California (la) Plumbers. Service Entrance Pressure Relief?

[whackit]

hello. Need an answer fairly quickly. I'm getting mixed opinions on whether I need to place a pressure relief valve (like a water heater one) at a service entrance or not. I'm getting some yes and some no. Nobody can give me a straight answer and can't get anyone at code desk on the phone (shocker). If anybody knows please chime in. Thanks!

 

[Jadnashua]

Residential water pressure should be kept at 80psi or less. If yours is higher than that, it should be reduced. A pressure release valve should not be used in water starved CA regions, as it will constantly be releasing (wasting) water! The proper way (IMHO) is a pressure reduction valve (PRV) which also would require installation of an expansion tank since the PRV converts what may be an open system into a closed one, and water heater operation will raise the pressure and end up wasting water - an ET provides a place for that expanding water to go without raising the pressure or throwing it down the drain.

 

[Sponsor]

 

[whackit]

I agree. It is common practice in Los Angeles to install a relief valve AFTER the pressure regulator at the service entrance. This seems redundant to a expansion tank. I am just wondering if this is an old throwback practice or if it is still necessary. I can't find any reference to it in the code. Hoping someone has some insight. See the attached photo for the commonplace layout.

 

[Terry]

Ther e should be a T&P on the water heater.
For a while, the city of Bellevue wanted a relief valve on the cold, but then later agreed that it was needed on the water heater, not the cold.
It's not a UPC code thing, it would be a "local" inspector thing. Only your inspector can say. You won't find that in the code book.

 

[Jadnashua]

The only time it would be useful is if you never maintained anything and your PRV or ET failed...a relief valve, if it was still working and not corroded shut, would limit the home's pressure to the value of the where ever the relief valve was set. My (limited to homeowner) experience is that while a PRV doesn't last forever, nor does an expansion tank, I'd rather have the pressure remain steady, and that takes a working PRV and ET. Code pretty much requires a defacto relief valve in the system on the water heater. None of these are great to be opening on a regular basis.

 

[Dj2]

From your picture:
What you have is normal installation in LA - Shut off on the main water in, a pressure reducing valve, a pressure relief valve and a hose bib for convenience.
We have millions of houses with exact same set up as this around here.
If you are still not satisfied, go to the Dept of Building and Safety and ask them, or better yet, get a hold of a building dept inspector.