| 摘要 |
A lift valve with an elastically deformable sealing diaphragm (24) which, under pressure, comes to rest against a valve seat (4). The valve plate (21) is connected to the housing (3) by spring elements and closes a first pressure space (23), to which fluid can be admitted, initially at a relatively low pressure P1, via a conduit (14). Between the valve plate (21) and the diaphragm (24) there is a second pressure space (26). The pressure P1 is sufficient to move the valve plate (21) into the closed position. A higher pressure P2 is then applied. At this pressure, the non-return valve (30) opens and pressure is admitted via a first conduit (28) to the second pressure space (26). The sealing diaphragm (24), which is provided with a fold (25) to allow greater expansion, continues to rest against the valve seat (4) until the pressure in the first pressure space (23) is reduced. The second non-return valve (31), which opens at a comparatively low differential pressure allows relief of the second pressure space (26) via a second conduit (29) into the first pressure space (23). The valve is particularly suitable for use in large fittings in pipes carrying liquid metal, e.g. in nuclear power stations. <IMAGE>
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