| 摘要 |
A diaphragm valve (1) comprises a valve body (2) having a diaphragm opening (4) to which is fitted a closure diaphragm (5). The diaphragm seals against a seat (8) formed on a weir (7) of the valve body to close the valve (1) to fluid flow. Tongues (10,11) are moulded integrally with the diaphragm and extend into the flow passage (6) in the region of the central longitudinal plane of the valve. The tongues (10,11) tend to impede flow through the valve when the diaphragm (5) is close to the seat (8) and thus improve the flow characteristics of the valve so that it can be used as a flow control valve. |
