Welding to non pressure support lugs after PWHT

[txcadman]

I have a heavy lift contractor asking if he can weld a lug onto an existing support trunnion in order to install this boiler. See the attached image. This trunnion is on a boiler that is PWHT, however, can the contractor weld the trunnion without any issue with PWHT because it is a non pressure containing component? Is there reference in ASME Section I that can be referenced for this application?

 

[weldstan]

Your weld of the trunnion appears to be onto the pressure part, in which case PWHT would be required under ASME I.

 

[txcadman]

The trunnion is existing. The eye pad lug is the only thing being added.

 

[SnTMan]

Care to reveal the materials involved?

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[txcadman]

ASTM A335 P12 is the trunnion pipe material. SA 302 Gr B is the shell material.

 

[SnTMan]

Might be useful to know the LUG material also...

But a guess.... Low chrome trunnion >> PWHT

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[r6155]

For this weld I suggest a local heat stress relief. See AWS D1.1 Structural Welding Code.

Regards

 

[txcadman]

I did not get a material from our lift contractor as it is conceptual to see if they can even do it. We would be at liberty to specify the required material.

 

[Mateeng]

Eye pad Weld to trunion (non pressure part to no non pressure part) allowed without PWHT. Only approved WPS to be used. No weld without PWHT on pressure boundary is permitted.

 

[Some Curious Guy]

I am taking a very lenient view of the intent of the Code.
1) Welds joining pressure part to pressure part or non pressure part to pressure part would require PWHT as per the provisions of the code.
2) Welds joining non pressure part to non pressure part does not generally require PWHT by the code. However the intent of PWHT is to provide a safe and strong weld joint whether it be pressure part weld or non pressure part weld. Hence it is better to evaluate the material combination and the weld thickness of the non pressure part to non pressure part weld to decide if the weld requires PWHT or not.

 

[r6155]

Lifting lugs are a load bearing components, carrying the entire vessels loads. Hence any failure of the Lug welding could be a serious safety issue.

Minimum preheat and interpass welding of 110 ºC is required in AWS D1,1 –
I insist: local stress relieving is needed, by heat or ultrasonic

Also remember the need of a proof test of lifting lug,

Don’t Assume Anything!! Check, Re-Check And Check Again

Regards