Piping weldolet Branch connection 3

[subrata169]

Dear Friends,

We are facing one problem regarding 2" dia Piping weldolet Branch connection.

The main header line was 8" dia. which has already Hydrotested.
Now, there are some modification came and needs to be installed 2" dia weldolet on 8" dia header line.

My question,is as per ASME B 31.3, Is it required re-Hydro again in entire 8" dia loop?

Comments please.............

 

[XL83NL]

Is it new construction, has the spool not been taken into use yet?
If so, then retest by applying B31.3.
Otherwise, use an inspection code like API 570 to determine the appropriate steps forward.

 

[subrata169]

Yes, it is new construction. But as per our standard says that joint shall be considered as a golden joints and go for RT and MT or PT.
RT is not feasible for that joints. Then what is your suggession.

 

[racookpe1978]

A 2 inch weldolet fillet geometry onto an 8 inch pipe should be a straightforward RT (xray) shot from two sides - actually, from all four quadrants. Why is your RT group saying they cannot get a decent, readable shot?

 

[XL83NL]

To answer the OP's original question, it then need to be rehydroed.

 

[gtaw]

What is the fluid service category?

Best regards - Al

 

[DekDee]

racookpe,
Having been a radiographer for 4 years I can assure you it is definitely not a "straight forward" shot.
Getting two shots transverse to the run pipe is easy enough, however the weld is very distorted and nigh on impossible to interpret.
How do you get shots of the quadrants that are longitudinal to the run pipe - positioning the film so it is in contact with the weld and actually capturing the weld on the film ?
Regards,
DD

 

[RoboCop16]

Subrata169,

So you missed out a 2" connection and you now wish to add it to the already hydro tested header - but you don't want to repeat the hydro test because it is just too much work?

I don't think it is good practice to skip the hydro test for no better reason than that. But you may get away with, by quoting ASME B31.3 345.2.6, which states that "If ... additions are made following the leak test, the affected piping shall be retested, except that for minor repairs or additions the owner may waive retest requirements when precautionary measures are taken to assure sound construction".

I.e. you need the plant owner to issue a waiver to you for skipping the hydro test and also take precautionary measures, e.g. additional NDE as per paragraph 345.9. If I was the owner - and unless you have better justification than you have given here - I would refuse the waiver.

I suggest that the best way forward is that you bite the bullet and repeat the hydro test .

 

[sk10009]

It's better to do hydro-test for main and branch pipes .

 

[pdprao]

Radiography on 2" weldolet will not give any meaningful results and it is not a code accepted practice.

If possible, you can carryout the re-hydro-test on the the new line. (which may not be feasible too)

You can follow the following steps as additional examination and request for waiver of hydrotest.
1) Carry out DPT on each pass of nozzle weld and butt-weld.
2) If it is Carbon steel ,carryout MPT on finished weld.
3) As radiography is not meaningful , perform UT examination.

With additional examinations one can accept the welds as a special case.

 

[subrata169]

Dear Friends,
Pl. find attached figure which needs to be radiography testing as per client specification and this joint considered as a GOLDEN joints. If it is in simple butt weld(pipe to pipe/elbow) then no issue. we can can take RT and simple skip Re-hydro.
But the joint configuration is (Stub-on) 2" weldolet to 8" dia header pipe.

Is it possible to get:
1. proper sensitivity of RT
2. We can take maximum 2 exposures in 180 deg.Then what about longitudinal area in run pipe(8").

 

[RoboCop16]

subrata169,

An ASME B31.3 golden weld is a non-hydrotested weld , which instead is examined per 345.9.1. That section specifies RT or UT, not necessarily RT.

If your client insists on RT, then you should tell him that RT is not adequate for this geometry, as pdprau and others have pointed out.

Or just do the d... hydrotest!

 

[XL83NL]

Whats with all the bullocks on RT and UT (which both seem to be impossible on this geometry), while the OP is asking if a hydrotest needs to be redone?
RoboCop16 has given the right answer already in his 1st post. PS: a golden weld ist nicht im Frage.

 

[racookpe1978]

"Golden weld" ?????

That photo shows a huge gap on one side; an off-center weldolet position; an off-90 degree joint to the 2 inch pipe; no weld-prep grinding to clean metal on EITHER piece of steel for the tacks; no curved prep on the weldolet; and two very, very ugly "tack-welds-from-hell" to try to glue together a 3/4 inch (20 mm) opening!


And you want to skip the hydrotest?

 

[gtaw]

The piping codes include requirements for such branch fittings, but not under the heading of "weld-o-let or thread-o-let" or other trade names. One would have to look under the heading of integrally reinforced branch fittings.

Best regards - Al

 

[XL83NL]

Yeah, but what do those requirements have to do with hydrotesting or NDE of integrale reinfor de fittings?

 

[Duwe6]

For a 'Golden Weld' on an integrally reinforced welded branch connection fitting [sure is easier to write O'Let], the 'gold standard' is to have the welding inspector there to witness the welding of the root. And with the ugly, bridged tacks in your photo I would be using a hand-picked welder and watch the root myself. Root is then dye-penetrant tested - PT, DPT. Not only assures surface fusion but assures a leakfree weld. After completing the weld, dye-penn the final.

None of this is in B31.3, but is is industry standard in power plants and petrochem. It works. Attemping to RT or UT an O'let weld most assuradely does not.

 

[XL83NL]

That photo shows a really messy fitup. Do as duwe said. And take racookpe's 'advice'.