Joint of Category C for lethal-service vessel 2

[szoghbi]

When vessels are to contain lethal substances, UW-2 (1)(b) says that all joints of Categories C shall be:
Type Nº1 (Butt joints as attained by double-welding....) or
Type Nº2 (Single-welded butt joint with backing strip other than those included under 1 ) of Table UW-12.

Does this imply that I cannot weld a socket weld Flange to a 3/4"-nozzle when the vessel contains a lethal substance?

Thanks for your help.

 

[prex]

Yes, as you said, you can't.

prex

http://www.xcalcs.com

Online tools for structural design

 

[PVRV]

Its too bad Prex is right; BUT

1. Perhaps a TIG butt-joint that is 100% RT'ed.

Or,

2. Utilize a 2" nozzle with 2" flange reduced downstream
to 3/4".

Cheers

Pains of 3/4"

 

[PVRV]

Good Luck findind 2" butt welded flanges

 

[deanc]

Try a lap joint or a "VanStone" ANSI B16.9. Make sure to review UW-2 a1c. Welders will need to be qualified to small dia.