| 摘要 |
<p>A Valve comprises a rolling diaphragm 7 supported at its outer periphery by an annular support member 8 within which the diaphragm rolls in response to inlet pressure so as to uncover an outlet opening 20 in the support member, thereby to allow the escape of said pressure. Preferably, the diaphragm 7 is annular and is supported at its inner periphery by a guide member 9 that engages on abutment 19 when the outlet opening 20 is closed by the diaphragm, and that guides the diaphragm as it rolls back and opens the outlet opening 20. Preferably, the outlet opening 20 is of reduced width towards that part which is first uncovered by the diaphragm in operation. The valve may include a two part housing 1,4 with the support member 8 located between the two parts and with the outer periphery of the diaphragm 7 gripped between one part of the housing 4 and the support member 8.</p> |
