Thermal Expansion With Pressure Valve

Old 05-05-04, 09:42 AM
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Thermal Expansion With Pressure Valve

I had a pressure-reducer installed (line pressure was 100 psi). Now I seem to be getting pressurization from thermal expansion of the water heater backing up into what is now a closed system. I assume there's some straightforward solution - can someone explain what it might be and how it works? Thanks.
Old 05-05-04, 09:54 AM
Ed Imeduc's Avatar
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You can put a bladder expansion tank anywhere in the home on the water line cold or hot. This should take care of it for you. I see that some citys call for them now if you have a backflow check in the water line.

Old 05-05-04, 06:02 PM
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An expansion tank will solve problem.

PRV should have intregal bypass built in to allow back pressure to be relieved. Pressure reducing valve is different than backflow preventer which creates closed system.
Old 05-05-04, 09:57 PM
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Click on products, then thermal expansion.

Make sure when you install an expansion tank that you precharged the tank to the setting of PRV FIRST, and without water in the tank. The expansion tank should be installed between the top of the tank and the shut off valve, the location where thermal expansion is most common.
Old 05-06-04, 06:16 AM
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Thanks to Ed, notuboo and Dunbar for your responses

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