World-leading supplier of critical flow control solutions IMI Critical Engineering has been tasked by international energy company Statoil with designing and building some of the largest ever production choke valves to be used topside on the Aasta Hansteen SPAR Platform in the Norwegian Sea.
The SPAR platform is a floating installation that is secured to the seabed and includes conventional topsides and processing facilities. This type of platform is specific to deepwater operations and will also be a first for use on the Norwegian continental shelf.
The platform will work to a depth of around 1300 m, 300 km off the Norwegian coast and is part of the first deep water field development within the Norwegian Sea. The medium will be transported to the surface at substantial speeds, requiring high-specification production choke valves to control the flow– which could potentially contain particles and other contamination - into the main process and so avoid excessive load and damage to other equipment and minimise risk to personnel.
IMI Critical Engineering’s IMI CCI Design Engineering team in Vienna, Austria, designed these innovative production choke valves. The IMI CCI Brno manufacturing facility in the Czech Republic has completed manufacturing and testing of the four 12 in. x 12 in. production choke valves - believed to be some of the largest ever produced - to the internationally recognised ASME 2500 standard.
The valve body was fashioned using a high isostatic pressure (HIP) process based on an innovative Y-globe design with the actuator at 45° to the main valve body. The valves also incorporate IMI CCI’s patented DRAG® technology featuring solid tungsten carbide components, selected for their strength, durability and impact resistance and also ensuring premium control and reliability in some of the world’s most arduous conditions.
An additional consideration was the need to reduce the valve’s operating noise output to 75dBA or below to limit the effect of noise on platform workers – a figure significantly lower than the usual 85dBA or above in these applications. This was achieved through honing the design of the trim in what was also one of the largest solid tungsten carbide DRAG® disk stacks to ever be built. High blast load resistance was also integrated into the design to enable it to withstand the effects of explosions.
IMI Critical Engineering’s Michael Pedigo explained: “Taking into account the high quality, material and performance requirements, coupled with the highly challenging geometry of the valves and associated sensitivity of the trim manufacturing and machining process, we are safe to say the task was accepted and accomplished as a complete team effort.”
“The high flow rate necessitated a valve of this size and our experience in manufacturing production choke valves and harnessing the unique performance attributes of DRAG® technology, enabled us to deliver on time and on budget and in line with our ethos of engineering great solutions for our customers.”
The assemblies containing the valves are now being dry-constructed and are set to enter service during 2016.
Statoil added: “We have collaborated with IMI Critical Engineering on a number of projects worldwide and have always been impressed with their ability to understand each application and the deliver a solution which meets our specific requirements.”
Adapted from a press release by David Bizley