Access fittings are Branches under API 1104?

By swsweld (****)

Date 09-04-2014 15:50

To attach the Cosasco to an existing in service pipe it would be considered a Branch Weld= The completed weld joining a branch pipe or branch fitting to a run pipe.

Depending on the size of the Cosasco and the size of the carrier pipe you may be required to weld a reinforcement pad, reinforcing saddle, full encirclement sleeve, encirclement tee, encirclement tee and saddle or just a weld-o-let.

So, depending on your situation, you may only use fillet welds for the Cocasco (in service portion) but in most cases only weld-o-lets that requires full penetration butt weld (CJP) with fillet reinforcement are needed.

Also, depending on the heat loss numbers and/or carbon equivalency, temper beads may be needed.

By Octavio Date 09-04-2014 22:45

Thank you SWSWELD, there is a contractor who wants to weld them in service using a sleeve welding procedure. What would be the main reasons why NOT to do so? I would appreciate any comments.

Octavio-.

By swsweld (****)

Date 09-05-2014 11:40

A sleeve procedure (re-pad, saddle, split tee, etc) might be needed for stress purposes, to spread the stress of an attachment over a larger area.

Also, sleeve procedures might be needed because the location where the Cosasco is needed has corrosion or nearing its min. wall limitation. Upstream/downstream 1'-00" each way might be good metal so welding a sleeve at that location will resolve the corrosion issue and place the Cosasco where it was intended to be.

I think the RP is that the carrier pipe must be 2X the diameter of the Cosasco fitting or it needs a repad or split tee, etc. I might be wrong on that…Site specifications may differ.
You can put a 2" Cosasco on a 6" pipe without a repad but not on a 3" pipe.

If you have good sound metal and no sizing issues, a weld-o-let for the Cosasco is all that you need. Of course, the Engineer may need to be involved in there are other concerns.

By jarsanb (***)

Date 09-09-2014 19:06

They have a WPS qualified to appendix B API 1104 20th edition or later for sleeves (circumferential fillets) and want to apply that procedure to a branch connection welded in-service? Answer would be no. Table B-1 clearly separates the testing criteria (as clear as API gets at least). Although the type and number of tests are identical, the results of such testing can vary significantly with regards to hardness measurements. Pass sequence and root opening are important variables in an in-service application.