| 摘要 |
A valve device in a fluid system comprising a valve housing (10) provided with an inlet opening (11) and at least one outlet opening (12) and a valve seat (13) in connection to said inlet opening. The device further comprises a valve rod (16) which by means of actuating means (18, 22) is displaceable towards and away from the valve seat (13) and a diaphragm (17) of a flexible material which is actuatable by the valve rod and acts as a sealing against the valve seat (13). In order to indicate the presence of leakage through the diaphragm (17) without leaking to the environment and/or to make it possible to apply a counter pressure on the inside of the diaphragm in order to prevent collapse thereof at high process pressures the valve rod (16) is hollow and at or close to its end facing the diaphragm (17) is provided with a hole (25) through which the inner hollow space (24) of the valve rod communicates with the inside of the diaphragm. |
