PTFE bellows compensator, also known as expansion joint, expansion joint, is a flexible, thin-walled, transverse corrugated with expansion function of the device, it is composed of metal bellows and PTFE. The working principle of bellows compensator is mainly to use its elastic deformation function, the compensator pipeline due to thermal deformation, mechanical deformation and a variety of mechanical vibration and axial, angular, lateral and combined displacement, the compensation function has pressure resistance, seal corrosion resistance, temperature resistance, impact resistance, vibration and noise reduction function, play a role in reducing pipeline deformation and improving the service life of the pipeline.