RE: Re: Cryogenic pipework standards

>This
>means that the fabrication has to be corrected by removing the weld plus 6
>mm of base metal on each side before welding (using WPS that is impact test
>qualified). This also means a new fitting (in most cases)
This particular fabrication corrected itself, as crappy welding often does, and the vessel was scrapped. Of course the idiots who let it happen are still at large. I doubt there was a weld procedure. The thank was apparently bought second hand, and some bozo with just enough sense to be dangerous decided to have a look inside. He got a hole burned in one of the heads, went in and welded (as if!) the drop back in place when he came out. It didn't look like he'd cleaned up the kerf where the opening had been burned, so he had to bridge the gap and leave a wretchedly made root pass in place. The weld was highly restrained, the heat affected zone was very brittle, slag was everywhere and on top of it all the opening was burned in an area where the plate was laminated. This is the sort of thing covered by common sense before you get so far as a WPS.

Christopher Wright P.E.    |"They couldn't hit an elephant from
chrisw@skypoint.com        | this distance"   (last words of Gen.
___________________________| John Sedgwick, Spotsylvania 1864)