What special equipment is needed for each assembly method?

To ensure that good quality butt fusion joints are made it is essential that the correct equipment is used. The welding machine and associated equipment used must be robust enough to handle the size and weight of the pipe to be joined. It is essential that the correct pressures be maintained on the pipe ends during each phase of the procedure. To achieve this only hydraulically operated equipment should be used.

Many modern butt fusion machines include data logging facilities that record several parameters during each step of the fusion process, for use within a Quality Assurance system. This may include the GPS system identifying the location of where the joint was made.

Ancillary equipment, rollers, supports, etc. should also be used to aid alignment, reduce the effect of pipe drag during the fusion process and minimise the risk of damage to the pipe surface.

It is essential that operators of the equipment are familiar with relevant health and safety issues for the equipment being used and are fully trained it its correct use. Operators must be qualified and hold an operator badge conforming to ISO 12176 Part 3

Equipment suitable for butt jointing PE pipe can be supplied by many manufacturers and as discussed in the “What is butt fusion” pages of this website comprises of manual, semi-automatic and automatic welding machines. Butt fusion Butt fusion equipment must conform to ISO 12176 Part 1

Electrofusion
The equipment comprises the electrofusion fitting itself and an electrofusion control unit (ECU). The ECU has a data reading capability, normally in the form of a barcode scanning pen or other hand held device. This is used to prove the ECU with the details of the fitting being used, so that the correct fusion time/temperature cycle is automatically selected. Most ECUs have failsafe features so that incorrect procedures or the wrong fittings cannot be used.

Nearly all modern ECUs include data logging facilities of the fusion process and parameters for use within a Quality Assurance system. Such facilities will also record when incorrect procedures or fittings where used and some ECUs use a GPS system to also record the location at which the joint was made. The data logging facilities must conform to ISO 12176 Part 4  

As with butt fusion machines, it is essential that operators are familiar with system health and safety issues, are fully trained and qualified in its correct use and hold an operator badge conforming to ISO 12176 Part 3.

The principal ancillary equipment are the pipe peelers used to remove a 0.2 mm thick layer of the pipe skin prior to it being inserted in to the electrofusion fitting, and the welding clamps that hold the pipes firmly in place during the welding process. The use of rerounding clamps may also be necessary if pipe ends have a higher than allowed degree of ovality.

Traccoding (Traceability Coding)

This is a traceability system. It is based on a 40 digits (pipes) or 26 digits (other components) numerical code which is usually displayed in the form of a barcode on the pipes or other components. This barcode contains information about the manufacturer, product type, size, production site, batch, PE compound, SDR value etc.

Some end user organisations may require that the equipment used for the fusion welding of PE pipe systems must be suitable for recording the Traccoding information given on the pipes and fittings. More information can be found at www.traccoding.com.

Mechanical Assembly
Besides a torque wrench, little special equipment is required when assembling mechanical fittings and PE pipes.

The only exception is with the plastic compression fittings, where it is advised that plastic pipe wrenches, similar to the ones shown in the following images, are used to minimise the risk of the fitting surface being damaged by metallic wrenches and spanners etc.

Images courtesy of Borouge

References

ISO 12176-1:2017 Plastics pipes and fittings - Equipment for fusion jointing polyethylene systems - Part 1: Butt fusion
ISO 12176-2:2008 Plastics pipes and fittings - Equipment for fusion jointing polyethylene systems - Part 2: Electrofusion
ISO 12176-3:2011 Plastics pipes and fittings - Equipment for fusion jointing polyethylene systems - Part 3: Operator's badge
ISO 12176-4:2003  Plastics pipes and fittings - Equipment for fusion jointing polyethylene systems - Part 4: Traceability coding