SPLIT TEE 3

[abdolmaleki1975]

Hello dear friends and experts;
I have a few questions about Split Tee
First, if the material of the main pipe body (pipeline) is API.5L.X60, can A 516 GR.70 sheet be used to make the split tee body? (of course calculated with a higher thickness)
Second, for the split tee with the size of 40x16 inches, if the body of the split tee is made of API 5LX.65, is it possible to use a flange with ASTM A105 material instead of the ASTM A694 GR.F52 flange (for example, for a 16 inch outlet)?
Thirdly, if the answer to the second question mentioned above is positive, can E70S filler be used instead of E6010 penetrating electrode for the root pass for welding API 5LX.65 extruded body and 16 inch ASTM A105 branch flange (it should be noted that The received PQR is accepted)
Thank you for your guidance.

 

[LittleInch]

I'm not fully following you.

Split tees are mad bigger than the existing pipe so that they can be placed around the existing pipe and then welded back to form a compete tee, normally welded to the existing pipe with fillet welds at the ends.

Why would an X70 tee be thicker?

Yes you can use an A105 flange, but the 16" branch connection to the flange in X65 would need to be a lot thicker to match the thickness of the A105 flange material at the butt weld connection.

you need to provide a sketch or drawing to understand exactly what you mean and avoid misunderstanding.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[abdolmaleki1975]

Hello LittleInch
I know what Split T is and I have currently ordered two of them from a manufacturer, the first one is a Split Tee 40 to 16 inches and my order was to use f 52 flange, but the manufacturer suggested a 105 flange. In addition, the data presented in the w p s used the e 70s filler instead of the e 6010, and as mentioned, the presented p q r result has been confirmed.
The second split tee ordered is from size 30 to 10 inches, and instead of the body material x.60, the manufacturer has given sheets with a 516 gr.70 material.
Regarding the reason for the difference in thickness that you mentioned, due to the difference in the yield stress of the two materials, the a 516g r 70 sheet has a lower yield stress and as a result, a greater thickness.

 

[LittleInch]

OK, I didn't know off hand what A 516 grade 70 was, but yes, looks more like Grade B in API 5L terms. So yes you can use it so long at it is thicker than the existing X60 pipeline.

You can us an A105 flange, but need to know what thickness is being used at the weld connection with the X65 tee as this may reduce your design pressure to less than the flange rating if it's too thin. Ask for details of the tee thickness at the flange interface.

If the WPS is ok, then I can't see a reason why not.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[abdolmaleki1975]

Yes, you are right, the thickness of the flange is calculated and thicker, the only limitation is the diameter of the hot tap drill. Because the higher thickness of the flange reduces the inner diameter.
Other friends, I would be grateful if you would not spare me your valuable comments.
Thank you for your guidance.

 

[1503-44]

I would spec the Flange material with MSS-SP-44 WPHY Gr 60 or 70.
A105 is a 36,000 yield, so welding to anything above X52 may cause some difficulty. If your weld procedure works for that yield difference, it's OK.

Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[akpipelineengr]

A516 Grade 70 does not correspond to 5L X70. API grades are given in terms of SMYS, but A516 is for pressure vessel plate and gives grades in terms of UTS (because that's what governs their allowable stress in Section VIII).

A516 Grade 70 is 70 ksi UTS, but only 38 ksi SMYS, so it is as LittleInch says, roughly equivalent to 5L or A106 Grade B.

 

[1503-44]

Thanks for the correction. 70 is UTS.
I'll delete that bit above.

Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[abdolmaleki1975]

Sorry, friends, maybe I didn't express my meaning correctly, where I work, the material is not easily available, and most of the time, the manufacturers or sellers determine the conditions. so even though I know all the things related to the design , but the material should be based on the conditions of the market I have to choose.
so please help me if the suggestions are correct or not.

 

[LittleInch]

What do you think?

You need to give us thicknesses to answer Q1 and 2.

If the weld procedure has been tested and verified by a welding engineer then I can't see why the different filler can't be used.

But the decision is yours not ours.


Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[dik]

Neat discussion... I didn't know they even made these.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[SJones]

If you know about the design then you will know what the pipeline design standard will allow in terms of materials and thicknesses.

For a shop weld, with a qualified welding procedure specification, the change in welding process and filler for the root pass should be acceptable subject to satisfactory NDT. The key point is the arc mode: for a high reliability root pass, the modified short circuit mode, e.g. STT, should be used.

It would be helpful to know the defined minimum design temperature. Please do not quote -29 deg C, or -46 deg C

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[dik]

You forgot the... Why the unusual temperatures and not -30C or -45C or -50C? Is this a F conversion issue?

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[SJones]

No dik, it's a lack of understanding about the difference between minimum design temperature and threshold temperature for avoiding Charpy testing, or if Charpy tested, the Charpy test temperature

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[dik]

Thanks....

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[abdolmaleki1975]

Dear LittleInch,
The thickness of the 40 inch split T's body is and with material x 65 , is equal to 20 mm, and when the same material is extruded, the thickness of 16 inches is reduced to 15 mm on the branching side. Also, the material and thickness of the existing pipeline is 40 inches API5LX.65 and its thickness is 21 mm.
Regarding the second device, which is a split tee in size 30 x 10 inches and the body of the tee is made of A 516 GR.70 sheet, the thickness of the body of the tee is 20 mm and the thickness of the branch is 12 mm. Also, the material and thickness of the pipeline is API 5LX60 and the location class is B

Dear SJones,
The design and operating temperatures are within the regular range, that is, in the range of 18 to 60 degrees Celsius.

Thank you for your time and patience

 

[GD2]

Abdulmaleki1975,
Yes, you can always weld higher strength steel to a lower strength steel but couple of factors will kick-in, like:
1. pre-heat/PWHT based on the higher strength strength steel, if applicable.
2. Selection of the welding rod/filler wire based on the lower strength steel.
3. Weld strength property will be somewhere in between the strength of the base materials (more so towards the lower strength). You need to evaluate the weld strength to check if it meets codes/design requirement. Obviously, the pressure strength for the lower strength component will be compensated by higher wall thickness.


As my predecessors, you must qualify a WPS first.

Some standard limits the stress ratio as S[sub]1[/sub]t[sub]1[/sub]=S[sub]2[sub][/sub][/sub]t[sub]2[/sub] where S[sub]1[/sub]/S[sub]2[/sub]is limited to maximum 4.

Is the query on the branch connection for hot tap operation? If that's the case, what is the process fluid? If it's hydrocarbon, you also need to develop a 'Hot Tap' Procedure, specially so, if the WPS dictates a Preheat/PWHT.

GDD
Canada

 

[abdolmaleki1975]

Dear GD2,
The preheat temperature is 100 degrees Celsius and the inter pass temperature is 250 degrees.
The natural gas fluid is methane in the gas transmission system with a pressure of 1050 psi
Of course, I think there is no need for heat treatment due to the conditions of thickness and fluid
Thank you for your kind opinion and your comments were very valuable

 

[1503-44]

I kind of agree, "you can always weld higher strength steel to a lower strength steel", but the question to Dr Frankenstein was "what have you done". 30ksi to X60 will need a wall thickness for pressure of the 30 material twice the thickness of the X60. What does the transition look like. If it is just a weld (no transition pup) and of a strength somewhere between 30-60 ("leaning to 30), the weld cannot transition from a thickness of 0.5" to 0.25" and still withstand 1000 psi. If the weld remains a constant thickness of 0.5" then you must use a pup of X60 with 0.5" wall thickness and then you still have to weld the 0.5"thick X60 pup to the 0.25" X60 line pipe, which requires another X60 pup of 0.5" thickness, or with a long machined taper bored transition from 0.5 to 0.25" wall.
Those problems can be made easier by increasing the strength of a transition pup, say to X52 and avoiding machining taper bores altogether. In other words, by keeping the strength difference across the weld limited to more manageable values.

Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

OK,

More details always helps.

The 40" x 16" tee with the A105 flange looks at a superficial level to be good.

The reduction in wt (21 to 15) is balanced by the reduction in wall thickness due to diameter change from 40 to 16, but then increased due to the reduction in yield strength.

So this works out at about 15mm so it looks like the A105 flange is good at 15mm wt, but as you say, the ID is smaller so you need to make sure your cutter head fits.

For the second tee you don't actually say what the wall thickness of the existing X60 pipeline actually is, so we can't tell if the Grade 70 material is thick enough or not.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.