Patent ID: 6901754

Claim:
A pressure compensation circuit for a hydraulic system having a primary pump and a secondary pump connected to a supply line, a return line connected to a system tank, at least one hydraulic service connected to the supply line and the return line, and a load-sense circuit which senses a load pressure at each hydraulic service, the pressure compensation circuit comprising: a check valve connecting the secondary pump to the supply line and preventing fluid flow from the supply line to the secondary pump; a first bypass compensator valve selectively providing a path between the supply line and the return line in response to pressure in the supply line being greater than pressure in the load-sense circuit by at least a first amount; and a second bypass compensator valve selectively providing a path between the outlet of the secondary pump and the return line in response to pressure in the supply line being greater than pressure in the load-sense circuit by at least a second amount, wherein the second amount is less than the first amount.