The following information is intended to assist our customers with current standards and regulations. All information should be verified and checked that it is up to date, before being relied on.
This document provides guidance how to best handle and store Polyethylene Pipes and Fittings.
“Polyethylene pipes and fittings are light in weight and easy to handle compared to many other materials. They have considerable resilience, flexibility and resistance to impact. However PE pipes and fittings can be scored by sharp edges and can be distorted under load, particularly at higher temperatures. Therefore, in general, PE pipes and fittings should not be dropped, indented, crushed or impacted and should not be subjected to rough handling during loading and unloading operations. Pipes and fittings must not be stored or transported adjacent to heat sources, such as engine exhausts, boilers, naked flames or hot water or steam lines. While PE is very resistant to low temperatures, as the temperature drops below 0⁰C the impact resistance will slowly reduce, and therefore more care should be taken to avoid damage by impact.”
This document sets out the principal requirements for equipment, jointing procedures, maintenance, servicing and calibration of equipment, records and training for jointing by socket electrofusion, and saddle electrofusion. It is recommended to refer to the supplier or manufacturer of electrofusion fittings, in case the installation instructions specify different hdpe pipe jointing methods.
“Electrofusion fittings are currently available in the size range DN16 to DN1200. Larger sizes are under development. The key to consistently making satisfactory joints is to follow the jointing procedure with particular emphasis on pipe surface preparation, avoidance of contamination, machine calibration, as well as temperature monitoring and control. Pipes and fittings of different SDR can be joined together by the electrofusion process, e.g. DN250 SDR11 and SDR17 pipe can be successfully electrofused using a DN250 SDR17 fitting. Some manufacturers supply electrofusion fittings for thinner pipes, down to SDR33 whereas others limit the use of some saddle type fittings to SDR11 or thicker. These limitations are usually detailed on the fitting body or on the packaging. If in doubt, check with the supplier or manufacturer, as unsatisfactory joints are likely to occur if the fitting/pipe combination is incorrect. Pipes manufactured from different grades of PE materials- (for example PE80 and PE100) can be jointed successfully using electrofusion. Before welding it is important to confirm that all components have adequate nominal pressure rating for the operating conditions and the PE materials comply with AS/NZS 4131.”
This document is a guide to butt fusion of polyethylene (PE) Pipe using AS/NZS 4130 material as a basis.
“Butt welding involves the heating of two pipe ends to fusion temperature and then subsequently joining the two ends by the application of force. However, a successful butt weld requires the correct combination and sequence of the welding parameters time, temperature and pressure. Various proven butt fusion methods with minor differences have been in use in different countries for many years. ISO 21307 contains three distinct fusion methods described below for pipe and fittings. It is essential that the parameters specified for a given method are followed. Do not mix and match parameters from each method.”
This document provides guidance relating to the geometric specification of metal backing flanges suitable for the use with PE flange adaptors in the sizes DN20 through to DN100 and flanges in accordance with Australian Standards.
“Where there is a need to join polyethylene pipe to pipe of another material or ancillary equipment such as valves and pumps then mechanical flanges may be used. They provide not only a means of transition but a fully end load resistant joint that can also be disassembled for maintenance purposes. As the thicknesses of these flanges differ, and therefore the pressure rating of the flange, care should be taken to ensure the pressure rating of the flange used is suitable for the system which it is being used on. Since polyethylene pipe systems are end load bearing, care must be taken where connection is made to pipe of another material, to prevent pull-out of any non-end-load bearing joints.”
2.1.2 Surface Preparation – Cleaning
The surfaces to be EF welded must be completely clean and free of contaminants. It is essential to clean the peeled surface with unused approved alcohol wipes to remove traces of dirt, mud and other contamination. Do not under any circumstances use methylated spirits, acetone, methyl ethyl ketone (MEK) or other solvents to clean the fusion area. Rags of any kind with or without any alcohol solvent are not to be used to clean the fusion area given the possibility of introducing dye, dirt, detergent, fabric conditioner or other contaminants into the fusion zone.
Other important factors relating to the use of alcohol wipes:
Cleaning of the prepared surface is a critical step and one that has the potential to introduce contaminates if not done correctly – remember this is the surface that is about to be welded and the presence of contaminates can readily result in a poorly welded joint.
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