摘要 |
A pilot-operated spool valve includes a body defining a bore. A supply port and a load port are in fluid communication with the bore. A spool is disposed in the longitudinal bore, and the spool and the body cooperate to define a command chamber at a first end of the spool, which command chamber is adapted to receive fluid at a command pressure supplied to the body. The spool is movable in the bore to control fluid communication between the supply port and the load port. A pressure space is defined in at least one of the body and the spool between the command chamber and both of the supply port and the load port in all operative positions of the spool. The pressure space is supplied with pressurized fluid such that leakage from the command chamber is minimized or eliminated. |