Plastic Pipes Conference Association # 2010 Vancouver
Welding plastic piping systems via direct contact with a heating element and pressure, known as conventional butt fusion (CBF), has been successfully used for many years. However, there are a number of downsides to using manual driven CBF. First, there are many dependent equipment variables involved which the installer must recognize; the setting and monitoring of a timer, temperature and pressure. Long term system integrity can suffer if the installer is not vigil over each parameter. Making consistently good welds can be difficult as the skill needed is often high1 or requires the use of computer numerical control (CNC) fusion machines. On the other hand, the advent of Infra-Red non-contact welding with overlap (IR-O) has gained wide industry acceptance since introduction in the early 1990s2 for its ease of use. Mandatory temperatures and time specific to the piping material being welded is set by the associated equipment software. Additionally, there is no need to monitor pressure since the IR-O system depends on weld overlap instead. For a few years following the introduction of IR-O equipment the parameter most targeted for improvement was the length of time needed to sufficiently cool a weld before removal of the pipe from the equipment clamps. In follow up improvements since, the IR-O addressed these concerns by way of equipment enhancements and installed proven cooling techniques that reduce the length of time by more than 40% over other systems. The authors wish to address the benefits of IR-O welding while specifically calling attention to speed, weld integrity and ease of use that can be imparted to polyethylene (PE) piping system installations. Additionally, the advantages of overlap verses pressure welding will be discussed.