| 摘要 |
PURPOSE:To simplify maintenance, security and adjustment and improve reliability by providing a differential pressure generation device for normal and reversed flow inside a tubular path for a fluid flowing in a normal and a reversed direction and connecting the said device to a differential pressure transmitter through a plural number of electromagnetic valves for switching and a pneumatic-type pressure transmitter. CONSTITUTION:When a fluid flows in a normal direction A, the 2 side of a pneumatic-type pressure transmitter is at high pressure and the 3 side at low pressure. If the secondary pressure of the pressure transmitter is above a set value of a pressure setter 5 provided inside a tubular path 13, electromagnetic valves 6, 7 are opened and electromagnetic valves 8, 9 are closed at a signal to such effet. On the high pressure side of a differential pressure generation device for normal and reversed flow 1, an input is made into an inlet Ha on the high pressure side of a differential pressure transmitter 4 through a pressure transmitter 2 and an electromagnetic valve 6. While on the low pressure side, an input is made into an inlet La on the low pressure side through a pressure transmitter 3 and an electromagnetic valve 7. Next, when a fluid flows in a reversed direction B, the electromagnetic valves 6, 7 are closed and the electromagnetic valves are opened at a signal by the pressure setter 5. Tubular pathes 14, 17 are switched over to tubular pathes 15, 18, putting a pressure of a transmitter 3 to Ha and a pressure of a transmitter 2 to La. Thus it is possible to simplify maintenance and security procedures and improve reliability. |
