Inflatable bags for lifting pipeline off sea-bed - where upper bag used as jack is located on lower bag forming cushion on sea-bed

摘要

In a deflated state, the bags are flat, so they can easily be drawn under a pipeline. A lower bag forms a cushion, which is divided into two compartments are joined together by transverse hinges. Above the lower bag, is an upper inflatable bag used as a jack. The upper bag is inflated via two inlet valves so it lifts a pipe resting on the middle of the upper bag. Each end of the lower bag is pref. provided with eyes in which bars can be inserted for easy manipulation of the bags. The double bag can pref. be wound round a roller when flat, for easy transport to the seabed. Used for oil or gas pipelines, to aid maintenance work; to prevent corrosion by lifting the pipeline off corrosive materials; or to lift one pipe off another.