It is a type of product which consists of sliding flanged pipes, a flange (retainer ring), a rubber ring, studs and nuts. It is used for easy installation and un-installation of valves or similar equipments to pipe line or to each others. Face-to-face dimension of dismantling piece can be changed (±) 25 mm to perform its duty.

The space between two flanges at the pipe line, where dismantling piece to be installed, should be the same with face-to-face dimension of dismantling piece mentioned in the catalogue. The shortest face-to-face is obtained by sliding two flanged pipes of dismantling piece on each others. The dimension is 25 mm shorter than catalogue value. This feature makes possible to install or un-install a valve or any other equipment or to fix flange gaskets.
One flange of dismantling piece is connected to the flange of pipe line. Then, other  flange of dismantling piece is connected to other flange of pipe line by sliding flanged pipes on each others. Dismantling piece is fixed by tightening studs and nuts. Retainer ring in the middle, which presses on rubber ring, is also tightened till sealing  performance of rubber ring is acceptable. Installation job is completed.
For un-installation job, these steps are followed from the end.