Patent ID: 7318556

Claim:
A flow line safety valve, comprising: a tubular member for connection to the flow line, the tubular member having a passage therethrough for the flow of fluid from the flow line; a seat located within the passage; a valve element located in the passage upstream of the seat, the valve element being movable from an open position upstream of the seat to a closed position in engagement with the seat if the fluid flowing through passage reaches a selected flow rate; a bias member that biases the valve element toward the open position; a tube located within the passage, the tube protruding in an upstream direction from an annular shoulder; the tube having an open upstream end that is sealingly contacted by the valve element while in the closed position and which serves as the seat; and wherein the bias member comprises a coiled spring that has a downstream portion encircling the tube and bearing against the shoulder, the coiled spring having an upstream end that engages the valve element.