Breather valve for gas pressure regulator - has membrane with sealing element to shut valve if pressure in regulator chamber rises due to damage to main diaphragm

摘要

The space above the diaphragms in a gas pressure regulator is allowed to breathe by means of a valve. This has a diaphragm of its own to which is attached a sealing element. The two sides of the diaphragm are connected via a restricted flow passage with the upper side vented to atmosphere. If a significant pressure develops below the diaphragm e.g. because of damage to the main diaphragm, the diaphragm is pushed up. The central element then seals against the outlet, preventing the escape of toxic or inflammable gases. The space above the main diaphragm is connected to inlet port (2a) and then via restrictor (3) to the outlet port (2a) and thus to atmosphere. Across the central chamber of the valve there is a diaphragm (6). This is tensioned by spring (4) which keeps sealing element (8) away from the outlet port (2c). So long as the only gas movement is caused by the main diaphragm, the diaphragm (6) retains the posn. shown. However, if a gas flow develops which restrictor (3) will not pass, the rise in pressure in the chamber below diaphragm (6) causes this to move up and seal port (2c). This prevents the escape of gas entering the regulator chamber e.g. via a leaky diaphragm.