摘要 |
<p>A non-return valve (1) comprising a valve member (2) having a circumferential face and a channel (3, 4) having a mouth on either side thereof, the mouth (5) at one end of the channel being sealable by a valve element in the form of an O-ring (9). Said one mouth of the channel is located in a groove (7) sealed by the valve element, which groove has circumferential edges provided on parts (6a, 6b) which, by a setting mechanism, are steplessly adjustable and fixable relative to each other.</p> |