Is electrofusion joining considered a fool-proof process?

The author would like to refute the common myth that the joining of polyethylene pipes and fittings by electrofusion method is a fool proof process. This myth is based on the theoretical consideration by many operators that the electrofusion joint integrity is control by the computer processor and independent of the fitting design, surface preparation, alignments and power sources. This paper addresses the precautions during testing, evaluation and installation of electrofusion fittings based on the several laboratory root cause failure analysis of exhumed in-service electrofusion joints. The goal here is to stress the importance of precautions in selecting fittings design and during installations. These precautions are categorized as below:

1. The ploughed wire versus concealed wire design
2. The external and internal inspection of joining pipes and fittings
3. Surface preparation
4. Scraping tools and their maintenance
5. Alignment of joining pipes, pipe roundness and clamps
6. Fusion, clamping & cooling time
7. Power sources

The implementation of the recommendations made in this paper would help gas utility operators to enhance their PE distribution system integrity and extend service life.