Abstract: A proportional flow valve wherein inlet fluid pressure urges a main valve member toward a valve seat. A cylindrical bearing ring is mounted on the main valve member and slideable within an axial bore leading from the main valve seat to an outlet port for axially stabilizing the main valve member and limiting pressure differential across the main valve member while the bearing ring is at least partially disposed within the axial bore. The outer circumference of the bearing ring may have circumferential grooves for producing eddy currents and turbulence to enhance the limitation of pressure differential across the main valve member.

Abstract: A proportional flow valve wherein inlet fluid pressure urges a main valve unit having a main valve member and a surrounding diaphragm toward the valve seat. The diaphragm is connected to the valve body and has a bleed passageway to enable inlet fluid to pass from an inlet port below the main valve unit to a reservoir above it. The area of the main valve unit exposed to the reservoir is substantially greater than the area of the main valve unit exposed to the inlet port. A solenoid actuator determines the position of a pilot valve sealing member which controls the flow of inlet fluid from the reservoir through a pilot opening in the main valve member to an outlet port to selectively relieve the pressure above the main valve unit thereby permitting the main valve unit to move away from the main valve seat.

Abstract: A valve having a flexible diaphragm for opening and closing the valve. The diaphragm is biased into valve-closing position by a ridge, formed in the valve body, which presses the diaphragm toward the valve seat. A rigid backup washer is secured to the diaphragm solely by an elastomeric type adhesive. A bleed hole in the diaphragm establishes communication between the valve inlet port and a chamber on the side of the diaphragm opposite the valve seat. The bleed hole is in the margin of the diaphragm which is sandwiched between two portions of the valve body.