CUSTOMER:  BP Coryton

PROBLEM: The butterfly valve used to isolate the second flare system was not functioning correctly and was passing refinery gas, and to overcome this a spade had been fitted between the downstream flange of the valve and the line flange.  In order to carry out the required maintenance work to the down stream pipe work however, this joint had to be broken – and it was this that caused the problem, as it meant the spade would need to be removed.  Knowing that the valve was not sealing properly, the risk of a release during the pipe work replacement was unacceptable.

The situation arose when modification work was required to the pipework on the refinery’s large diameter dual flare system.  The line is active at all times to protect the refinery production plants, so complete isolation would mean a refinery shutdown.

SOLUTION: Furmanite, the specialty services company, was called in to help with the problem, and proposed an innovative solution that would allow the spade to be secured in place and retain live-side joint integrity, while at the same time achieving the goal of enabling the flange bolts to be released and removed in safety, so that the required maintenance work could take place.   A detailed feasibility study of the concept was undertaken to ensure it was sound and, once accepted by BP, then manufactured the hardware and installed the securing clamps.  Once the necessary work had been completed, the pipework was then reinstalled and recommissioned safely, with no disruption to production.

The solution comprised specially-designed securing clamps which were fitted between each flange bolt.  These were secured to the outside of the spade, and clamped behind the valve flange to hold the spade against the valve joint.  Once they were in place, the flange bolts could be removed so that the modification work BP needed to do could be carried out.

OUTCOME:  The  bespoke clamp design overcame the problem created by a malfunctioning valve enabling necessary modification work to be undertaken to pipe work safely and, critically, without releasing refinery gas.