ID Plumber flashcards

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

Fixture unit (drainage)

A unit of measure expressing the probable load a fixture places on the drainage system; one drainage fixture unit equals 1 cubic foot per minute of flow, or 7.5 gallons per minute.

Building drain

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

Air gap

An unobstructed vertical distance through free atmosphere between a potable water outlet and the flood-level rim of a receptor, equal to at least twice the pipe diameter or 1 inch, whichever is greater.

Trap seal

The vertical depth of water in a trap that prevents sewer gas from passing into the building; the seal must be at least 2 inches and not more than 4 inches deep.

Grease interceptor

A device that separates fats, oils, and grease from kitchen wastewater by gravity so that grease does not accumulate in the building drainage system or public sewer.

Vent stack

A vertical vent pipe that extends from the drainage stack to the outdoors, providing air to the drainage system and relieving pressure so trap seals are not siphoned.

Developed length

The total length of a pipe run measured along its centerline, including vertical and horizontal segments plus equivalent lengths for fittings and valves, used for sizing.

Residual pressure

The pressure remaining at a fixture or outlet while water is flowing; codes require a minimum of 8 psi at flush tanks and 15 psi at flushometer valves.

Pressure-reducing valve

A device installed where static water pressure exceeds 80 psi to reduce pressure to a safe level for the piping, fixtures, and appliances in the building.

Backflow preventer

A device or assembly that prevents the reverse flow of water into the potable supply; selection depends on the hazard level, and assemblies require annual testing.

Temperature and pressure relief valve

A safety valve on a water heater that opens when temperature or pressure exceeds set limits, with a discharge pipe terminating within 6 inches of the floor or to the exterior.

Thermal expansion tank

A tank installed on a closed water system to absorb the volume increase of heated water, preventing excessive pressure buildup and relief valve discharge.

Water closet clearance

The required spacing around a water closet: 15 inches from the centerline to a side wall and 30 inches of clear space in front of the fixture.

High-efficiency toilet

A water closet that flushes at 1.28 gallons or less per flush, compared with the standard maximum of 1.6 gallons per flush for water closets.

Building sewer

The pipe that carries sewage from the building drain, starting outside the building foundation, to the public sewer or private sewage disposal system.

Cleanout

An accessible fitting with a removable plug that allows a drain or sewer to be cleared; required at the base of stacks and at changes in direction over 45 degrees.

Trap arm

The portion of a fixture drain between the trap weir and the vent connection; its length is limited by trap size to prevent self-siphonage of the trap seal.

Indirect waste receptor

A fixture that receives wastewater from an indirect waste pipe through an air gap or air break, preventing backflow into the fixture or the potable water supply.

Gray water

Wastewater from lavatories, showers, bathtubs, and laundry that excludes toilet and kitchen sink waste, and may be reused for subsurface irrigation or flushing where approved.

Reclaimed water

Treated wastewater approved for nonpotable uses, conveyed in purple pipe with warning labels and separated from potable piping by approved backflow assemblies.

Sediment trap

A tee fitting with a capped nipple installed at the inlet of a gas appliance to collect debris and prevent it from entering the appliance controls.

Gas pressure test

A test of the gas piping system with air before it is placed in service; typical requirements are 10 psi for 30 minutes or 3 psi for 30 minutes depending on system pressure.

Appliance connector

A listed flexible connector that joins a gas appliance to the piping; it must not be concealed and cannot pass through walls, floors, or ceilings.

Drainage slope

The fall of a horizontal drain per unit of length; 2-inch and smaller pipe requires 1/4 inch per foot, while 3-inch and larger require at least 1/8 inch per foot.

Rainfall to flow

The conversion of roof area and rainfall intensity to flow: 1 inch per hour on 1 square foot equals 0.0104 cubic feet per second, or about 4.67 gallons per minute.

Pipe volume formula

The volume of water in a pipe in gallons equals 0.0408 times the diameter in inches squared times the length in feet; used for expansion and system sizing.

First-hour rating

The amount of hot water a water heater can supply in the first hour of use, starting with a full tank, used to match heater size to peak demand.

Plan legend

The key on a plumbing drawing that identifies symbols for water, drainage, vent, and gas lines, allowing the reader to interpret the piping layout correctly.

Permit expiration

A plumbing permit typically expires if work does not start within 180 days of issuance or is suspended for a set period, unless extended in writing.

Authority having jurisdiction

The organization or official responsible for enforcing the plumbing code, approving materials and methods, and conducting inspections of permitted work.

Stop-work order

A written notice issued by the code official requiring work to halt because it is unsafe or not in compliance, remaining in effect until corrected and re-inspected.

Joist hole limit

In solid sawn joists, bored holes must not exceed one-third the joist depth, must be located away from the middle third of the span, and at least 5/8 inch from edges.