Conduit seals in hazardous locations - An ongoing safety issue the past and the future

Abstract

The use of electrical conduit seals to prevent the release of an explosion from an explosion-proof enclosure and to minimize the passage of flammable vapor and gas migration to an ignition source is as prevalent today as it was yesterday in the petrochemical industry. With the harmonization of international standards and recent equipment advancements, options are available to reduce the use of conduit seals for a more reliable, safe, and maintainable installation. The harmonization of the standards is reviewed, specifically on the International Electrotechnical Commission, National Electrical Code, and Canadian Electrical Code requirements for equipment in hazardous locations. Electrical conduit seal condition data from a 30-year-old petrochemical facility are provided, to illustrate that the threat of gas migration at a facility is real. The collection of these data was achieved by applying new devices allowing for the removal of the conduit seals. An overview of this application and how it was achieved is provided. The outlook on the future development with equipment rated for hazardous locations to reduce conduit seal requirements is explored.