CO Plumber flashcards

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

Water column pressure

One foot of vertical water column creates 0.433 psi of static pressure; conversely, 2.31 feet of water column equals 1 psi of pressure.

Drainage slope requirement

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

Air gap definition

The unobstructed vertical distance through free atmosphere between the lowest opening of a water supply outlet and the flood level rim of the fixture or receptacle it serves.

Backflow causes

Backflow is reverse flow of water in a piping system caused either by backsiphonage from negative supply pressure or by backpressure downstream of a cross-connection.

Trap seal depth range

Every fixture trap must maintain a water seal of at least 2 inches and not more than 4 inches, blocking sewer gas while still allowing the fixture to drain freely.

Excavation protective threshold

Excavations 5 feet deep or more require a protective system such as sloping, shoring, or a trench shield; excavations deeper than 20 feet need design by a registered engineer.

Vent terminal above roof

A vent stack must extend at least 6 inches above the roof surface, and higher where the roof is used for purposes other than weather protection.

Confined space oxygen range

Atmospheric testing before entry must show oxygen between 19.5 and 23.5 percent by volume, with flammable and toxic gases below established exposure limits.

Copper tube Type K

Type K copper has the heaviest wall thickness of the three common types and is marked green; it is used for underground water service and other buried lines.

Lead-free solder definition

Solder and flux used to join potable water piping must contain no more than 0.2 percent lead and must be labeled as lead-free by the manufacturer.

Dielectric union purpose

A dielectric union or nipple separates copper pipe from steel or galvanized pipe, breaking the electrical path that drives galvanic corrosion between dissimilar metals.

PVC primer requirement

Solvent-welded PVC joints require listed purple primer applied to both the pipe end and fitting socket before cement, followed by a quarter-turn during assembly.

PEX joining methods

PEX is joined only with mechanical insert fittings using copper crimp rings, stainless steel clamp rings, or approved compression fittings; solvent cement is never used on PEX.

Hubless cast iron joint

No-hub cast iron soil pipe is joined by a neoprene gasket sleeve compressed with a stainless steel band clamp, which allows slight flexibility and misalignment.

Thrust block function

Concrete thrust blocks are poured against fittings at bends, tees, and reducers on buried pressure pipe to transfer water thrust into the surrounding soil.

Copper support spacing

Copper tubing 1-1/4 inch and smaller must be supported at least every 6 feet horizontally; 1-1/2 inch and larger tubing every 10 feet.

T&P relief valve setting

A temperature and pressure relief valve on a water heater opens at 210 degrees F or 150 psi, whichever occurs first, and must be rated for the heater input.

T&P discharge pipe rules

Relief discharge must be full size, flow by gravity, have no valves or traps, and terminate unthreaded not more than 6 inches above the floor or outside above grade.

Thermal expansion control

A water heater installed in a closed system with a check valve, pressure-reducing valve, or backflow preventer requires an expansion tank or other approved expansion control device.

FVIR water heaters

Gas-fired water heaters must be listed as flammable vapor ignition resistant, using a sealed burner compartment and flame arrestor to prevent ignition of vapors near the floor.

Sediment trap location

A sediment trap, or drip leg, is required on the gas piping at each appliance, installed downstream of the appliance shutoff valve and as close as practical to the inlet.

Fixture residual pressure

Flowing water pressure at a fixture outlet must be at least 8 psi; flushometer valves serving water closets and urinals require at least 15 psi to operate properly.

Water closet spacing

A water closet must have at least 15 inches from its centerline to any sidewall and at least 21 inches of clear space measured in front of the bowl.

Shower valve type

Shower control valves must be of the pressure-balancing or thermostatic mixing type so that changes in supply pressure or temperature do not cause scalding.

Permit requirement

A permit must be obtained before installing, altering, or replacing plumbing piping, fixtures, or water heaters, unless the specific work is listed as an exemption in the code.

Rough-in inspection

The rough-in inspection is requested after drainage, vent, and water piping are installed and tested, but before any of that piping is covered or concealed.

Final inspection timing

The final inspection is requested after fixtures are set, appliances are connected, and the system has been tested and is ready for use.

Colorado Plumbing Code basis

Colorado adopts the International Plumbing Code together with state amendments as the Colorado Plumbing Code, administered through the State Plumbing Board.

DWV water test

Drain, waste, and vent piping is tested with water under a 10-foot head held for at least 15 minutes with no loss of level, or by an approved air test.

Master plumber role

In Colorado the master plumber is the licensee authorized to contract for plumbing work, obtain permits, and supervise journeymen and apprentices on the job.

Concealed work exposure

If piping is covered before the required inspection, the code official may order the covering removed so the work can be examined and tested.

Alternative material approval

The code official may approve materials or methods not named in the code when evidence shows they are equivalent in quality, strength, effectiveness, and safety.