CLIENT BACKGROUND

Compact flanges were used on a NPS 40 gas line on an offshore platform. The compact flange joints proved very difficult to seal during assembly and commissioning. They are also difficult to maintain, as small imperfections can cause leakage of the seal ring. A back-up plan was formulated that involved using a kamprofile gasket in place of the compact seal ring. This required very accurate joint assembly, to ensure that an adequate buffer against leakage could be established with the kamprofile gasket.

CHALLENGES

Leakage of these joints would not only shut the platform down, but – if ignited – it would have the potential to severely damage the platform infrastructure. In addition, envisaged maintenance issues with the current design would likely extend future turnarounds, potentially costing more than $5million per day in lost production and turn-around costs.

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SOLUTION

RT-Bolts were machined into a set of 3-1/4” diameter x 30” long A320-L7 bolts, to facilitate accurate assembly of the joint, should the kamprofile gasket option be employed.

CONCLUSION

The RT-Bolts passed the end-user inspection, verification and testing with flying colours and are now in storage, for use when required. The accuracy and repeatability of the bolts was confirmed by the multinational end-user client’s engineers via comprehensive site acceptance testing.