Inlet/Outlet alignment tolerances

[JoelGuelph]

Hello,
We are having some problems with the alignment of some inlet and outlet ports on a low pressure water conditioning "vessel". It is not build to vessel code, but I was wondering if there is either a standard or a "rule of thumb" tolerance for inlet/outlet port alignment. Our units with ANSI 150-2" flanges are giving the welding trouble the most trouble.

The ports are 180deg from each other on an 8" vessel. We have had customer complaints that they "are too far out". These units are generally installed by plumbers into residential and light commercial applications, and are not intended for process plants. Is there a plumbing code standard that anyone knows about?

I'd like to give our welders a tolerance, but I'm not sure what is reasonable. The sales managers says they need to be "perfect", of course he'd say that.

Any tips or suggestions will be greatly appreciated.

 

[DSB123]

JoelGuelph,
By the sizes it appears that the equipment is no more than a "pipe" fabrication/spool. If that is the case then the Pipe Fabricators Institute provides a document giving fabrication tolerances. From memory I think it is Document ES3.

 

[JoelGuelph]

Thanks DSB.

I will look into it. Is there anyone willing to paraphrase it for me, as it'll take sometime to get it ordered and into delivered?