Are there any standards or codes of practice applicable to the assembly methods?

Butt fusion

Butt fusion procedures require the application of temperature and pressure over time to the mated ends of the pipes or fittings. The procedures developed in different European countries are all similar in principle but different in detail. All have been tested and all produce satisfactory joints when the procedures are followed correctly.

The differences between the procedures are in the level of pressure to be applied, the time for which it is to be applied and the temperature of the hot plate. Depending on the procedure this can be between 210 & 240 °C.

In addition to the national standards there is an international standard, ISO 21307:2017 which covers the three main procedures, which are listed below and shown in the following diagram.

                   ·         single low-pressure fusion jointing procedure

                   ·         dual low-pressure fusion jointing procedure

                   ·         single high-pressure fusion jointing procedure

Image courtesy Borouge

Within Europe the various national codes of practice on butt fusion are the following:

Electrofusion

There is less variation in electrofusion procedures. The barcodes on the fittings cause the electrofusion control Unit (ECU) to be programmed with the correct time and temperature cycle for that fitting.

Mechanical Assemblies

Whilst there are standards for the mechanical fittings and flanges themselves, there is no standard or code of practice regarding how to undertake mechanical assemblies. A good reference however is the TEPPFA guide on the flange jointing of PE pressure pipes:

A-Good-Practice-Guide-for-Flange-Jointing-of-Polyethylene-Pressure-Pipes

References

ISO 21307:2017 Plastics pipes and fittings - Butt fusion jointing procedures for polyethylene (PE) piping systems