硫黃回收單元不銹鋼三通閥裂紋修復(fù)處理2021-03-24
A stainless steel three-way programmable switching valve in the sulfur recovery unit of a natural gas purification plant developed a leak, affecting the normal operation uptime of the facilities. In order to develop valve repair procedure, factors such as material, welding, structure, and process medium were analyzed. It is concluded that the “chromium-depleted zone” is formed in the inter-granular area during welding, resulting in inter-granular corrosion. To tackle this problem, small heat input welding and post weld solution treatment methods were developed for repair. Finally, the crack of the three way valve was successfully repaired to allow the normal operation of the device. The successful application of the repair process provides an effective method for the repair of cracks in austenitic stainless steel caused by chromium depletion.