Return to the Plumbing Forum | Post a Follow-Up

 o
Water Pressure, what's right?

Posted by staze (My Page) on
Sun, Apr 19, 09 at 22:44

Hello All,

I'm a bit lost at this point, so I'm hoping to get yet another answer to a question that seems to have no "right" answer. =/

I have a simple hose-bib pressure gauge that matters static pressure. On my house, it reads 92-96psi (not the most precise scale). From what I can find online, thats either "okay" or "high". A page on the lowes site says anything above 80 is bad, and another site say anything below 115psi is okay. I haven't had any appliance failures, and the pipes don't knock since I fixed one of the pipe hangers in the crawl space.

All the pipes in my house are copper, so the risk of bursting is fairly minimal. The house was built in '79. I purchased it in 2007. There is a water tank on the hill behind my house, which probably accounts for the high pressure.

Judging my the reading on the water meter on my house, I'd guess it was replaced 10-20 years ago (hard to tell since I don't know the average water use for the previous owner). But, I don't have an expansion tank on the water heater, and the pressure does not rise above the 92-96, so I'm guessing there is no backflow preventer (when did those become a standard part of pressure reducers?) Likewise, when I purchased the house, the home inspector didn't mention the lack of an expansion tank.

I'm really hoping to get a solid answer here. I'm planning to call the local utility tomorrow and see what they say.

(The Mass. Plumbing code, (found here: http://www.mass.gov/?pageID=ocaterminal&L=6&L0=Home&L1=Licensee&L2=Division+of+Professional+Licensure+Boards&L3=Board+of+State+Examiners+of+Plumbers+and+Gas+Fitters&L4=Statutes+and+Regulations&L5=Rules+and+Regulations+Governing+Plumbers+and+Gas+Fitters&sid=Eoca&b=terminalcontent&f=dpl_boards_pl_cmr_248cmr1000b&csid=Eoca) does say 80 P.S.I.G. )

Thanks very much! I really would rather not spend $500 to install a pressure reducer, but I'd rather do that than have something go wrong. =/


Follow-Up Postings:

 o
RE: Water Pressure, what's right?

Sorry gotta pay. Some homeowner insurance policies will not cover water damage if the pressure is above 60.


 o
RE: Water Pressure, what's right?

That seems odd since the UPC seems to dictate 55-80psi. =/

Will post again once I talk to the local utility. I'm hoping I have a pressure regulator already that just needs adjusting (the previous owner maybe wanted higher pressure. =/


 o
RE: Water Pressure, what's right?

Quote: "Some homeowner insurance policies will not cover water damage if the pressure is above 60."

WRONG!

The homeonwers insurance must cover any pressures which are equal too or less than the code defined maximum.

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

The PRV must be equipped with an internal by-pass for thermal expansion relief OR the homeowner must install an expansion tank in the near proximity of the water heater.

Ref:
International Residential Code IRC-2903.4
Uniform Plumbing Code UPC-608.3


 o
RE: Water Pressure, what's right?

Lazypup,

Thanks very much for this. You actually hit upon the whole reason this came up. I don't have an expansion tank, and I was looking at why I didn't, or if I needed one, and it seems that pretty much all the tanks max out at 80PSI, which given my current pressure, won't work. =P

It seems odd, ultimately, that the utility is not required to install PRVs since it's their system that causes excessive pressure, and I thought there was something about the water main in your house (until it splits, or whatever) actually being property of the utility.

Lazypup, could it be that I have a PVR that needs adjusting, that also does not have a backflow preventer (since my pressure doesn't go up due to thermal expansion, and I don't have an expansion tank, the conclusion is either that A. I don't have a PVR, or B. I have a PVR that allows for thermal expansion somehow).

Thanks! And thanks for the UPC chapters. The building codes website for the State of Oregon is down, so I can't check it.


 o
RE: About the expansion tank...

Lazypup,

Also, about the expansion tank. I have copper flex pipe (that's got threaded connections) between the cold shutoff and the water heater. I'm curious if it's "allowed" to basically insert a tee between the shutoff valve and the flex pipe, then screw the tank into the open part of the Tee, or, to screw the Tee into the top of the water heater, connect the perpendicular part of the Tee to the flex tubing, then screw the tank into the Tee directly above the water heater. In both cases, the expansion tank would be above the water line, and vertical, but in the latter case it wouldn't be strapped to the wall (it would just be free standing), where in the first example, it would be strapped to the wall.

Thanks very much!


 o
RE: Water Pressure, what's right?

lazypup
Thats a mighty bold statement. How can you speak so strongly about homeowner policies written 1500 miles away?


 o
RE: Water Pressure, what's right?

For those of us who have actually studied the building codes and are aware of how they are created the answer to your question is very easy. Insurance companies are the greatest single influence on the creation of codes.


 o
RE: Water Pressure, what's right?

So, turns out I do have a PRV (I was digging to give a plumber access to the main so I wouldn't have to pay him to do it). It was right beside the meter box, buried under the sod. gar! It was also buried in mud and sediment... I'd think about rebuilding it except the fact that the adjustment screw is completely corroded, and I can't find any brand or model name on the unit at all.

But, it's obviously bad/malfunctioning (calling the local utility, they said I'm getting full street pressure for my area). I'm going to finish excavating it so it can be replaced, but it might be that I can do it myself. I guess the big question is, how much access do I need to give myself? The manufacturers say you have to check them yearly, but do you really? I've never had a problem with sediment in the lines, so I'm not sure cleaning the screen regularly would be an issue.

If I do get a PRV that has an expansion bypass, should I still install a thermal expansion tank, just so the pressure isn't rising to the point that it's being pushed back out the PRV?


 o
RE: Water Pressure, what's right?

I just copied and pasted "Lazypups" response because That Is Correct...

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

The PRV must be equipped with an internal by-pass for thermal expansion relief OR the homeowner Must Install an Expansion tank in the near proximity of the water heater.

Ref:
International Residential Code IRC-2903.4
Uniform Plumbing Code UPC-608.3


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Plumbing Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here