| 摘要 |
<p>A valve (10) for controlling fluid flow to and from an actuatable device (30 ) includes a housing (34) defining a chamber (90) for establishing fluid communication between a fluid supply (14) and the actuatable device (30). A spherical ball (120) controls fluid flow through the chamber (90). The housi ng (34) has a housing seat (84) on which the ball (120) can be seated. A piston (100) movable in the chamber (90) in response to a control input has a pisto n seat (106) on which the valve element (120) can be seated. The valve (10) ha s an exhaust condition in which the ball (120) is seated on the housing seat (84) and is spaced apart from the piston seat (106), and a supply condition in which the ball is seated on the piston seat and is spaced apart from the housing seat, and a hold condition in which the ball (120) is seated on the housing seat (84) and the piston seat (106) is seated against the ball (120) simultaneously.</p> |
