| 摘要 |
<p>A valve intended to open in response to a pressure difference between the interior of the valve and the exterior thereof comprises a diaphragm which in its closing position is conical. The diaphragm has an opening which is normally closed by means of a valve stem. Arrangements are made to prevent communication between the interior of the valve and the exterior thereof until said diaphragm has been deformed to a substantially planar shape.</p> |
