| 摘要 |
A gas flow metering valve comprising a metering member (4) which moves within an aperture (41, 42, 43) in the valve housing (10). The aperture is shaped so as to have a cross section which decreases into the narrowest part of the aperture and then increases on the downstream side of the narrowest portion. The closure member (4) is conveniently of conical section but may have outer walls shaped in accordance with exponential or some other desired curve. |
