Fusion bonding of non-pressurized process piping: A new technology and a new approach

Conference · Mon Jul 01 04:00:00 EDT 1996

OSTI ID:253820

Cooper, R J; Pinder, R ^[1]

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1. Evanco Environmental Technologies, Inc., Bracebridge, Ontario (Canada)

Perhaps the best-known method of thermoplastic fusion bonding for process piping is hot-plate or heated-tool butt welding. Despite the age of this method and the considerable research available on the subject, in practice, this method of heat fusion relies largely on the skill and knowledge of the machine operator. Hence, the quality of the completed fusion bond is largely dependent on human factors. Another method for joining thermoplastic process piping with heat fusion has been through the use of electrofusion fittings or couplings. A sleeve with an embedded resistance wire is slipped onto mating pipe ends, and welding takes place by electrically heating the resistance wire and forming a molecular bond on the outside surface of the mated pipes. While butt welding tends to rely heavily on the knowledge and experience of the machine operator, electrofusion fittings tend to rely more on automated mechanisms such as the software in the computerized fusion box. An alternative form of thermoplastic welding that employs the features of both butt welding and electrofusion couplings has recently been developed. This unique method employs the principles of electrofusion for performing butt welding. The authors have successfully demonstrated this technology at a major US chemical manufacturer`s facility to produce reliable, leak-tight fusion joints in non-pressurized, process piping applications. Research and practical experience were blended to provide consistent fusion quality based on monitoring key fusion parameters, while still relying on the experience and training of a fusion operator.

• OSTI ID: 253820
• Report Number(s): CONF-960156--; ISBN 1-57698-001-4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
BONDING
ELECTRIC HEATING
MATHEMATICAL MODELS
PIPE JOINTS
PIPES
QUALITY CONTROL
TECHNOLOGY ASSESSMENT
THERMOPLASTICS