High pressure inflatable plug device

An inflatable expansible multisize plug device for sealing the interior of a high pressure pipeline section and for locking engagement therewith, comprising:

• a) a cylindrical body structure having a circular cross-section, and including a central plate member and removable inner and outer plate members attached thereto via a plurality of longitudinally extending bolts disposed a predetermined distance from the axis of said body structure, wherein said central plate section has a first predetermined diameter, and said inner and outer plate sections have a second predetermined diameter which is greater than said first predetermined diameter, whereby a circumferential recessed area is formed, and in which said sealing member is disposed, said outer plate member further having a raised screw mounting structure longitudinally formed thereon, said body structure further having spacially parallel, circumferential, T-shaped annular channel structures formed between said central member and inner and outer members, respectively, said channel structures each being formed by concentric and aligned circular channels in adjacent surfaces of said central member and said respective inner and outer members, an inner channel structure being formed between said central member and said inner member, and an outer channel structure being formed between said central member and said outer member, whereby said channel structures each have a compressive width which is provided via sequential tightening of said connection bolts;
• b) a unitary inflatable sealing member constructed of an elastomeric material with a durometer range of 50 to 85 shore A, said sealing member being disposed angularly about said body structure, and forming an inner cavity between said sealing member and said body structure, said sealing member having a generally rectangular, open bottomed cross-section having an outer contact wall of a continuous predetermined longitudinal width and a radially continuous, non-folded circumference, and a pair of depending radial walls, said outer contact wall being substantially flush with said inner and outer plate section perimeters, each said radial wall terminating in a T-shaped sealing ring, said sealing rings being sealingly disposed in said body structure channel structures, whereby said sealing rings are compressed in their operative disposition within said channel structures between 20 to 40 percent of their uncompressed cross-sectional dimensions by sequential tightening of said body structure bolts;
• c) means to permit ingress and egress of fluid into said inner cavity, whereby said sealing member outer contact wall is expansible radially outwardly a distance less than 125 percent of the length of said radial walls;
• and
• d) a plurality of radially aligned locking screws, being arranged to mechanically engage the pipeline interior wall, said locking screws being disposed in said screw mounting structure.