Fast weld field trials - high productivity butt fusion jointing of polyethylene pipes

This research work took place up to and during 1997 and the results hereafter are from that research. However, since then there has been additional research work. For the purposes of this paper the principles remain fundamentally consistent; however, the reader should recognise the concept has been relined since the paper was initially published. The butt fusion procedures used in the UK water and gas industries, which determine the total time taken to complete a successful joint, have remained largely unchanged since their harmonisation in 1990. The parameters evolved to suit manually operated butt fusion machines and reflected the fact that the minimum achievable heater plate removal time, for up to 250 mm diameter, was between 6 and 8 s, during which the operator had to manually operate a hand pump to remove the heater. With standardisation of automatic butt fusion, and typical heater plate removal times of 2 s, the potential exists to reduce considerably the on site jointing time and thus enable substantial financial savings. Trials to date have been exclusive to second generation medium density polyethylene PE80, due to its known tolerance to variances in jointing parameters, which can occur with manual machines working in site conditions. Further work to determine the fast weld parameters of third generation high density polyethylene PE100 is planned for the future. PRC/1556 (C) 1999 IoM Communications Ltd.