weldability of API 5L X70 to A106 Gr B
weldability of API 5L X70 to A106 Gr B
(OP)
i was wondering what are the weldability constraints or limitations or if it's even acceptable to weld two pipes with large mismatch in SMYS, will that be a cause or induce any issues? i appreciate all the answers in advance





RE: weldability of API 5L X70 to A106 Gr B
RE: weldability of API 5L X70 to A106 Gr B
for example i know that B31.8 I-1.1(c) states to match the material with higher SMYS, and B31.4 as well.
i searched BPVC IX and API 1104 but didn't find anything
we normally match the material with higher SMYS until i recently heard about 1:1.5 limits on SMYS inequality to eliminate stress riser. i am not sure where that came from but i strongly doubt the validity of it.
RE: weldability of API 5L X70 to A106 Gr B
RE: weldability of API 5L X70 to A106 Gr B
RE: weldability of API 5L X70 to A106 Gr B
the customer pipeline is API 5L X70 , and the sleeve is A106 Gr B, the customer is asking me whether this large SMYS mismatch will induce any stress riser, the problem he is asking me for proof whether from code or design?
RE: weldability of API 5L X70 to A106 Gr B
The could be a design issue if the designer doesn't consider all the issues related to design such as fatigue if there is thermal cycling, bending, the effects of stress risers, proper reinforcement, etc.
API basically addresses how the WPS and welder qualified and testing and acceptance criteria for the welding. It is not a design standard, that's where B31.8 comes into play.
Best regards - Al
RE: weldability of API 5L X70 to A106 Gr B
RE: weldability of API 5L X70 to A106 Gr B
RE: weldability of API 5L X70 to A106 Gr B
procedure for the higher strength group shall be used".. Same for the repair WPS if you qualify them separately.
If you do this routinely, you may want to develop an API 5L-X70 to API 5L Grade B WPS qualified with additional testing (impact [at the design temperature] and hardness) not required by the 49CFR Part 192.7 referenced edition of API 1104 (20th). This due diligence will demonstrate the ability to make sound welds to both yourself and the regulator. Be aware, however, this specific combination (API 5L-X70 to API 5L Grade B ) will only apply to the combination API 5L-X70 to API 5L Grade B materials.