US Patent 7143788 High temperature line expansion installation with bellows

An flexible coupling is shown for an insulated piping system of the type used to convey steam and other high temperature fluids. The coupling uses a flexible bellows and additional insulating and joining components to couple conventional lengths of insulated pipe. The bellows arrangement compensates for any relative movement of the inner fluid conveying pipes with respect to the outer layers of insulating material and outer jacket in order to protect the integrity of the assembly and prevent the intrusion of water or other contaminants which could lead to corrosion or early failure of the piping system.