IA Plumber flashcards

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

Concealed piping inspection

Drainage, vent, and water piping must be tested and inspected before being covered or concealed; the authority having jurisdiction must approve the installation before concealment.

DWV air test

Drainage and vent systems may be tested with air at 5 psi for at least 15 minutes with no pressure drop, as an alternative to a 10-foot water head test.

Approved

Material, device, or method accepted by the authority having jurisdiction as meeting the code, usually evidenced by listing by a recognized testing agency.

Building drain

The lowest piping of a drainage system that receives waste from inside the building and extends 30 inches beyond the outside face of the wall.

Trap seal

The vertical depth of water in a trap that prevents sewer gas from passing through, measured from the trap weir to the top of the dip.

Pressure head conversion

One psi equals 2.31 feet of water column, and one foot of water column equals 0.433 psi; multiply height in feet by 0.433 to find static pressure.

Hazen-Williams formula

Head loss in feet equals 4.727 times length times flow to the 1.852 power, divided by C to the 1.852 power times diameter to the 4.87 power.

45-degree offset multiplier

For a 45-degree offset, multiply the offset by 1.414 to get the travel, and the offset equals the travel times 0.707.

Drain slope 2 inch and smaller

Drainage pipe 2 inches and smaller is pitched at 1/4 inch per foot (2 percent); 3-inch pipe may be at 1/8 inch per foot where approved.

Cleanout at base of stack

A cleanout is required at the base of each soil or waste stack and at each change of direction of 45 degrees or more in the building drain.

Trap arm fall limit

The fall of a trap arm may not exceed one pipe diameter, so a 1-1/2-inch trap arm can drop at most 1-1/2 inches before it is vented.

Vent above flood level rim

A fixture vent must rise at least 6 inches above the flood level rim of the fixture before any horizontal offset, except where the vent is a wet vent.

Vent through roof height

Vent terminals must extend at least 6 inches above the roof surface, and 12 inches where snow accumulation is likely, and be unobstructed.

Wet vent definition

A wet vent is a vent that also serves as a drain for one or more fixtures, limited to bathroom groups on the same floor in most codes.

Trap seal depth

A trap must maintain a water seal of at least 2 inches and not more than 4 inches, measured from the weir to the top of the dip.

Grease interceptor purpose

A grease interceptor separates fats, oils, and grease from kitchen waste before discharge to the sewer, and must be sized by code and cleaned regularly.

S-trap prohibition

S-traps are prohibited because they can siphon their seal; a fixture drain must connect through a vented trap arm to a vertical or horizontal branch.

Pressure-reducing valve threshold

A pressure-reducing valve is required when the water supply pressure exceeds 80 psi, and the reduced pressure is typically set to 50 psi.

Water hammer arrestor

A device with a trapped air chamber or piston installed near a quick-closing valve to absorb the shock wave and prevent pipe noise and damage.

Minimum fixture pressure

Fixtures must receive at least 8 psi residual pressure under normal flow, and flushometer valves typically need 15 to 25 psi to operate.

Water closet 1.6 gpf

A water closet may use no more than 1.6 gallons per flush, a standard set by federal law, though some codes allow 1.28 gpf high-efficiency models.

Showerhead flow limit

Showerheads are limited to 2.5 gallons per minute at 80 psi, a federal standard that applies to each showerhead in a shower.

Water closet side clearance

A water closet must be at least 15 inches from its centerline to any side wall and have at least 21 inches of clearance in front.

T&P relief valve setting

A temperature and pressure relief valve is typically set to open at 210 degrees Fahrenheit or 150 psi, whichever occurs first, and must not be capped.

TPR discharge termination

The relief valve discharge pipe must be full size, flow by gravity, and terminate 6 inches above the floor or outside, with no threaded end.

Water heater in garage

A water heater installed in a garage must be elevated so the ignition source is at least 18 inches above the floor to avoid vapors.

Sediment trap

A sediment trap or drip leg is installed downstream of the appliance shutoff valve and upstream of the controls to catch debris and moisture.

Gas shutoff valve location

A manual shutoff valve must be installed in the gas piping within 6 feet of the appliance and be readily accessible.

Gas piping pressure test

Low-pressure gas piping is commonly tested with air at 10 psi for 10 minutes with no pressure drop before the meter is connected.

Air gap

An air gap is the unobstructed vertical distance between a water supply outlet and the flood level rim of a fixture, at least twice the pipe diameter.

RPZ device

A reduced-pressure principle assembly has two check valves and a relief valve that discharges if differential pressure is lost, protecting against high-hazard backflow.