Fixture unit

In plumbing, a Fixture Unit (FU) or Drain Fixture Unit (DFU) is "a unit of measure, based on the rate of discharge, time of operation and frequency of use of a fixture, that expresses the hydraulic load imposed by that fixture on the sanitary plumbing installation".[1] A Fixture Unit is not a flow rate unit but a design factor. A fixture unit is equal to 1 cubic foot (0.028 m3) of water drained in a 1+1⁄4 inches (32 mm) diameter pipe over one minute.[2] One cubic foot of water is roughly 7.48 US gallons (28.3 L; 6.23 imp gal). A Fixture Unit is used in plumbing design for both water supply and waste water.

Different fixtures have different flow requirements. In order to determine the required size of pipe, an arbitrary unit is used for pipe sizing which takes into account the likelihood that all the fixtures will not be used at the same time. This is called "fixture unit" (FU). 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 US gallons per minute (0.014 m3/s) while 2000 FU represents only 330 US gallons per minute (0.021 m3/s), about 1.5 times the flow rate.

Fixture unit values can be determined using charts from the International Plumbing Code or similar codes in local jurisdictions.

There are situations where a design provides for more FUs being discharged than being supplied. This occurs in situations where liquids may infiltrate or are added to a draining system, such as might happen in a large sports venue. Examples of how this could occur include rain water infiltration.

References

  1. ^ Limited., Standards Australia International (2003). Plumbing and drainage. Part 0, Glossary of terms. Standards New Zealand. (3rd ed.). Sydney, N.S.W.: Standards Australia International. ISBN 0733755240. OCLC 155925252.
  2. ^ Available at: https://mycomfortheroes.com/expert-tips/what-is-dfu-drainage-fixture-unit/ [Accessed March 14, 2020]


Stub icon

This fluid dynamics–related article is a stub. You can help Wikipedia by adding missing information.

Content Disclaimer

Informasi ini disarikan dari Wikipedia dan disajikan kembali untuk tujuan edukasi. Konten tersedia di bawah lisensi CC BY-SA 3.0. Kami tidak bertanggung jawab atas ketidakakuratan data yang bersumber dari kontribusi publik tersebut.

  1. The information displayed on this website is sourced in part or in whole from Wikipedia and has been adapted for the purpose of restating it. We strive to provide accurate and relevant information, however:
  2. There is no guarantee of absolute accuracy. Wikipedia is an open, collaborative project that can be edited by anyone, so information is subject to change.
  3. It is not intended to constitute professional advice. The content displayed is for informational and educational purposes only. For important decisions (e.g., medical, legal, or financial), please consult a professional.
  4. Content copyright. Wikipedia is licensed under the Creative Commons Attribution-ShareAlike License (CC BY-SA). This means that content may be reused with appropriate attribution and shared under a similar license.
  5. Responsible use. Any risk arising from the use of information from this website is entirely the responsibility of the user.