| 摘要 |
1465835 Valves BOC INTERNATIONAL Ltd 28 April 1975 [6 Feb 1974] 05448/74 Heading F2V A valve for maintaining a predetermined minimum pressure within a gas cylinder, and attached within the cylinder to the normal cylinder valve, comprises a spool 18 having an annular seating surface (24) which coacts with an 0-ring 12 to close the valve. The spool is biased by two springs 20, 22 such that when the predetermined minimum pressure is reached in the cylinder the valve is closed. For re-charging the cylinder the spool moves in the opposite direction to that in which it opens to allow gas to flow out of the cylinders. Each half of the spool has a chamber 26 which opens into the outer surface of the spool between the seating surface (24) and the ends 25. |
