| 摘要 |
<p>A valve, comprising a body which forms a cylindrical flow channel defined by side walls and having a fluid inlet provided at one end of the channel and an outlet provided in the side wall of the channel, and a closing device which comprises a piston connected to one end of a rod. The piston is provided with an upper flange facing the rod and a lower flange facing the inlet, which therebetween define a groove with at least two piston rings fitted therein. The piston rings are preferably in contact with each other. The rod may further comprise a push pipe and a pull rod extending through the push pipe, the upper flange being connected to the push pipe and the lower flange to the pull rod and the gap between the upper flange and piston rings being fitted with a sealing ring of a flexible material.</p> |
