High Flow/Low Pressure Relief Valve

[JDG1977]

I'm looking for a relief valve that will handle 150-200 gpm and maintain a low pressure (10-20 psi or even lower if possible). Ideally the valve would have the capability of controlling the relief setting electronically (or with a pilot pressure that could be controlled electronically). The ideal relief setting range would be around 5 psi to 250 psi. This is for a test stand application where we currently have a valve capable of limiting the pressure to about 75 psi. We have a new use for the stand though that needs even lower pressures. I've looked around for a new relief, but so far I haven't found anything that looks like it will work. Any ideas? Thanks in advance.

 

[keyardee]

This custom made relief valve could be made with external pilot (electric,pnumatic ) for a variable range.Please furnish more details about the testing medium ,end connection details,set pressure accuracy range etc for further development.You may also contact propel@vsnl.com for further details.

 

[JDG1977]

This is kind of a jack of all trades test stand that is used for any type of system/component performance testing for hydraulic systems. The stand has two large piston pumps for high pressure testing and a screw pump that we use for high flow low pressure testing. The valve I am looking for is for the screw pump circuit. We recently added an electric pump drive to this test lab next to this test stand so that we can test the entire hydraulic system in the lab from the pump to the implement. Since we were modifing an old test stand/lab we were not able to locate the pump drive as close to the stand reservoir as we would have liked. This makes gravity feeding the pump on the pump drive difficult. Our hope was to charge the pumps on the drive using the screw pump circuit. We want the pressure to be low to simulate as closely as possible the gravity feed condition we see on the machine. We have tried several combinations of reliefs, reducers etc, but haven't been able to lower the pressure to a point we are happy with. There may also be a better way of doing this that someone can think of. The test fluid is 10W30. I am flexible on the end connections altough would prefer either split flange of a manifold type connection. Desired pressure range would be around 5-1000 psi. Accuracy of +/- 10% would probably be acceptable.

 

[WWTraveler]

Try the ERV valve from Valvtechnologies. Although it is designed for steam, it could probably be used for liquid. The ball valve design should help you for the amount of flow you need and the electronic controller will handle the different set points. Good luck.

 

[valvetech]

If you do not need safetey relief you may want to try a back pressure regulator.
The valve will stay closed to hold pressure in the line up to the set point and then open to relieve the pressure when it rises above the set point, the media can then be piped back into the system at some other point.
Available in piloted or self-operating versions depending on your needs. Jordan Valve offers both piloted and self-operating versions that can be air actuated and will allow you to remotely change your set point as your requirements change.
I am sure that Fisher and other manufacturers have similar products.