Abstract: A pilot-operated valve has a main poppet controlling fluid flow between inlet and outlet ports in response to pressure in a control chamber. Fluid flow through a pilot passage, linking the control chamber and the outlet port, moves an exhaust spool between first and second positions to control fluid flow through passages in the main poppet. The first position blocks flow between the control chamber and the outlet port and provides a path between the control chamber and the inlet port. In the second position, flow between the control chamber and the outlet port is enabled, and a second path, that is more restricted than the first path, is provided between the control chamber and the inlet port. When the valve closes, flow through the first path allows movement of the main poppet at a faster rate than during opening when flow occurs through the more restricted second path.

Abstract: A pilot-operated valve has a main poppet controlling fluid flow between inlet and outlet ports in response to pressure in a control chamber. Fluid flow through a pilot passage, linking the control chamber and the outlet port, moves an exhaust spool between first and second positions to control fluid flow through passages in the main poppet. The first position blocks flow between the control chamber and the outlet port and provides a path between the control chamber and the inlet port. In the second position, flow between the control chamber and the outlet port is enabled, and a second path, that is more restricted than the first path, is provided between the control chamber and the inlet port. When the valve closes, flow through the first path allows movement of the main poppet at a faster rate than during opening when flow occurs through the more restricted second path.

Abstract: A hydraulic valve has a main poppet that engages and disengages a valve seat to control the flow of fluid between an inlet and an outlet. Movement of the main poppet is governed by a pilot valve element the opens and closes a pilot passage in the main poppet. The pilot valve element is slideably received in a bore in an armature. The armature is biased toward the main poppet by a first spring and a second spring biases the pilot valve element outward from armature bore and toward the main poppet. The second spring has a lesser spring rate than the first spring. Upon engagement of the pilot valve element with the main poppet continued application of the engaging force causes the second spring to collapse and the pilot valve element to slide within the armature, thereby absorbing some of the force that could otherwise adversely affect the valve.

Abstract: A modular solenoid valve has a housing including a valve seat having a valve chamber connecting an inlet port and an outlet port. A poppet is movable in the chamber between a valve open position and a valve closed position. An elongate movable pilot valve is partially received in a pilot valve chamber in the poppet for controlling the position of the poppet, the pilot valve including first and second axially spaced, radially extending throughbores. A reciprocally movable solenoid plunger is operably associated with the pilot valve for positioning the pilot valve. A pin is inserted through either the first bore to connect the pilot valve to the plunger in a normally closed valve configuration or the second bore to connect the pilot valve to the poppet in a normally open valve configuration. A solenoid coil controls the position of the plunger to move the pilot valve to an actuated position.