GA Plumber flashcards

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

Fixture unit

A measure of the probable hydraulic load imposed by a fixture on the drainage or water supply system; one drainage fixture unit equals about 1 cubic foot per minute, roughly 7.5 gallons per minute.

Air gap

The unobstructed vertical distance through free atmosphere between a potable water outlet and the flood-level rim of a receptor; it must be at least twice the pipe diameter and never under 1 inch.

Reduced pressure zone assembly

A testable backflow preventer with two check valves and a differential relief valve that protects against both backsiphonage and backpressure; it is required for high-hazard connections and must be tested periodically.

Trap seal depth

The vertical distance between the crown weir of a trap and the top of its dip; the code requires a seal of not less than 2 inches and not more than 4 inches.

Trap arm length

The developed length of pipe from the trap weir to the vent connection; it is limited by trap size, such as 5 feet for 1 1/4 inch and 8 feet for 2 inch traps.

Developed length

The total length of a pipe run measured along the centerline of the pipe and fittings, including the equivalent length added for valves and fittings when sizing water piping.

Building drain

The lowest piping of a drainage system that receives waste from inside the building and conveys it to the building sewer, extending 30 inches beyond the outside wall.

Building sewer

The drainage pipe that carries sewage from the building drain to the public sewer or private sewage disposal system; it must be at least 3 inches in diameter.

Drainage slope rule

Horizontal drainage pipe must slope at least 1/4 inch per foot for sizes 2 1/2 inches and smaller, and at least 1/8 inch per foot for pipe 3 inches and larger.

Crown vent

A vent connected at the crown weir of a trap; it is prohibited because the connection point is too close to the trap to prevent siphonage reliably.

Wet vent

A vent that also serves as a drain for fixtures on the same floor; permitted only under specific code conditions with sizing limits and no downstream fixtures.

Backwater valve

A device installed on a drainage line to prevent sewage from reversing into the building; it is required where fixture flood-level rims are below the next upstream manhole.

Cleanout interval

Cleanouts must be provided at the base of stacks, at the upper end of horizontal drains, and at intervals not exceeding 100 feet in horizontal drainage piping.

Flood-level rim

The top edge of a fixture or receptor from which water would overflow onto the floor; it establishes the reference point for air gaps and indirect waste.

Indirect waste

Liquid waste that discharges into the drainage system through an air gap or air break into a trapped and vented receptor rather than by direct connection.

Grease interceptor

A device that separates and retains fats, oils, and grease from kitchen waste before the effluent enters the drainage system; it must be vented, accessible, and cleaned regularly.

Pressure-reducing valve

A valve that reduces incoming water pressure to a lower downstream setting; required where static pressure exceeds 80 psi, and it creates a closed system needing thermal expansion control.

T&P relief valve

A listed temperature and pressure relief valve on a water heater, typically set at 150 psi and 210 degrees F, discharging full size by gravity to a safe location.

Relief valve discharge

The pipe from a T&P valve must be full size, untrapped, unvalved, and terminate not more than 6 inches above the floor or outside the building, with no threaded end.

Water heater drain pan

A pan not less than 1.5 inches deep with a drain of at least 3/4 inch, required where a water heater leak would cause damage to the building or its contents.

Minimum fixture pressure

The pressure at a fixture inlet must be at least 8 psi flowing for the fixture to operate properly; where static pressure exceeds 80 psi, a pressure-reducing valve is required.

Water closet clearances

A water closet must be set at least 15 inches from its centerline to a side wall and have at least 21 inches of clear space in front of the bowl.

Shower temperature limit

Shower valves must be pressure-balancing, thermostatic, or combination type, and must limit the delivered water temperature to a maximum of 120 degrees F.

Sediment trap

A dirt pocket installed at an appliance inlet, upstream of the controls, using a minimum 3 inch nipple and cap to collect debris before it reaches the gas valve.

Appliance connector

A listed flexible connector used to connect a gas appliance to the piping; it may not exceed 6 feet, be concealed, or pass through a wall, floor, or ceiling.

Vent termination height

A vent stack must extend at least 6 inches above the roof surface and be flashed; the vent must be sized by fixture units and cannot double as a drain.

Air admittance valve

A one-way valve that admits air into the drainage system to protect trap seals; it is permitted only where approved and must be installed above the fixture flood-level rim with access.

DWV air test

A test of the drainage system using compressed air at 5 psi held for at least 15 minutes without a drop, used as an alternative to the water test.

DWV water test

A test in which the drainage system is filled with water to a 10 foot head above the highest point and held at least 15 minutes without leakage.

Combustion air rule

Fuel-burning appliances in a confined space require outdoor air openings; where indoor air is used, at least 50 cubic feet of volume per 1,000 Btu of appliance input is required.

Trench protection

Excavations 5 feet deep or more require sloping, shoring, or shielding, a ladder within 25 feet of lateral travel, and spoil piles kept at least 2 feet from the edge.

Reaming copper tube

Copper tubing must be reamed to its full inside diameter after cutting to remove the burr, which otherwise causes turbulence, noise, and flow restriction.