Pipeline safety – Protection against lightning related disturbances
Due to the increased risk when transporting large amounts of crude oil and the relevant final products, special personal and environmental protection measures are required. Various standards like IEC 62305, other national regulations, for instance in Germany the Ordinance on Industrial Safety and Health (BetrSichV), Technical Rules for Operational Safety (TRBS), Technical Rules for Hazardous Substances (TRGS) or Technical Rules for Flammable Liquids (TRbF) describe measures and inspections that ensure safe construction and/or operation of pipeline facilities with focus on fire and explosion protection measures. Since lightning and other overvoltage constitutes an ignition source, suitable protection measures must be taken to reduce this hazard source to the greatest possible extent. Also depending on the pipeline design different approaches are required particularly with regard to external and internal lightning protection measures. To prevent ignition sparks in case of direct lightning strike, there are innovative solutions for isolated lightning protection systems in combination with High Voltage resistant down conductors. Another important aspect is the protection of safety systems, special approved non sparking equipotential bonding system, protection of isolated flanges with special spark gap solutions as well as the protection of people against high touch voltages in case of high voltage failures. This voltage controlled surge devices protect the people with no negative effects to the Cathodic Protection system on the pipeline. Last but not least a ring earthing system to avoid high potential differences with multiple connection to the internal equipotential bonding system.