inch.

Roll grooving forms the groove without removing wall material; cut grooving removes metal and is limited to Schedule 40 and heavier pipe.

Sling capacity falls as the leg angle moves away from vertical; never exceed the tagged working load limit, and remove slings with broken wires or cuts from service.

Support long stock on pipe stands or a tripod, and keep hands clear of threading-machine rolls, chucks, and rotating pipe.

Use a chain wrench or tong for large-diameter or coated pipe that a jaw wrench cannot grip without crushing or scarring.

Store pipe on dunnage, chocked, with limited stack height; never roll pipe off a truck bed or leave a stack unsecured.

Inspect grinders, saws, and hydraulic tools before each use; guards stay in place and abrasive wheels must be rated for the tool's RPM.

Steel sprinkler pipe is specified as ASTM A53, A106, A135, or A795; Schedule 10 and Schedule 40 are the common wall thicknesses.

Threaded joints are generally limited to 2 in and smaller; cut threads are tapered to ASME B1.20.1 and made with cutting oil to protect the dies.

Grooved couplings require the manufacturer's torque, a lubricated gasket, and metal-to-metal contact between the housing halves.

Welded pipe requires qualified welders and qualified procedures (ASME Section IX); NFPA 13 accepts welding performed to AWS D10.9.

Copper tube for fire protection is ASTM B88 Type K, L, or M, with K the heaviest wall; joints are brazed with BCuP filler or made with listed press fittings.

CPVC is joined with listed solvent cement, and the cure time before pressure testing depends on pipe size and ambient temperature.

Use dielectric unions or listed transition fittings between steel and copper to prevent galvanic corrosion.

Grooved mechanical tees and outlet fittings must be installed at the listed hole size and must not be used to carry bending loads.

NFPA 13 maximum hanger spacing for Schedule 40 steel: 1 in = 12 ft, 1-1/4 in = 15 ft, 1-1/2 in = 20 ft, 2 in = 25 ft, 2-1/2 in = 30 ft, 3 in and 3-1/2 in = 35 ft, 4 in = 40 ft, 6 in = 50 ft, 8 in = 60 ft.

Sway bracing: lateral braces at intervals not exceeding 40 ft and within 20 ft of the end of the pipe; longitudinal braces not exceeding 80 ft apart.

Lateral braces resist motion perpendicular to the pipe; longitudinal braces resist motion along the pipe axis.

The minimum hanger rod diameter is 3/8 in; use clevis hangers, adjustable swivel hangers, or trapeze assemblies listed for the load.

Hangers attach to building structure, never to ductwork, ceiling grid, or other piping; sprinkler pipe cannot be used to support other systems.

Vertical risers are supported at the base and at each floor with riser clamps sized to the pipe.

Building seismic joints and floor penetrations require listed flexible couplings placed within the distance specified from the joint or sleeve.

Hanger loads include pipe, fittings, insulation, and water content; the water roughly doubles the weight of small-diameter Schedule 40 pipe.

Elevation pressure: 1 ft of water column = 0.433 psi; 2.31 ft of water column = 1 psi.

Sprinkler discharge: Q = K√P, where Q is gpm, K is the listed K-factor, and P is pressure in psi at the sprinkler.

Hazen-Williams friction loss: p = 4.52 Q^1.85 / (C^1.85 × d^4.87), with C about 120 for steel pipe and about 150 for cement-lined or plastic pipe.

Design density (gpm/ft²) multiplied by the design area (ft²) gives the sprinkler demand; the design area increases about 30% for dry systems and steep-slope ceilings.

The hose stream allowance is added to the sprinkler demand, and standpipe demand is added when the systems share a water supply.

NFPA 13 requires a 10% safety margin: the available supply curve is reduced in flow and pressure before it is compared with the system demand point.

The minimum operating pressure for a sprinkler is 7 psi (0.5 bar).

The remote area is the hydraulically most demanding area; branch lines, cross mains, and riser nipples are sized from the calculated flows.

Flow from a smooth-bore outlet: Q = 29.83 c d² √P, with d in inches and P in psi.

Wet pipe systems are the default; dry pipe systems are used where piping is subject to freezing and are limited to 750 gal of system capacity.

Preaction systems use closed heads plus detection; single-interlock, double-interlock, and non-interlock arrangements differ in whether the valve trips on detection, on a head operation, or either.

Deluge systems use open sprinklers and a deluge valve, releasing water over the entire protected area when detection operates.

Temperature ratings: ordinary 135–170°F, intermediate 175–225°F, high 250–300°F, extra high 325–650°F.

NFPA 13 color code: 135–170°F uncolored or black, 175–225°F white, 250–300°F blue, 325–375°F red, 400–650°F green.

Standard spray sprinklers are spaced no more than 15 ft apart and protect no more than 225 ft² (light hazard), 130 ft² (ordinary hazard), or 100 ft² (extra hazard) each.

Pendent deflectors are positioned 1–12 in below the ceiling, upright deflectors 1–12 in above the pipe, and sidewall deflectors 4–12 in below the ceiling.

Common K-factors are 5.6, 8.0, 11.2, 14.0, 16.8, 22.4, and 25.2.

ESFR sprinklers are calculated for 12 operating heads, use K 14.0 or larger, and are limited to the storage heights shown in the manufacturer's listing.

Class I standpipe: 2-1/2 in outlets for fire department use. Class II: 1-1/2 in hose stations for occupants. Class III: both.

Standpipe systems are hydrostatically tested at 200 psi for 2 hours, or at 50 psi above the maximum working pressure when that value is higher.

Required residual pressure is 100 psi at the topmost outlet, with 500 gpm for the first standpipe, 250 gpm for each additional standpipe, and a maximum of 1,250 gpm.

Class II systems are designed for 100 gpm at 100 psi residual pressure at the topmost 1-1/2 in outlet.

Fire department connections use two 2-1/2 in inlets, are mounted 18–48 in above grade, and are marked with the system they serve.

Private fire service mains (NFPA 24) are buried below the frost line, restrained with thrust blocks at bends and tees, and valved at the connection to the public main.

Hydrants typically have two 2-1/2 in outlets and one 4-1/2 in pumper nozzle; bury depth and breakaway features follow NFPA 24.

Manual standpipes require a fire department connection; automatic wet standpipes are kept pressurized by the domestic supply or a fire pump.

Fire pumps are listed to NFPA 20 and rated at churn, 100% flow, and 150% flow points.

Pump curve limits: shutoff pressure no more than 140% of rated pressure, and 150% of rated flow delivered at not less than 65% of rated pressure.

Standard ratings run from 25 to 5,000 gpm; the pump is selected so the system demand falls on the acceptable part of the curve.

The jockey pump starts about 10 psi below normal system pressure, and the fire pump starts about 5–10 psi below the jockey pump setting.

A fire pump requires a listed controller, a reliable power source, and where required an automatic transfer switch and an alternate source.

NFPA 25 requires a weekly no-flow (churn) run and an annual flow test of the fire pump.

NFPA 13 water supply duration: 30 min for light hazard, 60–90 min for ordinary hazard, 90–120 min for extra hazard.

Suction piping must avoid air pockets and excessive fittings; a positive suction supply is preferred over a lift.

Core standards: NFPA 13 (sprinklers), NFPA 14 (standpipes), NFPA 20 (pumps), NFPA 24 (private mains), NFPA 25 (ITM), and NFPA 72 (alarm), plus the locally adopted building code and NFPA 1/101.

Sprinkler working plans and hydraulic calculations must be approved by the authority having jurisdiction before installation begins.

Plans show the hazard classification, density/area, pipe sizes, hanger and bracing locations, and the hydraulic reference points.

Only listed and approved devices may be installed, and each must be installed in accordance with its listing and the manufacturer's data sheet.

"Shall" marks a mandatory requirement; "should" is a recommendation and is not enforceable in the same way.

Submittals include shop drawings, product data, and material certificates; specification sections generally follow CSI MasterFormat Division 21.

Changes to approved plans go through an RFI and a written change order; field changes cannot be made without AHJ approval.

Hydrostatic test: 200 psi for 2 hours, or 50 psi above working pressure if that is greater, with no leakage allowed.

Dry pipe and preaction systems receive a 40 psi air test held for 24 hours with no pressure loss beyond what temperature change explains.

Main drain test: open the 2 in main drain fully and record static and residual pressures, then compare with the baseline to detect closed valves or supply problems.

The inspector's test connection flows one sprinkler equivalent; on a wet system the waterflow alarm must operate within 90 seconds.

NFPA 25: gauges checked weekly or monthly, alarm devices tested quarterly, and the main drain test performed annually.

Dry valves get an annual trip test and an internal inspection every 5 years; gauges are replaced or recalibrated every 5 years.

An impairment requires notification of the AHJ, a tag on the valve, and compensating measures such as a fire watch.

A spare sprinkler cabinet stocked with heads matching the installed types and the correct wrenches must be maintained on site.