Orbital welding S/S sch.10

Date 12-17-2008 00:15

I'm the QA/QC for this XXX CM and they are making a Biological job for XXX Biological Comp. The issue is the client ask for a specific manufacturers on the 4" sch. 10 piping and fittings. We make the fittings inspections as required but the fittings specially the 90 degree elbows have an oblicity deffects (from .06 thru .040 in several cases) we red flag this but the client have an specific suppier for this fittings. The one who is having a real bad time is the mechanical contractor because I'm rejecting most of the welds because of incomplete penetration, they have the approval to work over the fittings so they can have better welds on the OD but they stiil have problems on the inside.
What I need to know if there are 90 degree S/S sch. 10 who can match with the piping (like in the electropolished tubing for tubing)? Remember they are using orbital welding machines!

Thanks!

By spgtti

Date 12-30-2008 02:15

I haven't ever seen any pipe fittings which align like a tube fitting would. Has the contractor tried using a step program to produce a heavier root penetration? On severely out of round and high/lo fit ups we have used c-clamps with SS 1" angle iron welded to both sides of the clamp and "squeezed" the misalignment down, once you get it spread out add a few button tacks with a manual rig until you put the head on it.

By Kix

Date 01-05-2009 20:06

Have them manually weld the poor fit-up joints and the problem is solved. The orbital will be inconsistent with poor fit-up and would have the settings changed dam near every time to produce a good weld. What grade of stainless are you using? Straight fittings are out there, you just have to find a good supplier. The electropolished fittings that work are a pretty penny though.

By spgtti

Date 01-06-2009 02:58

How 'bout an update?