Plumbing

Master Plumbers April FAQs: Do you know the answers?

Thinking about interchanging Gas PEX components? Here’s what you need to know about proprietary systems and why compatibility matters.

Q: Can I Interchange Gas PEX components?

A: Gas PEX systems are proprietary systems, defined as - manufacturer-specific system using matched components, which may require special tools for installation. In practise, these are complete gas piping or component systems that are designed, tested, and supplied by a manufacturer as an integrated solution. Because they rely on specific materials, fittings, and installation methods, these systems must meet strict requirements to ensure safety, compliance, and long-term performance. Common examples of proprietary systems include Auspex, Duopex, and Rehau Rautitan.

All components must be those specified or supplied by the manufacturer. Substituting parts or mixing components from different systems is prohibited unless explicitly authorised by the manufacturer (Clause 4.5.3).

Each proprietary system must be suitable for its intended use, meaning it must be approved for the relevant gas type, operating pressure, temperature conditions, and installation environment.

Installation must strictly comply with AS/NZS 5601.1:2022, Table 4.2, and the manufacturer’s installation instructions. These requirements form part of the system approval and specify jointing methods, support spacing, protection from damage, and testing. Deviating from the manufacturer’s instructions is not permitted, even when alternative methods may be acceptable for non-proprietary pipework (Clause 4.5.2).

Finally, proprietary systems must be clearly identified. The maker or trade name must be permanently marked, with a durable label installed adjacent to the gas meter, LP gas tank, cylinders, or other gas supply points (Clause 4.5.4).

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