ACE Issue 22 2019 | Page 25

Single Unit Double Block And Bleed Valves – Compact Solution For Extra Safety F rom reservoir to final product the oil and gas industry is concerned about safety. When an operator wants to isolate a pipeline, whether this is part of the routine operation of a facility, to carry out maintenance, or in response to a potential crisis, it’s critical that the valve used is 100 per cent effective. Following the events of the Piper Alpha disaster, double isolation has become mandatory. By combining two isolation ball valves and an intermediate bleed valve within a single compact assembly, Oliver lead the world with their range of double block and bleed (DBB) valves. Single unit DBB’s cut down potential leak paths for emissions to the environment. Being more compact that using single isolate valves assembled together to form a double block and bleed configuration, reduces space and weight in installations and provides and overall safer solution. Another key advantage is that the whole system can be built to have the same face-to-face length as a standard single isolate valve, as specified in the relevant international standards – API 6D and ASME B16.10. Not only does this mean the system can be easily installed into an existing system without any re-working of the surrounding pipes, but also that the space required for a DBB system is reduced by more than half. This frees up room for other equipment and easier personnel access or, in the case of floating facilities, saves critical weight and space. Oliver have recently manufactured their 220,000th DBB valve. Demonstrating the popularity of the single unit DBB. As global energy businesses face challenges like increasingly inaccessible oil and gas reserves and the need to reduce fugitive emissions, technological innovation at ground level will play a central role in delivering solutions. Single unit DBB valves are just one example of how the valve industry has developed in recent years in response to industry needs. Paul Shillito M.Sc., M.Phil., D.M.S., C.Eng., F.I.Mech.E. Technical Director at Oliver. www.valves.co.uk 25