Precautions recommended by IEC for non-conductive piping
When non-conductive piping is used at filling stations, the International Electrotechnical Commission (IEC) recommends the following precautions:
- To avoid pinholing the pipe must have an electrical breakthrough strength of 100 kV or at least 4 mm polyethylene wall thickness.
- Plug or earth welding socket pins
- Earth all metal parts of joints and pipes
- Check this earthing regularly
- Keep unburied lengths of pipe (in chambers) as short as possible
- Limit flow rates to 2.8 m/s (may not be enough for biofuels that may generate more static)
- No fuel in unburied pipes
- Interlock safety valves must be used on fill lines to prevent air from entering the system and mix with the fuel vapors
When conductive pipes (plastic pipes with dissipative lining) are used, the corresponding precautions are fewer:
- Earth the lining
- Check the earthing regularly
KPS conductive pipes require less work during installation and maintenance. With conductive piping you can have fuel flowing at any speed no matter what type of biofuel components that are used in the fuel!
A non-conductive system with correct bonding and grounding of all metal objects:
Note that this fill point should also be equipped with interlock safety valves on the fill connection points in order to fully comply with safety recommendations.
Non-conductive systems as they are usually installed – without bonding and grounding of metal objects:
All metal objects in tank and dispenser chambers must be bonded and grounded in a non-conductive system. The bonding and grounding must also be checked regularly, a time consuming and expensive task even on smaller stations.