Monitoring system for liquified petroleum gas road tanker - ensures stationary tank is not overfilled by using electronic level closing valve and triggering alarm

摘要

When the road tanker (3) is alongside the storage tank (1), a supply pipe (2) is connected between an electromagnetic valve (5) on the outlet of the mobilee tank (4) and the inlet connection on top of the stationary tank (1). Set into the access collar on the top of the stationary tank is a level detection switch (7) and probe (8). The level switch is connected via cables (8,9) and loose connectors (11,12) to a control unit (10) on the bed of the tanker. The control unit incorporates an amplifier with a window discriminator and a drive circuit for the outlet valve (5). The level detector on the stationary tank operates with voltages of less than 1.2V and a current of less than 0.2mA, and therefore presents no fire hazard. When the tank is nearly full an audible alarm is sounded, and when it is full, the outlet valve is closed.