Abstract: A two-way cartridge valve for aggressive media has a replaceable module including a main valve seat, a diaphragm sealing member for the valve seat, and a pilot seat. In one embodiment, a leaf spring is employed to bias the diaphragm toward the open position for actuation under conditions of minimal pressure differential. In another embodiment a resilient support is provided for the diaphragm behind the region of engagement with the main seat.

Abstract: A solenoid actuator comprising a coil or coils of electrical wire and a plugnut and movable core within the coil(s). A magnetic yoke surrounds the coil(s), the axis of the latter extending across the magnetic circuit defined by the yoke. Relatively large and small permanent magnets are associated with the yoke on opposite sides of the axis, the magnets producing flux in opposite directions. A flux sensor, closer to the small magnet, senses changes in direction of the flux. When the core and plugnut are separated, the large magnet flux predominates throughout the yoke. When the core engages the plugnut, the small magnet flux predominates in its portion of the yoke, this change in flux direction being detected by the sensor. Thus, the sensor can be used to indicate the position of the core with respect to the plugnut.

Abstract: A slow-opening valve including a main valve, a chamber for receiving a control fluid other than that controlled by the main valve, and a member within the chamber responsive to the volume of control fluid in the chamber for opening and closing the main valve. A solenoid pump, including an armature and an electrical solenoid for vibrating the armature, produces fluid flow in small increments with respect to the chamber to effect opening of the valve. An auxiliary valve, which opens and closes in response to the position of the solenoid pump armature, controls flow of fluid with respect to the chamber for closing the main valve.