NC Plumbing Contractor flashcards

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

Qualifying individual

The person who meets the experience requirement and passes the licensing exam; the contractor's license is held by the business but tied to this individual.

P-2 plumbing license

A limited North Carolina plumbing contractor classification restricted to residential work on one- and two-family dwellings, narrower than the unlimited P-1 license.

Plumbing permit

Official authorization from the local inspections department that must be obtained before plumbing work starts, triggering required rough-in and final inspections.

State code preemption

The NC State Building Code, including the plumbing code, is adopted statewide, so local governments enforce it but cannot adopt less stringent local plumbing rules.

Fixture unit

A numerical measure of the load-producing effect a fixture places on the drainage system or of the probable water demand it creates in the supply system.

Flood level rim

The top edge of a fixture or receptacle from which water will overflow onto the floor or surrounding area; used to set air gaps and backwater protection.

Air gap

The unobstructed vertical distance through free atmosphere between the lowest opening of a waste or water outlet and the flood level rim of the receiving fixture.

Minimum drainage pipe size

No drainage pipe, fixture drain, or branch may be installed smaller than one and one-quarter inch nominal diameter under the plumbing code.

Drainage pipe slope

Horizontal drainage pipe 2-1/2 inches and smaller must slope at 1/4 inch per foot; pipe 3 inches and larger must slope at 1/8 inch per foot.

Trap seal depth

The vertical depth of the water seal in a fixture trap, required to be at least 2 inches and not more than 4 inches.

Trap arm length

The developed length from the fixture outlet to the vent connection, limited by drain size: 1-1/4 in = 5 ft, 1-1/2 in = 6 ft, 2 in = 8 ft, 3 in = 12 ft, 4 in = 16 ft.

Vent terminal height

A vent stack must extend at least 6 inches above the roof surface and must be located away from windows, doors, and outdoor air intakes.

Maximum static pressure

Pressure at fixtures may not exceed 80 psi; where the supply exceeds that, a pressure-reducing valve must be installed ahead of the distribution system.

T and P relief setting

A water heater temperature and pressure relief valve is set to open at or below 210 degrees F or 150 psi, with a full-size gravity discharge.

Thermal expansion control

A closed water system created by a check valve, pressure-reducing valve, or backflow preventer requires a thermal expansion tank or approved expansion control device.

Water service minimum size

Building water service pipe must be at least 3/4 inch nominal, while individual fixture supply piping may be reduced to 1/2 inch minimum.

Water closet clearances

A water closet needs at least 15 inches from its centerline to any sidewall or partition and at least 21 inches of clear space in front of the bowl.

Toilet flush volume limit

Water closets installed in new or altered work may not exceed 1.6 gallons per flush, and urinals may not exceed 1.0 gallon per flush.

Washer standpipe height

A clothes washer standpipe must be at least 2 inches in diameter and must terminate between 18 and 30 inches above the trap weir.

Trap primer purpose

A trap primer adds water to a floor drain or similar trap to replace evaporation and prevent sewer gas from entering the building through a dry seal.

Reduced pressure zone assembly

A testable backflow preventer with two check valves and a relief valve, required for high-hazard connections and installed above grade and accessible.

Minimum air gap size

The air gap must be at least 1 inch or twice the effective opening of the outlet, whichever dimension is greater, measured above the flood level rim.

Grease interceptor requirements

A grease interceptor must be sized for the connected fixture flow, vented, accessible for cleaning, and must receive only kitchen waste, not sanitary or storm drainage.

Hose bibb protection

Hose bibbs and sillcocks must be protected against backflow with a vacuum breaker or an approved backflow device to prevent cross-connection.

Isometric riser reading

On a plumbing isometric, vertical lines represent risers and the angled lines represent horizontal runs, with 45-degree offsets showing combined horizontal and vertical change.

Gallons per cubic foot

One cubic foot of water contains 7.48 gallons; this factor converts a calculated pipe or tank volume into gallons for system volume and chlorination calculations.

Psi to feet of head

Multiply pressure in psi by 2.31 to obtain feet of head, or divide feet of head by 2.31 to obtain psi for pressure and elevation calculations.

Trench cubic yards

Multiply length by width by depth in feet and divide by 27 to obtain cubic yards of excavation; add allowances for bedding, backfill, and soil swell.

Claim of lien deadline

In North Carolina a mechanics lien claim must be filed within 120 days after the claimant last furnished labor or materials to the improved property.

Notice to lien agent

A subcontractor or supplier on a project with a designated lien agent must give written notice to that agent within 15 days after first furnishing labor or materials.

Performance bond

A surety bond guaranteeing the contractor will complete the work according to the contract; it protects the owner, while a payment bond protects subcontractors and suppliers.

Retainage

A percentage, commonly 5 percent, withheld from each progress payment until substantial completion or punch list closeout to protect the owner against incomplete work.