Hydraulic circuit utilizing a compensator pressure selecting value

PCT No. PCT/JP90/00667 Sec. 371 Date Apr. 9, 1991 Sec. 102(e) Date Apr. 9, 1991 PCT Filed May 24, 1990 PCT Pub. No. WO90/14519 PCT Pub. Date Nov. 29, 1990.A hydraulic circuit arranged to prevent the load pressure in one of the hydraulic actuators at the time of starting from becoming abnormally high thereby preventing fluid under pressure from being relieved by the safety valve when a plurality of hydraulic actuators are operated at the same time, wherein the function of one of the pressure compensating valves is temporarily enhanced by introducing the load pressure in the hydraulic actuator so as to supply a large quantity of fluid under pressure to the hydraulic actuator connected to the pressure compensating valve so that the operating speed of the hydraulic actuator can be increased. This hydraulic circuit comprises a compensation pressure selecting valve adapted to supply normally the highest load pressure to the spring chambers of the pressure compensating valves, and supply the load pressure in the hydraulic actuator connected to each of the pressure compensating valves to the spring chamber of each of the pressure compensating valves when either one of the operating valves is operated for the full stroke.