Abstract: A cryogenic circuit which comprises a tank for the liquid and vapor phase of the cryogen; there being a flow control valve connected at opposite ends to the liquid and vapor sides of said tank with a check valve being interposed between said vapor side and said flow control valve. The flow control valve contains a single outlet orifice directly connected to the vapor inlet. A valve arrangement is interposed between the liquid inlet of the said flow control valve and its single outlet; said valve arrangement comprising a ball valve with associated components between same and the liquid inlet to cause said valve to operate as a control valve and with a spring bearing against the upper side of said ball to adapt same for check valve usage when the associated control valve components are withdrawn under predetermined pressure conditions.

Abstract: A stamping press system, the press having a ram, a driving means for the ram, and an electrically energizable ram control device for causing the driving means to drive the ram through a stamping cycle. The press is guarded by a barrier movable between an open position permitting operator access to the point of stamping operation and a closed position barring such access. A press trip control for the system has a pair of actuators, one for each hand of the operator. Upon their concurrent actuation, the actuators cause movement of the barrier to the closed position and energization of the ram control device initiating a stamping cycle. Provision is included for preventing such energization thereby preventing a stamping cycle if the barrier is not closed. Circuitry of the system prevents re-energization of the ram control device, thus preventing a further cycle until the operator has removed both hands from the actuators.