How to Calculate Blind Flange Thickness With Opening
How to Calculate Blind Flange Thickness With Opening
(OP)
Dear All
any clause for Calculating Blind Flange Thickness with opening grater than 1/half of flange OD(flat head
this Bolting joint as per UG-34(j)
Blind flange 20" (As Per B16.5)
Nozzle OD 438
Thickness 37 Thk min
as per UG-39(C)(1) i have to go Appendix 14 but scope of Appendix-14 is
The shell-to-flat head
Joint shall be either integral, as shown in Fig. UG-34
sketches (a), (b-1), (b-2), (d), and (g), or a butt weld, or a
full penetration corner weld .
.
my joint configuration as per UG-34(J)
any clause for Calculating Blind Flange Thickness with opening grater than 1/half of flange OD(flat head
this Bolting joint as per UG-34(j)
Blind flange 20" (As Per B16.5)
Nozzle OD 438
Thickness 37 Thk min
as per UG-39(C)(1) i have to go Appendix 14 but scope of Appendix-14 is
The shell-to-flat head
Joint shall be either integral, as shown in Fig. UG-34
sketches (a), (b-1), (b-2), (d), and (g), or a butt weld, or a
full penetration corner weld .
.
my joint configuration as per UG-34(J)





RE: How to Calculate Blind Flange Thickness With Opening
Regards,
Mike
RE: How to Calculate Blind Flange Thickness With Opening
also I have to do calculation for compensation of opening as per UG-37 ?
yogesh
RE: How to Calculate Blind Flange Thickness With Opening
No, if you designed it as a flat end then you would also have to do the reinforcing checks but the reducing flange already includes the reduced area in the calculation.
RE: How to Calculate Blind Flange Thickness With Opening
Regards,
Mike
RE: How to Calculate Blind Flange Thickness With Opening
it clear to me
yogesh
RE: How to Calculate Blind Flange Thickness With Opening
It does not sound right to me. You say the flange is B16.5, now you will change the thickness, that means the bolt length will change too. Is it still qualified as B16.5 ? Many times, B16.5 flange will fail App 2, but that does not mean the flange is no good. I have seen reinforcing calc for studed nozzel on blind in the past.
RE: How to Calculate Blind Flange Thickness With Opening
No, it is custom to App2 (even if the thickness does not change).
RE: How to Calculate Blind Flange Thickness With Opening
then we have to increase thickness also stud length
Can i design it as per flat head (UG-39)?
opening will be grater then 1/half OD flange(large opening)
or it comes under U-2(g)
just for information
yogesh
RE: How to Calculate Blind Flange Thickness With Opening
To make it clear the one I have seen reinforceing calc is for small nozzles (2"-6") not greater than 1/2 of the flange size.
Flange needs additional rigidity check to prevent leak. Head or shell just needs simple reinforcement.
You nozzle OD is no greater than 20". that means you are cutting less area than a regular flange. What's missing is the hub area. If you can build a hub to simulate the standard flange, you will be fine without calc.
Other way: weld a weldolet, that will give you a big chunk of steel and the blind will be very rigid.
Or, use 20" standard flange (not blind), and weld to a reducer, then weld to nozzle, so you don't need to run any calc.
To check any B16.5 standard flange or blind by App. 2 has no meaning at all in the first place, because most of them will fail. Insisting doing that will yield you a special design flange if you are happy with that.
RE: How to Calculate Blind Flange Thickness With Opening
Calculate per Appendix 2, disregarding any contribution by the nozzle. If a standard blind is not thick enough, make one from plate. No big deal.
Regards,
Mike
RE: How to Calculate Blind Flange Thickness With Opening
Mike, why are you suggesting design it as loose?
RE: How to Calculate Blind Flange Thickness With Opening
Don't forget to take a look at "optional" type flanges in Apx 2 as well. This may permit the flange to be considered as integral with a simpler weld detail.
EngAddict, I suggested loose because a) it is simple, and b) I didn't read the OP carefully enough at first to realize it had an attached nozzle:)
Regards,
Mike
RE: How to Calculate Blind Flange Thickness With Opening
Mike
joint configuration is like this
dish to 20" std neck (B36.10) to 20" Wnrf Flange (B 16.5 #150) to 20" Blind flange to self reinforcing Nozzle neck OD 438 mm thickness 37mm( neck height more then 200mm)
blind to neck joint is like UW16.1(e)
yogesh
RE: How to Calculate Blind Flange Thickness With Opening
Regards,
Mike
RE: How to Calculate Blind Flange Thickness With Opening
its not In Apx 2 Fig 2.4 (7)
see self reinforcing neck is not welded to Vessels
vessels to 20" nozzle neck to 20" wnrf flange
20" Blind flange with self reinforcing nozzle opening is bolted to wnrf flange
so Blind flange is bolted Cover
it clear to u
regards
yogesh
RE: How to Calculate Blind Flange Thickness With Opening
Then you said "20" Blind flange with self reinforcing nozzle opening" and "so Blind flange is bolted Cover", leading me to the same conclusion.
How about a sketch?
Regards,
Mike
RE: How to Calculate Blind Flange Thickness With Opening
u r right blind to reinforcing neck joint construction was equivalent to Fig 2.4 (7).
what about bolted joint between blind flange and weld neck flange.
Regards
yogesh
RE: How to Calculate Blind Flange Thickness With Opening
Regards,
Mike
RE: How to Calculate Blind Flange Thickness With Opening
Regards
Spoonful
RE: How to Calculate Blind Flange Thickness With Opening
please find sketch of joint configuration
yogesh
RE: How to Calculate Blind Flange Thickness With Opening