Fixture units, flow rates, pressure, pipe sizing and pump basics.
40 cards · mixed cards · AI-written, checked twice. Edit anything.
- What is a fixture unit (FU)?
Show answer
A unit of measurement representing the load that a plumbing fixture places on the water supply and drainage system- How many fixture units does a standard lavatory faucet represent?
Show answer
1 fixture unit (1.0 FU)- What is the typical fixture unit value for a bathtub?
Show answer
2 fixture units (2.0 FU)- What is the flow rate capacity of a standard lavatory?
Show answer
0.5 to 1.5 gpm (gallons per minute)- What is the maximum water velocity recommended in supply piping?
Show answer
8 feet per second, though some codes specify 6 feet per second to reduce noise- What is the minimum water pressure required at fixture outlets?
Show answer
20 psi minimum, with 50-60 psi typical- Define static pressure.
Show answer
Water pressure in a piping system when no water is flowing- Define dynamic pressure.
Show answer
Water pressure in a piping system while water is actually flowing- What is residual pressure?
Show answer
The pressure remaining in the system after accounting for friction losses and fixture demand- How many fixture units is a kitchen sink?
Show answer
2 fixture units (2.0 FU)- What is the maximum trap arm length for a 1.5 inch diameter trap?
Show answer
5 feet- Define friction loss in piping.
Show answer
The pressure drop that occurs due to resistance as water flows through pipes, fittings, and valves- What is the standard allowable friction loss for design purposes?
Show answer
5 psi per 100 feet of pipe- What pressure loss occurs at valves and fittings?
Show answer
Typically 5-15 psi per valve or fitting, often estimated using equivalent pipe length- What is a centrifugal pump?
Show answer
A pump that uses rotating impellers to move water by centrifugal force, commonly used in domestic water applications
FlashKeepers