Butt fusion cooling times, speeding up the process - Effect of ambient temperatures

This author presented the thought provoking paper “Butt Fusion Cooling Times, Speeding Up the Process” at Plastic Pipes XV held in Vancouver, British Columbia, Canada.. That presentation discussed testing of heavy walled pipe using various fusion standards and the resulting cooling times with relative joint strength. The tests revealed the interfacial temperature and the actual time required to cool the joint interface to a safe temperature before removing from a machine and handling the pipe That information gave us the actual joint temperature when the pipe can be and currently is being removed from machines according to ISO, German, British and USA Standards. The testing noted differences in interfacial temperatures at the end of the cooling cycle and the actual strength of the joint when it is lifted from the machine. Also some controversy arose because of the question as to whether ambient temperature has an effect on cooling times of butt fused joints. Do ambient temperature differences account for the high interface temperature in fusions using certain parameters? Do the differences in ambient temperatures from one locale to another prohibit use of some parameters being used safely in that climate without modification? If the cool temperature target is 90° C in an average ambient temperature of 15° C, what happens when the same cooling time is used in a climate with an average ambient temperature of 26° C? This paper reviews the testing to date which attempts to answer those important questions.