Sewage Systems Alarm

Protecting water and sewage systems in petrol station 

For economical and safe operation of a gasoline separator, also referred to as petrol separator, a separator alarm system is used to detect the gasoline thickness and/or the top level of the gasoline in the separator.

This feature is also required item according to EN 858-1:2002 standard. Apart from designations and general construction principles, this European/International standard also defines the functional requirements for separator installations. In keeping with the standard, gasoline separator installations have to be equiped with an autonomous alarm system. This alarm systems needs an approval and marking for the use in hazardous areas, Zone 0.

In due time before reaching the maximum storage volume (oil layer thickness) in the separator, a modem alarm system in keeping with EN 858-1 indicates by acoustic and optical signal that gasoline accumulated has to be removed. If it has be assumed that an overflow will occur in the separator, a second probe will release an acoustic an acoustic/optical warning isgnal in due time before reaching the highest level.

The alarm system is a complete system consisting of several components : sensors, control unit, housing and mounting set. The block diagram indicates the basis arrangement of the individual components. Depending on the application three sets of warning systems are differentiated:

Single-channel, storage volume/oil layer thickness detection only 
Single-channel, overflow detection only 
Duas-channel, oil layer thickness and overflow detection 

Overflow Sensor

Detection of the maximum fluid level in gasoline separators 
Differentiation between air and fluid 
For the detection of a high fluid level when the coalescence filter is clogged or the float stop is closed 
Robust, reliable and compact 
No moving parts 
The overflow sensor consist of a PTC resistor, wich is energized by the control unit, which increases the PTC resistor temperature. When entering into fluids, the temperature and thus the current consumption of the sensor changes and an alarm is released.

Layer Thickness Sensor

Detection of the layer thickness in oil/petrol separators 
Differentiation between water and oil/petrol 
Robust, operationally safe and compact 
No moving parts 
Maintenance-free 
The sensor sonsists of a small electronic element, which generates a HF signal by means of an oscillator. The signal changes depending on whether the sensor tip is in water or in air/oil. In combination with the control unit an alarm signal is triggered

System set advantages

Single and dual channel version 
Complete monitoring set, ready for connection including fastening set 
Plug-an-play commissioning 
Safety through optical and acoustic alarm signals 
Proble installation in Ex Zone 0 
2 isolated layout parts 
Monitoring of sensor errors 
Alarm repetition 
Easy installation and height adjustement of the sensors