Using Standard B16.9 Concentric reducer for a vertical stripper.

[Steve.sw90]

Dear all,
I am working on a produced water stripper, which has bottom shell diameter as NPS 18" with length of 1250mm and Balance stripper is NPS 12" in dia. Hence we have to use a conical transition from 18" to 12", I wanted to check with you guys if anyone have ever used standard B16.9 conical reducers as conical transition for vertical vessels with external pressure, How did you cover it in requirements of UG-32,32 and App 1-5? As in B16.9 I couldn't find detail dimensions of reducer.

Thank-you
Regards,
Stephen

 

[r6155]

See again B16.9 2018 for details dimensions.
See UG-33(g)for convex pressure (not UG-32)
See 1-8 (not 1-5)

Regards

 

[MJCronin]

Are you building your own pressure vessel ?

What codes or standards are you using ?

Is the design pressure over 15 psig, or is there any external pressure expected ?

MJCronin
Sr. Process Engineer

 

[XL83NL]

This discussion holds some similarities with this one;

https://www.eng-tips.com/viewthread.cfm?qid=379214

When you would've asked this question for a 6"x3" reducer, I think no one would've frowned their eyes. When it becomes bigger, people start to get more nervous, somehow.

How I see it is that when the reducer passes both UG-27 and UG-28 for the wall thickness, you're OK. What's the rationale of doing UG-32/-33 when you have something that's allowed by the Code under UG-44?
I could be mistaken, so Im open to any Code expert telling me otherwise (provided it's well argumentend )

Huub

 

[r6155]

@ XL83NL
1)As you can see in ASME B16.9 2018 table 6.1.11 reducers from 18 x 16 to 18 x 10 the end-to-end is the same = 15”
2)For external pressure, as (OP) mentioned, see ASME VIII Div 1 UG-33 (g) (4) and Figure UG-33.1 (e) the equivalent length “Le” is not the same for these reducers. Then UG-28 is not applied for this part of the pressure vessel.

Regards