TYPE OF SHELL - CYLINDRICAL TYPE OF DISHED END - TORISPHERICAL SIZE OF THE TANK = 1.5m dia X 1.8m height
SL.NO. 1
ITEM DESIGN INTERNAL PR.
NOTATION UNIT kg/cm2 p
FORMULA
DATA 1.02
2
DESIGN TEMP.
T
Deg.C
100.00
3
VESSEL OUTSIDE DIA.
D
mm
1512.00
4
ALLOWABLE STRESS
f
kgf/mm2
9.80
5
WELD JOINT FACTOR
J
6
ASSUMED SHELL THK
ts
7
t/D0 RATIO
8
TYPE OF DISH HEAD
9
CROWN RADIUS
Rc
10
KNUCKLE RADIUS
11
0.85 mm
REMARK
REFF . APPENDIX A IS2825 MATL IS 2002 Gr 2A IS 2825,PAGE 8 ,CLASS 2
6.00 (ts/D)
0.0040
REF.IS:2825,PAGE 20
IS-4049/TABLE 2
ELLIPSOIDAL
mm
1500.00
IS4049(PARTII),TABLE 2
rn
mm
150.00
IS4049(PARTII),TABLE 2
VESSEL INSIDE RADIUS.
R
mm
(D - 2*ts)/2
750.00
12
DEPTH OF DISHING
Dd
mm
Rc-(SQRT((Rc-R)*(Rc+R-2*r n)))
290.66
IS4049 (PARTII), PAGE 1
13
DEPTH RATIO
Dd/D
0.19
REF.IS:2825,PAGE 20
14
C FACTOR
C
1.70
REF.IS:2825 PAGE 20
15
SHELL THK (MIN)
tsmin
mm
p*D/((200*f*J)+p)
0.93
REF.IS:2825,PAGE 13,CLAUSE3.3.2.2
16
DISH THK (MIN)
tdmin
mm
p*D*C/((200*f*J)
1.57
REF.IS:2825,PAGE 21,CLAUSE3.5.3
DESIGN OF RING STIFFNERS ADJACENT TO SADDLE (REF.PRESSURE VESSEL DESIGN HAND BOOK ALONG WITH THIS CALCULATION) Diameter of the tank D 1500 mm Radius of the tank r 750 mm 2.46 Length of the tank(cylinderical part) L 1800 mm Thickness of the shell t 6 mm Design Internal pressure p 1.02 kg/cm2 14.51 Design temparature T 100 C Saddle width b 250 mm 9.84 Corrossion Allowance C 3 mm Tank weight (Empty) W1 843.53 kg Weight of Nozzles 1400.00 kg Tank weight (content) W2 4000 kg Total weight W 6243.53274 kg Yield strength of steel fy 250 N/mm2 Load per saddle support P 3121.76637 kg Saddle angle of contact q 120 deg. A 320 mm 1.05 H 831 mm 2.72 Allowable stress of bolt S 140 N/mm2 Outer radius of the tank ro 756 mm 29.76
ft
psi inch
ft ft inch
DESIGN OF SADDLE: a.Stresses in shell: 1.Maximum longitudinal stress due to bending at mid span(S1) S1 = + or - 3*K1*P*L/(p*r*r*t) where, L=Length of tank in ft. L 6.00 ft r = Radius of the tank in inch. r 29.53 inch K1 0.58 (PAGE-164 OF PRESSURE VESSEL DESIGN HAND BOOK) t=thk. Of the shell in inch t 0.236 inch 0.472441 P=Load per saddle in lbs. P 6883.494846 lbs 0.709 S1 111.12 psi Longitudinal stress due to pressure, SE = (p/2t)(r+0.6*t) SE Total combined stress = S1+SE
911.09 psi 1022.21 psi
2.Tangential shear stress in plane of saddle(S'2), A>R/2, K'2 = S'2=(K'2*P/rt)*((L-2A-H)/(L+H))
S'2
<
15000 psi
<
12000 psi
1.171 155.91 psi
3.Ring compression in shell over the saddle(S5), To reduce the stress, use 16mm thk. Wear plate. Shell thk. t Wear plate thk. t1 tT
K5 =
0.76
(PAGE-178 OF PRESSURE VESSEL DESIGN HAND BOOK)
0.236 inch 0.236 inch 0.472 inch
S5 = K5*P/tT(b+10tT)
S5
760.16 psi
Assume frictional co-efficient
fo
0.1
Shear force at the saddle base, fo*P
V
688.35 lbs
<
16000 psi
63.31
1.8 mm 0.07 inch
(m)
Xo = r*Sin60 / rad 60
Xo
25 inch
Bending moment: M = V*(63.31-Xo)
M1
26368.66 lb-inch
M = Pa*b/2
Pa
5358.11 lbs 24299.83 N
No of Anchor bolts
N
4.00 Nos.
is counteracted by the weight of the vessel.
Net area of the tension bolt
an
173.57 mm2
Assume dia. Of the bolt
q
12.00 mm
452.16 >
173.57
HENCE O.K. LENGTH OF THE ANCHOR BOLT: Max. force in Anchor bolt, F1 = Pa/N
F1
6074.96 N
Hence bond force to be developed
6074.96 N
BOND FORCE PRODUCED, p x q x Lb*tb THEREFORE, Lb =F1/(p x q x tb)
Lb
134.35 mm
Hence provide the anchor bolt length of 140.00 mm
Saddle design: a. Top flange thickness:tf: Pp =P/ro((1+cosb)/(p-(2/3)p+cosbsinb)) b = 120 degree
Pp
188.44 lb/inch
Bending moment,Mb = (Pp/b)*(b/2)*(b/4)
Mb
231.84 lb/inch
Flange thickness, tf = (6Mb/Sa)^0.5
tf
Provide Flange plate thickness of b. Web thickness. Use 12mm thk. Plate tw Calculate the max.allowable ht. "h" of a 1 in wide strip column, Area Radius of gyration , r = sqrt(I/A)
0.27 inch
6.73 mm
8.00 mm
0.31 inch
0.472 inch 12.00 mm 0.472 inch under Pp
aw I
0.472 in^2 0.039370079 mm4
r
0.288675135
P/a = 18000/(1+(1/18000)*(h/k)^2) We get, h = tw*((1500/Pp)(18000*tw-Pp))^0.5 h
121.55 inch
3087.361 >
350
c.Base plate thickness: Max.stress = S = M/Z = 0.5(Q/2*m)(b/2)/(tb^2/6) tb = (P*b/(26400*m))^0.5
tb
Provide Base plate thickness of Check for Bearing pressure: P/b*m
6.02 inch
152.85 mm
12 mm
0.48 inch
9868.79 psi
Max. Horizontal splitting force: F = K8*P F Area required at bottom cross section ar = F/(0.66*18000)
1404.23 lb
ar
0.12 inch^2
9.84
<
750 psi (allowable)
0.31 inch 0.472 inch 13.78
0.48 9.84 af aw ab
3.10 6.51 4.72 14.33 inch^2
N
3.00 nos.
Total available area
Number of stiffners: N = (m/24)+1.
N HAND BOOK)
HENCE O.K.
HENCE O.K.
SEL DESIGN HAND BOOK)
HENCE O.K.
ht of the vessel.
63.31
allowable)
