Cracking Causes of Flashed Vapor Pipeline on the Top of Carbon Black and Water Treatment Unit

The cracking causes of flashed vapor pipeline on the top of carbon black and water treatment unit were studied from 3 aspect: material composition, corrosion environment and stress distribution. The results show that the cracking characteristic was strain corrosion, interaction between Cl- and H2S, unsuitable pipeline manufacture, and large tensile stress caused by welding and installation consisted of the basic conditions of stress corrosion cracking.