Pressure regulator install for water hammer

Using a Valve like that will only throttle the volume and not the pressure.

Some Valves want to be opened or closed, and may leak in a different position.

Use whatever works for you.

You only need 40-50 psi for your house, 60 is nice, so a Pressure regulator is what you need to fix your problem and be done with it.


Have Fun.

DonL said:

Using a Valve like that will only throttle the volume and not the pressure.

Some Valves want to be opened or closed, and may leak in a different position.

Use whatever works for you.

You only need 40-50 psi for your house, 60 is nice, so a Pressure regulator is what you need to fix your problem and be done with it.


Have Fun.

Click to expand...

Thanks DonL,

I used a RV camper pressure reducer rated at 40 psi on the front loading washer and the outdoor hose bibb and still got water hammer at the tank-less WH. Throttling the flow so far has produced best results . Water dept said they have not had any customer complaints like this. I think I would put the expansion tank in before the PRV and see what happens per hj.
The other thought I had was to isolate the problem 1/2" cold water fixture line with a check-valve and a hammer arrestor so the shock wave cannot travel back to the tank-less WH inlet line. Anyone have any thoughts on this? Trying to keep it simple.

Thanks,
boater bill

I did a job with water hammer in Sammamish.
When the neigbor turned their water on and off, it hammered the piping next door.

They also had a PRV valve before it went up into the plumbing. My solution was to run some PEX piping from the incoming shutoff, and then a 3/4" Mini-restor before the new PRV valve. I wanted to provide hammer protection before the PRV.
It worked.

Not sure what the camper PRV is supposed to do? If you install a PRV on your main supply and some shock arrestors on the laundry supplies , you will probably solve the issue. An expansion tank should be installed with a prv so you can set the pressure on both but I still don't think that you will need one.

Jerome2877 said:

Not sure what the camper PRV is supposed to do? If you install a PRV on your main supply and some shock arrestors on the laundry supplies , you will probably solve the issue. An expansion tank should be installed with a prv so you can set the pressure on both but I still don't think that you will need one.

Click to expand...

Thanks Jerome,
The RV camper PRV is set at 40 psi and installed at the shut-off valve of the washer. There is a hammer arrestor at the washer. So at 40 psi and a hammer arrestor it still generates water hammer. Same scenario at hose bibb+PRV+garden hose+spring loaded nozzle generates water hammer at 40 psi when the nozzle slams shut. Seems like the shock wave needs to be dissipated some where other than the tank-less WH. Maybe expansion tank and no PRV.

Thanks,
boaterbill

boaterbill said:

Thanks Jerome,
The RV camper PRV is set at 40 psi and installed at the shut-off valve of the washer. There is a hammer arrestor at the washer. So at 40 psi and a hammer arrestor it still generates water hammer. Same scenario at hose bibb+PRV+garden hose+spring loaded nozzle generates water hammer at 40 psi when the nozzle slams shut. Seems like the shock wave needs to be dissipated some where other than the tank-less WH. Maybe expansion tank and no PRV.

Thanks,
boaterbill

Click to expand...

The main reason for water hammer is pressure spikes from quikly closing valves. If the pressure is reduced (meaning on your main comming into the house) Then the spike will also be reduced. The shock absorber may not be able to handle the pressure spike because the pressure is too high. So I would first start with a PRV (set to about 60 psi) and if that doesn't do it then add the expansion tank.

Jerome2877 said:

So I would first start with a PRV (set to about 60 psi) and if that doesn't do it then add the expansion tank.

Click to expand...

That is what I would do. PRV on the Input to the House.

Chances are, You can use the California Flow Regulating Washer Discs for the rest of the problems.


It is not Rocket Science, but theory still applies.