Patent ID: 8047219

Claim:
A method of plugging a pipeline employing external elastomeric seals comprising the steps of: (a) affixing to the exterior of a pipeline first and second spaced apart collars, each collar having a forward sealing end and a rearward end, each forward receiving end having a circumferential recess therein; (b) welding said rearward end of each collar to the pipeline so that an operating space is provided between said forward sealing ends of said collars; (c) positioning opposed elastomeric seal in said circumferential recesses of said collars; (d) affixing a containment housing to said opposed collars providing a confined space around the pipeline and surrounding said operating space between said collars, said confined space being accessed by a passageway; (e) inserting a cutting tool through said passageway and cutting and removing a length of pipeline between said collars providing opposed pipeline end surfaces; (f) positioning first and second seal cups between said collars, each seal cup having a forwardly extending circumferential lip of internal diameter greater than the external diameter of the pipeline and of external diameter less than said circumferential recess at each of said collars; and (g) applying force to move said first and second seal cups away from each other and said circumferential lips of said seal cups into engagement with said opposed elastomeric seals secured by said collars to compress said elastomeric seals into sealing engagement with said pipeline exterior surface adjacent each said pipeline end surfaces.