Pilot actuator and spool valve assembly

摘要: A pilot actuated spool valve assembly includes a body that defines first passage, second passage and flow passage. unitary is at least partially positioned in the has seat seat. member moveable between an up position which closes down control hydraulic surface body. It open to At one of body, define volume fluidly connected when its position. The exposed fluid pressure volume. finds preferred application hydraulically fuel injector having direct needle valve.