BTEB Plumbing flashcards

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

Fixture unit

A relative measure of the load a fixture places on a drainage or supply system; one water closet is about 3 drainage fixture units and 2.5 supply fixture units.

Building drain

The lowest horizontal pipe inside the building that receives soil and waste from stacks, running to the building sewer outside the foundation wall.

Trap arm length

The distance from a fixture trap weir to its vent connection; limited by pipe size, about 5 ft for 1.5 in and 6 ft for 2 in pipe.

Static pressure loss

Pressure drops 0.433 psi for every foot of elevation rise above the water source; one foot of water column equals 0.433 psi.

Vent stack height

A vent stack must extend at least 6 in above the roof and at least 12 in above any roof area within 10 ft when used for other purposes.

Drain slope rule

Drain pipe 2.5 in and smaller slopes at least 1/4 in per ft; 3 in and larger may use 1/8 in per ft but never less.

Copper type K

The thickest copper tube, used underground and for heavy-duty service where wall thickness and pressure resistance matter most.

Copper type L

Standard-weight copper tube used for interior water supply lines; a common choice for above-ground domestic water piping.

CPVC pipe

Chlorinated polyvinyl chloride rated for hot water up to about 200 F at reduced pressure; uses its own solvent cement, not PVC cement.

Solvent cement joint

Cut square, deburr, prime, apply cement to both surfaces, insert with a quarter turn, hold 30 seconds, and cure before testing.

Dielectric union

A fitting that separates dissimilar metals, such as copper and galvanized steel, to prevent galvanic corrosion at the connection.

No-hub coupling

A cast iron pipe joint using a neoprene gasket wrapped by a stainless steel band clamped with screws, replacing lead-and-oakum joints.

Lead-free solder

Solder required on potable water lines; heat the fitting rather than the solder and keep the joint dry while soldering.

PEX tubing

Flexible cross-linked polyethylene tubing used for water supply; use brass or copper fittings and follow manufacturer temperature and pressure ratings.

Trap seal depth

The water seal in a fixture trap must be at least 2 in and no more than 4 in deep to block sewer gas without causing slow drainage.

Water closet flush volume

Standard water closets use 1.6 gallons per flush; high-efficiency models use 1.28 gpf or less; urinals commonly use 1.0 gpf or less.

Wet vent

A vent that also serves as a drain for one or two fixtures on a single floor, provided it is one size larger than the drain it serves.

Cleanout spacing

Cleanouts are required at the base of each stack, at horizontal changes over 45 degrees, and at the building sewer, no more than 100 ft apart.

Backwater valve

A device required where the building drain is below the next upstream manhole, preventing sewage from backing up into the building.

Drainage fixture units

Load values per fixture: water closet 3, lavatory 1, bathtub 2, shower 2, kitchen sink 2, floor drain 2, washing machine 2, dishwasher 2.

Vent above flood rim

A vent must rise at least 6 in above the fixture flood-level rim before turning horizontal; horizontal vents slope back to the drain.

Air gap

The highest level of backflow protection, created by a physical separation between a water outlet and the flood-level rim of a receptacle.

RPZ device

A reduced-pressure zone backflow preventer used for high-hazard connections; a double check valve is only for low-hazard protection.

Trench protective system

Any trench 5 ft deep or more requires shoring, sloping, or shielding unless in stable rock; a competent person inspects daily.

Soil sloping ratios

Type C soil slopes 1.5 to 1, Type B slopes 1 to 1, and Type A slopes 3/4 to 1 horizontal to vertical for trench protection.

Water heater relief valve

Set at or below the tank pressure rating, piped full size to within 6 in of the floor or a drain, and never capped or plugged.

Pressure test criteria

Water piping is tested at 1.5 times working pressure but not less than 100 psi for at least 2 hours; DWV is tested to 10 ft of head or 5 psi.

Estimating waste factor

Add about 5 to 10 percent extra pipe and fittings to a material takeoff to cover cuts, errors, and normal installation waste.

Labor unit

An estimating value expressed in hours per fixture or per 100 ft of pipe; overhead and profit are added as a percentage on top.

Confined space entry

Before entry, test for oxygen, flammable gas, and toxic gas; keep an attendant outside and have a rescue plan ready.

Galvanized steel pipe

Steel pipe with a zinc coating joined by threaded fittings; connect to copper only through a dielectric union to prevent corrosion.

Fixture drain size

Minimum drains: water closet 3 in, lavatory 1.25 in, bathtub 1.5 in, and kitchen sink 1.5 in.