# Incoming Water Line PSI?



## Hardly Working (Apr 7, 2005)

I've got a guy who has low pressure just off the main feeder. I tested it via a hose hib just off the main line which runs rather slow. What's the average water pressure you see inside the house on the main line? Is it possible for sediment to have lodged in the meter or main shut in the ground?


----------



## Teetorbilt (Feb 12, 2004)

This is going to vary given many of the responses posted here.

Are you doing a flow test or a pressure test? I would suggest a pressure test first, flow already seems a problem.


----------



## Ron The Plumber (Oct 10, 2006)

Min working pressure should be 40 psi, great working pressure is at 60 psi, 80 psi is pushing the limits of code.

Whay type of pipe are you talking about here?
How Old is the house?
How far from meter to house?


----------



## Teetorbilt (Feb 12, 2004)

To clarify Ron, I'm on a well. 35-50 PSI. The municipality for which I once worked attempted to maintain pressures of 60 -80. Near towers or plants, that could often go to 90 or 100.

Obviously, this is not your problem. Get a pressure gauge, connect it to the house, make sure that nothing is running and read the pressure.


----------



## Hardly Working (Apr 7, 2005)

Pipe is copper 3/4" running about 40' meter to the house. Planning on tapping into the line coming into the house in the crawlspace to tap a pressure gauge and put in a in house shut off valve. Only valve is on the street. Teetor love those big numbers. Who needs soap when you can just blast off the grim from the day with 60+ psi. Thanks for the numbers. The city said it was within spec whatever that may be.


----------



## Ron The Plumber (Oct 10, 2006)

If there is a pressure reducing valve on the line, the screen could be clogged.

Any tree between the meter and house, possible kink in line.

You sure the valve at meter is fully on.


----------



## Double-A (Jul 3, 2006)

Volume and pressure are closely related. Most homeowners want volume, but complain of pressure problems.

If you have a galvanized water service that is older than 14 years, its over its service life. In Little Rock, its not uncommon to find homes with 80+ PSI at the house, but because of a galvanized service, they get less than 2 gallons per minute maximum volume.

You can buy a pressure gauge that will screw onto a hose bibb (regular 3/4" garden hose threads). 

Ron has pointed out two of the most common possibilities. Time to do some research. 

Be sure the shut off at the street is open fully.


----------



## Hardly Working (Apr 7, 2005)

I did open and close the meter valve a few times just to see if that might dislodge something in the line and free it up. The homeowner said that it just went soft a few weeks back and he didn't know why. Thanks for the info on the hose bib gauge Double-A. The hose bib that I want to test off of is a direct tap off the main line just inside the crawl space.


----------



## Double-A (Jul 3, 2006)

If it just 'went soft' in the last few weeks, then I would strongly suspect the regulator and I think Ron hit on the exact problem.

Our fire department tests fire hydrants in spring and fall by opening them to about 3/4 and then closing again. This stirs up the stuff that settles out of the water in the supply mains. If he got a good shot of something like that, it would easily take down the volume through his regulator in a hurry.


----------



## Ron The Plumber (Oct 10, 2006)

Do the test at that hose bibb, it you have low pressure then you could suspect a pressure reducing valve, if the pressure looks good at that time then leave under test, turn on a faucet inside and look at guage, if pressure drops off big time this still can indicate pressure reducing valve or kink in line.

My thought is you have a kink or PRV valve causing this.

Another thought is, meter has malfunctioned, never encountered a failed meter but there is always a chance of it.


----------



## Hardly Working (Apr 7, 2005)

Just the other side of the meter at the back flow pvr assy.


----------



## Double-A (Jul 3, 2006)

Hardly Working said:


> Just the other side of the meter at the back flow pvr assy.


You lost me here. What is 'just the other side of the meter at the back flow pvr assy.'?

If you mean an RPZ, then check the wye strainer for debris.


----------



## CE1 (Dec 30, 2005)

A Back Flow Preventer is in place to prevent any water from say a pool from going back into the City water system. Essentially preventing the contamination of the city water system from chemically treated water in the house. You might have a back flow preventer problem. This needs to be checked on a regular basis. I just had to replace a 2" BFP on a commercial job the other day. I could not get it to pass the test and was getting wide variations in flow and pressure. After I took the BFP apart to but in a repair kit I found that the thing was totally FUBAR. I had to replace it with a new one.


----------



## CE1 (Dec 30, 2005)

Double-A said:


> You lost me here. What is 'just the other side of the meter at the back flow pvr assy.'?
> 
> If you mean an RPZ, then check the wye strainer for debris.


I think he was talking about a "BFP" assembly. This will help explain a back Flow Preventer:

http://www.watts.com/pro/divisions/backflowprevention/support/support_faq_backflow.asp

:whistling


----------



## Double-A (Jul 3, 2006)

A reduced pressure zone backflow preventer is just one type of BFP. I was just pointing out that its protective wye strainer might have a larger shot of junk in it.


----------



## CE1 (Dec 30, 2005)

Double-A said:


> A reduced pressure zone backflow preventer is just one type of BFP. I was just pointing out that its protective wye strainer might have a larger shot of junk in it.


And I was stating that the BFP might be FUBAR. Because the insides of one of those sukers are very Complicated and they use plastic parts which break easlly. Most people and HO's do not know that BFP's need to be inspected and checked for proper operation on a regular basis otherwise it can make alot of people sick or worse yet kill somebody. There was a incident a few years ago where a U.S. Navy ship had a bad BFP and the entire ship's crew got sick becaause of the BFP not working correctly. So watch out there people.


----------



## Teetorbilt (Feb 12, 2004)

You also have to recognize that most older homes don't have any of these valves. I'm not sure of the exact date that they were mandated for new construction but I have yet to see anything about them being required for older HOMES. 

Comm. is different and they have been required to be retro-fitted.

Pressure problems are usually a simple fix as there is generally only one source. Flow problems are most often a restriction somewhere and can be a beast to locate.


----------



## CE1 (Dec 30, 2005)

Teetorbilt said:


> You also have to recognize that most older homes don't have any of these valves. I'm not sure of the exact date that they were mandated for new construction but I have yet to see anything about them being required for older HOMES.
> 
> Comm. is different and they have been required to be retro-fitted.
> 
> Pressure problems are usually a simple fix as there is generally only one source. Flow problems are most often a restriction somewhere and can be a beast to locate.


 I must apoigize for sounding so harsh but this issue that I feel very strongly about and you might say it is a hot button for me. I am certified to install. repair and test BFP valves and got into this work just because nobody else was doing it and it was a service that was needed. Whenever I do not see one I will try to talk the customer into installing one even if it is just a simple outside hose connected BFP for a a swimming pool (less than $20). This is pretty cheap insurance. :thumbsup:


----------

