Liquid filled seal

Claim 1

In a pipe system having a plurality of pipes, each pipe having a spigot end and a socket end with a circumferentially extending rectangular groove of predetermined depth and diameter formed in the spigot end, and the spigot end of one pipe fitting into the socket end of an adjacent pipe length in a spaced nested relationship thereto, the improvement of a liquid-filled radial seal disposed in said groove for effecting a seal between the spigot and socket ends of adjacent pipes, said liquid-filled radial seal comprising: a. an annular body portion having: i. inner and outer circumferentially extending walls and first and second radial displacement walls for supporting said inner and outer walls normally in a spaced relationship, said walls having a nominally uniform thickness for defining a continuous internal annular cavity therein, ii. a first sealing portion extending radially from said inner circumferentially extending wall comprising a section of material with a plurality of circumferentially extending sealing rib means formed therein for engaging the circumferentially extending surface of said groove, said first sealing portion and said inner wall having a total radial dimension that positions a portion of said radial walls and said cavity radially beyond the pipe surface at the spigot end, and iii. a second sealing portion extending radially from said outer circumferentially extending wall comprising a section of material with circumferentially extending, triangularly-shaped sealing ribs means engaging an inner surface of an overlying socket end of a pipe, the overall radial thickness of said inner and outer walls of said seal being greater than the predetermined depth of the groove, and b. a non-compressible liquid filling said internal cavity.