spillover valve

[jalover]

Hi everybody, i need some help. Does anybody knows what is mean by "spillover valve in a hydraulic system, what is the function of this. Is this same with pressure relief valve.
thanks in advance.

 

[zeusfaber]

Not a term I've heard before, but I suspect it's referring to a compensating valve that bleeds off the flow from a fixed-displacemement pump when there is no load-demand.

In small systems, this can be done using a pressure relief valve as you suggest.

In larger systems, it is often better to put a valve immediately after the pump which normally sits open bleeding the pump flow to tank, but which can be piloted closed by a line which monitors the pressure on the load side of the directional control valve (or whatever else is being used to control fluid to the load).

This arrangement has the advantage that when the load is isolated, the compensating valve bleeds the flow off at a much lower pressure than a relief valve would - so everything runs much cooler. When fluid is routed to the load, the compensating valve is piloted closed, and the full pump flow (and attendant pressure) becomes available to the load.

A.