This procedure defines butt fusion as a joining method for connecting pipe to pipe or pipe to pipe fittings. Butt fusion is commonly used e.g. for PE or PP pipes and pipe fittings. These instructions describe principles and are not intended to guarantee compatibility of different polyethylene or polypropylene grades.
Appendix A provides indicative welding parameters.
This document describes a welding method and parameters that have been found suitable for conditions in the Nordic countries (S, FIN, N, DK), for temperatures down to -10°C and a wall thickness of not more than 70mm. For lower temperatures and thicker pipes, a verification welding is needed. Please refer to instructions from pipe
and/or welding machine suppliers. Investigations into lower allowable ambient temperatures for welding are ongoing.
Other similar welding documents , , , , ,  are found in the bibliography.
Pipes with peelable layers are not covered in this document. Please refer to pipe supplier’s recommendations.