Piping Failures

We have experience a piping failure in our ethylene oxide piping system. Material is 304L and piping is EWR Class 1. Failure mechanism is stress corrosion cracking (SCC). Root cause is the injection of heavy dosage EDS (e-dichloride) - over 1500 ppm based on lab analysis. All the conditopn for SCC to exist was present - temperature, material, chloirde and residual stresses.

Shot term repair is the use of bolted clamp to contain the leak. long term fix is the in-kind replacement of the complete EO piping system (close to million dollar). If youre hit with the same failure, never attempt a weld repair. it almost always never work.. Aging test indicated that duplex piping is resistant to SCC. However, the LCC that we've run indnicated that its not cost effective. The permanent fix is to ensure that chloirde is never allowed to rise above 50 ppm. Heat treatment is of little use also.

Has anybody expereinced any SCC.? Received on Tue May 29 05:56:00 2001