Reinforcement requirement for 02 offtakes at circumference (same plane) of pipe

[Muhammad Ijaz]

02 1"-3000# half couplings are required to be installed on 4"-3.05mm thk pipe made of 316L. Design Pressure = 1kg/cm2g and Design Temp = 166 deg C

02 offtakes shall be 90 degree apart on circumference (same plane) of pipe.

I understand that no additional reinforcement is required as half couplings are self reinforced pipe fittings.

However, for more clarity, is there any requirement of reinforcement pad for these 02 offtakes as per ASME B31.3?


Regards,

Ijaz

 

[LittleInch]

Drawing please.

And do you mean Oxygen O2 or number two?

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[Muhammad Ijaz]

Two (02 No.) offtakes.

 

[MJCronin]

Ijaz..

To which piping code/standard are you building this system ? ASME B31.3 ?

Your selected piping code will tell you more about the reinforcement acceptability

Have you thought this thing through ? Have you made a sketch and drawn this assembly to scale ?

I believe that you might have an overlap of the welding joint... but a sketch made to scale would help



MJCronin
Sr. Process Engineer

 

[LittleInch]

When I googled half coupling this is what I got

Now this is not an integrally reinforced branch fitting so I have no idea how you're going to weld a flat end piece to a round pipe, especially one 4" OD.

Did you actually mean a "threadolet"??

If you do do this do one at a time otherwise you won't have a lot of pipe left and it may end up rather bent...


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[Muhammad Ijaz]

Sketch for 1"-3000# offtakes (02 no.) from NPS 4" pipe is attached.

Applicable code is B31.3.

I dont mean threadolet. only 1"-3000# half coupling of A-182 F316L.

 

[LittleInch]

Well your design pressure is low but temperature is high.

I assume that you just intend to insert these stub fittings into the bigger pipe?

You need to do the calculation to b31.3 to see if you need more reinforcement.

I can't see why you can't use a proper fitting and think it will look very odd, but probably will work.

Your HAZ will overlap as it won't be possible to stick to 17mm weld difference. And only do one at a time.

Why can't you stagger these?

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Also: If you get a response it's polite to respond to it.

 

[Muhammad Ijaz]

Actually 4" line is jacketed by 6" pipe and exposed length of 4" pipe is about 200 mm approximately.

Staggering of offtakes is not possible i.e. two different planes circumferencially.

Installation of offtakes 180 degree apart is also not possible because of RCC wall on other side.