JIPMKWA
Mechanical
- May 8, 2014
- 51
We are welding new bottle headers into the second pass of the secondary superheater. I wanted to confirm alignment tolerances according to the code. But I cannot find anything that specifically references "Headers". Part PW-33 is for shells and vessels (including pipe or tube used as a shell).
The joint design is a compound bevel starting out at 37.5 degrees for 3/4 of an inch and then tapering to a 10 degree bevel the rest of the way out. The headers are 1.750" thick. If the base metal thickness at the weld is 1.750" , according to that table - you're allowed 1/8t which is .21875 ( 7/32" ). That seems excessive to me for a GTAW root & SMAW fill and cap. Am I missing something ?
Even for tube or pipe as per PW-34.1 , It says alignment shall be such as to provide complete joint penetration. To me if you have a good enough welder , as long as you burn into the bevels you can be completely misaligned.
I attached a sketch of the joint design. Thank you for your time
The joint design is a compound bevel starting out at 37.5 degrees for 3/4 of an inch and then tapering to a 10 degree bevel the rest of the way out. The headers are 1.750" thick. If the base metal thickness at the weld is 1.750" , according to that table - you're allowed 1/8t which is .21875 ( 7/32" ). That seems excessive to me for a GTAW root & SMAW fill and cap. Am I missing something ?
Even for tube or pipe as per PW-34.1 , It says alignment shall be such as to provide complete joint penetration. To me if you have a good enough welder , as long as you burn into the bevels you can be completely misaligned.
I attached a sketch of the joint design. Thank you for your time