Abstract: An improved foreign particle resistant valve assembly having a pressure responsive diaphragm main valve member activated by a pilot valve which controls flow through small orifice passages whereby pressure forces are created across the diaphragm main valve member to permit and prevent flow through the main flow section of the valve. Several arrangements illustrate various configured foreign particle-screening passages that protect the pilot valve orifice passages from blockage. The screening may be an integral part of the valve body or may be a removable member to facilitate cleaning or manufacture, and may be adapted to metallic or plastic valves. Other embodiments provide the means to enlarge a pilot pressure drop orifice passage which would then be less susceptible to foreign particle blockage and could also be combined with the screening passage means of the first embodiment.

Abstract: A hot and cold water mixing valve to maintain the outlet water temperature at a preset level by using electronic sensors to actuate low voltage, pulse operated solenoid valves to regulate pressure in control passageways. The control passageway pressure differential across a drive diaphragm causes the diaphragm to move in response thereto to change the position of the main mixing valve. Minimum electrical energy is thus expended to regulate the temperature level.

Abstract: A pilot operated valve assembly having a pressure responsive valve member for opening and closing a main valve, the pilot valve actuator permits a very small operating force and a short actuation travel which is less than the stroke of the main valve member. Compactness and manufacturing economy is attained by the incorporation of an insert structure within a valve housing to facilitate the arrangement of pilot valve and bleed passages that operate the pressure responsive main valve member. Valve construction permits an axial in line arrangement of pilot valve actuator and main valve member to further achieve a compact valve size and to ease manufacturing assembly.

Abstract: A flow modulating fluid control valve assembly utilizing a spring biased armature to directly operate a pilot passage in a main flow control valve. An electromagnetic coil assembly opens the valve by shifting the armature and its seal away from the pilot passage allowing the control valve to open and follow the armature until its seal again restricts the pilot passage and achieves a new force balance position for the control valve. Precise modulation is achieved by shaping the force vs. displacement curves for the electromagnetic assembly opening force acting on the armature and the same curve for the spring and other forces acting in a closing direction on the armature so they have substantially different slopes and intersect at a locus of points in the operating range of movement of the armature.