This is a restrained joint system which is normally used for joining fiber glass pipes with existing steel pipes and accessories like valves, pumps etc. It is also used where the installation has to be disassembled at a later stage. The fixed flanges are connected together as in fig-7 and two stub ends with steel slip on flange are connected as shown in fig-8. The hydraulic sealing between the flanges is accomplished with an elastomeric gasket, which may be flat type or O-ring type depending on the specifications. The torque value depends on pipe size, pressure and application.