Design Calculation for T-109 tank
TOTAL MIDDLE EAST
NEW BITUMEN TERMINAL IN TLBU
MECHANICAL DESIGN CALCULATION FOR SOFT STOCK STORAGE
TANK
(T-109)
Client
: Total Middle East
Contractor : Western Tanks & Pipes Company Ltd.
0
Rev. No.
Issued for Comments
Description
30/04/09
Date
Page 1 of 25
RS
Prepared
SVR
Checked
PS
Appoved
Design Calculation for T-109 tank
INDEX
S.NO.
DESCRIPTION
PAGE NO.
1
COVER
1 OF 25
2
INDEX
2 OF 25
3
DESIGN DATA
3 OF 25
4
YIELD & TENSILE STRENGTH OF MATERIAL
4 OF 25
5
SHELL THICKNESS
4 OF 25
6
BOTTOM PLATE THICKNESS
5 OF 25
7
ROOF PLATE
5 OF 25
8
ANNULAR BOTTOM PLATE -MINIMUM RADIAL WIDTH
6 OF 25
9
STABILITY CHECK AGAINST WIND VELOCITY
7 OF 25
10
CHECH OVERTURNING AGAINST WIDN LOAD
10 OF 25
11
SEISMIC ANALYSIS
12 OF 25
12
OVERTURNING MOMENT
14 OF 25
13
SHELL COMPRESSION
15 OF 25
14
TOTAL BASE SHEAR CALCULATION
15 OF 25
15
DYNAMIC HOOP STRESS DESIGN
16 OF 25
16
CHECK FOR FRANGIBLE JOINT
17 OF 25
17
COMPRESSION AREA CHECK FOR INTERNAL PRESSURE
18 OF 25
18
DESIGN OF ANCHOR BOLTS & ANCHOR CHAIRS
20 OF 25
19
VENT SIZE CALCULATION
23 OF 25
20
LOADING DATA
25 OF 25
Page 2 of 25
Design Calculation for T-109 tank
DESIGN DATA :
Inside Diameter of tank
=
18
m
Height of tank
=
18.8
m
Number of tanks
=
One
Product
=
Soft Stock Tank
Design code
=
API 650, 11th Edition + Add. 1, 2008 & API 2000
Appendices
=
E,M,P & V
Shell design
=
One Foot Method
Type of tank
=
Rafter Supported Cone Roof Tank
Maximum Liquid Level
=
18.3
m
Design liquid height
=
18.8
m
Specific Gravity
=
1.1
(1.1 to 0.9)
Design Specific Gravity
=
1.1
CA - Shell
=
0
mm
CA - Bottom
=
0
mm
CA - Roof
=
0
mm
Design Pressure (Positive)
=
2.45
KPa
2
( 25 G/cm )
Design Pressure (Vacuum)
=
0.5
KPa
( 5 G/cm 2)
Storage Pressure (Positive)
=
Atm.
KPa
Storage Pressure (Vacuum)
=
Nil
KPa
Live load on roof
=
1
KPa
Operating temperature (Max.)
=
140
°C
Operating temperature (Min.)
=
100
°C
Design Metal Temp. (Max.)
=
140
°C
Design Metal Temp. (Min.)
=
0
°C
Max. Filling Rate
=
500
m 3/hr
Max. Empting Rate
=
120
m 3/hr
Seismic design code
=
Appendix-E, API 650
=
0.075
=
Zone 1 (UBC)
=
1
Basic wind velocity
=
45
m/sec
Flash Point
=
> 200
oC
Seismic Zone Factor
Z
Seismic Zone
Importance factor
I
Page 3 of 25
Design Calculation for T-109 tank
YIELD & TENSILE STRENGTH OF MATERIAL
Material
Shell -1 SA 36
Yield (MPa) Tensile (MPa) Sd (MPa) St (MPa)
250
400
147.5
171
Shell -2 SA 36
Shell -3 SA 36
250
250
400
400
147.5
147.5
171
171
Shell -4 SA 36
Shell -5 SA 36
250
250
400
400
147.5
147.5
171
171
Shell -6 SA 36
Shell -7 SA 36
250
250
400
400
147.5
147.5
171
171
Shell -8 SA 36
Shell -9 SA 36
Bottom SA 36
250
250
250
400
400
400
147.5
147.5
147.5
171
171
171
Roof
250
400
147.5
171
SA 36
Temperature factor at max. design temperature as per Table M-1
=
0.885
SHELL DESIGN :
As per clause 5.6.3.2,
The minimum thickness of shell plates shall be
td
=
[(4.9 * D * (H-0.3) * G)/ Sd ] + C.A.
tt
=
(4.9 * D * (H-0.3) )/ St
Where,
td
=
design shell thickness, in mm
tt
=
hydrostatic test shell thickness, in mm
D = Nominal tank diameter, in m =
m
(Inside Tank Dia. + First Shell Course Thk.)
18.014
H
=
design liquid level, in m
=
height from the bottom of course under consideration to the top of the shell including the top angle.
G
=
Design specific gravity of the liquid to be stored, as specified by the purchaser
C.A.
Sd
St
=
=
=
Corrosion Allowance, in mm
Allowable stress for the design condition, in MPa
Allowable stress for the hydrostatic test condition, in MPa
Course
Material
H (mm)
W (m)
td (mm)
tt (mm)
t reqd.
(mm)
t prov.
(mm)
Shell -1
SA 36
18.80
2.50
12.18
10.50
12.18
14.00
Shell -2
SA 36
16.30
2.50
10.53
9.08
Shell -3
Shell -4
Shell -5
SA 36
SA 36
SA 36
13.80
11.80
9.80
2.00
2.00
2.00
8.89
7.57
6.25
7.67
6.53
5.39
10.53
8.89
12.00
10.00
Shell -6
Shell -7
Shell -8
SA 36
SA 36
SA 36
7.80
5.80
3.80
2.00
2.00
2.00
4.94
3.62
2.30
4.26
3.12
1.99
7.57
6.25
4.94
10.00
8.00
6.00
Shell -9
SA 36
3.80
1.80
2.30
1.99
Total
3.62
6.00
2.30
2.30
6.00
6.00
18.80
Wt.Wt.New Cor.
(MT) (MT)
15.55 15.55
13.33 13.33
8.88
8.88
7.11
8.88
8.88
7.11
5.33
5.33
5.33
5.33
5.33
5.33
4.80
4.80
74.53 74.53
Top shell course thickness
=
Page 4 of 25
6.00
mm
Design Calculation for T-109 tank
BOTTOM PLATE THICKNESS :
Bottom Sketch Plate Thickness :
As per Clause 5.4.1,
Minimum thickness required excluding C.A.
=
6 mm
Corrosion allowance (C.A.)
Minimum thickness required including C.A.
=
=
0 mm
6 mm
Thickness provided
=
10 mm
Annular plate thickness :
As per API 650 Cl.5.5.3 & Table 5-1
Effictive Product height of
=
HxG
≤ 23
=
20.68
≤ 23
Hence Table 5-1 is applicable
Maximum Stress in the 1st shell course (Product)
td = required thickness of first shell course
t = Provided thickness less corrosion allowance
Sd = Allowable stress
Product Stress
Hydrostatic Test Stress
tt = required thickness of first shell course
=
=
=
=
=
=
=
(td/t) * Sd
12.18
14.00
147.5
128.30
(tt/t) * St
10.50
t = Provided thickness ( constructed)
St = Allowable stress
Hydrostatic Test Stress
Maximum Stress in the first shell course
( Max. Product / Hydrostatic stress)
Thickness for Product Design
Plate thickness of first shell course to use Table 5-1
=
=
=
=
14.00
171.00
128.30
128.30
=
=
Add Corrosion allowance
Thickness for Product Design
Thickness for Hydrostatic Design
Plate thickness of first shell course to use Table 5-1
Thickness for Hydrostatic Design
=
=
=
=
=
mm
mm
Mpa
Mpa
mm
mm
Mpa
Mpa
Mpa
14
6 mm
0.00
6
14
6
6
mm
mm
Vs 128.30
mm
mm
Thickness of Annular Plate
=
6 mm
Provided Annular Plate thickness
=
12 mm
ROOF DESIGN :
As per clause 5.10.2.2,
Minimum nominal thickness required excluding C.A.
Corrosion Allowance (C.A.)
Minimum thickness including C.A.
=
=
=
5.00 mm
0.00 mm
5.00 mm
Thickness provided
=
6.00 mm
Page 5 of 25
Vs 128.30
Design Calculation for T-109 tank
ANNULAR BOTTOM PLATE -MINIMUM RADIAL WIDTH :
As per Cl.5.5.2, the minimum radial width of the annular plate at any point around the circumference
of the 'tank shall be either Aw1 or Aw2, whichever is greater.
Aw1 =Wr + t bot +
Where,
=
739 mm
t bot =Thickness of the bottom shell course
A proj =Projection of annular plate outside the shell
=
=
14 mm
60 mm
A lap =Annular-sketch lap
Wr =Minimum radial width between the inside of the shell
=
=
65 mm
600 mm
and any lap welded joint in the remainder of the bottom
Aw2
=
215 tb
=
567 mm
(HG)^0.5
Where,
tb
H
G
=
=
=
Thickness of the annular plate
Design Liquid level
Design specific gravity of product
=
=
=
12 mm
19 m
1.1
As per clause E.6.2.1.1.2, the annular plate under the shell is thicker than remainder bottom plate ,
the width of the annular plate(L) , in m, measured radially inward from the shell shall be greater than or
equal to 0.01723 ta x sqrt ( Fy/HGe):
L
=
0.01723 ta x sqrt ( Fy/HGe)
Min. radial width at any point around the circumference
Thicknness of annular is
less than or equal to
remainder of the bottom, Hence
ta = Thickness of tank bottom under the shell extending at the
distance, L from the inside of the shell( less corrosion allowance)
Fy = Minimum specified yield strength of bottom annulas
Min. radial width of Annular Plate at any point around the circum.
Provided radial width of Annular Plate at any point around the circum.
Page 6 of 25
=
=
=
676
815.29
Not Applicable
=
12.00 mm
=
=
=
221.25 Mpa
739 mm
800 mm
Design Calculation for T-109 tank
SHELL STABILITY CHECK AGAINST DESIGN WIND VELOCITY :
Design wind velocity
V
=
45.00 m/s
=
162.00 Km/hr.
Calculate as per Appendix -V
Design External Pressure( Vacuum)
Pe
=
Total Design External Pressure for design of shell
Ps
0.500 Kpa
= Greater of Pe or W+0.4Pe
=
1.26 Kpa
Where
W = Maximum wind pressure consistent with the specified design wind velocity
W=
0.0000333 ( V)² (Kg) (Kh)
V = Design Wind Velocity
Kg = Wind Gust factor
Kh = Wind Height factor
W
=
162.00 Km/Hr.
=
=
=
1.1
1.1
1.06 Kpa
The transformed height of the shell
Wtr = W x sqrt(t uniform/ t actual)^5
Where,
Wtr = transposed width of each shell course, in mm
W =actual width of each shell course, in mm
t uniform = ordered thickness of the top shell course
t actual = ordered thickness of the shell course for which the transposed width is being calculated
Course
Wtr (mm)
Wactual(mm)
t(Corroded mm)
9
8
876.85
974.28
1800
2000
6.00
6.00
7
6
5
974.28
974.28
474.61
2000
2000
2000
6.00
6.00
8.00
4
271.68
2000
10.00
3
2
1
271.68
215.29
146.44
2000
2500
2500
10.00
12.00
14.00
Total
Height of transposed shell =
18800 Minimum
5.18 M
=
Check that buckling will occur elastically in the unstiffened cylindrical shell:
( D/ts min) 0.75 [(HTS/D)(Fy/E)0.5 ] > 0.00675
=
Page 7 of 25
6.00
HTS
Design Calculation for T-109 tank
Where
D = Nominal tank Diameter
=
ts min = Minimum thickness of thinnest shell course, mm(cord.)
HTS - Height of the tranposed Shell
=
=
6.00 mm
5.179 m
H - Height of the tranposed Shell
=
18.80 m
Fy - Yield strength of components
18.014 m
=
E-Modulus of elasticity of roof plate material
0.018190 >
Hence Buckling will be elastic
147.5 Mpa
=
0.000675
191714 Mpa
Design External Pressure for an unstiffened tank shell shall not exceed the following
2.5
Ps < E / 45609(HTS/D)(D/tsmin)
Ps <
0.9360 >
1.25745
Hence Ok, shell will be stiffened
Calculate the number of buckling waves :
N²
=
SQRT ( 445 D³ /ts min x HTS²)
N²
=
127.128
N
=
11.2751 Say
<
<
10 (Max)
End Stiffners
Calculate the required properties of the top stiffner
Radial Load imposed to the shell
Vi
=
250Ps H
Vi
=
5910.0 N/m
Required Moment inertia of the top stiffner to be calculated as follows :
Ireqd
=
37.5 x Vi*D³/E(N²-1)
4
Ireqd
=
53.58 cm
Required area of the top stiffner region
Areqd
=
ViD/2f
Areqd
=
109.76 mm²
f - Allowable tensile stress
485 Mpa
t cone
=
6.00 mm
X shell
=
Length of shell with in tension/compression region
X roof
sin¢
=
=
=
13.4 * sqrt (D*ts1)
139.31 mm
Length of cone roof with in tension/compression region
=
=
13.4 x sqrt ( D* tcone/sin¢)
344
mm
=
Provided Section
X shell
X roof
0.1644
=
=
835.866 mm²
2061.52 mm²
Area Avilable
=
2897.38 mm²
Hence additional stiffener is not required
>
Page 8 of 25
109.76 mm²
100
100
Design Calculation for T-109 tank
Calculate the required properties of the bottom stiffner
Wshell
=
=
13.4 * SQRT( D x tsn)
212.80 mm
Radial Load imposed to the shell
Vi
=
250Ps H
Vi
=
5910.0 N/m
Required Moment inertia of the top stiffner to be calculated as follows :
Ireqd
=
37.5 x Vi*D³/E(N²-1)
4
Ireqd
=
53.578 cm
Required area of the bottom stiffner region
Areqd
=
ViD/2f
Areqd
X shell
=
=
=
=
=
X bottom =
=
tb
109.76 mm²
14.7 * sqrt (D*tsn)
233.45 mm
Thickness of bottom plate under the shell
12 mm
Length of bottom with in tension/compression region
384 mm
233.45
60
384
Section Length (bWidth W Area (A) Distance (D) M=AD
cm.
cm.
sq.cm. cm.
cu.cm.
1
1.20
6
7.20
3.00
21.60
2
24.54
1.4
34.36
6.70
230.23
3
1.2
38.4
46.08
26.60
1225.73
SUM ( 1+2+3 )
45.80
Dx = sum(M) / sum(A)
87.64
1477.56
=
Iyy
Ig
cm.^4
cm.^4
64.80
21.60
1542.5
5.61
32604 5662.31
34212
5689.52
16.86 cm.
D1 = sum(W) - Dx
=
28.94 cm.
I = Iyy + Ig - (sum(M)^2)/A
=
14991.2 cu.cm
The corner joint comprised of a portion of the shell and the bottom plate has a calculated moment
of inertia of
is not required
14991.2 cu.cm and will satisfy the inertia requirement. Hence additional stiffner
Page 9 of 25
Design Calculation for T-109 tank
CHECK FOR OVERTURNING AGAINST WIND LOAD :
As per clause 5.11.2
The wind load or pr. acting on projected areas of cylindrical surface
The wind load or pr. acting on projected area of conical curved surface
for a wind velocity of 190 Km/hr
=
0.86 Kpa
=
1.44 Kpa
The modified wind pressure can be calculated by multiplying (V/190) ^2 to the wind pressure
Wind pressure on the projected area of the cylindrical surface
=
P1
Wind pressure on projected area of the conical curved surface
Wind force on the cylindrical surface
Wind force on the conical surface
Where,
D = tank diameter, in m
R = tank radius, in m
H = tank height, in m
h = perpendicular height of roof, in m
Roof Slope
=
F1
F1
=
=
=
P2
=
D * H * P1 * 1000
211733.4 N
F2
F2
=
=
π * R * P2 * 1000
266806.0 N
=
18.014 m
=
=
=
9.007 m
18.80 m
1.50 m
=
1.00 :
0.625 kPa
1.047 kPa
N
2
N
6.00
Unanchored tanks shall satisfy both of the following uplift criteria:
1. 0.6Mw + MPi < MDL /1.5
8260192
>
5508765
2. Mw + 0.4MPi < (MDL + MF)/2
6643072
where,
MPi
where,
Mw
<
10206742
=
moment about the shell-to-bottom joint from design internal pressure,
Design Pressure
Pi
=
2.45
Kpa
2
Uplift force due to internal pressure
=
5624143 N-m
Pi*π*D /4*R =
=
overturning moment about the shell-to-bottom joint from horizontal plus vertical wind pressure,
=
F1 * (H/2) + F2 * (D/2)
=
4393415 N-m
MDL
=
=
Where, W =
MF
=
moment about the shell-to-bottom joint from the weight of the shell and roof supported by the shell,
W*D/2
=
8,263,147 N-m
917414 N
moment about the shell-to-bottom joint from liquid weight. The liquid weight (wL) is the weight
of a band of liquid at the shell using a specific gravity of 0.7 and a height of one-half the design
liquid height H. wL shall be the lesser of 1.4HD or the following:
=
Wa*D/2
=
=
WL x π* D
1348988.209
WL
=
=
59tb sqrt (Fby x H)
38052 N/m
WL
=
140.77*H/2*D
where,
Wa
=
12150337 N-m
N
N
where,
=
23836.81 N/m
Page 10 of 25
Design Calculation for T-109 tank
where,
Fby
=
minimum specified yield stress of the bottom plate under the shell Mpa
H
D
=
=
design liquid height, m
tank diameter, m
tb
=
required thickness (not including corrosion allowance) of the bottom plate under the shell in mm
that is used to resist wind overturning
Weight Details
UN CORRODED
MT
CORRODED
Shell -1
N
MT
15.55 152481.94
N
15.55 152482
Shell -2
Shell -3
13.33 130684.29
8.88 87113.19
13.33 130684
8.88 87113.2
Shell -4
Shell -5
Shell -6
Shell -7
Shell -8
Shell -9
Total Shell Weight
Roof weight
Roof Roof Structure
Top Curb Angle =
Ladders & Handrails
Shell Nozzle Weight
Roof Nozzle Weight
Shell Insulation Weight
Roof Insulation Weight
Total Weight
8.88
7.11
5.33
5.33
5.33
4.80
87113.19
69682.81
52256.30
52256.30
52256.30
47030.67
8.88
7.11
5.33
5.33
5.33
4.80
74.5
12.60
6.00
0.42
1.50
1.00
0.60
10.00
730875.01
123606.43
58839.90
4092.60
14709.98
9806.65
5883.99
98066.50
74.5
12.60
6.00
0.42
1.50
1.00
0.60
10.00
2.50
24516.63
109.15 1070397.69
87113.2
69682.8
52256.3
52256.3
52256.3
47030.7
730875
123606
58840
4092.60
14710.0
9806.7
5884.0
98066.5 (Considered Rock Wool insulation for
2.50 24516.6 shell & roof @ 180 mm thk. of 50 kg/sq.m
109.15 1070398 density)
TANK IS UNSTABLE FOR WIND AND HENCE TANKS ARE REQUIRED TO BE ANCHORED
Page 11 of 25
Design Calculation for T-109 tank
SEISMIC ANALYSIS
As per API 650, Appendix E
D
=
Site Classification
II
Z
=
=
Seismic Use Group (SUG)
Seismic Zone Factor
H
Zone I
=
=
Maximum Liquid Level
Seismic Zone
I
=
=
Importance Factor
1
SDS
=
The design, 5% damped, spectral response acceleration parameter at short periods
(T = 0.2 secs.), %g
(E.4.6.1-1)
Ss
=
=
2.5 Q Fa So
=
0.30
Mapped, maximum considered earthquake, 5% damped, spectral response acceleration
=
parameter at short periods (0.2 sec), %g
2.5 Sp
=
0.1875
Sp
So
=
=
=
S1
=
=
(Table E-5)
=
=
0.075
18.300
m
(E.4.3-1)
Design level peak ground acceleration parameter
0.075 (Seismic Zone 1)
Mapped, maximum considered earthquake, 5% damped, spectral response acceleration parameter
TL
=
=
=
=
=
=
=
=
=
=
=
=
at a period of zero seconds (peak ground acceleration for a rigid structure), %g
(E.4.6.1)
0.4Ss
=
0.075
Mapped, maximum considered earthquake, 5% damped, spectral response acceleration
parameter at a period of one second, %g
(E.4.3-2)
1.25 Sp =
0.094
Scaling factor from the MCE to the design level spectral accelerations.
(E.4.6.1)
1
Acceleration-based site coefficient (at 0.2 sec period)
(Table E-1)
1.6
Velocity-based site coefficient (at 1.0 sec period)
(Table E-2)
2.4
Force reduction coefficient for the convective mode using allowable stress design methods
4 (Table E-4)
(Mechanically Anchored)
Force reduction factor for the impulsive mode using allowable stress design methods
2 (Table E-4)
(Mechanically Anchored)
Regional-dependent transition period for longer period ground motion, seconds (E.4.6.1)
Tc
=
=
4 secs.
Natural period of the convective (sloshing) mode of behavior of the liquid, seconds
=
=
=
1.8 Ks * sqrt (D)
=
4.42
Coefficient to adjust the spectral acceleration from 5% – 0.5% damping
1.5
Ks
=
=
Sloshing period co-efficient
(E.4.5.2-c)
0.578 / sqrt [tanh*(3.68 H / D)]
=
Av
=
=
The maximum vertical seismic acceleration parameter
0.14 SDS
=
0.042
Ts
=
Fv S1 / Fa Ss
Ai
=
=
=
Impulsive design response spectrum acceleration coefficient, %g
SDS (I/Rwi)
0.007
≥
2.5 Q Fa So (I/Rwi)
Q
Fa
Fv
Rwc
Rwi
K
=
0.150
=
>
0.578
(E.6.1.3)
0.750
0.007
Page 12 of 25
(E.4.6.1-1)
(E.4.5.2-a)
Design Calculation for T-109 tank
When
Tc
Ac
>
TL
=
=
Convective design response spectrum acceleration coefficient, %g (E.4.6.1-5)
K SD1 (TL/Tc) (I/Rwc)
=
2.5 K Q Fa So (TsTL/Tc²) (I/Rw ≤
=
0.076
<
Ai
0.150
Effective Weight of Product & Center of action
D/H Ratio
Wi
=
Wp
=
=
Wc
=
=
Xi
=
=
0.230 (D/H) tanh (3.67 H/D) Wp
=
11377840 N
Height from the bottom of shell to the center of action of lateral seismic force related to the
=
=
impulsive liquid force for ring wall moment,m
[0.5-0.094(D/H)] H
7.457
m
Xc
=
Ws
=
=
=
=
=
Wr
=
=
0.984
<
1.333
Effective impulsive weight of the liquid, in N
(E.6.1.1-2)
39,515,676 N
Wi = [1 - 0.218 D/H] Wp
=
Total weight of tank contents based on the Design Specific gravity, in N
50,312,355 N
Effective convective (sloshing) portion of the liquid weight,N
(E.6.1.2.1-2)
Height from the bottom of shell to the center of action of lateral seismic force related to the
convective liquid force for ring wall moment,m (E.6.1.2.1-3)
{1.0-[cosh(3.67H/D)-1]/[(3.67H/D)sinh(3.67H/D)]} H
13.62 m
Total Weight of tank shell and appurtenances, N
759484 N
Total Weight of fixed tank roof including framing and any permanemt attachment, N
188330 N
Center of Gravity of Shell
Part
Width
(m)
(E.6.1.1-3)
Thk.
(mm)
Wt.
(MT.)
EY
EXY
Shell -1
Shell -2
Shell -3
Shell -4
2.500
2.500
2.000
2.000
14
12
10
10
15.549
13.326
8.8831
8.8831
1.25
3.75
6.00
8.00
Shell -5
Shell -6
Shell -7
2.000
2.000
2.000
8
6
6
7.1057
5.3287
5.3287
10.00
12.00
14.00
Shell -8
2.000
6
5.3287
16.00
Shell -9
Roof
1.800
1.5012
6
6
4.7958
18.604
95.15
17.90
19.30
Sum
C.G.
497.94
6.5565
953.85
10.025
Approx. Misc. Weight
Shell Appurtenances (1st Course)
Curb Angle (Top Course)
=
=
1.00 MT
0.42 MT
Roof Appurtenances
=
0.60 MT
Page 13 of 25
Design Calculation for T-109 tank
Xs
=
=
Height from the bottom of the tank shell to the shell's center of gravity
6.556
m
Xr
=
=
Height from the bottom of tank shell to the roof and roof appurtenances center of gravity
10.025 m
OVERTURNING MOMENT
As per clause E.6.1.5
The overturning moment due to seismic forces applied to the bottom of the shell shall be determined as :
Mrw
Mrw
=
=
SQRT {[ Ai (WiXi + WsXs + WrXr)]² + [Ac(WcXc)]²}
46,752,376 N-m
Anchorage requirement based on seismic load
J
=
Anchorage Ratio
=
Mrw
=
Where,
Wint
Wt
Wrs
Ge
Wa
(E.6.1.5-1)
(E.6.2.1.1.1 - 1)
D² [ Wt ( 1-0.4Av) + Wa - 0.4 Wint]
1.86
>
1.54
=
=
=
=
=
=
Calculated design uplift load due to product pressure per unit circumferential length, N/m
11034 N/m
Tank and roof weight acting at base of shell, N/m
(E.6.2.1.1.1-2)
=
=
=
=
3328 N/m
Effective specific gravity including vertical seismic effects
G(1-0.4Av)
=
1.082
Resisting force of tank contents per unit length of shell circumference that may be used to resist
the shell overturning moment, N/m
(E.6.2.1.1)
99 ta x sqrt ( Fy H Ge)
<
201.1 H D Ge
(E.6.2.1.1 - 1a)
65,512 N/m
<
71,698
=
=
=
[(Ws/πd) + Wrs]
16748 N/m
Roof load acting on the shell, N/m
65,512 N/m
Anchorge is not required if the below conditions are met
S.No.
Description
1)
Resisting force is adequate for tank stability
2)
Maximum width of annulus for determining the
resisting force is 3.5% of tank diameter Ls = Required
maximum width of Annular plate
3)
Shell compression satisfies the Clause E.6.2.2
4)
The required annulus plate thickness does not exceed
the thickness of bottom shell course
5)
Piping flexibility requirements are satisfied
FALSE
Requirement
J
<
1.86
>
Ls
<
N/A
Fc
59.45
ta
10
1.54
1.54
0.035 D
N/A
N/A
>
>
<
<
σc
14.32
ts
14.00
Piping system shall be designed for
the min. displacement in Table E-8
Hence, Anchor is required , tank is Mechanically Anchored
Page 14 of 25
Remarks
Not OK
OK
OK
OK
Design Calculation for T-109 tank
SHELL COMPRESSION
As per clause E.6.2.2
The maximum longitudinal shell compression stress at the bottom of the shell
J
=
1.857
>
1.54
Mechanically Anchored tanks
σc
=
(wt (1+0.4Av)+ (1.273 Mrw/D²)) x (1/1000ts)
σc
=
14.32 N/m
(E.6.2.2.2 - 1a)
As per clause E.6.2.2.3
Allowable longitudinal membrane compression stress in tank shell
GHD²/t²
<
44
33.33
<
44
Fc
Fc
=
=
( Where t = 10 mm)
83 ts /(2.5*D) + 7.5 SQRT(G*H)
<
59.45
MPa
<
Fc
>
σc
0.5Fty
110.625
Hence Safe
TOTAL BASE SHEAR CALCULATION
The equivalent Lateral force base shear shall be determined as difined as below :
V
=
Sqrt ( Vi² + Vc²)
(E.6.1 - 1)
=
6160861 N
Where,
Vi
=
Ai (Ws + Wr + Wf + Wi)
(E.6.1 - 2)
=
6099248 N
Wf
=
Weight of the tank floor,N
198,163 N
=
Vc
=
Ac Wc
=
869125 N
Sliding Resistance
Vs
=
μ ( Ws + Wr + Wf + Wp)(1 - 0.4 Av)
(E.7.6 - 1)
20237533.03
=
N
Where,
Vs
=
Average shear wave velocity at large strain levels
μ
μ
=
=
6160861
<
Friction coefficient for tank sliding
0.4
20237533.0
Seismic shear V does not exceed Sliding resistence Vs - HENCE OK
Page 15 of 25
Design Calculation for T-109 tank
DYNAMIC HOOP STRESS DESIGN
D/H Ratio
Y
=
=
0.984
18.00
<
>
1.333
13.51
=
0.75 D
Dynamic liquid Hoop force
As per Clause E.6.1.4
Ni
=
Impulsive hoop membrane force in tank wall , N/mm
(E.6.1.4 - 3a)
Nc
=
=
2.6 Ai GD²
Convective hoop membrane force in tank wall , N/mm
Y
=
=
1.85 Ac GD²cosh[3.68(H-Y)/D]/cosh(3.68H/D)
Distance from liquid surface to analysis point ( 300 mm from Bottom),m
Nh
Nh
=
=
Product Hydrostatic membrane stress, N/mm
4.9 GDY
σT
=
σh ± σ s
=
Ni
N/mm
139.21
139.21
139.21
139.21
139.21
139.21
139.21
139.21
Nc
N/mm
2.40
2.80
3.95
5.60
8.20
12.18
18.23
27.37
Nh
N/mm
1747.72
1504.98
1262.24
1068.05
873.86
679.67
485.48
291.29
t corroded
mm
14
12
10
10
8
6
6
6
σT
Mpa
136.08
138.16
141.13
121.44
127.26
137.05
104.56
72.28
σ s Allow
Mpa
196.18
196.18
196.18
196.18
196.18
196.18
196.18
196.18
Result
Shell -1
Shell -2
Shell -3
Shell -4
Shell -5
Shell -6
Shell -7
Shell -8
Y
m
18.000
15.500
13.000
11.000
9.000
7.000
5.000
3.000
Shell -9
1.000
139.21
41.13
97.10
6
40.39
196.18
OK
Course
Freeboard
For SUG II
δs
=
=
When,
Tc
Af
Af
=
=
=
0.5 D Af
0.62
m
2
2
Nh ± SQRT ( Ni + Nc + ( AvNh)
t
(E.6.1.4 - 4a)
2)
(E.7.2-1)
4.42
>
4
2.5 KQFaSoI(4Ts/Tc2)
0.07
Minimum Required Freeboard
0.7 δs
Provided Freeboard Height
=
=
0.44 m
0.50 m
HENCE OK
Page 16 of 25
(Table E-7)
OK
OK
OK
OK
OK
OK
OK
OK
Design Calculation for T-109 tank
CHECK FOR SHELL-TO-ROOF FRANGIBLE JOINT REQUIREMENTS :
As per Figure F-2, Detail-b
Top Angle
100 x 100 x 8 thk.
Wh
th
Wc
Rc
tc
tanθ = roof slope
Area of Curb angle section plus the participating roof & shell
Top angle provided
Ac
=
Cross sectional area of top angle
Wc
=
Max. width of participating shell
Where,
Rc
tc
Wh
=
=
=
Inside radius of tank shell
Thickness of shell plate (uncorroded)
Max. width of participating roof
=
0.167
=
=
=
=
100 x 100 x 8 thk.
1550
sq.mm.
0.6(Rc tc)^0.5
139.43
mm
=
=
=
=
=
9000
mm
6
mm
0.3(R2 th)^0.5 or 300 mm
(whichever is less)
171.94
mm
171.94
mm
=
Rc/sinθ
=
54744.86 mm
Where,
R2
=
length of the normal to the roof, measured
from the vertical centreline of the tank
th
=
Thickness of roof plate (uncorroded)
=
6
mm
As
=
Participating area of shell plate =
=
Participating area of roof plate
Wc x tc
836.56
Wh x th
sq.mm
Ar
=
=
=
=
=
=
1031.62 sq.mm
Ac + As + Ar
At
=
Total area of roof-shell junction
3418.18 sq.mm
As per clause 5.10.2.6.d, The frangible roof joint for anchored tanks of any diameter, the tank shall meet the
requirements of 5.10.2.6.a
Page 17 of 25
Design Calculation for T-109 tank
S.No
1
Requirement
The slope of the roof at the top angle attachment
does not exceed 2:12.
Actual
2
The roof support members shall not be attached to
the roof plate.
Roof support members are not
attached to the roof plate.
OK
3
The roof is attached to the top angle with a single
The roof is attached to the top angle
OK
continuous fillet weld on the top side (only) that does
not exceed 5 mm (3/16 in.). No underside welding of
with a single continuous fillet weld on
the top side only and does not exceed
roof to top angle (including seal welding) is permitted.
5 mm. No underside welding of roof to
top angle (including seal welding) is
provided.
The roof-to-top angle compression ring is limited
The roof-to-top angle compression ring
to details a - e in Figure F-2.
is limited to 'detail-b' in Figure F-2.
4
Slope of the roof at the top angle
attachment does not exceed 2:12
As per clause 5.10.2.6,
A
=
For frangible joint, the cross sectional area of the roof-to
shell junction shall not exceed the following:
W
=
Ws
Wrs
=
=
Total weight of the shell and any framing
(but not roof plates) supported by the shell & roof
Weight of the shell + miscellaneous items on shell
Weight of roof structure
=
W / (1390 tan θ)
=
=
=
=
=
3499.57
Ws + Wrs
818324
759484
58840
sq.mm
N
N
N
Total area of roof-to-shell junction, At < Area resisting the compressive force, A
A > At & HENCE SHELL - TO - JOINT FRANGIBLE JOINT
COMPRESSION AREA CHECK FOR INTERNAL PRESSURE
Design Internal pressure
Cross sectional area of tank
Weight of the shell/roof/support
Hence F.3 through F.6 shall apply
=
=
=
=
2.450 kPa
0.0245 kg/cm2
2548650 Sq.cm
62441.92 kg
96650.19 kg
=
Required compression area as per F.5.1,
A
=
200 * D^2 (P - 0.08 th)
Fy (tan q)
Where
D=
Nominal tank Diameter
=
P=
th =
Design internal pressure
Nominal roof thickness
=
=
18.014 m
2.450 kPa
6.00 mm
Fy =
Minimum specified yield strength
=
250 Mpa
tanθ =
Roof slope
=
0.167
As per M 3.3 of API 650 the yield strength of material shall be multiplied by the ratio of the reduction factor
Page 18 of 25
Remarks
OK
OK
Design Calculation for T-109 tank
Hence
Material Yeiel strength ( MDT)
Ratio
Where,
A
=
=
250 x
=
=
221.25 Mpa
1.08 > 1
0.885
Hence ok
total required compression area at the roof to shell junction, in sq.mm
Required Compression Area
Provided Compression Area
=
=
=
3068.51 sq.mm
3068.51 sq.mm
3418.18 sq.mm
Provided compression area is adequate
As per cl.F.4.1, the maximum design pressure, for a tank that has been constructed P:
P
=
(A)Fy(Tan ¢)/(200*D^2)+0.08th
P
=
2.67 Kpa
As per cl.F.4.2, the maximum design pressure, limited by uplift at the base of shell, shall not exceed:
Pmax
=
0.00127DLS
+0.08th -
D^2
Where,
Pmax
DLS
0.00425 M
D^3
=
=
maximum design pressure, in Kpa
Total weight of the shell & any framing (but not roof plates)
M
=
=
=
supported by the shell & roof, in N.
916391 N
Wind moment
(Tank is provided with Ancharoge, hence M=0)
4393415 N-m
Pmax
=
-
1163.82
+
0.48
324.5
=
4.07 Kpa
Pmax > Design Pressure
Hence safe
0
5845.62
As per F.4.6,Calculated Failure Pressure
Pf
Pf
=
=
Calculated minimum failure pressure ( kPa)
1.6 P -0.047 th
4.00 Kpa
=
As per Cl. F.4.3, the maximum design pressure for tank with a weak shell to roof attachment
P max
0.8 Pf
<
3.20 Kpa
<
Hence all the above conditions are meet for Appendix -F calculation
Page 19 of 25
Design Calculation for T-109 tank
DESIGN OF ANCHOR BOLTS & ANCHOR CHAIRS
DESIGN OF ANCHOR BOLTS :
Provide
=
Root area of bolt
=
Corrosion allowance
Area available
=
=
48 mm. Dia. Bolts x
1458.00 sq.mm
36
nos.
0 mm
1458.000 sq.mm
As per clause 5.11.3
The design tension load per anchor
tb
=
=
Mw
=
4393415 N-m
Diameter of the anchor circle
Number of anchors
d
N
=
=
18.227 m
36 nos.
Weight of the shell plus roof supported by the shell (corroded)
less 0.4 times the uplift from internal pressure.
As per clause E.6.2.1.2 - Mechanically Anchored tank
W AB
=
Calculated design uplift load on anchors per
unit circumferential length, N/m
2
=
[(1.273 Mrw / D ) - Wt (1-0.4 Av)]
=
177972 N/m
PAB
=
The anchor seismic design load
W
=
Overturning moment about the shell-to-bottom joint from
horizontal plus vertical wind pressure
=
=
(4Mw/dN) - (W/N)
59539 N
-1E+06 N
E.6.2.1.2-1
E.6.2.1.2-2
W AB (π D/N)
279775 N
Uplift load as per table -5-21 a
Uplift load Case
Design Pressure Condition
[(P – 0.08th ) × D²] – W1
Test Pressure
[(Pt – 0.08th ) × D²] – W1
Failure Pressure
[(1.5 x Pf - 0.08th) x D 2] - W3
Frangilbility Pressure
(3 x Pf-0.08 th)x D2 -W3
Wind Load
[4 × Mw/D] – W2
Seismic Load
[4 × Ms/D] – W2
Design Pressure + Wind
[(P – 0.08th ) × D²] + [4 Mw/D] – W1
Net Uplift, Load/Bolt
U (N)
(N)
Stress/Bolt (Mpa)
Allowable Stress
Remarks
(Mpa)
-915751.37
-25437.5
-17.4
105
OK
-915751.37
-25437.5
-17.4
140
OK
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
-94842.06
9,310,945
59804.27
-2634.5
-1.8
200
OK
258637.4
177.4
200
OK
1661.2
1.1
140
OK
262933.1
180.3
200
OK
Design Pressure + Seismic
[(P – 0.08th) × D²] + [4 Ms/D] – W1
9465591.1
Page 20 of 25
Design Calculation for T-109 tank
W1
=
=
Dead load of shell less C.A. and any dead load other than roof plate acting on shell less C.A. in N
916391 N
W2
=
Dead load of shell less C.A. and any dead load including roof plate acting on shell less C.A. in N
1070398 N
W3
Dead load of shell including C.A. and dead load other than roof plate acting on the shell including C.A. in N
P
=
=
=
916391 N
Design pressure, Kpa
=
2.45 kPa
th
Pf
=
=
Roof plate thickness, mm
Calculated minimum failure pressure, Kpa
=
=
6.00 mm
4.00 kPa
Pt
=
Test Pressure kPa
=
2.45 kPa
Max Governing Load at each bolt
279775.5
AISI T-192 Volume II, Part VII- ANCHOR BOLT CHAIRS
Minimum cross sectional area of bolt Ab
=
Yield strength of bolt (A 36)
Fy
=
N
P
a
b
c
d
e
=
=
=
=
=
=
2.26 inch2
250 N/mm 2
279775 N
7.87 inch
7.87 inch
1.18 inch
1.89 inch
4.00 inch
f
=
2.93 inch
g
h
k
J
m
=
=
=
=
=
t
=
0.94 inch
24 mm
Q
PCD
=
=
2.36 inch
717.60 inch
60 mm
18227.05 mm
Diameter of the tank
Radius of Shell
D
R
=
=
708.66 inch
354.33 inch
18000 mm
9000 mm
Weld Size
w
=
0.2362 inch
6 mm
Design Load
Top plate width
Top plate length
Top plate thickness
Anchor Bolt Diameter
Anchor Bolt eccentricity
Distance from outside of top plates to
edge of hole
Distance between vertical plate
Chair Height
Vertical Plate Width ( Average)
Vertical plate thickness
Bottom plate thickness
Bottom shell course thickness + RF
Pad
Annular/Sketch Plate Projection
Pitch Circle Diameter
Top Plate Design
Critical stress in top plate, S
3.94
13.78
5.12
0.55
0.39
1458 mm 2
=
200
200
30
48
101.53
62.871 Ksi
mm
mm
mm
mm
mm
74.47 mm
inch
inch
inch
inch
inch
100
350
130
14
10
=
=
2
P / f c * (0.375 g - 0.22 d)
16.30
Ksi
=
1146.18
<
mm
mm
mm
mm
mm
1682.51 kg/cm 2
Bending plus direct stress in shell at top plate, Sb = P e / t2 * [(1.32Z / {(1.43ah 2/Rt + (4 a h 2)0.333} + (0.031 / (R t) 0.5)
=
15.57
Ksi
<
1682.51 kg/cm 2
=
1094.85
=
=
1.0 / [{0.177 a m / (R t)
0.995
Where,
Z = Reduction Factor
HENCE OK
Page 21 of 25
0.5
2
}*(m / t) + 1]
Design Calculation for T-109 tank
Vertical Plate:
Minimum Thk. is Greater of 0.5 inch or 0.04 (h-c)
=
=
0.5 or
0.5 or
=
=
jk
2.82
0.5039 inch
12.8 mm
>
>
P/25
2.51
HENCE OK
e
f
g
a
j
b
Radius
RF Pad
k
h
Q
PCD
Weld Size Calculation
Wv
=
=
P/(a+2h)
1.77 Ksi
WH
=
Vertical Load on wels
=
Pe/(ah+0.667h²)
=
1.07 Ksi
=
(Wv 2 + W H2)0.5
2.07
<
W
=
2.27 Ksi
HENCE OK
Page 22 of 25
0.04( h - c)
0.50
Design Calculation for T-109 tank
VENT SIZE CALCULATION
As per API 2000,
D
=
Tank Diameter in m
H
V
Vi
Vo
=
=
=
=
Tank Height in m
3
Tank Capacity in m
3
Maximum Filling Rate in m /hr
Maximum Emptying Rate,m 3/hr
Flash Point of Liquid
=
18.00 m
=
59.06 feet
=
=
=
18.80 m
4784.02 m 3
500.00 m 3/hr
120.00 m 3/hr
0
> 200
C
=
=
=
61.68 feet
###### bbl
3,145 bbl/hr
=
755 bbl/hr
=
Inbreathing (Vacuum Relief)
(a)
Required venting capacity for liquid movement out of the tank (clause 4.3.2.1.1)
iQ1
=
0.94 Vo
(b)
iQ2
(c)
iQt
=
112.80 Nm3/hr
Required venting capacity for thermal inbreathing (Table -2B, Notes a)
=
0.169 V
=
808.5 Nm3/hr
Required venting capacity for inbreathing
=
iQ1 + iQ2
=
921.3 Nm3/hr
Outbreathing (Pressure Relief)
(a)
Required venting capacity for liquid movement into the tank (clause 4.3.2.2.1)
oQ1
=
1.01 Vi
=
505.00 Nm3/hr
(b)
Required venting capacity for thermal outbreathing (Table -2B, Notes b)
oQ2
=
60 % of inbreathing
=
485.1 Nm3/hr
(c)
Required venting capacity for outbreathing
oQt
=
oQ1 + oQ2
=
990.1 Nm3/hr
Size and Number of Free Vents
D1
=
Size selected, in inch
D
=
Inside Diameter of Vent
(a)
Vent Flow Area without Screen (A1)
2
A1
=
π/4 * D
(b)
=
=
6 Inch Schedule 40/Std.
155.96 mm
=
19104 mm 2
=
0.019 m 2
f1
Vent Flow Area with Screen (A2)
Wire Size = 60 meshes per sq.inches
=
Nominal screen area
37%
A2
=
=
7068.4 mm 2
=
0.007 m 2
(c)
Mean Velocity Vm
=
41.93 m/s
=
2E+05 m/hr
Vm
f1*A1
=
2*g*ΔP
f*d
Page 23 of 25
Design Calculation for T-109 tank
Where,
ΔP
d
=
Maximum difference venting pressure =
=
Density of Vapour
=
f
g
=
=
Total Resistance co-efficient
Acceleration due to gravity
=
=
224.25 mmH2O
224.25 kg/m 2
1.25 kg/m 3
2.00
9.8 m/s 2
(d)
Inbreathing / Outbreathing Capacity, Q
1 - Without Screen
Q1
=
2 - With Screen
Q2
=
A1 * Vm
=
2,884 m 3/hr
A2 * Vm
=
1,067 m 3/hr
(e)
Quantity of Free Vent required, N
1 - Without Screen
N
=
Max. ( iQt or oQt) / Q1
=
0.34335 SET(S)
2 - With Screen
N
=
Max. ( iQt or oQt) / Q2
=
0.928 SET(S)
Provide
SET(S) of
2
6
Inch Schedule 40/Std.
Page 24 of 25
Free Vent with Screen
Design Calculation for T-109 tank
LOADING DATA :
Shell
Bottom plate
74.53 Mt
20.31 Mt
Fabricated Weight
Product wt.
132.7 Mt
5122 Mt
Roof plate
Roof Structural
12.60 Mt
6.00 Mt
Test water wt.
Operating Weight
4784 Mt
5255 Mt
Top Curb Angle
Ladder & Platform
0.42 Mt
1.50 Mt
Hydrotest Weight
Wind shear
4917 Mt
49 Mt
Shell appurtenances
Roof appurtenances
1.00 Mt
0.60 Mt
Wind moment
Seismic shear
Anchor chair
Misc. wt.
Insulation Weight ( Shell)
2.80 Mt
0.45 Mt
12.50 Mt
Page 25 of 25
Seismic moment
Size and Number of anchor bolts
Bolt Circle Diameter
448 Mt-m
628 Mt
4767 Mt-m
M 48 x 36 Nos.
18.23 m