Short-stroke valve assembly for modulated pulsewidth flow control

A short-stroke solenoid-actuated valve (54) suitable for pulsewidth modulated operation including a plurality of components formed of powdered metal, preferably a 400-series stainless steel compressed to about 6.0g/cm, to be sound absorptive and ferromagnetic; resilient radial seal means (50) disposed in an annular groove in an outer surface of the valve for sealing against a cylindrical receiving surface; metal mesh shaft seal means (48) for inhibiting leakage from the valve into the actuator; and a dielectric polymeric encapsulant (47) loaded with a thermally conductive particulate substance (66) to increase the heat-transfer modulus of the encapsulant.