Valve including piston with spaced apart plates

Claim 1

A valve of integral construction comprising: a supporting structure to serve as the body of the valve and provide bearing surface for the internal parts of the valve; a duct within the body of the valve to allow the passage of fluid through the valve, the duct leading to the exterior of the valve so as to provide entrance and exit locations of the valve; a plunger to control the passage of fluid through the duct, said plunger terminating the flow of fluid through the valve when located within the duct; a piston integrally assembled with the plunger, said piston comprising a plurality of discs having sealing means between the discs pressing against the interior walls of the actuating fluid chamber and the plunger, the sealing means comprising a plurality of O-rings, the discs being held in place by two clamps confined in grooves located in the plunger to form an integral assembly between piston and plunger; a fluid actuating chamber confining the piston and integrally constructed with the valve body, the fluid actuating chamber containing means to allow actuating fluid to enter and leave the chamBer for purposes of acting against the piston and positioning the plunger within the valve fluid duct; means to seal the fluid actuating chamber from the valve fluid duct to prevent continued mixing of either medium by the other, the valve fluid duct adjacent the sealing means being tapered; a bleed duct to convey to the exterior of the valve leakage actuating fluid or leakage valve fluid so as to prevent continued intermixing of either to the other in the event of malfunctioning of the sealing means; and means to seal the valve fluid duct when the plunger is located within the duct.