Abstract: The valve mechanism is of the type which is provided with a device for automatically controlling the motion of the valve body.The motion of the valve body is determined by the presence of pressure of medium at the outlet end of the valve and is adapted to be controlled by hydraulic damping means connected to the valve body and acting in one direction, manual adjusting means being adapted during opening of the valve, to effect a restricted initial displacement of the valve body in opening direction to permit pressure build-up at the outlet side of the valve.

Abstract: The present invention relates to a device adapted to be fitted on a pipe end as an emergency device for shutting off fluid flowing out through the pipe under pressure, and is especially intended for use in drilling or extraction plants for oil. This device comprises two interconnected units provided with a throughpassage and includes means for guiding the device into position over the effluent fluid jet to permit pulling the device onto the pipe end, a means which senses the device as it achieves engagement with the pipe end and is adapted to branch off fluid from the jet at this moment, and cylinder-piston means or the like adapted to be actuated by such branched-off pressure fluid and arranged to act, on one hand, on clamping means for retaining the device to the pipe end and, on the other hand, on valve means for closing the throughpassage.