External pressure axial compensator insulation material of steam buried pipeline uses high Cl-containing material. During construction and after use, the outer protective pipe is destroyed and Cl-rich solution accumulates and concentrates on the surface of corrugated pipe, which constitutes the medium environment for stress corrosion of austenitic stainless steel. Compensator manufacturer

When the bellows are pressed, stainless steel is subjected to residual deformation stress in the large bending deformed component. The stress level is increased and the stress corrosion probability and rate are accelerated when the residual stress is superimposed on the stress caused by the axial displacement of the bellows under working load.

By using SA240-316L with strong resistance to intergranular corrosion and stress corrosion, solid solution heat treatment was carried out after the compensator was manufactured, and the material with low Cl-content was used as insulation material. Good results were achieved.