The SOLAS regulation for cargo tank venting, purging, gas freeing and ventilation specifies a system consisting of pressure transducers in each tank with a monitoring system in the cargo control room. The monitoring system must include alarms for over- and underpressure in the tank.
System description GT-302 pressure transducers measures the vapour pressure in each cargo tank. These are connected to an analogue input modules through zener-barriers. An atmospheric pressure transducer is also connected. For stand alone applications we use our standard midi operator station to display all information. This unit have outputs for acoustic/visual alarm devices.
Alarm limits There are four alarm limits for each sensor, PIAHH, PIAH, PIAL and PIALL. The PIAHH and PIALL alarms are related to the design pressure of the tanks. These alarms cannot be suppressed. The PIAH and PIAL alarms are also related to the tank design pressure, but are changeable and can be set for surveillance of the P/V valve settings. When vapour emission is allowed, these alarms can be suppressed to avoid unwanted alarms.