Gas installers and those who specify pipework for gas installations will be familiar with the challenge of ensuring compliance with the numerous organisations, guidance documents and standards that relate to gas installations in the UK. It is a task made all the more challenging by revisions and updates to existing standards and codes, many of which are cross-referenced by other gas guidance documents and regulations and by the publication of new standards.
Take the issue of copper and stainless press fittings for gas installations, for instance. Press-connections formed with copper and stainless tube are a fast, economical installation solution that requires no heat or open flame, unlike soldering or brazing. SANHA, for example, manufacture press fittings in both stainless steel and copper, with an integrated HNBR O-ring, clearly identified for gas applications.To install the pipework, the gas fitter must be registered as competent to work on a gas installation. The Gas Safe Register maintains the register of businesses and operatives who are competent to undertake both piped natural gas and liquefied petroleum gas (LPG) work in Great Britain, Northern Ireland, the Isle of Man and Guernsey.
The Gas Safe Register also publishes a document on legislation and standards which defines all legislative, normative and informative documents recognised by the organisation. The publication sets out a hierarchy of documents in order of their significance. First it details Statutory Acts, or Regulations that are legally enforceable including Health & Safety legislation, gas safety legislation, building legislation, including Building Regulations. It then details documents supporting this legislation before finally giving details of relevant British and European standards and Institution of Gas Engineers and Managers (IGEM) documents.
When a Gas Safe officer inspects work undertaken by registered businesses or installer, they will first assess an installation against the manufacturer’s installation instructions and “where these are not available or relevant”, against criteria as specified within legislative documents and gas standards referred to in its legislation and standards document.
Registered installers or pipework specifiers should select a pipe and fitting that has been certified for use with gas. Product certification, or product qualification, is the process of confirming a certain product has passed performance and quality assurance tests and meets qualification criteria stipulated in contracts, regulations, or specifications (typically called "certification schemes" in the product certification industry).
SANHA Press gas Series 10000 copper and Press gas Series 11000 lead free Siliconbronze fittings are certified by BSI as meeting the requirements of BS 8537:2010 and by Germanisher Lloyd, a European safety standard for oil, gas and industrial applications for the Shipping Industry.
For specifiers and installers of stainless steel pipes for gas, however, the process is not so clear cut. The difficulty is that currently EN standard FprEN 10352:2012 exists as a draft. Even though SANHA’s stainless steel products have been certified in Germany by DVGW GH5614, a German Standard body for Gas and Water, in the UK the certification body is BSI and it certifies to EN standards which, in the case of stainless steel, is currently in draft form. So, to give installers confidence in its products, SANHA has had its stainless press fittings range certified by BSI to this draft standard, which is known as a verification certificate
How does all of this come together? Specifiers and contractors need to select products that comply with all of these criteria. However, confusion can occur with the publication of new standards and revisions to existing standards, particularly when these are referenced by documents supporting legislation.
The picture regarding copper press fittings for gas is clouded by revisions to BS 6891, for example. 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 same application. However, the revised standard, currently out for consultation, is expected to allow press-end joints for copper and copper alloy up to 35mm diameter, if fittings confirm to BS 8537:2010 Specification for press ends of plumbing fittings for use with metallic tubes for domestic installations.
Likewise, there can be confusion over interpretation of documents. For example, stainless press fittings can be used up to 108mm diameter for gas. However, paragraph 6.2.1.1 of the IGEM document says “Pipe and fittings shall be joined as indicated in table 4”, and table 4 only mentions screwing or welding and above 54mm, only permits welding. Some people reading IGEM/UP/2/edition3 have misinterpreted this as saying that you cannot use press-fittings above 54mm diameter for gas. In fact, because you are not faced with a choice between welding and screwing when using press fittings, this restriction does not apply, so installers are free to use press fittings up to 108 mm diameter without having to weld.
Responsible Manufacturers such as SANHA have to keep abreast of all of these changes. SANHA is also involved with the development of new European pipework standards. Geert Van den Abbeele, head of research and development at SANHA sits on several EN standards committees says:
“Many SANHA employees now work within industry associations and standardisation 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
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
Where necessary SANHA often even takes the lead in convening such technical working groups. It is important therefore for customers to know and trust that our advice is impartial and that the products and solutions we offer are the best available.”
