Water Supply Hammering - PRV

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ckev70

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I'm in CA with copper piping. Every time the clothes washer turns on the pipes rattle. I've already installed the Water Hammer Arrestors at the both hose bibs without any success of stopping the water hammer.
I measured the water pressure from a hose bib and it exceeded what is expected (sorry it's been a long time since i did this so i think it was in the 80+ PSI)
I've got a PRV ready to install and will also want to change out the gate valve for a ball valve.

Should the shutoff valve be 1st inline from the water supply followed by the PRV or vise versa?
Configuration 1: Water Supply -> Valve -> PRV
Configuration 2: Water Supply -> PRV-> Valve
I would expect config 1 to be more serviceable but checking since i've seen generic pictures with Conf 2 on the local water dept web site (not specific for installing PRV)

Also any tips on removing the old valve and or reconfiguring the piping?

Water Supply Inlet is from the ground.
Water Supply to house is through the air vent/grill
Left side is water supply for the yard.
 

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Diehard

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If your water supply pressure is 80+ you should have a PRV. It's actually a plumbing code requirement when pressure exceeds 80 psi.

When you say, "want to change out the gate valve for a ball valve.", is that gate valve located within the house or is it the one I see outside?

Typically the PRV should be preceded by an isolation valve. However, it's nice to have an additional valve downstream of the PRV. This allows you to isolate it from the house side, preventing water flowing back from when water to service it, clean the integral filter, or whatever.

I would also look at those pipes that are rattling and see if you can add a bit of support to stabilize them. If accessible, of course.

Water hammer is indirectly the result of high water pressures. The cause of the water hammer is the rapid stopping of the high velocities, that are commonly the result of higher pressure. So if you were able to throttle down the flow to the washing machine, those quick closing valves would have a much lesser impact.
 

ckev70

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If your water supply pressure is 80+ you should have a PRV. It's actually a plumbing code requirement when pressure exceeds 80 psi.

When you say, "want to change out the gate valve for a ball valve.", is that gate valve located within the house or is it the one I see outside?

Typically the PRV should be preceded by an isolation valve. However, it's nice to have an additional valve downstream of the PRV. This allows you to isolate it from the house side, preventing water flowing back from when water to service it, clean the integral filter, or whatever.

I would also look at those pipes that are rattling and see if you can add a bit of support to stabilize them. If accessible, of course.

Water hammer is indirectly the result of high water pressures. The cause of the water hammer is the rapid stopping of the high velocities, that are commonly the result of higher pressure. So if you were able to throttle down the flow to the washing machine, those quick closing valves would have a much lesser impact.

There is only 1 gate valve as you described.
I'll setup the PRV with a valve on both sides.
I believe the pipes going into the house are rattling. I'll get those tightened down.
 
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