Axial pressure bellows also commonly referred axial bellows expansion joints and axial bellows compensator, the product is made of stainless steel corrugated pipe culvert compensation components, connectors and support flange welded rod combination. Bellows culvert itself has stretching deformation characteristics, so the axial pressure bellows expansion joints using a flexible stainless steel tube deformation characteristics to absorb thermal expansion and contraction deformation of the pipe at the temperature and pressure changes generated. Axial bellows expansion joints are usually used to compensate for axial displacement of the pipe, generally do not have to compensate for lateral and angular displacement. Rod bellows axial pressure on the rigid support mainly from the pre-deformation and make adjustments to use, can not be used to withstand the pull and thrust pipes. Axial corrugated compensator compensator prohibited before installing duct work is not a good pressure test, so as not to stretch bellows compensation losses. Botou Huayu Bo Bellows Manufacturing Co. sales compensation divided into: axial, lateral and angular metal compensator three categories. Axial type can be divided into: Axial internal pressure, axial external pressure, duplex, unconstrained type, damping type, rotary, sleeve, bypass pressure, pressure balanced straight pipe, internal and external pressure Balanced, buried internal pressure, external pressure buried and square as compensation. Lateral type can be divided into: small rod horizontal compensation, large rod horizontal bellows and so on. Angular type can be divided into: one-way hinge compensator, universal hinge bellows and spherical as compensation.