Excess flow check valve versus check valve

[ris2]

What is the difference between an excess flow check valve and a normal check valve. We have an excess flow check valve in one of our systems and I would like some more information on this valve.

 

[budt]

In oil hydraulics, an "Excess Flow Check Valve" would be a Check Valve with a spring that requires the system to reach a preset pressure before any flow goes thru it. (Actually a Relief Valve made from a Check Valve) A "Check Valve" allows flow in one direction, stops flow in the opposite direction.

In other situations there may be other reasons for the different terms.

Bud Trinkel CFPE
HYDRA-PNEU CONSULTING, INC.
fluidpower1 @ hotmail.com

http://www.fluidpower1.us

 

[EGT01]

I suppose excess flow valve can have different meanings depending on your area of industry. The type I'm familiar with are valves that are normally open and will allow flow to occur in either direction. However, if the flow exceeds a certain value in the forward direction, it will cause the valve disk to seat and stop the flow. So where a check valve prevents flow in the reverse direction, an excess flow valve will prevent excessive flow in the forward direction.

There's quite a few websites with this info. The best thing to do is look for the manufacturer's name on your valve then check for info from them. Otherwise, here's a link

http://www.ecii.com/L500F.htm