Private Service Main

[MechEng2007]

What is the maximum water pressure in private service mains? The question was asked by a sprinkler fitter who was tested on it. Thank you in advance.

 

[PEDARRIN2]

Probably depends on the pipe material and joint type.

Ductile iron flanged piping goes from 150 psi to 350 psi depending on pipe diameter.

This is according to my US Pipe and Foundry catalog.

HDPE pipe goes up to ~200 psi.

 

[stookeyfpe]

NFPA 24 has no pressure limit, and this standard governs private service mains. The pipe must be designed to supply the demand at a minimum pressure of 150 PSIG. The minimum hydrostatic test pressure is 200 PSIG or 25 PSIG over the design pressure if the operating pressure is > 200 PSIG.

 

[DavidCR]

Accessories such as hydrants, valves, test headers, etc. are rated to 175-250-300psi.So keep that in mind.