Sure. Lots of 'em. I remember a large bore piping system in our ethylene oxide system that we inspected due to leaks (cause is SCC). The line is between the reactor and compressor. At the end of the day, its almost covered with dye. Under good lighting condition, the cracks are visible. The photo shown in AWS is almost a perfect matched of what ive come across as far as SCC is concern. When you start cutting a section here and there, follwed by grinding to prep, then DP is one quick way of checking before applying the root pass But I'll be very hesitant to perform a PWHT (note that the pipe is no longer new, the wall thickness is 10S, its large bore and its SS) after the hot work. And will not hydro the repaired piping system to 1.5X.
Some say replace it with duplex. But after ive gone over the cost, availability of material, work duration and that we're sure of whats causing the problem - then Ive recommended that no upgrade is necessary. Save us a bundle of money and shorter work period. Still no PWHT. Im not sure if everyone is aware of the resources and time period involve in PWHT - a lot. .
[Non-text portions of this message have been removed] Received on Wed Sep 07 04:33:00 2005
This archive was generated by hypermail 2.1.8 : Mon Oct 27 2008 - 20:24:09 EDT