Internal sleeve seal and method of use

An internal sleeve seal for sealing joints in a pipeline, the seal comprising,

• a tube-shaped, pliable collar member having dovetail annular locating means defined thereon at the end portions thereof, the dovetail locating means extending radially outward from the collar member and being adapted to engage the interior surface of a pipeline,
• at least two circumferentially recessed portions defined in the collar member at axially spaced locations thereon and between the locating means, the recessed portions each being defined at the adjacent collar portions thereof by axially parallel annular member surfaces of the collar member;
• a ring cushion of elastic gumlike material positioned in each recessed portion and attached thereto by vulcanized areas, and
• tension ring means positioned internally of the collar member at the recessed portions, and adapted to be expanded radially outward.

A method of internally sealing discontinuities in a pipeline, the method comprising:

• moving a tube-shaped, pliable collar member having annular locating means defined thereon at the adjacent end portions through a pipeline,
• positioning two ring cushions of elastomeric gumlike material located in recessed portions defined in the collar member at axially spaced positions on either side of the pipeline discontinuity,
• expanding tension ring means within the collar member radially outward at the recessed portions to urge the ring cushions into sealing contact with the internal surface of the pipeline to form a sealing volume adjacent the discontinuity and between the ring members and the collar member, and
• substantially containing each ring cushion within the recessed portions of the seal with the ring cushions urged against the pipe surface.