There is growing interest in multilayer gas pipe or polyethylene/aluminium and cross-linked polyethylene/aluminium macro-composite pipe for domestic gas piping systems. The product’s popularity has increased for a range of reasons, including:
Despite this, concerns have been raised by consumer, government and industry representatives about incompatibility between “˜proprietary’ multilayer piping systems and possible problems associated with extending or repairing an existing system in the event that fittings for the system to be repaired or extended had been withdrawn from market. In such a situation, it was acknowledged that if installers were unable to obtain the correct proprietary fitting, incompatible or unsuitable fittings may be used in an attempt to join one proprietary piping system to another. Such practices could have serious safety implications.
Installation requirements for multilayer gas piping systems are published in Australian Standard AS5601 – Gas Installations (soon to replaced with AS/NZS5601) and product requirements are set out in AS4176 – Polyethylene/aluminium and cross-linked polyethylene/aluminium macro-composite pipe systems for pressure applications. Publication of the new AS/NZS5601 is scheduled for late 2009 and further details about the draft AS/NZS 5601 are available from Standards Australia.
Draft AS/NZS5601 incorporates requirements designed to help mitigate the effect of the concerns raised, including requirements for an installer to provide for future system extension or repair using “˜conventional’ connections at strategic points in the piping system. One example is provision of connection points compatible with standard plumbing fittings (i.e. ISO 7.1 – BSPT compliant fittings) at accessible intervals not exceeding 10 metres. The provision of connection points would eliminate the need to replace an entire gas piping system in a dwelling in the event that fittings for a specific proprietary piping system had become unavailable. In such a case, the flow-on costs to consumers need to be considered. In addition, regulatory authorities raised the issue of training for installers of proprietary piping systems, both in terms of training quality and availability.
To help address these issues, AGA offered to host an industry forum so that stakeholders, including manufacturers and suppliers of multilayer piping systems, installation contractors, government regulatory authorities and consumer representatives could work together to find a solution that will deliver the required safety outcome and take into account consumer interests and the cost to industry. The industry forum, held on 3 February at AGA’s head office at Braeside, Victoria, was well supported, with delegates from AGA, Auspex, Consumers Federation of Australia, Energy Safety WA, Flowpex, Gas Pex, Georg Fischer, Iplex, National Copper, Office of the Technical Regulator SA, Pipex, Rehau, Standards Australia, Valsir Pexal and Valsir SpA Italy.
The forum helped identify many different views and provided a useful opportunity for stakeholders to consider possible solutions. There were many constructive suggestions made, including the possible development of a “˜universal adapter’ to join different proprietary systems. Industry representatives agreed to investigate this option, noting that the suitability of a “˜universal adapter’ would need to be evaluated for each propriety piping system.