SUVIDYA INSTITUTE OF TECHNOLOGY
Mumbai : 400055
SAMPLE DESIGN CALCULATION - SKIRT SUPPORT DESIGN OF VERTICAL COLUMN
REFERENCE
Pressure Vessel Design Manual by Dennis R. Moss
VESSEL DESIGN DATA AND WEIGHT CALCULATION
CODE
ASME SEC. VIII, DIV. 1 LATEST
P
DESIGN PRESSURE
T
DESIGN TEMPERATURE
250
E
WELD JOINT EFFCIENCY
0.85
CA
CORROSION ALLOWANCE
6.0 / F.V
Barg
Deg. C
1.5
mm
MATERIAL OF CONSTRUCTION
SHELL
SA 515 GR. 70
SKIRT
IS : 2062 GR. A
CONSTRUCTION DETAILS
D
SHELL ID
H
Overall Column Height
h
SKIRT HEIGHT
1.5
Met
30.4
Met
5
Met
OTHER INFORMATION
Liquid Hold up : 1500 mm from Bottom T.L.
Type of dished end : 2 : 1, Ellipsoidal
Insulation : Yes (HOT) 100 mm.
Internals : 30 Trays (Valve Type)
Complete column is divided into 6 section as shown in the sketch below
Sr. No
II
III
IV
V
VI
1
Mean Diameter
LEVELS
units
mm
I
1536
1512
1512
1510
1510
1508
Total
2
Height
mm
5000
5000
5000
5000
5000
5390
3
Shell/Dish
Kg
2750
2240
2240
1860
1860
1655
4
Body Flange
Kg
0
0
0
0
0
0
5
Nozzles
Kg
100
160
160
160
160
160
6
Trays /Packing
Kg
0
400
700
600
700
600
7
Liquid Hold up
Kg
0
3530
910
780
910
780
8
Water Total
Kg
0
9200
8830
8830
8830
9200
9
Insulation/Attachme Kg
500
300
300
300
300
300
10
Erection Weight
Kg
2850
2400
2400
2020
2020
1815
13505.00
11
Operating Weight
Kg
3350
6630
4310
3700
3930
3495
25415.00
12
Testing Weight
Kg
2850 12000
11930
11450
11550
11615
61395.00
13
Shut Down weight
kg
3350
3400
2920
3020
2715
18505.00
3100
Calculation is based on
a
Erection Weight : 3 + 4 +5
Kg
13505.00
b
Operating Weight : 3 + 4 +5+6+7+9
Kg
25415.00
c
Test weight : 3 + 4 + 5 +6+8
Kg
61395.00
d
Shut Down weight : 3 + 4 + 5 + 6 +9
Kg
18505.00
1 OF 8
SUVIDYA INSTITUTE OF TECHNOLOGY
Mumbai : 400055
SAMPLE DESIGN CALCULATION - SKIRT SUPPORT DESIGN OF VERTICAL COLUMN
REFERENCE
Pressure Vessel Design Manual by Dennis R. Moss
WIND MOMENT CALCULATION
CODE
IS : 875
Do
Vessel Outside Diameter
In
Insulation Thickness
1.512 Met
De
Effective Vessel diameter = ( De + 2. In)
Site
Near Mumbai
Vb
Basic Wind speed (From IS : 875 for
site near Mumbai)
K1
Risk Factor
K2
Terrain Height Factor
0.1 Met
1.712 Met
40 ,m/s
1
Level - I
1
Level - II
1
Level - III
1
Level - IV
1
Level - V
1
Level - VI
1
K3
Topography Factor
1.0
Vz
Design Wind speed ; ( Vb . K1. K2 . K3 )
m/Sec
Pz
Wind Pressure ; ( 0.6. Vz2 ) / 9.81
Kg / m2
H
Height of each section
Met
Af
Cross section area subjected to wind load
m2
Fx
Wind Load ; ( Pz . Af )
hi
Height from base to plane under consideration
hx
Height from base to C.G of respective section
V
Total Shear load
Mb
met
met
 Fx
Moment at the base  Fx . Hx
5091.39 Kg.
77363.7282 Kg.met
Mb
Mt
LEVELS
559271.675 lb.ft
Mb - hi . [ V -( 0.5. Pz. De . hi ) ]
Vz
Pz
m/sec
Kg/m2
Kg.met
De
H
Af
Fx
hi
hx
met
m2
Kg
met
met
Fx. Hx
Mt
Mt
Kg. Met
lb. Ft
VI
40.00
97.86
1.712
5.39
9.23
903.01 25.00 27.695 25008.9881 2433.6242299694
V
40.00
97.86
1.712
5.00
8.56
837.68 20.00 22.500 18847.7064 9042.8866152905
65372.11
IV
40.00
97.86
1.712
5.00
8.56
837.68 15.00 17.500 14659.3272 19840.528205505
143429.56
III
40.00
97.86
1.712
5.00
8.56
837.68 10.00 12.500
10470.948 34826.549000612
251765.30
II
40.00
97.86
1.712
5.00
8.56
837.68
5.00
7.500
6282.56881 54000.949000612
390379.34
I
40.00
97.86
1.712
5.00
8.56
837.68
0.00
2.500
2094.1896 77363.728205505
559271.67
V
5091.39
Mb
17592.96
77363.7282
2 OF 8
SUVIDYA INSTITUTE OF TECHNOLOGY
Mumbai : 400055
SAMPLE DESIGN CALCULATION - SKIRT SUPPORT DESIGN OF VERTICAL COLUMN
REFERENCE
Pressure Vessel Design Manual by Dennis R. Moss
SEISMIC MOMENT CALCULATION
FIND OUT BASE SHEAR ; ( Vh )
(As per procedure given in IS:1893-2002)
SITE
MUMBAI, INDIA
ZONE
III
Z
ZONE FACTOR
I
IMPORTANCE FACTOR (Table - 6 - IS:1893-2002)
1
R
RESPONSE REDUCTION FACTOR (Table - 7 - IS:1893-2002)
4
Sa/g
AVERAGE RESPONSE ACCELERATION CO-EFFICIENT
0.16
2.5
Cl. 6.4.5 - IS:1893 - 2002, Soil - Medium soil sites
Ah
DESIGN HORIZONTAL ACCELERATION SPECTRUM
Ah
(Z x I ) / ( R x (Sa/g))
Wo
Total Weight of vessel , Operating
0.016
25415.00 lb
56014.66 lb
Vh
Horizontal Seismic Force ; ( Ah . Wo )
H
Overall Height of vessel
D
Uniform column Diameter
t
Thickness of shell
0.2362205 in
ht
(2/3).H
597.48971 feet
T
Period of Vibration
= 0.0000265 . ( H/ D)2 . (Wo. D / ht ) 0.5
Ft
896.23 lb
99.6792 feet
5.61536 feet
0.2070943 Sec
Lesser of followings
0.07 . T. Vh
12.992353 lb
0.25*Vh
224.05864 lb
Ft
Governing
12.992353 lb
F
Lateral Force applied at C.G of vessel ; ( Vh - Ft )
883.24 lb
Mb'
Overturning Moment at base ; ( Ft . H) + 2/3 . (F. H)
59988.985 lb. Ft
Comparing Mb & Mb' -- Governing Moment is effective due to wind. Use Mb for further calculation.
3 OF 8
SUVIDYA INSTITUTE OF TECHNOLOGY
Mumbai : 400055
SAMPLE DESIGN CALCULATION - SKIRT SUPPORT DESIGN OF VERTICAL COLUMN
COMBINED STRESS ANALYSIS
COMBINED STRESS ANALYSIS TO BE CARRIED OUT FOR FOLLOWING CONDITION
A
ERECTION CONDITION
B
OPERATING CONDITION
C
TESTING CONDITON
STRESS SHALL BE CALCULATED INDUCED DUE TO
A
B
C
DEAD WEIGHT
INTERNAL PRESSURE
WIND OR SEISMIC EFFECT
 xt
 xc
Longitudinal stress, Tension
( Pi . D / 4 t ) + (48. Mt / pi . D2. t ) - ( Wh/ Pi. D. t)
Longitudinal stress, Compression
( - ) ( Pe. D / 4 t ) - (48. Mt / pi . D2. t ) - ( Wh/ Pi. D. t)
LOADING CONDTION : ERECTION
LEVELS
Weight of each
Section
VI
lb
4000.26
Shear Load
Wh
lb
4000.26
Mt
D
t (New)
 xt
Allowable Limit
S1E1
Allowable Limit
Factor B
lb.ft
17592.96
in
59.53
in
0.236
PSI
230.62
PSI
17000
PSI
-411.76
PSI
-11000.00
 xc
V
4452.08
8452.34
65372.11
59.53
0.236
1002.10
17000
-1384.84
-11000.00
IV
4452.08
12904.42
143429.56
59.53
0.236
2326.36
17000
-2910.70
-11000.00
III
5289.6
18194.02
251765.30
59.53
0.236
4184.44
17000
-5008.31
-11000.00
II
5289.6
23483.62
390379.34
59.53
0.315
4946.48
17000
-5744.02
-11000.00
I
6281.4
29765.02
559271.67
59.53
0.472
4768.24
17000
-5442.15
-11799.97
NOTE
EFFECT DUE TO INTERNAL AND EXTERNAL PRESSURE TO BE IGNORED DURING ERECTION STAGE
ALLOWABLE STRESS CALCULATED AT AMBIENT CONDITION
WELD EFFICIENTY : 0.85
LOADING CONDTION : SHUTDOWN
LEVELS
Weight of each
Section
lb
lb
lb.ft
in
in
VI
5983.86
5983.86
17592.96
59.53
0.177
V
6656.08
12639.94
65372.11
59.53
0.177
IV
6435.68
19075.62
143429.56
59.53
III
7493.60
26569.22
251765.30
II
6832.40
33401.62
I
7383.40
40785.02
NOTE
Shear Load
Wh
Allowable Limit
S1E1
 xc
Allowable Limit
Factor B
PSI
PSI
PSI
PSI
247.61
17000
-608.89
-11000.00
1209.72
17000
-1972.87
-11000.00
0.177
2915.52
17000
-4067.24
-11000.00
59.53
0.177
5326.43
17000
-6930.57
-11000.00
390379.34
59.53
0.256
5880.69
17000
-7276.84
-11000.00
559271.67
59.53
0.413
5306.84
17000
-6362.18
-11799.97
Mt
D
t (Corroded)
 xt
EFFECT DUE TO INTERNAL AND EXTERNAL PRESSURE TO BE IGNORED DURING ERECTION STAGE
ALLOWABLE STRESS CALCULATED AT AMBIENT CONDITION
WELD EFFICIENTY : 0.85
LOADING CONDTION : OPERATING
LEVELS
Weight of each
Section
lb
lb
lb.ft
in
in
VI
7702.98
7702.98
17592.96
59.53
0.177
V
8661.72
16364.70
65372.11
59.53
0.177
IV
8154.80
24519.50
143429.56
59.53
III
9499.24
34018.74
251765.30
II
14612.52
48631.26
I
7383.40
56014.66
NOTE
Shear Load
Wh
Allowable Limit
S1E1
 xc
Allowable Limit
Factor B
PSI
PSI
PSI
PSI
699.71
14875
-744.79
-11000.00
1601.28
14875
-2169.31
-11000.00
0.177
3255.18
14875
-4315.58
-11000.00
59.53
0.177
5605.54
14875
-7239.46
-11000.00
390379.34
59.53
0.256
5911.32
14875
-7653.28
-11000.00
559271.67
59.53
0.413
5325.81
14875
-6595.21
-11799.97
D
t (New)
 xt
Allowable Limit
S1E1
 xc
Allowable Limit
Factor B
PSI
PSI
Mt
D
t (Corroded)
 xt
ALLOWABLE STRESS CALCULATED AT DESIGN TEMPERATURE.
WELD EFFICIENTY : 0.85
LOADING CONDTION : TEST
LEVELS
Weight of each
Section
lb
lb
lb.ft
in
in
PSI
PSI
VI
25599.46
25599.46
17592.96
59.53
0.236
342.55
14875
-258.41
-11000.00
V
25456.20
51055.66
65372.11
59.53
0.236
669.98
14875
37.52
-11000.00
IV
25235.80
76291.46
143429.56
59.53
0.236
1555.17
14875
891.22
-11000.00
III
26293.72
102585.18
251765.30
59.53
0.236
2969.20
14875
2273.74
-11000.00
II
26448.00
129033.18
390379.34
59.53
0.315
3699.38
14875
3154.16
-11000.00
I
6281.40
135314.58
559271.67
59.53
0.472
3952.59
14875
3573.36
-11799.97
NOTE
Shear Load
Wh
Mt
ALLOWABLE STRESS CALCULATED AT DESIGN TEMPERATURE.
WELD EFFICIENTY : 0.85
HYDROSTATIC TEST PRESSURE IS 1.5 TIMES DESIGN PRESSURE + EFFECT DUE TO STATIC HEAD
SUCH BIG COLUMN HYDROTESTD IN HORIZONTAL CONDITION IN WORKSHOP
EXTERNAL PRESSURE WILL BE ZERO IN ABOVE CALCULATION
CONCLUSION
STRESSES INDUCED DURING DIFFERENT CONDITIONS ARE WELL WITHIN IN ALLOWABLE LIMITED AND HENCE PROVIDE THICKNESS ARE ADEQUATE
4 OF 8
SUVIDYA INSTITUTE OF TECHNOLOGY
Mumbai : 400055
SAMPLE DESIGN CALCULATION - SKIRT SUPPORT DESIGN OF VERTICAL COLUMN
REFERENCE Pressure Vessel Design Manual by Dennis R. Moss
ANCHOR BOLT CALCULATION - EQUIVALENT AREA METHOD
REFER TABLE 3.33 FOR NO. OF BOLTS
SHELL O/D
N
8 Nos
RECOMMENDED MAXIMUM NO.OF ANCHOR BOLTS
12 Nos.
NO. OF BOLTS ASSUMED
MATERIAL OF CONSTRUCITON FOR ANCHOR BOLTS
Fs
Fc
n
Mb
Wb
d
r
w
59.45 in
RECOMMENDED MINIMUM NO.OF ANCHOR BOLTS
ALLOWABLE TENSILE STRESS FOR ANCHOR BOTLS,
(REFER TABLE 3.34)
ALLOWABLE COMPRESSIVE STRESS FOR CONCRETE,
(REFER TABLE 3.35)
RATIO OF MODULUS OF ELASTICITY OF STEEL TO
CONCRETE (REFER TABLE 3.35)
OVERTURNING MOMENT DUE TO WIND
WEIGHT OF VESSEL AT BASE - TEST WEIGHT
OUTSIDE DIAMETER OF SKIRT
OUTSIDE RADIUS OF SKIRT
WIDTH OF BASE PLATE
12 Nos.
SA36
19000 PSI
1000 PSI
12
559271.67
135314.58
64.00
32.00
5.00
lb.ft
lb
in
in
in
APPROXIMATE VALUE OF ' K '
K
[ 1 / ( 1 + (Fs / n.Fc))]
0.387
CO-EFFICIENT FROM CHART
Cc
1.64
Ct
2.33
J
0.783
Z
0.427
TENSILE LOAD IN STEEL ; ( T )
T
(Mb - Wb - Z.d )/ J.d
8459.65 lb
REQUIRED ROOT AREA ; (Ab)
Ab
( T. pi . d / Fs . r . Ct )
ROOT AREA OF ONE BOLT : Ab / N
Ra
PROVIDED ROOT AREA
1.200 in2
0.1000 in2
0.302 in2
SELECTED BOLT DIAMETER : 0.75" HENCE OK
STRESS IN EQUIVALENT STEEL BAND ; ( ts )
ts
( N. Ra ) / ( pi. d )
0.0180 in
EQUIVALENT TENSILE STRESS IN ANCHOR BOLT ; ( fs )
fs
T / (ts . r . Ct )
6293.7 PSI
COMPRESSIVE LOAD IN CONCRETE ; ( C )
C
T + Wb
143774.23 lb
EQUIVALENT COMPRESSIVE STRESS IN CONCRETE ; ( fc )
fc
C / ([ (w - ts )+n. ts].r.Cc )
527.02 lb
RECHECKING ' K ' USING ACTUAL' fs' and ' fc'
K
[ 1 / ( 1 + (fs / n.fc))]
0.501 lb
SINCE THIS VALUE OF ' K ' IS DIFFERENT THAN THAT WAS ASSUMED. HENCE RECALCULATE
5 OF 8
SUVIDYA INSTITUTE OF TECHNOLOGY
Mumbai : 400055
SAMPLE DESIGN CALCULATION - SKIRT SUPPORT DESIGN OF VERTICAL COLUMN
REFERENCE Pressure Vessel Design Manual by Dennis R. Moss
ANCHOR BOLT CALCULATION - EQUIVALENT AREA METHOD
TRIAL - 2
APPROXIMATE VALUE OF ' K '
w
WIDTH OF BASE PLATE
K
RATIO OF MODULUS OF ELASTICITY OF STEEL TO
CONCRETE (REFER TABLE 3.35)
CO-EFFICIENT FROM CHART
n
5.50 in
0.300
12
Cc
1.51
Ct
2.442
J
0.781
Z
0.438
TENSILE LOAD IN STEEL ; ( T )
T
(Mb - Wb - Z.d )/ J.d
8481.3 lb
REQUIRED ROOT AREA ; (Ab)
Ab
( T. pi . d / Fs . r . Ct )
ROOT AREA OF ONE BOLT : Ab / N
Ra
PROVIDED ROOT AREA
1.148 in2
0.0957 in2
0.302 in2
SELECTED BOLT DIAMETER : 0.75" HENCE OK
STRESS IN EQUIVALENT STEEL BAND ; ( ts )
ts
( N. Ra ) / ( pi. d )
0.0180 in
EQUIVALENT TENSILE STRESS IN ANCHOR BOLT ; ( fs )
fs
T / (ts . r . Ct )
6020.4 PSI
COMPRESSIVE LOAD IN CONCRETE ; ( C )
C
T + Wb
143795.88 lb
EQUIVALENT COMPRESSIVE STRESS IN CONCRETE ; ( fc )
fc
C / ([ (w - ts )+n. ts].r.Cc )
522.24 lb
RECHECKING ' K ' USING ACTUAL' fs' and ' fc'
K
[ 1 / ( 1 + (fs / n.fc))]
0.510 lb
NOW CALCULATED VALUE OF 'K' IS VERY CLOSE TO ASSUMED VALUE
AND SIZING IS ADEQUATE
SUMMARY
db
SIZE OF BOLT DIAMTER
N
NO. OF BOLTS
w
WIDTH OF BASE PLATE
MOC OF SELECTED BOLTS
0.75 in
8 Nos.
5.50 in
SA36
6 OF 8
SUVIDYA INSTITUTE OF TECHNOLOGY
Mumbai : 400055
SAMPLE DESIGN CALCULATION - SKIRT SUPPORT DESIGN OF VERTICAL COLUMN
REFERENCE Pressure Vessel Design Manual by Dennis R. Moss
DESIGN OF ANCHOR CHAIR
SELECTED TYPE OF ANCHOR CHAIR - TYPE -3
R
tsk
OUTSIDE RADIUS OF SKIRT SHELL
SKIRT SHELL THICKNESS
30.000 in
0.472 in
a
2 in
c
1.5 in
e
c - (db/2)
h
1.125 in
12 in
l
a+c
tc
COMPRESSION PLATE THICKNESS
1.00 in
tb
BASE RING THICKNESS
1.00 in
w
Width of Base Ring
b
SPACING BETWEEN TWO GUSSETS
3.5 in
5.5 in
2.500 in
A
COMPRESSION PLATE WIDTH
tg
GUSSETS THICKNESS
4.5000 in
0.5 in
64 in
d
BOLT CIRCLE DIAMETER
N
NO.OF ANCHOR BOLTS
db
DIAMTER OF BOLT HOLE IN BASE PLATE
bs
SPACING BETWEEN ANCHOR CHAIR
21.63 in
Fs
ALLOWABLE TENSILE STRESS FOR ANCHOR BOTLS,
(REFER TABLE 3.34)
19000 PSI
Ra
PROVIDED ROOT AREA
0.302 in2
8 Nos.
1.75 in
7 OF 8
SUVIDYA INSTITUTE OF TECHNOLOGY
Mumbai : 400055
SAMPLE DESIGN CALCULATION - SKIRT SUPPORT DESIGN OF VERTICAL COLUMN
REFERENCE Pressure Vessel Design Manual by Dennis R. Moss
DESIGN OF ANCHOR CHAIR
BASE PLATE DESIGN - TYPE 3
CHECKING THICKNESS BETWEEN TWO GUSSETS
MAXIMUM ANCHOR BOLT FORCE ; (P)
P
Fs . Ra
5738 lb
BENDING MOMENT ; (Mo)
Mo
P. b / 8
1793.125 lb. in
REQUIRED THICKNESS ; ( tb)
tb
[ ( 6 . Mo) / ( (w-db).Fs) ]0.5
0.389 in
CHECKING THICKNESS BETWEEN TWO ANCHOR CHAIR
RATIO
l / bs
0.162
BENDING MOMENT PER UNIT LENGTH - REFER TABLE 3.36
Mx
0.00379. fc. b2
My
-0.465. fc. l
Mo
GREATER OF Mx or My
12.37 lb. in
-2974.83 lb.in
2
-2974.835 lb.in
REQUIRED THICKNESS ; ( tb)
tb
[ ( 6 . Mo) / Fs ]0.5
0.969 in
tb
GREATER OF ABOVE
0.969 in
PROVIDED BASE PLATE THICKNESS ; ( tb )
1.00 in
COMPRESSION PLATE THICKNESS CHECK - TYPE 3
MINIMUM THICKNESS OF TOP PLATE ; tc
tc
[ ( P / Fs. e )(0.375.b - 0.22 db) ]0.5
0.385 in
PROVIDED TOP COMPRESSION PLATE THICKNESS ; (tc)
1.00 in
GUSSET PLATE THICKNESS CHECK - TYPE -3
REQUIRED GUSSET THICKNESS ; ( tg )
tg
P / ( 18000. l) > 3/8 "
0.0911 in
PROVIDED GUSSET PLATE THICKNESS ; (tg)
0.50 in
SKIRT SHELL THICKNESS CHECK - TYPE 3
Z
1
0.000732
[(1.77 . A. h2)/ (R. tsk)0.5] [(tb / tsk)2] + 1
424.00 PSI
S
SINCE S < 25000 PSI, HENCE PROVIDED SHELL THICKNESS IS ADEQUATE
8 OF 8