Confusion in the industry
At IBEX Australia, we often ask whether our Tubepress® and Impress® stainless steel press-fit tube and its related products are AGA approved. But the question should be: Do the Tubepress® and Impress® systems have gas approval?
The answer is YES, Tubepress® and Impress® do hold gas approval.
We speak to many engineers, and there is often some confusion over the difference between gas approval and AGA approval. This confusion stems from the fact that AGA was once the only certifying body able to issue gas approval in Australia. While this was true in the 1980s, it is certainly no longer the case.
In those days, gas pipework was installed using screwed galvanised steel and copper. The AGA was the only appliance approval body and covered appliances such as heaters, gas hot water units and the like. However, the pipework was categorised separately and came under the Plumbers Commission.
Appliance vs pipework approval
Gas appliance approval is separate from pipework approval, and there are now several certifying bodies able to certify pipework for gas applications.
These certifying bodies are:
Gas Appliance Certification:
- SAI Global
(Source: Gas Technical Regulators Committee)
Gas and Water Pipework Certification:
- Australian Certification Services
- CertMark International
- IAPMO R&T Oceana
- DNV GL Business Assurance
- SAI Global
(Source: Australian Building Codes Board)
As shown above, AGA is one of eight certifying bodies that can provide pipework approval for gas. The key here is that any products used in the field are tested to the relevant standards. Tubepress® and Impress® are professionally pressure tested and fully comply with the relevant standards.
Below this article is the downloadable certification that supports this approval. The other statements attached are from the German manufacturers of Tubepress® and Impress® (known as Nirosan in Europe®) and go beyond AS 5601 into the Biogas area.
Type A and type B gas appliances
A common question: Are Tubepress® and Impress® approved for piping in Type B appliances?” The answer again is YES. Type A appliances are your standard heaters, hot water units, etc. Type B appliances are generally industrial applications such as boilers, furnaces, etc. which require “double shut-off devices” on the gas supply, routine maintenance and inspection and other considerations.
Plumbing and gas-fitting have always gone hand-in-hand, and pipework standards AS5601 (Gas) and AS5200 (Plumbing) both refer to AS3688 standards for the testing regime of pipe and fittings for approval in both fields. A result of the testing is the accreditation of the Watermark certificate for plumbing and Gas certificate for gas applications. AS5601 calls up yellow HNBR O rings for gas applications. Tubepress series 17000 has yellow HNBR O rings.
Tubepress® and Impress® are approved for Biogas, provided IBEX Australia is given details of the gas mixture/s (material safety and data sheet) and the operating pressure and temperature. This information is sent on to the German manufacturer for testing and approval for use.
Biogas is beyond the scope of AS5601, and the technical knowledge of industry experts, manufacturers with relevant experience and specific application guarantees, are often used as a reference point.
Some Biogas mixtures may be better suited to FKM or even EPDM O rings as opposed to the HNBR O rings stipulated in AS5601. We refer to our German manufacturers for guidance and assessment in this scenario.
Biogas is mostly methane from a tip or animal waste and piped into a generator or industrial machine. Generally, polyethylene (PE) pipe is used to collect the gas, but stainless steel pipework is used in the plant, often referred to as the “gas train”.
As stated, our Tubepress® and Impress® 316L stainless steel piping solution hold gas approval. This approval has been issued by Australian Certification Services and can be downloaded using the below link.
Having discussed this topic in great detail with many of our clients recently and sought to clarify with industry bodies, we figured it would be time for us to share this knowledge with the rest of the industry.