Abstract: A remotely controllable fluid valve includes a solenoid-armature arrangement which functions as an electro-magnetic spring having improved force-displacement characteristics over a mechanical spring. The solenoid magnetizes a pair of axially spaced, sleevelike field poles. The armature is so shaped and initially positioned relative to the field poles that: as the armature, supported in one pole, moves further into the other pole, the axial magnetic force thereon decreases at a decreasing rate with the rate of decrease being greater at higher levels of solnoid energization.

Abstract: A pilot operated flow regulating valve which can be remotely controlled by varying the energization to a solenoid. The valve consists of a normally-closed, spring-biased, pressure-differential-actuated, main valve element and a pressure-compensated, pilot flow valve employing a solenoid acting like a remotely controllable electromagnetic spring to control the flow of fluid through the pilot valve and the pressure difference across the main valve element.

Abstract: A pilot operated flow regulating valve which can be remotely controlled by varying the energization to a solenoid. The valve consists of a normally-closed, spring-biased, pressure-differential-actuated, main valve element and a pressure-compensated, pilot flow valve employing a solenoid acting like a remotely controllable electromagnetic spring to control the flow of fluid through the pilot valve and the pressure difference across the main valve element.