AL Plumber flashcards
AL Plumber · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Plumbing permit
- A permit is required before beginning new plumbing installation, alteration, replacement, or repair unless the work is specifically exempted by the code or the authority having jurisdiction.
- Fixture unit
- A fixture unit is a measure of the load-producing effect of a plumbing fixture on the drainage system; fixture unit values are used to size drainage and vent piping.
- Air gap
- An air gap is the unobstructed vertical distance through free atmosphere between a potable water supply outlet and the flood-level rim of a fixture or receptacle.
- Developed length
- Developed length is the measured length along the centerline of a pipe including fittings and changes in direction, used for pipe sizing and pressure-loss calculations.
- Water column pressure
- One psi equals about 2.31 feet of water column, so static pressure in psi can be calculated by multiplying head in feet by 0.433.
- 45-degree offset travel
- For a 45-degree offset, the travel or diagonal length equals the offset multiplied by 1.414, because the secant of 45 degrees is approximately 1.414.
- Scale reading
- On a drawing with a scale of 1/4 inch equals 1 foot, a measured line of 1/4 inch represents 1 actual foot; multiply drawing length by the scale factor.
- Water closet fixture units
- A water closet typically carries 3 drainage fixture units, while a lavatory carries 1 and a bathtub or shower carries 2 in standard plumbing fixture-unit tables.
- Toilet clearance
- A water closet must have at least 15 inches from its centerline to a sidewall and at least 21 inches of clear space in front of the bowl.
- Showerhead flow limit
- A showerhead is limited to a maximum flow rate of 2.5 gallons per minute at 80 psi under federal efficiency standards for residential fixtures.
- Residual pressure
- Fixture supply pressure must remain at least 8 psi for flush tanks and general fixtures and at least 15 psi for flushometer valves under flowing conditions.
- Pressure-reducing valve
- A pressure-reducing valve is required when static water pressure exceeds 80 psi, and a thermal expansion control device is also needed on a closed system.
- Water hammer arrestor
- A water hammer arrestor is installed near quick-closing valves to absorb pressure surges caused by sudden stoppage of water flow in piping.
- Drain slope
- Sanitary drainage pipe 2.5 inches and smaller slopes at 1/4 inch per foot; 3-inch through 6-inch pipe slopes at 1/8 inch per foot; larger pipe slopes at 1/16 inch per foot.
- Cleanout interval
- Cleanouts are required at the base of each stack, at each horizontal drainage pipe run of 100 feet, and at changes in direction greater than 45 degrees.
- Backwater valve
- A backwater valve is installed on drainage fixtures below the street or sewer level to prevent sewage from reversing into the building during a sewer backup.
- Building drain
- A building drain is the lowest piping of a drainage system that receives waste from inside the building and extends to a point 30 inches outside the building wall.
- Vent terminal height
- A vent stack must extend at least 6 inches above the roof, and vent terminals must be located away from windows, doors, and air intakes as required by code.
- Wet vent
- A wet vent is a vent that also serves as a drain for fixtures, and it is permitted only for specific fixture combinations and sizes listed in the plumbing code.
- Air admittance valve
- An air admittance valve admits air into a drainage system to protect trap seals and must be installed in an accessible location with at least one valve per vent system.
- Trap seal depth
- A fixture trap must maintain a water seal of at least 2 inches and not more than 4 inches to prevent sewer gas from entering the building.
- Grease interceptor
- A grease interceptor is required for commercial kitchen waste lines to separate fats, oils, and grease before the waste enters the sanitary drainage system.
- Indirect waste
- An indirect waste receptor receives liquid waste through an air gap or air break so the waste cannot back up into a fixture or contaminate potable water.
- T&P relief valve
- A temperature and pressure relief valve on a water heater is set to open at about 210 degrees Fahrenheit or 150 psi and discharges by gravity to a safe location.
- Thermal expansion tank
- A thermal expansion tank is required on a closed potable water system to absorb the increased volume created when water is heated in the water heater.
- Water heater drain pan
- A water heater drain pan is required where leakage could cause damage; the pan drain must discharge by gravity to an approved indirect waste receptor.
- Reduced pressure zone
- A reduced pressure zone backflow assembly provides high-hazard protection by maintaining a pressure differential between the potable supply and the hazard; it must be tested annually.
- Air gap backflow
- An air gap provides the highest degree of backflow protection because it creates a physical separation between the potable water outlet and the flood-level rim.
- Hose bib vacuum breaker
- A hose bib vacuum breaker is a non-testable device installed on a threaded hose connection to prevent backsiphonage of contaminated water into the potable supply.
- Sediment trap
- A sediment trap or drip leg is installed at the appliance connection to collect dirt and debris before it can enter the gas controls or burner.
- Natural gas heating value
- Natural gas is commonly assumed to have a heating value near 1,000 Btu per cubic foot, while liquefied petroleum gas is near 2,500 Btu per cubic foot.
- Gas piping test
- Gas piping must be pressure tested with air or inert gas before being placed in service; the test pressure and duration depend on the system pressure and code requirements.