Re: CHEMICAL CLEANING FOR NEW PIPLEINES

Let us say that the following has been performed. Hydrostatic Testing to B31 code requirement. NDE. No rejection noted/defect found
Qualified welding
Stress and flexibility analysis OK
Material is compatible with the service and traceable. Walkthrough/punchlist during cold functional test with emphasis at support location. OK
As-built confirm design layout.

What more is left. If its SS material, then one other possibility is buildup of biomounds resulting in UDC initiating MIC leading to failure of weld joints (and only weld joints – good weld joints). Possible Root cause – improper layup procedure. Such failure has been fairly documented by NIDI and NACE. What is interesting is that most reported failure happen during the commissioning and only weld joints has been attacked – one smart bug. The failure mode however is leak before break, which is not consistent with what has been posted – sudden bursting. Received on Sat Aug 02 07:30:00 2003