structural welding directly on pipeline forbidden

[jfduroch]

According to the ASME it is not allowed to make longitudinal welding directly on a pipeline wall.
I have seldom seen any circonferential welding directly on the external wall of a pipeline. Standard practice I have seen were to limit to butt welds only.
I could not find any standard that would forbid me to weld directly on the external side of a pipe joint (indeed I am taking about a fully qualified and ndt-ed weld).
Could someone provide me reference of a guidance, code, norm or standard that does not allow to weld structural components (such as beam, clamp, etc...) directly on pipe (ie pressure vessel)
Thanks

 

[metengr]

Could you please describe your specific application. This will determine what ASME Power Piping Code would apply.

 

[stanweld]

ASME B31.1 Section 121.8 and ASME B31.3 Section 321.3 define requirements for structural attachments and niether preclude welding in the longitudinal direction on the external surface. Similarly, Section UG-55 and Appendix G of ASME VIII, Div.1 provide requirements and guidelines for structural attachments and does not preclude welding directly to the shell in the longitudinal direction.

 

[SJones]

ASME B31.4, 421.1, item (d), p 32.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/