Valve assembly

摘要

The system (10) has a pilot control valve (13) including a 3/2 way valve, and a main valve arrangement whose main valves (11, 12) include 2/2-way valves. The pilot-control valve moves one of the main valves into an open position so as to direct a path for a high pressure fluid to a space above a piston (17). The pilot-control valve connects the space to a low-pressure tank (28) so as to relieve pressure in the space above the piston via another main valve. The pilot-control valve opens the latter main valve and closes the former main valve.