NCCER Sprinkler Fitter flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Fall protection height, construction

OSHA requires fall protection when employees work 6 feet or more above a lower level in construction; general industry triggers at 4 feet.

Confined space oxygen range

Entry is permitted only while oxygen is between 19.5 and 23.5 percent by volume; readings outside that range require ventilation, respiratory protection, and permit controls.

Hot work fire watch

A fire watch stays at the location during brazing, cutting, or grinding and continues after work stops until all slag and ignition sources are cooled.

NPT thread taper

Standard pipe threads are tapered 1 in 16, which is 3/4 inch per foot of length, so overtightening can split fittings and thin-wall pipe.

Back-up wrench purpose

A second pipe wrench is placed on the fitting or valve so turning force is not transferred into the piping, hangers, or equipment connection.

Sling capacity at angle

A sling's capacity decreases as its legs move away from vertical; the working load limit applies to the actual leg angle and must never be exceeded.

Roll versus cut grooving

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

Dielectric union function

A dielectric union or listed transition fitting separates steel from copper to stop galvanic corrosion driven by dissimilar-metal contact in the presence of water.

Brazed copper joint filler

Copper sprinkler tube is brazed with BCuP filler at roughly 1,100 to 1,500 degrees Fahrenheit, producing a joint stronger than the tube itself when properly made.

Threaded joint size limit

Threaded pipe joints in sprinkler systems are generally limited to 2 inch and smaller; larger pipe is joined by grooving, welding, or flanging.

Hanger spacing for 2 inch pipe

NFPA 13 allows a maximum hanger spacing of 25 feet for 2 inch Schedule 40 steel pipe, and 12 feet for 1 inch pipe.

Lateral sway brace spacing

Lateral braces are placed at intervals not exceeding 40 feet and within 20 feet of the end of the pipe run, resisting motion perpendicular to the pipe.

Longitudinal brace spacing

Longitudinal sway braces resist motion along the pipe axis and are spaced at intervals not exceeding 80 feet in NFPA 13 systems.

Minimum hanger rod size

The smallest rod permitted for sprinkler hangers is 3/8 inch; rod size and hanger type are selected from listings for the calculated load.

Feet of head to psi

One foot of water column equals 0.433 psi, so a 10 foot rise adds 4.33 psi of pressure and a 10 foot drop subtracts the same.

Sprinkler K-factor formula

Discharge from a sprinkler is Q equals K times the square root of P, where Q is gpm, K is the listed K-factor, and P is pressure in psi.

Hazen-Williams C factor

The Hazen-Williams roughness coefficient is about 120 for unlined steel pipe and about 150 for cement-lined or plastic pipe; a higher C means less friction loss.

Dry pipe system capacity limit

A single dry pipe system is limited to 750 gallons of capacity, which controls how much water must enter before the farthest sprinkler flows.

Standard spray maximum spacing

Standard spray sprinklers are spaced no more than 15 feet apart and protect no more than 225 square feet each in light hazard and 130 in ordinary hazard.

Pendent deflector distance

A pendent sprinkler deflector is positioned 1 to 12 inches below the ceiling, while an upright deflector sits 1 to 12 inches above the pipe.

Sprinkler temperature color code

NFPA 13 color code: 135 to 170 degrees Fahrenheit uncolored or black, 175 to 225 white, 250 to 300 blue, 325 to 375 red, and 400 to 650 green.

Standpipe class definitions

Class I provides 2-1/2 inch outlets for fire department hose, Class II provides 1-1/2 inch hose stations for occupants, and Class III provides both.

Standpipe hydrostatic test

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.

Standpipe flow requirement

The most remote standpipe must supply 500 gpm at 100 psi residual at the topmost outlet, with 250 gpm added for each additional standpipe up to 1,250 gpm.

Fire pump 150 percent point

A fire pump must deliver 150 percent of rated flow while holding at least 65 percent of rated pressure, and its shutoff cannot exceed 140 percent of rated.

Jockey pump setting

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

Light hazard water duration

NFPA 13 requires a 30 minute water supply duration for light hazard, 60 to 90 minutes for ordinary hazard, and 90 to 120 minutes for extra hazard.

NFPA 13 scope

NFPA 13 governs the design and installation of automatic sprinkler systems, covering hazard classification, density, spacing, hangers, and acceptance testing.

Working plan approval

Sprinkler working plans and hydraulic calculations must be approved by the authority having jurisdiction before any pipe is installed on the project.

Hydrostatic test pressure

New sprinkler piping is hydrostatically tested at 200 psi for 2 hours, or 50 psi above working pressure if that is greater, with no leakage allowed.

Main drain test purpose

The main drain test compares static and residual pressure at the riser to a baseline, revealing a closed valve, obstruction, or degraded water supply.

Inspector's test alarm time

The inspector's test connection simulates one sprinkler; on a wet system the waterflow alarm must operate within 90 seconds of opening the valve.