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View Full Version : What valve to use?


duke of earl
10-02-2011, 02:27 PM
Open Loop water source heat pumps-do you guys use hydronic zone valves or is there a less expensive slow opening/slow closing valve available? I ran into a unit this week that had a rainbird sprinkler valve that had cracked as a result of water hammer.
meoberry
10-02-2011, 02:39 PM
Open Loop water source heat pumps-do you guys use hydronic zone valves or is there a less expensive slow opening/slow closing valve available? I ran into a unit this week that had a rainbird sprinkler valve that had cracked as a result of water hammer.

There is a couple of tricks I have used for water hammer. The best one was to go down to the auto parts store and pick up enough premium heater hose to make a loop on the inlet and outlet on the valve or unit. The hose will absorb the shock almost completely eleminating the hammer. Another was to put a riser on the pipe that will trap air absorbing the shock. But I have had those loose the trapped air over time. Slow closing valves work best but are expensive. The hose is the most practical way. Just tell customer that it will have to be replaced every five years.:.02:
a.desisto
10-02-2011, 05:31 PM
I one time saw a fitting with an air bladder built into, almost like a small extrol tank, to absorb the shock. I can't remember the name though. :confused:
chuckcrj
10-02-2011, 05:44 PM
I've seen almost all possible configurations for valves on open loop WSHP.

The only one that is trouble free and quiet was a slow opening Taco zone valve style valve. A lot easier, faster, and cheaper than adding all sorts of stuff to try to control the water hammer.
mgenius33
10-02-2011, 06:51 PM
I one time saw a fitting with an air bladder built into, almost like a small extrol tank, to absorb the shock. I can't remember the name though. :confused:

Hammer arrestor. They can be purchase at the big name stores aswell.

I agree with chuckcrj though, the better valves are the way to go.

Many of the broken valves I've seen are due to using pipe threading compounds that can cause overtightening. I like to use the blue leak lock. Seams to work well, but you have to watch how tight you make the fittings. They are only plastic female adapters, and will crack very easily.