Situation

Heavy leakage of a large bore Single Isolation Valve.

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Gascade is a JV between Gazprom and Wintershall. Gascade operates several gas transport pipelines. One of them is the OPAL, or Baltic Pipeline. The OPAL connects the North Stream pipeline landing point in North Eastern Germany with the Czech Republic.

 

The pipeline has a diameter of 56″ (or 1,400 mm) and a max operating pressure of 100 bar. One of the valve stations was suffering from a severe passing single full-bore ball valve. Greasing has been tried multiple times but did not provide the desired effect, and the severe leakage persisted.

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Gascade requested Valvetight if the vacuum technology would work on such a very heavily passing single valve. Valvetight developed a high capacity model of the DBB-SAVER specifically for this case, to be sure the leak rate could be handled. This DBB-SAVER was connected to the body cavity vent and successfully achieved to create a vacuum-lock between both seats, granting a safe work area downstream of this valve.

 

The DBB-SAVER technology was since then approved for future use also within Gascade.

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Result

Providing a safe work area downstream of the valve.