After some searching the web I am failing to find any available ball-check valves (described on: https://www.archtoolbox.com/materials-systems/plumbing/plumbingvalvetypes.html) that I can use with my pex plumbing. Currently I have a swing check valve but it makes a loud bang each time my washing machine cycles so a plumber I once talked to told me you could get a vertical check valve that has a ball sitting in a seat they close very quietly. I know I could also get a spring-loaded valve, but liked the idea of the ball-check. Does such a thing exist? Are there any examples you can link me to?

Apparently this is considered off-topic? For those voting it as such, where else can I ask if such things exist? Please provide an alternative. If you want me to word my question differently, here goes: I have a thermal expansion tank because the city has a check valve at the road for my house and after a shower, pressure would build up in my pipes in excess of 90psi after expansion. So I installed an expansion tank, solved that problem. New problem is that after a shower and the expansion tank absorbs the pressure, if I turn on a cold valve in the house the expansion tank first pushes out some hot water before city water enters the pipes and you would get a short blast of hot water. I solved this by using a swing check valve separating my hot and cold lines in the house so that the expansion tank can never push hot water back to the cold. Problem is that the swing valve is noisy, especially when the inlet valve on the washing machine closes and sends a pressure wave back through the cold side that pushes up the swing valve and quickly closes it, causing a bang (not from water hammer mind you, but from the brass flap closing). I would like to try a different valve that would be quieter and I would like to avoid a spring valve because that would induce a slight amount of back pressure to my hot water lines and I think a ball-check valve could be a quiet, effective solution. Does anyone have experience that agrees with this or a better alternative? I'm not opposed to examples of products.

  • First off, why do you need a check valve at all? Washer machines normally pump up only waste high and then dump into a stand pipe. It should not be a closed system anyway. Where is your machine pumping to? – ArchonOSX Jan 4 '18 at 17:27
  • I'm referring to supply.... not waste. The valve is to separate my hot/cold lines in the house so that when the hot water expansion tank builds up pressure it won't be able to push hot water out through the cold side. – kd7iwp Jan 4 '18 at 17:35
  • @ArchonOSX - Seems that he is talking about PEX which is more likely the water feed lines to the washer. – Michael Karas Jan 4 '18 at 17:38
  • So you want something that accepts the PEX directly instead of just threading into it with male/female adapters? – JPhi1618 Jan 4 '18 at 18:50
  • @JPhi1618 yes, I would like to just crimp PEX onto the valve. If there isn't something like that I am fine with threading in adapters and crimping my PEX to that, but seems like an extra step that would be slightly preferable to avoid. – kd7iwp Jan 4 '18 at 19:01

I haven't seen any direct-crimp check valves, but I have seen some "sharkbite" style spring check valves. They take up very little room and are easy to install.

Sharkbite check valve

These will work on PEX or other types of pipes and can be removable if you think it has become inoperable. I personally prefer anything with moving parts to be threaded or otherwise removable to make replacement or repair easier, but that's not an absolute rule.

  • Unfortunately this is not what I am asking for and I know about these already. I want to find a product that does not have a spring, or a swing. I want to find a gravity controlled ball-check valve. Thanks! – kd7iwp Jan 4 '18 at 20:49

The valve is to separate my hot/cold lines in the house so that when the hot water expansion tank builds up pressure it won't be able to push hot water out through the cold side.

I don't understand the part about "pushing hot water out through the cold side".

However, thermal expansion can be a problem that causes higher pressure and leaks at faucets and that is why they make expansion tanks for the hot water side of your water heater. One should be added to the hot water supply line next to the water heater.

The loud banging you are hearing may be water hammer from the washer turning off the supply lines. Both lines should have anti-hammer devices near the ends of the lines.

Swing gate valves are designed to be installed horizontal since they do not contain a spring. They will not work properly in a vertical leg. The hot and cold water lines do not need to be connected with a check valve.

  • I put in the swing valve and it solved the problem I was experiencing, but since it has a physical moving tab that is brass-on-brass it makes an annoying clang when it shuts. I would prefer to do a vertical ball-check valve as originally described, if I can find one as I believe that would be quieter since the ball rests on a rubber o-ring. Reason for the valve is after thermal expansion in the tank, when I turn on cold water 10 minutes later the expansion tank pushes a squirt of hot water into the cold lines and the check valve successfully prevents that. – kd7iwp Jan 4 '18 at 20:48

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