ASME B31.3 pipe system connection with ASME B31.4 pipeline system

[Headache2013]

Dear Specialist;

We designed a piping system under ASME B31.3 code (Cl 150) which we want to tie in to Pipeline System designed under ASME B31.4 code.
The tie will be by welding a tee which materila ASTM A234 Gr WPB to Pipeline pipe which material is API 5L X60.

a) Is this connection acceptable or not from all point of views (code acceptability, weldability, stress...etc).?
b) if it is not possible, is possible to connect the same tee to API 5L Gr B pipeline pipe.

Thank you

 

[Headache2013]

TEST ANSWER

 

[shanib154]

hi

There is no problem having a code break in a pipeline system provided that every segment in the system have MAOP(Maximum Allowable Operating Pressure) more than the required system MAOP.

and why would you want to install a WPB grade TEE on and X60 grade pipleine?. If TEE run is part of the pipeline ,use WPHY 60 grade TEE with same wall thickness of the pipeline and specify the code break point at tee branch weld connection.

 

[Headache2013]

Thank Shanib;

1) is MAOP concept equivalent to design pressure concept?
2)API 5L X60 is the existing pipeline pipe. We want to connect a B31.3 piping system using a WPB tee because this is what is available in our material shop. Is it possible (technically) to do this or not? Is there any concern related to welding, stress, code endorsment...etc?

Regards

 

[shanib154]

hi,

The concept of system MAOP is same as the design pressure.

It is techically possible two dissimilar materials.In that case ,the welding and PWHT procedures shall follow special requirements mentioned in ASME 31.4 .Some of them are:
434.8.8 Preheating and Interpass Temperature : When welding dissimilar materials having different
preheating requirements, the material requiring the
higher preheat shall govern.
434.8.9 Stress Relieving:In welds between dissimilar materials, if either
material requires stress relieving, the joint shall require
stress relieving.
The illustrations in Fig. 434.8.6-2 (ASME B31.4)illustrate acceptable preparations for joining pipe ends having unequal wall thicknesses and/or
materials of unequal specified minimum yield strength by butt welding.

hope this might help...

 

[shanib154]

hi,

The concept of system MAOP is same as the design pressure.

It is techically possible to weld two dissimilar materials.In that case ,the welding and PWHT procedures shall follow special requirements mentioned in ASME 31.4 .
Some of them are:
434.8.8 Preheating and Interpass Temperature : When welding dissimilar materials having different preheating requirements, the material requiring the higher preheat shall govern.
434.8.9 Stress Relieving:In welds between dissimilar materials, if either material requires stress relieving, the joint shall require stress relieving.

The illustrations in Fig. 434.8.6-2 (ASME B31.4)illustrate acceptable preparations for joining pipe ends having unequal wall thicknesses and/or materials of unequal specified minimum yield strength by butt welding.
434.8.2 Welding Processes and Filler Metal : If base metals of different tensile strengths are
to be joined, the nominal tensile strength of the weld metal shall equal or exceed the tensile strength of the weaker of the two.

hope this will help...

Regards
Shanib

 

[Headache2013]

Thnak you Shanib