Pressure tube sealing

A sealing mechanism comprises an elastic packing around a seal cylinder, an outer cylinder slidably fitted into the lower end of the seal cylinder through a spring, a cam cylinder and a claw mounting ring each slidably fitted in the outer cylinder, and a radially rotatable claw mounted to the ring. A glove mechanism has a piston cylinder with a piston rod for locking the sealing mechanism. For mounting the sealing mechanism on a pressure tube, the piston rod is inserted into the cam cylinder and the cylinder is actuated to push the cam cylinder while the sealing mechanism is locked with the glove mechanism. At this place the sealing mechanism is unlocked from the glove, the cam cylinder descends due to its weight to engage the claw with the tube, and the weight of the sealing mechanism is applied through the claw to the tube and to thereby support it, while the packing is elastically deformed by the weight of the sealing mechanism. So long as the sealing mechanism is perfectly installed on the tube, the glove mechanism can not be demounted, and since the initial packing force is automatically increased by the sealing mechanism, the seal is assured by the packing. (Ohno, Y.)