Overfill Protection

Liquip overfill protection systems are safe, reliable and manufactured to world recognised codes and regulations.

With Factory Mutual, ATEX and IECEx approvals, Liquip’ s terminal and depot based overfill protection equipment is compatible with industry recognised electronic optic and thermistor overfill probes on tanker fleets and compliant with other applicable codes such as Institute of Petroleum Code and American Petroleum Institute Recommended Practice 1004 (APIRP1004).

The Liquip electronic overfill protection monitors, probes and accessories are available in a range of configurations and compatible and interchangeable with other industry standard brands.

Liquip manufacture three base models for different applications with variations such as voltages, earthing methods, probe type and numbers of probes easily accommodated in each model.




  • Reliable fail-safe operation
  • Detection and shutdown response of less than 0.5 seconds
  • Self checking circuitry
  • System diagnostics
  • Integral grounding functions on all monitors is provided at no extra cost (no need for separate grounding monitor)
  • Automatic detection and switching between 2 wire and 5 wire modes
  • Compatibility with 2 wire, 5 wire and thermistor probe types
  • Maintenance free with solid state circuitry requiring no adjustment

Have you really been grounded? Much has been claimed about the specific features and functions of various grounding systems. What is actually important is a basic understanding of the properties of static electricity and its need to escape to ground by jumping to objects with a lower electrical potential.

Following a large static spark at a terminal equipped with a dedicated earthing monitor, Liquip surveyed available earth assurance systems and ‘unearthed’ shortcomings in their operation. Many of these criticisms were due to incorrect installation methods, though the equipment itself was sound. Liquip therefore added simple features to our tanker and terminal mounted equipment to improve the effectiveness of the grounding systems.

On the tanker, it is essential that the common earth wire be grounded through the tank structure. Many tankers only have the bumper bar or truck plug earthed, not the tanker.

A comprehensive range of tanker mounted overfill equipment is available from Liquip. Please refer to our Tanker Equipment catalogue for more details.

Recent upgrades to Liquip’s range have made them even more resistant to fluctuating electrical power supplies and lightning strikes. However, please ensure adequate electrical protection for your installed electrical equipment.