Spigot PSI pressure

[Cygarbuff]

What should the standard pressure be for an outdoor spigot? I have three and two are between 90-95 and the one in the driveway (most important one for washing cars) is only 40. It's ok for getting dirt off my hands. Is this normal?

 

[TedL]

If you're talking static pressure (without water running) they should all be the same if they have the same supply. So, how and under what conditions are you measuring?

That said, 90 is high, higher than most toilet, washer, etc. manufacturers specify, and more than needed.

Is ther a pressure reducing valve on the premises?

 

[Sponsor]

 

[Jimbo]

Out here , it is not unusual for one or more bibbs to be taken off BEFORE the pressure regulator, and others after. The way water come in to the houses, it is usually the front bibb on hi, and the back yards bibbs on lo.

 

[Gary Swart]

Unless there is a pressure reducing valve in the supply line prior to the hose bib, the pressure will be whatever your city water main's pressure is. 90 psi is too high for household appliances, but would be fine for a hose bib. If the bib with 40 psi does not follow a PRV, the pipe could be restricted. However, static pressure where no water is flowing would be the same regardless of pipe size or restrictions.

 

[Cygarbuff]

There is a reducing valve in the house as the pressure coming in from the street is high. All appliances and shower and faucets are just right. As well as those two hose bibs (side and backyard) the driveway one is the one at 40. I jave a pressure reading gauge I screwed onto the sill to give me those readings. I would like more pressure but wanted to double check as I did not know what was normal

 

[Gary Swart]

It would appear that the bib with the 40 psi branches off the main supply line after the PRV. You need to understand that static pressure, the pressure you get when you put the gauge on the bib with no water being used, is not affected by a small pipe, clogged pipe, or faucet partly closed. Those factors would affect flow or volume, but not static pressure.

 

[Thatguy]

"Code Maximum is 80psi.

In any installation where the static head pressure exceeds 80psi, whether the excess is constant or intermittent the homeowner is required to install a PRV (pressure reducing valve) to limit the water pressure to not more than 80psi.

Ref:
International Residential Code IRC 2903.3.1
Uniform Plumbing code UPC-608.2"

I think 30 was the minimum.

 

[Gary Swart]

He has a PRV for the household water. It's the one hose bib that has less pressure than he wants. He does not want to change the inside pressure.

 

[Jadnashua]

Your only choices are raise the PRV outlet pressure some to everything else in the house, or replumb that hose bib so that it branches off before the PRV.