SGB devices are used to monitor the tightness of inter-shell spaces in double-walled tanks.
There are two main types of this unit:
- overpressure – marked with DL
- under-pressure – marked with VL.
A pump constitutes an integral part of the system – it generates overpressure in DL systems and under-pressure in VL systems.
Overpressure units are mainly used in underground tanks. For aboveground tanks, under-pressure systems are recommended.
The selection of a number and power of its units is based on the tank space under monitoring.
- easy mounting
- maintenance-free operation
- easy data analysis – alarm in case of a detected leak
- a single unit can handle up to 8 tanks connected via a distribution strip
- the measuring unit can be mounted outside the EX zone in a service-staff room
- German quality – reliable operation
An overpressure leak detector, e.g. SGB DL280 (the most commonly used) is linked with this space by means of pressure and measurement lines.
Overpressure generated by the pump is measured and regulated by the pressure sensor.
When the operating pressure is reached, the generation of overpressure is stopped.
Under normal operation conditions, the indication of the leak detector is within these two limit values, with short operating periods and longer downtime periods, depending on a range of leakage and temperature fluctuations throughout the system.
If the limit values are exceeded, an alarm is activated.
Under-pressure units, e.g. SGB VL330 (the most commonly used) are linked with this space by means of two lines (pressure and measurement) – just like in the case of overpressure units.