| 摘要 |
1,105,832. Valves. L'AIR LIQUIDE, SOC. ANON. POUR L'ETUDE ET L'EXPLOITATION DES PROCEDES GEORGES CLAUDE. 25 Oct., 1965 [10 Nov., 1964], No. 46160/65. Heading F2V. A valve 2 which automatically disconnects an outlet 16 or 18 from a source 4 and connects it to a source 8 when the pressure at the source 4 falls, is prevented from making the change over until a sufficiently large pressure difference exists between the sources to overcome the action of at least two spring-biased balls 58 or analogous members. Polyamide cups or washers 59 which may be replaced by others of different size to alter the load applied by the spring to balls 58 are mounted in a cross bore of the valve member. The latter and a portion 6 of the housing having a restriction 38 to co-operate with the balls are also of polyamide. Each end of the valve member is fitted with a graphite charged polytetrafluoroethylene ring 46 urged by an elastomeric ring 42 into engagement with the valve bore. To facilitate movement of the valve and to relax the ring 46 when it is not in its sealing position, the bore may be stepped so that the ring passes first into a portion of larger diameter and then into a portion of intermediate diameter. A washer 20 limits the effect of outlet pressure on the operation of the valve which may have a manual, pneumatic electric position indicator. A pressure gauge may be connected to the outlet 18. |
