Gas pipe control valve controlled by leak detector - is prevented from closing until leak is detected

摘要

The valve (1) is mounted on a shaft (4) which may be rotated by the rack (6) acting on the pinion (5). The rack is actuated by the spring (7) but is normally held against the spring pressure by the armature (8) of the solenoid (10). When the solenoid is activated by an electrical signal from a malfunction or gas escape detector, the armature is retracted and the rack is then free to rotate the valve to the closed position. The jockey wheel (11) reduces friction and also operates the electrical interlock microswitch (12). Manual resetting of the valve is achieved by turning the squared end of the shaft (13) when the fault has been cleared. The main advantages are high speed response without the need for human monitoring.