Design of Conical shells for internal and External pressure to ASME Sec VIII Div 1

[DK44]

1. What code rules are applicable, while designing following components to ASME Sec VIII Div 1,under internal and external pressure.
1.1 Concentric conical shells
1.2 Oblique conical shells as used for Kettle shells of a Heat Exchanger.

2. PV Elite Uses the the term SLEN(stiffened length). This is observed to be less than the conical shell course length. How it is calculated?

 

[SnTMan]

DK44, this subject is much too complicated to explain adequately on an internet forum. You are going to have to read and understand the Code..

I suggest starting with UG-27, UG-28, UG-36. I will tell you these rules are applied to oblique or eccentric cones.

As well, you will need to come to understand what the software is doing. In other words it is either assuming a stiffened length from other data, or you are supplying it directly.

Regards,

Mike


The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[DK44]

In a particular design with following conditions, PV Elite results are as indicated there on.
1. Design conditions.
Oblique cone (kettle shell)
Int Design pr and temp = 29 kg/cm^2 @ 320
Ext design pr and temp = 1.055 Kg/cm^2 @ 320 C
Cone ID at large end = 3100 mm
Cone ID at small end =2184 mm
Cone axial length = 1650 mm
Cone thickness = 76 mm
Cone half apex = 29 degrees
Cone MOC = SA 240 UNS N08904

2. PV Elite results for external pressure.
Tca = 66.454 mm
OD = 3272.83 mm
SLEN = 1417.72 mm
D/t = 49.26
L/D = 0.433
A = 0.0101313
B = 603.84.
EMAP = 16.34 Kg/cm^2

3. PV Elite method of calculation for Tca, OD, SLEN are not provided.
I understand as per code, effective length Le to be calculated as per UG 33 (g). This Le, I understand PVE calls as SLEN
(stiffened length). But I do not get the value. Tca and OD calculation is also not known.
wish to know the calculation of these values. Grateful Can anybody help me.
Thanks in advance.

 

[SnTMan]

Ah, just occurred to me. I'm not familiar with PVElite, but when running cones in CodeCalc this program did not recognize oblique cones. I could produce results consistent with Code formulae only by adjusting input data such as cone angle, length and so forth.

Note that independently calculated correct results were needed to confirm CodeCalc output. I have no idea where and how PVE gets is data, or if such "lying" to the program is possible.

Good luck.

Regards,

Mike


The problem with sloppy work is that the supply FAR EXCEEDS the demand