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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.〔Paul R. Smith, ed. ''Facilities engineering and management handbook : commercial, industrial, and institutional buildings'',McGraw Hill,2001 ISBN 0-07-059323-X chapter 5 pages 5-198 through 5-201〕 ==Development== Electric trace heating began in the 1930s but initially no dedicated equipment was available. Mineral insulated cables ran at high current densities to produce heat, and control equipment was adapted from other applications.〔James Bilbro et al, ''Electric trace heating -state of the art'', Paper 69 TP 20-IGA,IEEE TRANSACTIONS ON INDUSTRY AND GENERAL APPLICATIONS, JULY/AUGUST 1969 pages 476-480〕 Mineral-insulated resistance heating cable was introduced in the 1950s, and parallel-type heating cables that could be cut to length in the field became available. Self-limiting thermoplastic cables were marketed in 1971.〔Ted Hammack and Stephen Kucklinca, ''Self-Limiting Electrical Heat Tracing:New Solution to Old Problems '' , IEEE Transactions on Industry Applications March/April 1977〕 Control systems for trace heating systems developed from capillary filled-bulb thermostats and contactors in the 1970s to networked computerized controls in the 1990s, in large systems that require centralized control and monitoring.〔 One paper projected that between 2000 and 2010 trace heating would account for 100 megawatts of connected load, and that trace heating and insulation would account for up to $700 million CDN capital investment in the Alberta oil sands.〔Derek Brooks et al., ''Reducing the total Cost of Ownership of Electric Heat Tracing Systems in Northern Alberta''〕 International standards applied in the design and installation of electric trace heating systems include IEEE standards 515 and 622, British standard BS 6351, and IEC standard 60208.〔Chet Sandberg et al, ''Electrical Heat Tracing:International Harmonization Now and in the Future'', IEEE Industry Standards Magazine, May/June 2002 pages 50-56〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Trace heating」の詳細全文を読む スポンサード リンク
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