This standard provides requirements for the testing, design, installation, and maintenance of electrical resistance trace heating in general industries as applied to pipelines, vessels, pre-traced and thermally insulated instrument tubing and piping, and mechanical equipment. The electrical resistance trace heating is in the form of series trace heaters, parallel trace heaters, and trace heater pads or panels. The requirements also include test criteria to determine the suitability of these trace heating devices utilized in industrial applications as applied in unclassified (ordinary) locations. The provisions of this standard should help ensure that process, fluid, or material temperatures are maintained and provide electrical, thermal, and mechanical durability to the trace heating system, such that in normal use, its performance is reliable and poses no danger to the user or surroundings. This standard is to serve as a complementary document to the current version of those national and international standards addressing electrical resistance trace heating. Revision Standard - Superseded. Specific testing requirements for qualifying electrical resistance trace heating for use in industrial applications in ordinary locations, as well as a basis for electrical and thermal design, are included in this standard.