Setting the standard

Despite the revised British Standard BS 6644 having been introduced in November of last year, reports from manufacturers and suppliers alike suggest that awareness of the standard’s requirements falls short of what it ought to be.

With a fundamental review of BS 6644 having taken place last year, the end result was a series of changes to the standard, which is the main legislation covering the installation of gas boilers above 70kW (net) in the UK. From our perspective as a manufacturer however, it has become apparent of late, that a number of professionals within the industry are suffering as a result of a lack of awareness of the changes.

Address the issue

The issue with the changes is that for larger output boilers, a number of consultants are only realising the need for these changes at the commissioning stage, once the boiler has been installed. Because the changes have seen the introduction of safety measures, incorporating these at the design stage of a project is far more convenient and cost effective over the long term than a forced retrofit later on.

Within our industry, there tends to be something of a ripple effect when it comes to the awareness of new legislation, regulation and standards, of which BS 6644 is one of many. The manufacturers and governing bodies tasked with forming and approving industry guidelines are inevitably the first to be aware of new or altered requirements, and there is then an obligation from consultants and engineers to keep abreast of developments such as these for the benefit of their work.

Keep up to date

Aside from optional membership of the British Standards Society (BSS), those concerned with industry legislation rely heavily on trade publications and manufacturer-led bulletins to keep up to date with changing rules and requirements. It is the very nature of the industry that sees us in a position where word of such changes trickle through to consultants over the months that follow their introduction, which can lead to the occasional and potentially costly misunderstanding as the requirements begin to transcend common practice.

With the peak heating season upon us, now is arguably the perfect time for those working within the commercial and industrial heating sectors to remind themselves of the requirements of BS 6644.

In simple terms, the changes to BS 6644 harmonise this standard with the lesser known standard, BS EN 12828, sections of which relate to the installation of boilers over 300kW on sealed systems. One of the main requirements of BS EN 12828 is the need for additional safety equipment to protect against the over-heating and over-pressurisation of individual boilers. Whilst cases of this happening in the UK tend to be few and far between, the reporting of instances on the continent has led to this introduction in the UK.

In order to comply with BS 6644, flash traps (liquid separators) are required to be fitted to the outlet of safety valves serving boilers in excess of 300kW, which will ultimately prevent the rapid expansion (or explosion) of water into steam from causing serious damage. As the standard does recognise that flash traps can be difficult and impractical to install, an allowable alternative is to double-up on the safety chain equipment to minimise the likelihood of a safety valve ever having to discharge.

Along with these requirements, a water level limiter must be fitted for boilers over 300kW, or boilers installed in a position where the system is lower than the boiler (i.e. roof top installations). These devices come in different forms and boiler manufacturers may seek approvals for slight variations on equipment.

Correct equipment

As these requirements look set to be more widely observed, it is now more important than ever for manufacturers to offer the correct safety equipment with their products. Not only will this equipment enable compliance with BS 6644, but will ultimately ensure the safe operation of the boilers installed by the end-user.

The central issue in relation to these changes is that if such safety features are omitted at the design stage, it is very difficult and expensive for the installation to be rectified later on.

With this in mind, contractors, consultants and specifiers are advised to work with a manufacturer which is able to offer a complete package of safety equipment in addition to high output boilers. By marrying the two together, additional costs and downtime can be kept to a minimum.

Using a pre-designed package guarantees the most compact and practical compliance with BS 6644 and we expect such packages will become commonplace as the awareness of the British Standard is raised further.

0