Hello!
I have a vessel drawing. Outside diameter of a cylindrical shell 1219 mm, a thickness 10 mm (material SA-516 Gr.70). On a shell weld on a pipe, with outside diameter 60,3 mm, thickness 8,74 mm (SA-333 Gr.6).
Welded joint (category D) with a complete penetration as is shown in Fig. UW-16.1 (c).
Explain, please, than the design engineer en is guided at welded joint sampling on UW-16? It was possible to use, for example, circuit designs presented on Fig. UW-16.1 (d); (e).
Perhaps the designer has accepted UW-16.1 (c) because has had a look WELDING PROCEDURE SPECIFICATION which was developed by the welding engineer where the similar circuit design of a welded joint has been shown?
Or all on the contrary, the welding engineer does WPS on the basis of what aspect of the joint on UW-16.1, the design engineer has put in pawn in the drawing of a vessel?
In that case, why the design engineer has chosen an aspect of joint UW-16.1 (c)?

Tell the rights I or not.
Having read Section VIII Division 1, I have fathomed that circuit design sampling on Fig. UW-16.1, depends on qualification of the welder and from its position in time weldings.
If the welder, makes connecting pipe welding to a shell with a complete penetration, being outside of the vessel case, the comprehensible circuit design UW-16.1 plays the pipe (с).
If the welder, makes connecting pipe welding to a shell with a complete penetration, being in the vessel case the comprehensible circuit design UW-16.1 (d) plays the pipe.
If welding is made both outside and from within means it is possible to use circuit design UW-16.1 (e).
I am right?

Mageslay,

I do not really understand your question.
Let me try to summary the basics:

The vessel Manufacturer is the orgnaisation stamping their U.stamp on the vessel.
They are responsible for the design and the correct planning of the vessel to met the Users requirements.

The Manufacturer shall make sure that the Code requirements are met. In excess of the minimm Code requirements there may be other considerations, like metallurgy, cyclic service, ageing, thermal stresses, or experience that will dominate the design, and require very special weld configurations, surface quality or number of layers and welding procedures.

Any change to a specified design by the fabrication people, or by suppliers of welded Parts (U-part stamped of course) will require the reconsiliation by the design responsible.

The responsible for welding will make sure that the WPS is qualified and that the welders and welding operators are qualified in order to deposit the weld metal in a correct manner. Again, any request for changes to specified design details must be reconsiled by the designers. As like the fabrication people can not just deviate from the WPS without concurrence of the welding responsible.

I hope this helps you to answer your query?

DK

Hello mageslay,

I am extremely sorry for the late reply. Apologies.

You have put a very good question. Before I answer that, let me clarify the cycle followed in the fabrication of a pressure vessel.
The fabricator will receive a datasheet from the client. He will carry out the mechanical design based on the information provided on the datasheet. Many a times the designer is separate from a fabricator. For example, the client could be BASF, Germany, the designer could be UDHE GmBH and the fabricator could be CBI (Chicago Bridge and Iron Company). It is the designer who dictates what joint is to be used in the construction of the vessel and that is the way it should be. He does not know, and does not need to know whether the fabricator has a qualified WPS/PQR as per the welding code. (In our case, ASME Sec IX). Hence the answer to your question is the design has to satisfy the need and the designer is free to use any weld detail given in the Code book.

There is another situation. The client could be BASF. But the designer and fabricator, both could be CBI (Chicago Bridge and Iron Company). In this case since the designer may or may be familiar with the WPS/PQR that may be present in the workshop. He may choose to design a vessel on a already qualified WPS/PQR to save time and cost. This is also correct but it may not be the best design possible, and hence less value for the client. In such a case, the client or his Authorised Design Review agency (like Lloyds, TUV etc) has to bring up the matter to his attention.

The bottom line is the designer is free to choose the best design keeping in mind the client requirements. The design has to be in line with the philosophy of the wonderful ASME Code, which is “safety”.


Regards,
Sharjeel Aslam

Hello again.

If the welder, makes connecting pipe welding to a shell with a complete penetration, being outside of the vessel case, the comprehensible circuit design UW-16.1 plays the pipe (с).
Right

If the welder, makes connecting pipe welding to a shell with a complete penetration, being in the vessel case the comprehensible circuit design UW-16.1 (d) plays the pipe.
Right. The fillet weld will be welded from the outside.

If welding is made both outside and from within means it is possible to use circuit design UW-16.1 (e).
Right

Regards,
Sharjeel Aslam

Thanks!