Nominal Wall Thickness for Olets (B31.1) Weld Size PWHT?

[JAYDEE23]

When determining PWHT requirments for an olet branch connection on a pipe how is one to know what the olet nominal thickness is? Seems these dimensions are not published but are an essential piece of the puzzle when dealing with PWHT requirments (determinig nom thickness of the weld). Any guidance/experience is much appreciated.

 

[metengr]

I presume your question is around use of forged weldolets on pipe, and sizing of the attachment weld?

 

[JAYDEE23]

Yes. I know what weld size to use (for say the re-enforcing fillet). What i don't know is how to determine weld size as it pertains to PWHT per B31.1 132.4.2 Fig A. (Nom branch wall thickness + fillet throat)

 

[JAYDEE23]

Ive searched high and low, including this forum, and find it intriguing this question never seems to get answered. What am i missing? how is one to deduce weld thickness (or nom wall) of an olet?

 

[metengr]

The nominal thickness for PWHT is well defined in the 2010 edition of ASME B31.1;

see section 132.4.2.E

If you are using an older edition of ASME B31.1, what is the edition? Also, the 2010 Edition of ASME B31.1 was an excellent improvement in defining nominal thickness with Figure 127.4.8. D and E.

 

[JAYDEE23]

I use both...I see it is more thoroughly explained but still the same. In short how is one to determine Tbn of an olet (this differs depending on Olet MFG). I am waiting on a response from Bonney Forge. These figures are not published. Are they?

 

[JAYDEE23]

Sorry, I use 07 09a and 2010

 

[metengr]

Ok, now I fully understand your question regarding the forged weld-o-let. I actually found a Bonney Forge catalog on-line that explained how to attach their weld-o-let on a branch pipe connection. The weld thickness is full penetration and is well described.

 

[XL83NL]

I have a copy of a Bonney Forge weldprofile.pdf which outlines the weldthickness requirements per type and size of olet fitting.
It may help you determining what the weld thickness is. See attach.

Also, PFI ES-49 also contains an excellent help/guide.

 

[JAYDEE23]

Full penetration does not tell me thickness. I am familiar with the Olet MFG recommended welding.

XL83NL,
That is exactly what i need! Just missing the 2 items i use most threaded and socket. Where did you get this??? Its excellent!

 

[XL83NL]

Dont really remember, to be honest.
Guess that all those hours of searching the webs for useful stuff every now n then pays off.

Now, the pdf I attached is only bonney forge/WFi I believe. 9/10 weldolets I see are from zjianhg jianhg, suanchan ghianh, etc.
Could there be much difference between different MFR's designs and weldmetalthickness?

 

[JAYDEE23]

There can be a considerable diiference in weld size. Bonney Forge vs WOI for instance. Thanks again for the resource.

 

[DSB123]

Weldolets should always be welded up to the "Weld Line" of the fitting. I know there are thousands of weldolets out there that are not welded to the weld line(i.e. fully welded out). If the weldolets are not fully welded out then the question for the Pipe Stress Engineer is "what SIF do I apply?" The Code SIF's for weldolets assume that the weldolet is fully welded out anything less and the Code/Manufacturer's SIF is not correct and in fact the weldolet could be introducint a crack initiation point dependant upon the weld profile.

 

[JAYDEE23]

Like this?

Yes its quite common unfortunately.

 

[XL83NL]

Seems a hard job getting the MFR convinced he's been always doing it not exactly right, even though he claims even the major companies/inspectors never denied such a weld in his 45 yr career in the weld shop.
Yeah, right.

 

[JAYDEE23]

XL, This is the second time i inspected this unit. I left the MFG with exact directions in addition to the cut sheet from the actual olet mfg with diagrams...still welded wrong..we will see what they come up with for the 3rd visit.