Counter balanced locking valve

A valve assembly comprising

• an output chamber for receiving a fluid under pressure, the output chamber having an inlet passage attachable to a source of fluid under pressure and an outlet passage attachable to a load,
• a check valve element in the output chamber operable in an opened condition, which permits forward flow of fluid under pressure in the output chamber from the source toward the load, the check valve element also being operable in a closed condition, which blocks back flow of fluid under pressure in the output chamber from the load toward the source, the back flow of fluid under pressure exerting a closing force upon the check valve element from within the output chamber,
• a counter force generating element located within the output chamber, the counter force generating element being coupled to the check valve element and operating in response to the back flow of fluid under pressure in the output chamber to apply a counter force urging the check valve element toward the opened condition, the counter force being less than the closing force, and
• a relief element located outside the output chamber, the relief element being coupled to the check valve element and including a force applying element which moves in response to an external solenoid to apply an external opening force, which in combination with the counter force, moves the check valve element to the opened condition against the closing force in the output chamber.

A valve assembly comprising

• an output chamber for receiving a fluid under pressure, the output chamber having an inlet passage attachable to a source of fluid under pressure and an outlet passage attachable to a load,
• a valve stem having a first stem portion located within the output chamber,
• a check valve element carried by the first stem portion in the output chamber, the check valve element being operable in an opened condition, which permits forward flow of fluid under pressure in the output chamber from the source toward the load, the check valve element also being operable in a closed condition, which blocks back flow of fluid under pressure in the output chamber from the load toward the source, the back flow of fluid under pressure exerting a closing force upon the check valve element from within the output chamber, and
• a counter force generating element carried by the first stem portion in the output chamber, the counter force generating element being coupled to the check valve element and operating in response to the back flow of fluid under pressure in the output chamber to apply a counter force urging the check valve element toward the opened condition, the counter force being less than the closing force.

A valve assembly comprising

• an output chamber for receiving a fluid under pressure, the output chamber having an inlet passage attachable to a source of fluid under pressure and an outlet passage attachable to a load,
• a valve stem having an axis and including a first stem portion located within the output chamber,
• a check valve element in the output chamber including a valve seat communicating with the inlet passage and a poppet carried for sliding movement on the first stem portion along the axis between an opened condition, in which the poppet is out of sealing engagement against the valve seat and which permits forward flow of fluid under pressure in the output chamber from the source toward the load, and a closed condition, in which the poppet is in sealing engagement against the valve seat and which blocks back flow of fluid under pressure in the output chamber from the load toward the source, the back flow of fluid under pressure exerting a closing force upon the poppet from within the output chamber, and
• a counter force generating element located within the output chamber, the counter force generating element being coupled to the poppet and operating in response to the back flow of fluid under pressure in the output chamber to apply a counter force urging the poppet toward the opened condition, the counter force being less than the closing force.