Abstract: A bolt-ring pipe connector system for connecting stub end pipe particularly thermoplastic pipe is shown. The bolt-ring has an outer vertical rim portion, an inner vertical rim portion and an interconnecting web portion provided with spaced bolt holes. The top side of the bolt-ring has a beveled and angular top surface. The bottom side of the bolt-ring has a contoured recess that provides a variable cross sectional diameter. The new, deformable, variable geometry, hollowed, bolt-ring can be flexed by slight deformations under constant bolt-load. As a result, all anticipated initial and operating changes in high-density polyethylene stub-end dimensions, such as those caused by bolt-up and thermal strain, are managed by the bolt-ring.

Abstract: A pipe coupling is shown for coupling adjacent ends of a pair of pipe sections where one of the pipe sections is formed of a polyolefin and the other pipe section is formed of a different material. The coupling includes an adapter formed of a length of pipe having a polyolefin pipe wall, the adapter having a fusing end for fusing to a successive length of polyolefin pipe and a coupling end. The coupling end has an integral flange which defines a bell end opening for the adapter. The bell end opening has a first region of reduced internal diameter for receiving a sealing gasket. The bell end opening also has a second region of further reduced internal diameter which forms a circumferential shoulder region therein for receiving a male spigot end of a mating pipe which is formed of the different material.