Asked by: Ramil Vallath
asked in category: General Last Updated: 1st March, 2020

How do you convert drainage fixture units to GPM?

How to Convert DFU to GPM
  1. Locate the Uniform Plumbing Code (UPC) for your state.
  2. Locate the drainage fixture unit rating for your device or system in the UPC.
  3. Divide the drainage fixture unit rating by 2 to get the gallons per minute of flow for your device or system.

Click to see full answer.


Moreover, how many GPM is a fixture unit?

The relationship between gallons per minute (gpm) and fixture unit is not constant, but varies with the number of fixture units. For example, 1000 FU is equivalent to 220 gpm, but 2000 FU is not double that, but is only 1.5 times as much, or 330 gpm.

Similarly, how many fixture units can a 2 inch drain handle? 710.1 Maximum fixture unit load

DIAMETER OF PIPE (inches) MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS (dfu)
2 6 24
21/2 12 42
3 20 72
4 160 500

Thereof, how are drain fixture units calculated?

A fixture unit is equal to one cubic foot of water drained in an 1 1/4 pipe over one minute (≈ 7.48 US gpm, ≈ 0.47 l/s). Fixture Units are used in plumbing design for both water supply (WFSU) and waste water (DFU).

How many fixture units is a floor sink?

709.1 Values for Fixtures

FIXTURE TYPE DRAINAGE FIXTURE UNIT VALUE AS LOAD FACTORS MINIMUM SIZE OF TRAP (inches)
Floor drainsh 2h 2
Floor sinks Note h 2
Kitchen sink, domestic 2 11/2
Kitchen sink, domestic with food waste disposer and/or dishwasher 2 11/2

33 Related Question Answers Found

How do I calculate GPM?

Does pipe size affect water pressure?

How many fixtures does a 1/2 water line have?


How do you size a vent pipe?

How many fixture units does a 3/4 water line have?

What is Hunter curve?


What GPM means?

What is water supply fixture units?

What size of drain is required for a combination tub shower?


How do you size a drain?

How many drainage fixture units are in the bathroom group?

What is a horizontal fixture branch?


What size is a kitchen sink drain pipe?

What is a unit trap?