| 摘要 |
<p>The sealing apparatus is designed to automatically maintain the pressure of a buffer fluid above that of the sealed fluid. The apparatus consists of a cylinder (1) which has a movable piston (4, 5) therein. The piston (4, 5) is coupled to a valve shaft (8) and a first chamber (Z) in communication with sealed fluid is disposed on one side of the piston and a second chamber (Y) is on the other side of the piston for continuous communication with the buffer fluid. Recharging means in the form of a valve (12) and third chamber (X) which contains buffer fluid at a pressure greater than (Y) are associated with the second chamber (Y) so that in response to failure of seals the buffer fluid pressure drops in chamber (Y) and the pistons (4, 5) rise so that shaft mounted valve (12) is disengaged from valve seat (14) allowing high pressure buffer fluid to be transferred from chamber X to chamber Y. The buffer fluid forces the piston down and closes the valve to maintain the pressure of the buffer fluid above the sealed fluid pressure. The apparatus also includes remote indicating means (9, 10) for providing remote indication of excessive leakage from the auxiliary or main seals or if the valve is leaking.</p> |
