Water shut-off before and after regulator

[Blindog]

I'm in the process of re-plumbing the water heater and the main coming into my daughters house. I'm accustomed to finding the meter at the line coming into the house but I find none, I assume it's outside somewhere. However, right after the feed pops through the cement there is a regulator and on each side of the regulator is a shut off valve. Why is this? To service the regulator without allowing water to drain back from the house plumbing? I'm re-plumbing from the regulator to the house branches. Should I put a valve back on this side of the regulator? Thanks.

 

[Reach4]

I don't know the answer to your question. I would suggest that you add a pressure gauge, or a place that you could screw a pressure gauge to. The reason would be to monitor the PRV and the thermal expansion tank performance.

 

[Sponsor]

 

[Blindog]

No thermos expansion tank that I am aware of. What kind of pressures should I expect to see and should I adjust the regulator? I can't say I've ever seen a system with a TET, how important is this? Thanks

 

[Reach4]

Some PRVs come with a thermal expansion bypass. With those, you may not need an expansion tank if the incoming water pressure is not too high. Other PRVs in effect have a check valve built in. Read about your PRV.

Usually with a PRV, you need an expansion tank. That absorbs the water expansion that happens when you use hot water, stop using water, and the water heater heats up the water.

With a pressure gauge, you can see what you are dealing with.

 

[Dj2]

A shut off valve between the meter and the PRV is normal practice.
A shut off valve between the PRV and the house is not necessary.
A pressure gauge pass the regulator is not a bad idea.
Pressure tank over the water heater is a good idea.
Sometimes water meters can be found in basements. In my city, they are under the side walks or parkways.

 

[Blindog]

What are min and max pressures that are acceptable?

 

[Dj2]

40 - 80 psi is the acceptable range.

 

[Blindog]

thanks, DJ2. Thermo expansion tank and gage installed. Tomorrow I'll try to get my manifold plumbed into the system.