Patent ID: 9523376
Filing Date: 2016-12-20
CPC Classification: F15B

Claim Text:
1. An on-off pilot stage valve arrangement for controlling at least one main stage valve, comprising: a first pilot valve discretely electrically operable between two states, an on state wherein the first pilot valve is open and an off state wherein the first pilot valve is closed, the first pilot valve having an input at which there is a first pressure and an output connected to said main stage valve, a second pilot valve discretely electrically operable between two states, an on state wherein the second pilot valve is open and an off state wherein the second pilot valve is closed, the second pilot stage valve having an input at which there is a second pressure and an output connected to said main stage valve, wherein both the pilot valves are configured to be off in case the arrangement loses electrical power, the arrangement further comprising a first fixed flow restrictor connected between the first pressure and the main stage valve and in parallel with the first pilot valve and a second fixed flow restrictor connected between the second pressure and the main stage valve and in parallel with the second pilot valve.