MS Plumber flashcards
MS 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.
- Fixture unit
- A dimensionless measure of the load a plumbing fixture imposes on the drainage or water supply system, used to size pipe from standardized tables.
- Air gap
- The unobstructed vertical distance between the lowest point of a water supply outlet and the flood-level rim of the receiving fixture; minimum is twice the effective opening or 1 inch.
- Reduced-pressure-zone assembly
- A testable backflow preventer with two independently acting check valves and a differential relief valve, protecting against both backpressure and backsiphonage in high-hazard applications.
- Backsiphonage
- Backflow caused by negative or reduced pressure in the supply piping, which draws contaminated fluid into the potable system through a cross-connection.
- Backpressure
- Backflow caused by downstream pressure exceeding the supply pressure, such as from a boiler, pump, or elevated tank connected to the potable system.
- Trap seal
- The water retained in a trap's dip that blocks sewer gas; it must be 2 to 4 inches deep and protected from evaporation or siphonage.
- Wet vent
- A vent that also serves as a drain for fixtures, permitted only for fixtures in the same bathroom group and sized at least 2 inches in diameter.
- Building drain
- The lowest piping of a drainage system that receives waste inside the building and conveys it to the building sewer at or outside the building wall.
- Building sewer
- The pipe carrying sewage from the building drain to the public sewer, private disposal system, or other point of disposal.
- Cleanout
- An accessible fitting with a removable plug that allows the drain to be rodded; required at the base of stacks, at direction changes over 45 degrees, and at intervals.
- Backwater valve
- A device installed on a building drain to prevent sewage from surcharging into the building when the public sewer backs up; it must remain accessible.
- Developed length
- The total effective pipe length used in sizing, equal to the actual run plus the equivalent length of fittings, valves, and elbows.
- Residual pressure
- The pressure remaining at a fixture outlet while water is flowing at peak demand; codes require a minimum, commonly 8 to 15 psi.
- Pressure-reducing valve
- A device installed where static supply pressure exceeds about 80 psi to lower pressure to a safe level and protect fixtures and piping.
- Thermal expansion tank
- A tank installed on a closed water-heating system to absorb the volume increase as water heats, preventing excessive pressure and relief-valve discharge.
- Water service pipe
- The pipe from the water main or other source of supply to the building served, installed below the frost line and separated from the building sewer.
- Flood-level rim
- The edge of a fixture at which water would overflow onto the floor; used to set air gaps, vent heights, and backflow device elevations.
- Flushometer valve
- A fixture valve that uses line pressure to flush a water closet or urinal; it requires a larger supply pipe and adequate flowing pressure.
- Indirect waste
- A drain that discharges through an air gap or air break into a receptor rather than connecting directly to the drainage system, used for food-service and sterilizer equipment.
- Grease interceptor
- A tank that traps fats, oils, and grease before effluent enters the sewer; required for food-service establishments and sized by fixture capacity and flow.
- Roof drain
- A fixture that collects stormwater from a roof and conveys it to a leader or conductor, sized by roof area and local rainfall intensity.
- Sewage ejector
- A pump and pit assembly that lifts sewage from a basement or below-grade fixture to a higher drain; the pit must be vented and gas-tight.
- Dielectric union
- A fitting with an insulating sleeve or washer that separates copper and steel piping to prevent galvanic corrosion at the joint.
- Solvent cement joint
- A PVC or ABS joint made with primer and cement; the pipe and fitting are coated, assembled with a quarter turn, and cured before pressure testing.
- No-hub coupling
- A cast-iron joint made with a neoprene sleeve and stainless-steel bands tightened to the manufacturer's torque specification.
- Press fitting
- A copper or PEX connection made by inserting the fitting and compressing it with a calibrated tool; the joint is mechanical rather than soldered.
- Slope formula
- Fall in inches equals run length in feet multiplied by the slope in inches per foot; 2-inch pipe uses 1/4 inch per foot, larger pipe 1/8 inch per foot.
- Drainage fixture units
- The sum of individual fixture ratings used to select horizontal and vertical drain sizes from the code's fixture-unit tables.
- Water heater recovery
- Gallons per hour of hot water a heater can produce, equal to input BTU/hr times efficiency divided by 8.33 times the temperature rise.
- Confined space entry
- Entry into a space with limited access and poor ventilation; requires a permit, atmospheric testing, a standby attendant, and retrieval equipment.
- Trench protective system
- Shoring, shielding, or sloping required for trenches 5 feet or deeper; spoil is kept at least 2 feet from the edge and a ladder is placed every 25 feet.
- Stop-work order
- An official directive halting work on a site until a violation is corrected; only measures needed to make the site safe may proceed.