Abstract: A gate valve including a valve housing defining a valve chamber having an opening therethrough along a flow path, a gate support supported within the valve housing between a closed position in the flow path, an open position outside of the flow path, and a service position extending out of the valve housing, and a dual actuator assembly having a service piston assembly having a service piston reciprocable within the valve housing, and an inner piston assembly having an inner piston reciprocable within the service piston assembly. The gate support is configured to reciprocate with the inner piston between the closed and open positions, and with the service piston between the closed and the service positions. A method of using the gate valve is also disclosed.

Abstract: An angle valve including a valve housing defining a valve chamber and having a valve opening, a driveshaft reciprocally extending into the valve chamber through a driveshaft opening, a boss extending downwardly from a top wall of the valve chamber around the driveshaft, and a bellows having a lower end mounted to the boss and an upper end mounted to the driveshaft so as to isolate the driveshaft and the driveshaft opening from the valve chamber. A method of using the gate valve is also disclosed.

Abstract: A clamp for quick release of a generally rectangular bonnet to the flange of valve body is disclosed. The upper side of the edge of the rectangular bonnet is formed with a bevel of about 20 degrees and the lower side of the edge of the body flange is formed with a similar bevel. The clamp consists of semi-circular ends and straight sides hinged together. One side is split and connected by a toggle latch. In cross-section, each clamp section is generally C-shaped, with the top and bottom arms of the C being beveled so that as the clamp sections are drawn inward the bevels wedge the bonnet against the flange. Locating pins fitting into holes in the plate and flange locate the parts and resist implosion when the valve body is subjected to vacuum. To maintain uniform clamping force around the circumference of the bonnet the bevels at the middles of the sides may be less wide than at the ends.

Abstract: A stand-alone electropneumatic closed loop servo system, with a separate gas supply to an air actuated cylinder, provides pressure, position, or fluid flow control of a variable conductivity valve in a device by automatically varying the conductance of the device. The air cylinder defines a control chamber and a smaller volume response chamber separated by a piston operatively connected to the variable conductivity valve. The gas supply includes a constant pressure line, with a pressure regulator valve and a check valve, into the control chamber and a variable pressure line, with a variable pressure solenoid valve, into the response chamber. A feedback signal from the device to a controller is compared to a desired pressure set point. The controller signals the solenoid to vary its output pressure thereby causing the piston to move accordingly to actuate the variable conductance valve.