HSE ISSUES REVISED GUIDANCE ON GAS TURBINE SAFETY

HSE press release E085:03 - 3 June 2003

HSE has launched a revised edition of its successful Guidance Note 'Control of safety risks at gas turbines used for power generation' (Guidance Note PM 84).

The guidance is primarily aimed at manufacturers, suppliers and operators of gas turbines (GTs) used for generating electrical power, but is also applicable to their use in oil and gas pumping and compression plant and similar applications. The new edition has been extensively revised since its original publication in 2000, providing much additional information, including:

• the design of enclosure ventilation;
• further guidance on selecting equipment for use in potentially explosive atmospheres; and
• risks from the use of liquid fuels.

The guidance will help in drawing attention to hazards associated with GTs and describes ways in which the associated risks can be eliminated or reduced to an acceptable level.

Roger Santon, Principal Specialist Inspector with the Process Material & Systems Safety Topic Group, part of HSE's Hazardous Installations Directorate, said: "Comments from the GT power generation industry prompted HSE to revise PM 84 and to include more information. The revision has been undertaken with help from both manufacturers and users, and I believe the new document represents clear, comprehensive, and achievable guidance which will help to further improve the high safety standards in this important industry."

HSE has taken this opportunity to also launch a new free information document, 'Health and safety risks from small gas turbines used for power generation'. This gives useful guidance on choosing the best location for small GTs, together with suitable risk reduction measures. Such machines are being used to provide electricity and hot water for medium sized-buildings such as nursing homes, retail food outlets, leisure centres etc.

GT power generation technology has its roots in modified aero-engines. Now due to the increased use of gas, much larger, purpose-built, units (up to around 330 megawatts) provide electricity for towns and cities, while smaller units provide much-needed power to hospitals and hotels. GTs are also used in the gas and petroleum industries to provide pumping and compression facilities, often in remote locations such as pipelines, and to generate electricity e.g. on offshore production platforms.

Copies of Guidance Note PM84 'Control of safety risks at gas turbines used for power generation' can be ordered online at http://books.hse.gov.uk ISBN 0 7176 2193 6, price £7.00.

Notes to editors

1. Both the revised guidance note and the information document were launched at a meeting of the Gas Turbine Users and Manufacturers Group hosted by HSE at the Health and Safety Laboratories in Sheffield on Wednesday 21 May 2003.

2. To control the noise generated by a GT it may be installed in an acoustic enclosure. Fuel is fed via a complex pipe system to the combustion chambers, making a leak foreseeable. GTs can also generate high external surface temperatures (in excess of 520o C on larger plant) capable of igniting the fuel, resulting in a fire or explosion.

3. Ventilation for GTs was originally provided for cooling but as the explosion risk became apparent ventilation was proposed as a means of diluting any escaping gas. However designs needed to be verified and computational fluid dynamics was used by the industry to model gas dispersion. HSE proposed a design criterion for the acceptable size of pockets of flammable gas air mixtures to be achieved by the ventilation design, which has been shown to be safe and achievable.

4. Small GTs could be installed in an existing plant room within a building. The fuel supply (e.g. natural or liquefied petroleum gas) has to be at a high pressure so that, in the event of a leak, more gas could be released into the building than from the normal gas supply. The most important safety factor, therefore, is choosing the correct location with regard to the use of the building. The guidance provides information on the use of gas detection, fire detection and fire resisting structures, depending on location.

Press enquiries

All enquiries from journalists should be directed to the HSE Press Office