NJ Master Plumber flashcards

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

Fixture unit definition

A measure of the load-producing effect of a fixture on the drainage system. One fixture unit equals 1 cubic foot per minute, or about 7.5 gallons per minute, of flow.

Developed length

The total length of pipe measured along its centerline and through fittings from the stack or main to the fixture. Used to select pipe size from capacity tables.

Building drain

The lowest piping of a drainage system that receives soil and waste from inside the building and conveys it to the building sewer, which begins at the building wall.

Minimum drainage slope

Horizontal drainage pipe 2-1/2 inches and smaller must slope at least 1/4 inch per foot. Pipe 3 inches and larger may slope 1/8 inch per foot where permitted.

Cleanout interval

Cleanouts are required at the base of each stack, at the upper end of horizontal branches, at direction changes over 135 degrees, and at intervals not exceeding 100 feet.

Trap arm length limit

The distance from the trap weir to the vent connection is limited by pipe size and slope, for example about 5 feet for 2-inch pipe, to prevent self-siphoning of the trap.

Vent stack termination

A vent stack must extend at least 6 inches above the roof, be sized not smaller than the stack it serves, and terminate in open air with an approved fitting.

Island vent

A loop vent using a foot vent and a loop above the flood level rim, used to vent a fixture that cannot be vented conventionally. It requires a cleanout at the foot vent base.

Trap seal depth

Each fixture trap must maintain a liquid seal of not less than 2 inches and not more than 4 inches, must be self-cleaning, and must be accessible for service.

Grease interceptor

A device required for commercial kitchen fixtures discharging fats, oils, and grease. It must be sized by capacity, fitted with a flow-control fitting, and accessible for cleaning.

Residual fixture pressure

The minimum residual pressure at a fixture is generally 8 psi for flush tanks and 15 psi for flush valves. Inadequate street pressure requires a booster pump.

Pressure-reducing valve

A device required when street pressure exceeds the code limit, typically 80 psi. A closed system also needs a thermal expansion tank or relief device.

Water heater T&P valve

A temperature and pressure relief valve installed within the top 6 inches of the tank, piped full size to a safe discharge point without traps or reductions.

Water closet clearance

A water closet needs at least 15 inches from its centerline to a side wall and 21 inches in front. The minimum compartment width is 30 inches.

Water-saving flush volume

Water closets must be the water-saving type with a flush volume not exceeding 1.6 gallons per flush. Urinals are limited to 1.0 gallon per flush.

Roof drain sizing

Storm drainage pipe is sized from design rainfall intensity, roof area, and runoff coefficient. A roof drain sits at the low point, with overflow drainage where required.

Backwater valve

A device required on sanitary or storm drains where the building drain may be subject to backflow from the public sewer. It must be installed so it can be serviced.

Drainage system test

Drainage systems must be tested with water or air before concealment. The test pressure and duration are set by the code and witnessed by the inspector.

Gas pipe support

Fuel gas pipe must be supported at intervals not exceeding 6 feet for horizontal runs and at each change of direction, and protected from damage and corrosion.

Gas sediment trap

A sediment trap must be installed at each gas appliance, along with a shutoff valve ahead of the appliance and a union or flanged connection for service.

Gas appliance connector

A listed flexible connector must not be concealed, pass through a wall, floor, or ceiling, or exceed the code length limit, typically 6 feet.

Air gap

The only absolute backflow protection. It must be at least twice the diameter of the supply pipe and never less than 1 inch above the flood level rim.

Reduced-pressure principle device

An RPZ backflow preventer is required for high-hazard connections. It must be tested annually by a certified tester with results reported to the water purveyor.

Backsiphonage

A reversal of flow caused when negative pressure in the supply line draws contaminant into the potable system, as opposed to backpressure from downstream pressure.

Hose bibb vacuum breaker

A backflow device required on all hose connections. Backflow preventers are also required on boiler feed lines, irrigation systems, and pool fill lines.

Master Plumber license

A license required to contract for plumbing work in New Jersey. A Journeyman Plumber may perform work only under a licensed master, and a contracting business must employ one.

Plumbing permit

Approval obtained from the local enforcing agency before work begins. Ordinary minor repairs and exposed fixture replacement with no piping change generally do not require one.

Certificate of approval

Issued after the final plumbing inspection passes. A certificate of occupancy for a new building cannot issue until plumbing final approval is granted.

Stack vent

The extension of a soil or waste stack above the highest fixture, terminating in open air. A vent stack is a separate vertical vent line.

Horizontal branch

A drain pipe connecting fixtures to a stack. Horizontal drainage pipe is any pipe installed at a slope less than 45 degrees from horizontal.

Pressure vacuum breaker

A backflow device used for low-hazard connections where it can be installed above the highest downstream outlet, preventing backsiphonage.

Sump pump discharge

Where gravity drainage is not possible, a sump pit with a cover and ejector or pump is used, and the discharge must be piped to a legal point of disposal.