Variable pressure control valve

A valve assembly for controlling flow from a pressurized source to a tank, the valve assembly comprising:

• a valve body having an inlet end and an outlet end, the valve body defining fluid passages for receiving fluid flow between the inlet and outlet ends;
• a piston mounted within the valve body to control the fluid flow, the piston being movable between an open position and a closed position;
• a cap member that mounts adjacent the inlet end of the valve body;
• a compensator device housed within the cap member, the compensator device being accessible through the inlet end of the valve body;
• a spring mounted between the piston and the compensator device, wherein the spring biases the piston toward the open position, wherein the spring is compressed when the piston moves to the closed position;
• wherein the compensator device is configured to axially rotate relative to the cap member to vary a compression of the spring to achieve a desired spring pressure rating;
• and
• wherein the cap member blocks one end of a spring chamber, wherein the compensator device includes a stem that projects through the cap member and a head that threads within the cap member, wherein the spring extends through the spring chamber and has spring end portions housed within the cap member and the piston, and wherein the stem includes a torque interface for allowing the compensator device to be turned relative to the cap member by a tool inserted through the inlet end of the valve body without requiring disassembly of the valve assembly to adjust the compression of the spring.