Top & Side Stab of New Branch Connection

[Zul78289]

Dear all,

pls help me because im new in tie-in issue. do you know any standard which rules about top or side stub in a new branch connection? we want to change the orientation of the new branch from top-stub to side-stub in order to minimize the construction work. another reason we want to change this orientation because this work will perform in 11 m elevation for the main pipe, if we choose top stub then the branch connection work will perform at 13 m elevation.

the size of pipe 20" #150 sch 40, the main pipe 20" #150 service flare.

the sketch attached.

thanks.

 

[XL83NL]

do you know any standard which rules about top or side stub

Rules in which way? From a pressure design thickness point of view, like B31.3? Or from a process point of view? Or ... ?
Regardless of any, you need to make sure youre following the rules of your design codes, which you havent specified.

 

[DGrayPPD]

From a piping design standpoint, generally all new tie-ins are made into the top of the pipe. This is to aid in constructability, as well as to allow for future expansion. Tying in from the side could potentially eliminate any chance for future expansion, as you've essentially blocked off the alleyway which could've been used for additional pipe.

If this is a flare header, then I would say the connections should be from the top, as made as 45 degree laterals, which it looks like you have. Given that this header should be sloping, making the tie-in from the top will help eliminate any potential liquid that develops from getting back into your laterals.

If you're looking for more industry standard literature, check out API 521 "Pressure Relieving and Depressuring Systems," particularly section 7.3.1.3.9.

Hope this helps.


"The only limits in life are those which we impose upon ourselves."

 

[mk3223]

You may see either type of connections existed in the existing plants, but agreed that the "Top" branch connection could be the typical piping design in the book.
OR, you may need a good justification of the side branch connection design to your Lead as well as the Client.

 

[pennpiper]

Zul78289,
Quick questions:
1, What is this system?
2, What is the size of the existing pipe?
3, What is the size of the new branch line pipe?
4, Are these pipes required to slope in the direction of flow?
5, What is the length of travel of this new pipe along side the existing pipe?
6, How is the existing header pipe supported?
7, How will the new pipe be supported?
8, Will Platform (and ladder) access be required for the valve on this new branch pipe?

If I had the answers to all of these questions, I would recommend the side entry.

Sometimes its possible to do all the right things and still get bad results