the pipeline through each hot tap tee inserting and securing plugging pigs into the pipeline cutting and removing the damaged section of pipeline and installing a new section of pipeline the apparatus includes a plugging pig for use during repair of a damaged pipeline comprising a body shaft a cup seal secured to the body shaft for engaging an interior wall of the pipeline a cam attached to the exterior of the body shaft a slip assembly for sliding on the cam and engaging a slip against the pipeline wall and a control mechanism for engaging and releasing the slip from the wall application_number US 26884599 A description the present invention relates to a method and apparatus for repairing a damaged section of a submerged pipeline referring to fig1 a once a damaged section d of a pipeline p is located the pipeline pressure is reduced to less than the ambient seawater pressure at the depth of the repair the flow in the pipeline p is shut off at the well head or production point not shown using conventional methods hot tap tees 10 with angled outlets are installed on either side of the damaged section d fig1 b the hot tap tees 10 are fitted with simple elastomeric seals 12 rated for the seawater depth of the repair structural capacity tees are not required because the tees will not be used at full pipeline pressure as shown in fig1 c angle cutting drilling machines 20 are installed on the tees 10 and full diameter holes are cut into the pipeline by a drill bit 22 referring.