Electric heat tracing, heat tape or surface
heating, is a system used to maintain or raise the temperature of pipes and
vessels. Trace heating takes the form of an electrical heating element run in
physical contact along the length of a pipe. The pipe must then be covered with
thermal insulation to retain heat losses from the pipe. Heat generated by the
element then maintains the temperature of the pipe. Trace heating may be used
to protect pipes from freezing, to maintain a constant flow temperature in hot
water systems, or to maintain process temperatures for piping that must
transport substances that solidify at ambient temperatures. Electric trace heating
cables are an alternative to steam trace heating where steam is not available
or unwanted.