Inspection stray currents

Pipelines on wharves that handle Class I or Class II liquids must be adequately bonded and grounded. Bonding between the wharf and the vessel is not allowed. Insulatingflanges or joints should be installed. If stray current isolation is used, the grounding connection(s) must be accessible for inspection (NFPA 30, Section 5.7.10). 

Electrolytic cells have historically been mounted off the ground at full basement height. Some of the arguments for elevating the cells include the need to electrically isolate cells from spills in the basement, to protect workers from stray current, to adjust the level of the cells, to inspect for leaks and perform repairs, and to limit pumping costs by employing gravity flow. With the advent of polymer concrete cells and of synthetic cell liners, the frequency of leaks and the need for electrical isolation have been drastically reduced. 

Apart from the above design improvements in more modem transit systems, several other remedial measures can be considered. Regular rail inspections are important for detecting problems with electrical continuity and faulty insulators. In addressing stray current problems of this nature, communication and cooperation between different organizations and stakeholders is most beneficial. Corrosion control coordinating committees are usually established for these purposes. 

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