An offshore oil platform located in the Danish North Sea was experiencing severe trim and body erosion on their water injection pump recirculation valves. These valves were in service since 2006 and were requiring frequent maintenance and spare parts. The customer started experiencing erosion issues after increasing the pressure drop through the valves. Due to the valves being on an offshore platform, the customer reached out to IMI CCI to provide a long term solution. Adding to the challenges was the requirement to maintain the original valve geometry. On top of this was the presence of sand in the produced water which was causing significant erosion to the plug and seating surfaces resulting in valve leakage.
The IMI CCI team, with vast experience and knowledge of these severe service applications, reviewed the new process conditions and valve sizing. The Valve Doctors® discovered that the original trim design was providing trim exit velocities of ~40 m/s, resulting in cavitation damage on trim parts and high velocity jets with sand impinging on the valve body. The upgrade solution proposed by IMI CCI included a new DRAG® design trim with up to 20 stages to reduce trim outlet velocity to less than 23 m/s, upgraded trim material to tungsten carbide and a characterised design disk stack to provide optimum controllability. The trim materials were upgraded to tungsten carbide to defend against sand and particulate erosion, and the wetted pressure boundary parts were covered with Alloy 625 cladding to protect against erosion. Further, the valve stroke was increased, and the upgraded disk stack custom characterised with 12 to 20 stages to provide optimum controllability for the new process conditions, all within the constraints of the original body. The 100D DRAG® valve, in the hands of our highly skilled Valve Doctors® and engineers, has once again proven to solve the most demanding of control valve applications.