there are disclosed methods of and apparatus for interconnecting lined metal pipes , applying in particular to the offshore oil and gas industry . corrosion is a common problem in the industry . lining pipes overcomes the problem , but welding sections of pipe together can be a complicated and time - consuming task , requiring dedicated and sophisticated tooling . more desirable is the ability to use conventional pipe - laying equipment with little additional tooling . as such , there are disclosed methods and apparatus compatible with known offshore connection methods , particularly where the spacing of joints on the pipe is less than 100 m . the chosen technique will not significantly impact the laying rate of the lined pipe , compared with unlined pipe . the method includes connecting lined pipes using a corrosion - resistant bridging member internally overlapping both linings , leaving a void space behind the weld region while at least the initial stages of welding are performed , and expanding the bridging member to provide a seal against the liners , in a controlled sequence . there is also disclosed a bridging member , tooling and pipelay apparatus suitable for use with this method .