Standard issues
Changes and updates to standards and guidance documents appear to be causing confusion about the use of press-fittings for gas installations. Barny Parks managing director of pipe and fitting manufacturer SANHA attempts to clear up any confusion.
Those who specify or install gas pipework and fittings will be familiar with the plethora of industry organisations, guidance documents and standards with which an installation must comply. It is a task made all the more challenging by the addition of new standards and the ongoing revisions and updates to both UK and European standards and codes. Many of these are cross-referenced by other gas guidance documents and regulations but not all of which have been updated, which can lead to confusion.
Using the example of copper and stainless steel press-fittings for gas installations highlights some of the issues.
The advantage of press-fittings is that they make the installation of pipework fast and economical and, unlike soldered or brazed jointing systems, press-fittings do not require heat or an open flame for installation. Press-fittings are suitable for use in a wide variety of systems including drinking water, compressed air, heating and cooling and sprinkler systems so in selecting press-fittings for gas installations the first thing installers or specifiers need to ensure is that the fittings have been certified for use with gas.
Product certification, or product qualification, is the process of confirming a product has passed performance and quality assurance tests and meets qualification criteria stipulated in contracts, regulations, or specifications. These are typically called ‘certification schemes’ in the product certification sector. SANHA, for example, manufacturers press fittings for gas installations; its copper and stainless steel fittings both incorporate a Hydrogenated Nitrile Butadiene Rubber O-ring seal and are marked with a yellow triangle, which clearly identifies the fittings as suitable for gas installations.
For specifiers of SANHA’s copper press-fittings the suitability criteria is straight forward: products are certified by the BSI as meeting the requirements of BS 8537:2010 Copper and copper alloys; plumbing fittings; specification for press ends of plumbing fittings for use with metallic tubes. SANHA’s Press Gas Series 10000 copper and Press Gas Series 11000 lead free Siliconbronze fittings are both BSI certified. In addition, they are also certified by Det Norske Veritas Germanischer Lloyd, a European safety standard for oil, gas and industrial applications for the shipping industry.
Confusion can occur, however, when copper press-fittings are used for domestic installations. The current version of BS6891:2005 Installation of low pressure gas pipework up to 35mm in domestic premises does not mention press-fittings, despite the existence of BS8537:2010, which is the standard for their approval in the sane application. The current standard, which is currently out for consultation, is expected to allow press-end joints for copper alloy up to 35mm diameter, providing fittings conform to BS 8537: 2010 Specification for press ends of plumbing fittings for use with metallic tubes for domestic installations.
The certification process for specifiers and installers of stainless steel press-fittings, is more convoluted because the current European standard for stainless steel BS EN 10352 Stainless steel plumbing fittings; fittings with press ends for metallic tubes is currently in draft form.
So, even though SANHA’s NiroSan Gas Series 17000 stainless steel products have been certified in Germany by gas and water standards body DVGW as being compliant with water and gas industry standard G5614 Permanent pipe joints for metal gas lines; press connectors, to be compliant in the UK the products have to be re-certified by the UK certification body BSI. The BSI certifies to EN standards, which in the case of stainless steel is currently only available as a draft. So, to give installers in the UK confidence in its stainless steel press-products, SANHA has had to have its range certified by BSI to the draft EN, so that it can be awarded a verification certificate.
Confusion can also be caused by the interpretation of documents. Stainless steel press-fittings can be used for gas pipework installations up to 108mm in diameter. However, in paragraph 6.2.1.1 of the Institution of Gas Engineers and Managers (IGEM) document, for example, it says: “Pipe and fittings shall be joined as indicated in Table 4”. Table 4 only refers to screwing or welding for jointing pipes up to 54mm diameter. What’s more, it only permits welding of pipes with a diameter greater than this. Some people reading IGEM/UP/2/edition3 have misinterpreted this as saying that you cannot use press-fittings above 54mm. This is wrong. In fact, because the issue of whether to screw or weld does not a apply to press-fittings the restriction does not apply to press fittings and so installers are free to use press fittings for gas pipes up to 108mm diameter.
For a compliant gas installation the fitter installing either a copper or stainless press-fitting installation must, by law, be registered as competent to work on gas installations. In the United Kingdom, the Isle of Man and Guernsey businesses and operatives deemed competent to undertake both piped and liquefied petroleum gas (LPG) work will be listed in the Gas Safe Register.
In addition to maintaining the competent person’s list, the Gas Safe Register also publishes a document that sets out which standards and legislation relating to gas installations the organisation recognises. This publication sets out a hierarchy of documents in order of their significance starting with Statutory Acts, or Regulations that are legally enforceable including Health and Safety legislation, gas safety legislation, Building Regulations and building legislation. It then lists the documents that support the legislation before finishing with the details of gas-related British and European standards and documents published by the IGEM.
Gas Safe also inspects installations to ensure work undertaken by registered businesses or installers is compliant with its criteria. First an officer will assess an installation against the manufacturer’s instructions and “where these are not relevant”, against criteria defined in the legislative documents and gas standards referred to in its documentation publication.
Why does all of this matter? Specifiers and contractors need to select products that comply with all of these codes and standards. Responsible manufacturers like SANHA have to keep abreast of changes in all the relevant standards and codes. In fact, SANHA is involved in setting new European pipework standards; its head of research and development, Geert Van den Abbeele, sits on several EN standards committees.
“For more than 20 years SANHA has closely monitored new legislation and standards involving pipework systems in order to develop and ensure our products meet all the requirements required of them. Many SANHA employees now work within industry associations and standardisation committees”
“As an industry leader, SANHA makes available its significant product knowledge whilst working on these various legislative bodies, to ensure that these standards reflect the state of the art, and deliver the best solution for the end user,” says Van den Abbeele.
