Explosion-proof valve operator

Claim 1

An explosion-proof solenoid operated fluid control valve operator mountable on a valve body and usable in an explosive surrounding atmosphere having a known ignition temperature, the valve operator comprising a solenoid coil, a one-piece cup-shaped solenoid housing formed of metal, the housing having a generally U-shaped cross section and including a generally cylindrical side wall surrounding the coil and a bottom wall integral with the side wall, a removable metal cap threadably secured to the top of the housing opposite its bottom wall, the bottom wall of the housing and its cap each having an opening generally concentric with the coil, an elongated sleeve assembly received within the coil and having opposite lower and upper end portions projecting through the openings in the bottom wall of the housing and its cap, the housing and its cap being movable as a unit longitudinally of the sleeve assembly, a nut formed of metal for mounting the valve operator to a valve body, the nut being fixed about the lower projecting end portion of the sleeve assembly in fluidtight sealed engagement therewith, the nut having an upper planar surface extending radially of the sleeve assembly for abutting engagement substantially coextensive with The bottom wall of the housing, and a fastener having a threaded connection to the upper projecting end portion of the sleeve assembly for engaging the cap and clamping the bottom wall of the housing into compressed engagement with the upper planar surface of the nut to form an assembly joint of a predetermined minimum length and maximum clearance defining a flameproof gas cooling escape path communicating with the inside of the housing to effect cooling of any gases passing therethrough under internal explosion pressures to a point below the ignition temperature of the surrounding atmosphere.