BEMCO STEEL INDUSTRIES CO. LTD.

DESIGN CALCULATIONS

CLIENT

PROJECT QP10-Q-6764_TypicalSteelWaterTower1500m³

Rev. Description Prepared

Reviewed
Approved Date

0 Mechanical Calculation H.M H.M M.B 25/2/2013

1- FOR INFORMATION ONLY

2- FOR APPROVAL
3- FOR CONSTRUCTION
 Design. Ref.Decuments
API 650 ,11TH.ED
M09
1 EVALUATION OF MATERIAL API650 -5.6.2 Tabel5-2a
2 EVALUATION OF SHELL THK. API650 -Clause 5.6.3.2
3 EVALUATION OFBOTTOM PLATE API650 -Clause 5.5
4 EVALUATION OFBOTTOM SKETCAPI650 - Clause 5.4
5 EVALUATION OF ROOF THICKNEAPI650- Clause5.10.4 & 5.10.5
6 STABILITY CHECK AGAINST WIN API650 - Clause 5.9.7.1
7 SHELL TRANSFORMER API650- Clause 5.9.7.2
8 WIND GIRDER STIFFENING API650- Clause5.9.5
9 OVERTURNING MOMENT AGAINSAPI650-Clause 5.11.1
WIND LOAD
10 UNANCHORED TANKS STABILITYAPI 650 -5.11.2
11 STABILITY CHECK SEISMIC API650-APPENDIX E
12 VENT SIZE CALC. API650-Clause -API2000
13 REINF. AROUND OPENING API650-Clause5.7
 STORAGE TANK DESIGN CALCULATION - API 650

1 .0 DESIGN CODE & SPECIFICATION

DESIGN CODE : API 650 11th Edition & 32-SAMS-05
SEISMIC CODE : UBC 97
VENTING CODE : API 2000

1 .1 TANK
Item number QP10-Q-6764_TypicalSteelWaterTower1500m³
Roof ( Open/Close ) : Close
Type of roof ( Cone-roof / Dome-roof / Flat-roof / NA ) : Cone-roof
Roof slop 1 : 6
Inside diameter , Di (corr. diameter14600 )mm = 14,600 mm
Nominal diameter, Dn = 14,610 mm
Tank height ,H = 9,750 mm
Free Board = 350 mm
Specific gravity of operating liquid , S.G. (Design) = 1
Maximum design liquid level, HHL = 9,400 mm
Min.Design Liquid level ,LLL = 400 mm
Insulation thickness = 0 mm
Bottom Slope 1 : 120
Depth of liquid outside level indicator scale = = 61 mm
12 LOADS
Wind Speed (Fatest mile wind speed ) = 150 kmph
Max.Design Wind Speed (3 seconds gust Wind ) = 150 kmph
Live Load , @ LL 120 kg/m
2
=
Rain Rates @ Misc.loads = 20 mm/hr

13 SEISMIC (UBC)
Tank Location (Elmadina)
Zone Factor = 0.75
Importance Factor = 1.3
Site Class = E

14 TEMPREATURE & PRESSURE

Design pressure : Upper , Pu (Atmospheric) = 0.00 mbarg
: Lower , Pl (Vac = 0.00 mbarg

Design temperature : Upper , Tu = 60 °C

Operating Temperature : Top. = 47 °C

15 PUMPING RATE
Pumping in 12579 m3/d = 524.125 m³/hr
pumping out 12579 m3/d = 524.125 m³/hr

16 CAPACITYS
Nominal capacity , V = 1,632 m³
Net capacity (based on LLL) = 1,507 m³
Operating Capacity (based on Operating level only) = 1,574 m³
Under Reading Level indicator Capacity = 18 m³
17 MATERIAL & MECHANICAL PROPERTIES

Component Material Tensile Yield Corrosion

Stress Stress Allowance
St(N/mm²) Sy(N/mm²) c.a.(mm)
PLATE
Shell Plate ( Mat'l Code # 1 ) (bot) A36 400.00 250.00 0.000
( Mat'l Code # 2 ) (top) A36 400.00 250.00 0.000
Annular Plate A36 400.00 250.00 0.000
Bottom Plate A36 400.00 250.00 0.000
Roof Plate A36 400.00 250.00 0.000
STRUCTURE MEMBERS 0.000
Roof structure (rafter,bracing,etc ) ASTM A36 400.00 250.00 0.000
STRUCTURE COLUMS A106 GR B 380.00 250.00 0.000
Top Curb Angle A36 400.00 250.00 0.000
Intermediate Wind Girder A36 400.00 250.00 0.000

Flanges ASTM A105

Handrails ASTM A 53 GR B Type E
Nozzle Bolts ASTM A 193GR B7 /A194 GR 2H H.D.G or Equial
Structure Bolts A307 / A 325M type 1 H.D.G
Material Plates Spec,s Steel Plates as Rolled Killed or Semi-killed steel
Pipes ASTM 106 GR B
Heater coils SS316L
Notice : as per API650 clause 2.2.2 -Max. plate thickness for plates A283 GR C = 25mm

18 STEEL PLATESPROPERTIES

1) Material HIC NO
2) Material Impact test NO
3) Material PWHC NO
4) Material ARAMCO APPROVED NO
5) Material PMI NO
 SHELL THICKNESS CALCULATION BY ONE-FOOT METHOD
2 .0 SHELL DESIGN
2 .1 GEOMETRIC DATA
Plate size used : 2,480 mm
Shell plate min. width as per API 650 : 1,870 mm

2 .2 MATERIAL & MECHANICAL PROPERTIES

No Material Specified Specified Yield stress Max. allow Max. allow Corrosion
used min. tensile min. yield reduction fac design hydro.test allowance
stress stress ( App. M ) stress stress
St (N/mm²) Sy (Nmm²) k Sd (N/mm²) St (N/mm²) c.a (mm)

2 A36 400.00 250.00 1.000 160 171.43 0.00

3 A36 400.00 250.00 1.000 160 171.43 0.00
4 A36 400.00 250.00 1.000 160 171.43 0.00
5 A36 400.00 250.00 1.000 160 171.43 0.00
6 - - - - - - -
7 - - - - - - -
8 - - - - - - -
9 - - - - - - -
- - - - - - -
- - - - - - -
- - - - - - -
2 .3 SPECIFIED MINIMUM SHELL THICKNESS
Specification API 650 11th Edition & 32-SAMS-05 :
Minimum thickness as per API 650 cl 5.6.1.1 = 5.00 mm
Minimum thickness provided = 8.00 mm
2 .4 SHELL THICKNESS CALCULATION BY ONE-FOOT METHOD ( CLAUSE 5.6.3.1 )

SI METRIC UNIT :-
Design shell thickness, ( in mm )
4.9Dn ( [H+Hi] - 0.3 ).G
td = + c.a
Sd
Hydrostatic test shell thickness , ( in mm )
4.9Dn ( H - 0.3 )
tt =
St
Gravitational force = 9.81 m/s

2 .5 CALCULATION & RESULTS

No. Mat'l Material Width t.design t.hydro. t.min tsc. Result

Code No. (mm) (mm) (mm) (mm) (mm)

2 2 A36 1,980 3.19 2.97 5.00 8.00 O.K.

3 2 A36 1,980 2.30 2.15 5.00 6.00 O.K.
4 2 A36 1,950 1.41 1.32 5.00 6.00 O.K.
5 2 A36 1,860 0.54 0.50 5.00 6.00 O.K.

TOTAL COURSES HEIGHT 9.7500 m

SHELL HEIGHT 9.7500 m Shell height ok
 2 6 ROOF HANDRAILS
(i) Roof Handrails calculations
Handrail average dia 14.62 m Pipes 48mm-sch 40
Average distance -X = 1m x
No.of Pipes 37 Pipe - length =1200mm
W,t of post pipes 176.4 kg
Weight of cir.pipes 367.44 kg
Weight of Flat Bars 216.3307 kg
Total Weight of Roof Handrails 760.14 ton

(ii) Stair Calculations

height 9.75 m
inclined angle 41 deg.
step 195 mm
width of tread 245 mm
No.of tread 50
total weight of tread 500 kg
Flat Bars 466.65 kg
No.of Plat,grating 2
Platforms and grating 269.09091 kg
W,t of pipes if duble handrails 237.78348153 kg
Total weight of stair 1473.52 kg 1,473.52 ton Stair length 14.86 m
###
(iii) Platforms Y
Platforms Claculations
Width of platform = 750 mm
We select grating type 32x5 mm
Unit w,t of Grating = 48.8 kg/m^2
total length of platform = 2402 m
Supportes channels-UPN 160 = 27,096 Kg
Intermediate Platform = 1279.25
Total weight of platforms= 117223.679 kg

Platform Skech
 BOTTOM & ANNULAR PLATE DESIGN
3 .0 BOTTOM PLATE & ANNULAR PLATE DESIGN
Annular plate used ? ( yes/no ) NO
BOTTOM PLATE
(i) Minimum thickness as per API 650 Clause 5.4.1 = 6.00 mm
Minimum thickness required ( 0.00 mm c.a ) = 6.00 mm
Therefore, use thickness of 16.00 mm (tb) is satisfactory.

(iv) Min. width of plate (cl. 5.4.1) = 1800 mm

Botom PLATE
(i) Nominal thickness of 1st shell course, tsc1 = 10.00 mm
Hydro. test stress in 1st shell course,
4.9Dn(H-0.3) = 67.65 N/mm²
St =
tsc1
where
Dn = Nominal diameter, Dn ( new ) ( based on 1st shell course )= 14.610 m
H = Design liquid level = 9.750 m
tsc1 = Nominal thickness of 1st shell course = 10.000 mm
Annular plate thickness ( As per Table 5-1a ) = 6.00 mm
Minimum thickness required ( 0.00 mm c.a. ) = 6.00 mm
Therefore , use thickness of 16.00 mm (ta) is satisfactory.
(ii) Min. shell-to-bottom fillet welds size (cl. 5.1.5.7) = 10.00 mm
(iii) Min. width projected inside of shell to edge of overlapping (cl. 5.5.2) = 600 mm
(iv) Min. radial width of annular plate (cl. 5.5.2)
215 ta
La = = 1122.00 mm
(HL. SG )0.5
where
ta = Annular plate thickness = 16.000 mm
HL = Maximum design liquid level = 9.40 m
SG = Design specific gravity = 1.00
(v) Min. width projected outside of shell ( cl. 5.5.2)(50 mm) = 50 mm
AW1, Width projected inside of shell to edge of overlapping = 600 mm
AW2,Width projected outside of shell = 70 mm
tsc1 Nominal thickness of 1st shell course = 10.000 mm
Width of Annular Ring Max.{ (AW1+AW2+tsc1) & La} = 1122 mm
Width of Annular Ring provided = 700 mm
Annular Ring outside diameter = 14690 mm
Annular Ring inside diameter = 13290 mm
Outer Diameter of Bottom Plates = 13390 mm

We will Use Bottom witout Anular

4 .0 CALCULATION ROOF COMPRSSION RING AGAINST INTERNAL PRESSURE
(APPENDIX-F CALCULATIONS)
Tank diameter = 14.6 m
Tank Weight = 536,763 N
as per F.1.2 .Internal Pressure X Cross sec.Area of Tank = 0N
Internal Pressure Uplift < Total Tank Weight
4 .1 COMPRESSION ZONE AREA AGAINST INTERNAL PRESSURE AS PER APPENDIX -F
4 1.1 Compression area as per API 650 clause F4.1
Areq. =D2 (Pi-0.08th)/ 1.1 tan ϴ = -465 mm2
Where : Internal Pressure Pi = 0.00 Kpa
Roof thickness th = 5.00 mm

4 1.2 Compression area avaialble

As per API 650 Fig.2 -Detail b
Curb Angle size in mm L 100 X 100 X 15
Area of Curb angle AC = 2775 mm2
ta =thickness of angle leg ta = 15.00 mm
tb=thickness of bar tb = 15.00 mm
tc=thickness of roof Plates tc = 15.00 mm
ts=thickness of top course of shell ts = 8.00 mm
Wc=Max.width of participating shell
Wc = 0.6(Rc ts ) 0.5 Wc = 145.00 mm
Wh =Max. width of participating roof
Wh 0.3 (R2 th )0.5 of 300mm Where is Less Wh = 141.30 mm
Rc =inside radius of tank shell Rc = 7300.00 mm
R2 =Length of the normal to the Roof ,measured from the vertical centerline of the tank
R2 =RC/(sin ϴ) R2 = 44370.66 mm
A
Total Area available =(Wh xth)+(Wc*ts)+Curb angl ava. = 4641.49 mm2
compression area >>ok

Detail -b

Girder stiffened as per clause 5.9.5

at distance 2400 mm & No.of stiffeners = 19 stiffener
Wind Girder Weight @Stiffeners = 1021.26 kg
5 .0 INTERMEDIATE WIND GIRDERS DESIGN
5 .1 MAXIMUM HEIGHT OF THE UNSTIFFENED SHELL ( CLAUSE 5.9.7.1 )

SI METRIC UNIT :-

H1 = (9.47 ts.cor) ts.cor 3

190 ² = 28.895 m
x
Dc V = 28895 mm

wher ts.cor = Top shell course thickness = 8.00 mm

Dc = Corroded tank diameter = 14.60 m
V = Wind design speed = 165.00 km/hr

5 .2 LOCATION OF INTERMEDIATE WIND GIRDERS

Shell Shell Actual Transposed Since H1 > H2, therefore the intermediate
course thickness width width wind girder is/are Not required
tsc.cor W Wtr
(mm) (mm) (mm) Minimum number of intermediate wind
1 10.00 1,980 1,133 girders required,
2 8.00 1,980 1,980 = 0
3 6.00 1,980 4,065
4 6.00 1,950 4,003 Location of intermediate wind girders from
5 6.00 1,860 3,818 top of tank,
L1 = - mm
L2 = - mm
L3 = - mm
L4 = - mm
L5 = - mm
transformed shell, 14,999 mm

Notes : Intermediate wind girders shall not

be attached to the shell within 6"of
a horizontal shell joint. See cl. 5.9.7.5
11 HEATING COIL Reff. Pressure Vessel Manual,procedure 6-8 & ASME

Heater Sketch as per Data sheet

Coil Development Length 436 m

4 group coils each group 109 m
Average Pipe Length 12 m
Total pipes 36 pipe
Heater w,t 15,816 kg
Pipe supportes approx. 7000 kg
Total w,t 22,816 kg
 ` Product
Product in

1.0
Stem in

Condensate
Steam Coil Data
1.1 Operating Pressure 4 ata
1.2 Pressure at inlet of Coil heater 4 ata
1.3 Steam temp.at design pressure of coil 168 0
C

1.4 Design Pressure 4 ata

1.5 Latent heat at inlet pressure,hfg 509.43 Kcal/kg ( Note-1)
2 Asphalt Data
2.1 type FUEL OIL
2.2 Density at low temp. ,D1 950 kg/m3
2.3 Specific Heat ,Cp1H 0.48 K cal/Kg 0C ( Note-2)
2.4 initial Temp., (Minim.Ambient Air Temp.),,T1 5 0
C
2.5 Final Temp.(Fuell Temp.to be maintained) ,T2H 110 0
C
2.6 Average Temp. ...,Tav = (T1+T2H) / 2 57.5 0
C
3 Tank insulation Material
3.1 Type LRB Mineral Wool (IS8183)
3.2 Density of the material 100 kg/m3
3.3 Cladding Material Aluminium ,22 SWG
4 Process Requirment Data
4.1 Volume of Liquid to be Heated ,V 2219.65 m3
4.2 Heating time ,Ht 72 hr ( Note-3)
4.3 Mass of Liquid to be Heated ,M1H =V*D1 2,108,668 m3
5 Heat Thermal Load Calculations
5.1 Temp. difference during intial heating of Fuel ,Dt =T2H- T1 105 0
C
5.2 Heat Load For intial Heating of Product,Q1=M1H*Cp1H*D 1476067.25 Kcal/hr
6 Heat Loss through Tank Shell ,Bottom, Roof During Intial Stage
6.1 Heat Loss through Tank Shell for Product if Tank Fully insulated
a Tank , D(Tank inner Dia.) 16 m
b Tank , h(Tank height ) 12 m
c Average thickness of tank shell without insulation t s 7 mm
d Average thickness insulation , t in 40 mm
e Outer Dia.of Tank shell without Insulation, Ds 16.0140 m
f Outer Diameter Of Insulation ,Din 16.0940 m
g Thermal conductivity of insulation ,Ki 0.043 W/cm 0C ( Note-4)
H Thermal conductivity of insulation ,Ki 0.0369800 kcal/hr m 0C
I Film Co-efficient, (Refer calc. at end),f 6.1774 kcal/hr m2 0C
J Average Temp.difference during intial heating of Fuel
K ∆Tav.= T2H-Tav. 52.5 0
C
L Rate of heat Loss through Tank Shell,QL
M qL =∆Tav./ [ ( Ds /2ki) * ln (Din/Ds) + (Ds/ f * Din) ] 42.3370870445144 kcal/hr m2 ( Note-5)
N Shell surface area ,As 603.713577055043 m2
S Heat Loss through Tank Shell ,Q2 =(qL*As) 25559.4742617345 kcal/hr
6.2 Heat Loss through Roof of Tank (insulated)
a Insulation Thickness Considered ,tr 40 mm
b Thermal Conductivity of the insulation,Ki 0.0369800 kcal/hr m 0C
c Film Co-efficient,(Refer
f calc. at end) 6.1774 kcal/hr m2 0C
d Average Temp.for heat loss during intial heating , Tav. 57.5 0C
e Average Temp.difference during intial heating of Fuel
f ∆Tav.= T2H-Tav. 52.5 0C
 g Rate of heat loss through Roof ,q r=∆Tav/[ (tr/ki)+(1/f)] 42.2180128201183 kcal/hr m2
g Roof Diameter ,RD ( Development) 16.08 m
h Surface area of Roof ,Ar 203.07757567629 m2
i Heat Loss through roof QLr =qr*Ar 8573.53169338015 Kcal/hr
7 Heat Loss through Bottom of Tank
a Surface area of Bottom of Tank,Ab 201.061929829747 m2
b Theraml Conductivity of Sand ,Ks 1 W/Mk
c Theraml Conductivity of Sand ,Ks 0.85999999828 kcal/hr m 0C
d Average temp.difference during initial heating of Fuel ,
e ∆Tav.= T2H-Tav. 52.5 0C
f Depth of sand bed ,X 1m
j Heat Loss Through Bottom Plates ,QB=(Ab*Ks* ∆Tav.) / X 9077.94611365718 kcal/hr
8 Heat Loss through Tank shell&Bottom&Roof During Shutt down /Manintenance (insulated)
a Tank inner Diameter ,Di 16 m
b Tank outer Diameter without insulation,Do 16.014 m
c Tank outer Diameter with insulation ,Doi 16.094 m
d Height of Tank shell ,h 12 m
e Thermal Conductivity of insualtion ,Ki 0.0369800 kcal/hr m 0C ( Note-6)
f Film Co-efficient .f (Refer calc.at end) 6.1774 kcal/hr m2 0C
g Temp.diff. During Maintenance /Shutt down , ∆T=T2H -T1 105 0C
h Rate of heat loss through Tank shell
j q m = ∆T /[ ( Do/2* Ki) * ln (Doi/Do) + (Do/Doi*f) ] 84.6741740890288 kcal/hr m2 ( Note-7)
k Shell surface Area ,As 603.449683272142 m2
l Heat Loss Through Tank Shell ,Qsm=As*qm 51096.6035353546 kcal/hr
9 Heat Loss through Roof of Tank (insulated)
a Insulation thickness Considered ,tir 40 mm
b Theraml Conductivity of the insulation ,Ki 0.0369800 kcal/hr m 0C
c Film Co-efficient .f (Refer calc.at end) 6.1774 kcal/hr m2 0C
d Temp.diff. During Maintenance /Shutt down , ∆T=T2H -T1 105 0C
e Rate of heat Loss through Roof during Main./shutdown,q r
f q r=∆T / [ ( tir / ki) + ( 1 / f) ] 84.4360256402365 kcal/hr m2
g Roof Diameter,Dr 16.08 m
h Surface area of Roof ,Ar 203.07757567629 m2
j Heat Loss through roof /Main./shutt down ,Q rfm =Ar *qr 17147.0633867603 kcal/hr
10 Heat Loss through Bottom Plates during Maintenance/Shutdown
a Surface area of Bottom Plates,Abm 201.061929829747 m2
b Theraml Conductivity of Sand ,Ks 0.85999999828 kcal/hr m 0C
c Temp.diff. During Maintenance /Shutt down , ∆T=T2H -T1 105 0
C
d Depth of sand bed ,X 1 m
e Heat Loss Through Btm Plates ,QBm=(Abm*Ks* ∆Tav.) / X 18155.8922273143 kcal/hr

11 HEAT REQUIRED PER HOUR TO HEAT TANK MATERIAL UP TO 110 0

C
a Product weight to be Heated ,M2 73460 kg
b Specific Heat of Product ,Cp2 0.502 kj /(kg 0c)
c Specific Heat of Product ,Cp2 0.12 kcal/(kg 0c)
d Temp.difference during intial heating ,∆T=T2H -T1 105 0
C
e Heating Time ,Ht 72 hr
f Heat req. for pumping in/out of asphalt Mass(M2) Qp=M 2Cp2∆T / Ht 12855.5 kcal / hr
12 TOTAL HEAT LOAD / HOUR
Intermittent heat load / Tank (for intial heating of Fuel
a Qint =Heat rate required forintial heating+Heat rate req.for product pumping(in/out)+Heat Loss
Qint= ( intermittent) = Q1+Q2+QLr+Qrf+Qp = 1532134 kcal / hr
Continous heat load /Tank(Temp.Maintenance for fuel) , Q cont
b
Q cont. = Qsm +Qrm+QBm 86399.5591494293 kcal / hr
13 HEAT TRANSFER AREA OF FLOOR COIL
a Pressure at inlet of Floor Coil Heater 4 ata
b Steam Temp.at Operating pressure,Ts 168 0C
c intial Product Temp.T1 5.9 0C
d Product final Temp. T2 60 0C
e Average Mean Temperature Difference ,AMTD =Ts-(T2+T1)/2 135.05 0C
Heat Transfer Coefficient (Steam Coil to Product),K 97 kcal/hr m2 0C
f
(Refer Spirax sarco Data book(Table24)
Heat Transfer area required for Floor coil Heater ,a h=Max(Qint ,Qcont.)/(AMTD*K)
116.96 m2
g
Considering 10% Margin in the surface area required 12 m2
Area of Coil He ACOIL 128.65 m2
14 TOTAL HEAT LOAD / HOUR
a LENGTH OF FLOOR COIL PIPE REQUIRED
b Provided pipe Size of coil heater
c Carbon steel Pipe : 3 in SCH 40 / ASTM A-106 GR B
d Pipe ND 89 mm
e Pipe Thk. 5 mm
f Pipe average Diameter 94 mm
h Pipe Surface area / m 0.2953 m 2/m
Coil Length = Coil Heater Area/ Pipe surface area 436 m
15 STEAM REQUIRMENTS
a Intermittent Steam requirement,Si =Intermittent Heat Load per hour /Latent heat of steam(Qnit./hfg)
b Si ( stea 3008 kg/hr
c Continous Steam requirement,Sc=Continous Heat Load per hour/Latent heat of Steam (Qcont./h fg)
d Sc ( stea 170 kg/hr
16 Calculation of Film Co-efficient
f (Covection ) =1.957*(TO.S.I-Ta.)0.25 *(2.57 V +1)0.5 5.72 W/m2.k
f (Radiation ) =5.7557*10 * E * (T
-8
O.S.I
-T )/(TO.S.I -Ta.)
4
a.
4
1.50 W/m2.k
where :
Ta. = Ambient air temp. 306 K
TO.S.I=Outside surafce temp.of insu. (considering Max.outside temp. as 60 0C 333 K
V =Average Wind speed 0.25 m/sec
E =Emissivity of finished surface 0.2
Film Co-efficient,f = Film co-efficient due to radiation+Fil co-efficent due to convection
f ,Film Co-effic 7.22 W/m2.k
f 6.18 kcal/hr.m2.0C

17 DESIGN CODE ASME B31.1 (PROCESS PIPING)

a PARA 304.1.2 STRAIGHT PIPE UNDER INTERNAL PRESSURE
Internal Pressure Design thickness Formula (3a) per ANSI B31.3 1999 Section304.1.2
Internal Design Pressure P 405.3 Kpag
Design Metal Temp. MDMT 295 °C
Outside Diameter of Pipe D 89 mm
Co-efficient From Table (3Y 0.4
Corrosion allowance Ca 1.5 mm
Joint Effeciency E 1
Pipe Material SA106 GR B 136823.3615 Kpag
Allowable Stress of Pipe S
Provided Thickness 5 mm
 Thickness as per Purchase Specification-12.5% Mill tolerance
12.5% oMr 0.1 " for rolled T 4.38 mm

t = PD / 2(SE + PY) 0.132 mm

tm= t + c 1.632 mm
Safe Design
DESIGN CODE ASME B31.3-ED. 1999- ADD.2000
PARA 304.2.3 MITER BENDS
Internal Pressure P 405.3 Kpag
Design Metal Temp.MDMT 295 °C
Outside Diameter of Pipe D 89 mm
Mean Radius r2 42 mm
Measured Miter Pipe WallTthk. 5.000 mm
Angle of Miter Cut q 18 °
Angle of Change in Directia 36 °
Corrodion Allowance Ca 1.5 mm
Joint Effeciency E 1
Miter Piece SA-516 GR 70
Allowable stress of Mite S 129680 Kpag
Effective Radius of Miter Bend
R1 =(A/Tan Ɵ )+(d/2) R1 121.44 mm
Where A=25
Procided bend Radius R1 200 MM
Radius of bend is grater than calculated
Design as per Para 304.2.3 (a) Multiple Miter Bends
The Maximum allowable internal pressure shall be the lesser value calculated
from equation (4a) and (4 q is < 22.5 °
Equation (4a)
Pm = SE (T-c) /r2 ( (T-c)/(T-c) + 0.643 tan q (r2(T-c))^0.5) Pm1 = 6269.3435754 kpag
Equation (4b)
Pm = SE (T-c) /r2 (R1-r2/R1-0.5r2) Pm2 = 21613.333333 kpag
Lesser of Equation (4a) & (4b) Pm = 6269.3435754 kpag

Pm>int.Pressure then Safe

18 STEAM HEATER COIL SPEC,S

COIL LENGTH 436 m

COIL PIPE ND 89 mm
PIPE SCH 40
FLG,S 150#WN#R.F
BEND RADIUS MI 200 mm
START UP STEA 3008 kg/hr
OPERATING STE 170 kg/hr
PIPE W,T/M 7.47 Kg
Coil w,t 3254 Kg
9 ROOF DESIGN
9 EVALUATION OF ROOF THICKNESS
(i) Tank
Tank diameter = 15 m
Roof slop 1 : 6
Roof thickness = 5.00 mm
Roof slope, ßRoof slope, ß° = 9.4695343 °
Roof height , Hr = 1,218 mm

(ii) No.of Rafters 28 Nos.

Max spacing bet,n rafters ,L =Л /No.of Raf. = 1,638.1 mm
Max spacing between rafter as per clause 5.10. = 1,915.1 m Safe
Min.thk.of Roof Plates as per 5.10.2.2 = 4.78 mm
Min.thk.of Roof Plates including corrosion = 4.78 mm
iii) Roof Loads

DL ( including Platforms) DL = 97.25 kg/m2

LL (Live Load ) LL = 120 kg/m2
ADDITIONAL LOAD AD = 50 kg/m3
External Pressure Pi = 0.00 kg/m2
Roof loading =Max(DL +(LL or SL )+0.4 Pe @ DL +Pe +0.4(LL or SL )
Roof Loading U = 267.25 kg/m2

Max. bending moment assumed simply supp. from one side and continous from other side
M=Winf.*L2/10 7171.45 Kg.cm/m
As per 5.10.3.1 .stress should not exceed limitations specified in AISC
Fa=0.75 FY = 1911.97 Kg/cm2
Req.Plate thickness of Roof , tr =(6*M /(B*Fb))=0.5 4.74394 mm
where
* Plate width B = 100 cm
* Corrosion allowance ca = 0.00 mm
* tmin.
Min.thk. including corr.allowan = 4.744 mm
* Provided thk.of Roof Plates tp. = 5.0 mm

Roof Plates Joint Efficiency (Lap joint) = 0.35

Roof Radius devlopment = 14.83 m
Weight of Roof Plates New = 6,946.4 kg
Weight of Roof Plates corroded = 6,946.4 kg
9 .2 EVALUATION OF ROOF STRUCTURE
Assumptions
1. Considering the effect of slope of roof negligible.
2. Load acting on the main & secondary rafters is considered uniformly distributed.
3. Assuming the effect of eccentricity loading on the center column negligible.
Roof Framing diagram

(i) No. of Rafters

Diameter of Crown Ring (Dc) = 0.6 m
Diameter of the tank, in m (D) = 14.60 m
Diameter of the ring, in m (DR) = 7.30 m
Total no. of rafters on the circumference of the shell, (nM+nS) = 28.00 Nos
Provided rafter center line spacing, in m = PI*D/n
= 1.638 m
< 1.885 m O.K.
(ii) Sizing of Secondary Rafters
span L = 3.65 m
spacing at shell S = 1.638 m
spacing at ring Sr = 0.819 m
average uniform distributed load (Area-A) = wunif. * (S+Sr)/2 = 328 kg/m
usi IPE 140 Self weight = 12.9 kg/m
Total uniform load acting on the beam including self weight, ws = 341 kg/m
Sectional modulus Z = 75.041296 cm³
Moment of Inertia Ix = 525.28907 cm4
As per AISC for uniformly distributed load :
Maximum bending moment acting on the beam M = ws*L²/8 = 568.27 kg-m
Minimum yield strenght for A36 structural material, Fy = 248 Mpa
Allowable bending stress of A36 = 0.66Fy = 165 Mpa 1686 kg/cm2
Modulus of Elasticity ,E = 200000 Mpa

Sectionl modulus required, in cm³ Z = M*100/f = 33.71 cm³

Safe
Section modulus Available < 75.04 cm³
Max.Bending stress , fb.max. = M/Z = 74.263752 Mpa
Use 14 NOS. IPE 140 As secondary rafters.
Beam deflection = 5*ws*L4 / (384*E*Ix) = 0.715 cm
Max.Deflection Allowable = L/360 = 1 cm
OK
(iii) Sizing of Main Rafters
Wc
Wt+2* Pm +_Wr
C

C2 ϴ

Rb Rf

7m

Load on Main Rafter due to Crown Strctu 11.86118 kg/Rafter

We consider total Rafter Load Mide spane of Raf821.553 kg
sum .Moment about Rb =0
Reaction At Crown Rf = 119.06 kg
Reaction At Shell Rb = 714.36 kg
Compressive Force C2 = 8595 kg
ß° =Roof Slope = 4.77 °
Ignor area carrying by Ring Beam
Rafter Length Lr = 7.02 m
Span Lr = 7 m
Use 14 NOS. IPE 200 As main rafters.
Weight Wr = 22.4 kg/m
Sectional modulus Z = 181.49478 cm³
Moment of Inertia Ix = 1814.9478 cm4
Radius of Gyration K = 8.330983 cm
Spacing at shell = 1.638 m
Spacing at Crown Ring 0.13 m
Triangular load acting on the beam wt = wunif * S = 0.00 kg/m
Concentrated load from ring rafters (at mid span),Pm =P+Self w,t = 664.21 kg
Max.Bending Moment ,M = 0.064 wt*L2 +Pm*L/4 +wm * L2 /8 = 1300 kg-m
Minimum yield strenght for A36 structural material, Fy = 248 Mpa
Allowable bending stress of A36 = 0.66Fy = 1669.0711 kg/cm2
Sectionmodulus required, in cm³ Z = M*100/fy = 78 cm³
Section modulus available < 181.49478 cm³
Safe
Max.Bending stress ,fb =M/Z = 70.218993 Mpa
Safe
Beam deflection .= ∆
∆ = 0.00652*wt*L4/E.Ix +P*L3/ 48*E*Ix + 5*wm*L4 / (384*E*Ix) = 1.429 cm
Max.deflection allowable =Lr/360 = = 1.951 cm
OK
The Member subjected to both axial and bending stress
Calculation allowables stress of compressive
Compressive force on Main Beam ,C =Rf/sinΘ = 1432.57 kg
Radius of Gyrati = = 83.30983 mm
Selndrness ratio , R =L/r = 84.32
Cc =Beam Selenderness Ratio = SQRT (2 ∏^2 x E / Fy ) = 154.1
Where : =
E=Modulus of Elasticity for Column material at design tempreature = 199000 Mpa
Fy= Yield stress for cloumns material at design tempreature = 165 Mpa
Fs = Factor Safety = 2.1
Since R = 84.3
Using AISC specification Formulas Section E 2 , let K=1
R 84.3 Since KL/r < Cc : eq(1) >>>>>>>Applicable
Allowable Compressive Stress , Fa
Fa =(([1-R^2/(2*Cc^2)]*FY)/F.S) = = 66.9 Mpa--------------(1)
Fa =(12 π^2*E)/(23 * R^2) = = 144.1 Mpa--------------(2)
Beam Cross section Area = 8388 mm2
Compressive stress , fc =C/A = 1.7 Mpa >>>>>Safe
Allowable Bending stress , Fb = 165 Mpa
Actual Bending stress , fb = 70.22 Mpa
Allowable compressive stress , Fa = 66.9 Mpa
Actual Compressive stress , fc = 1.7 Mpa
Sum.actual stresses to allowable should be less than 1
Max.Stress at top Flange =fb+fc 0.45 >>>>>ok
Max.Stress at BottomFlange =fc+f fb / Fb + fc/Fc < 1 71.89 Mpa
(iv) Sizing of Ring Rafters
span L = 1.638 m
Use 14 NOS. UPN 200 As ring rafters.
weight wr = 25.3 kg/m
Sectional modulus Z = 200.15232 cm³
Moment of Inertia Ix = 2001.5232 cm4
Total concentrated load P = 623 kg
Load due to part of roof load on ring Beams Wc = 0.00 kg/m =
Max.bending moment acting on the beam M = P*L/4 +wr*L2/8+wc*L2/8 = 264 kg-m
allowable strenght for A36 structural material, Fy = 1669.0711 kg/cm2
Sectional modulus required, in cm³ Z = M*100/f = 15.788842 cm³
< 200.15 cm³ Safe
Max.Bending stress ,fb =M/Z = 12.9 Mpa Safe
Beam deflection = P*L3/ 48*E*Ix + 5*wr*L4 / (384*E*Ix) = 0.014 cm
Max.Deflection Allowabel =L/360 = 0.46 cm OK
(v)Lateral Bracing (using LAMI,S THEOREM)

60
Lateral Bracing>>>>>>>>> X 60 X 6
C.S.A = 684 mm2
W, 5.4 kg/m
No. of Lateral Bracing along Main Beam+Ring Rafters which working as Lateral Bracin 3
Compressive transmitted from Main Rafter To Ring Rafter =Cx sinß/sinφ = 3218.96 kg
ß angle between Ring Beam and Main Rafter = 1.35 rad
φ angle between Main rafters = 0.45 rad
Tenstion stress ,fc = 15.39 Mpa
Allowable stress =0.68 Yield Stress( for Tenstion) 170 Mpa safe
Bracing weight ( Approx.) 780 kg
Design of Crown Ring TOP Part ( Reff.Roark 5 th eddition Tabel 17 Ref.No.7)

3
2

d 150 mm
c b 100 mm
1 s 10 mm
t 10 mm
h 130 mm
Compressive Forces on Crown Ring weld size 12 mm

Section size Area(A) x Ax Ax2 Ig =bh3/12

x h- cm Cm 2
Cm Cm 3
Cm 4
Cm4
1 13 x 1 13 0.5 6.5 3.25 1.08
2 1 X 10 10 5.5 55 302.5 83.33
3 1 X 10 10 5.5 55 302.5 83.33
∑ (total) 33 116.5 608.3 167.75

Xg =∑Ax /∑A = 3.530 cm

C =∑LT -Xg = 7.67 cm
IX = ∑ Ig +∑ AX2 -[ (∑AX)2 /∑A ] = 364.7 Cm4
Zx = Ix / C = 47.55 Cm4
Crown Radius Corroded ,R 600 mm 0.6 m
ψ = Angle Between Raters 26 °

α = 1/2 Angle between Rafters 12.9 °

1/α =360 /(2∏*α) 4.456 radians
1/sin α 4.494
1/Tanα 4.381
Horiz.Load on Ring "H" =C *cos(Θ) = 14.0 KN
C.S.A OF Corroded Crown Ring ,A = 3300 mm 2
0.003 m 2
Section Modulus ,Zyy 47553 mm 4

Moment Between Rafters Forces is "Mo"

Mo = (H *R/2)*(1/sin α -1/α) 2E+05 N
Compression in Ring is "No"= H /2 *(1/sinα) 31458 N
Mo/Z 3.323 N/mm 2
No/A 9.533 N/mm 2
Total Comp.Stress in Ring =Mo/Z +No/A 12.86 N/mm 2
Allowable stress =0.67 yield stress 167.5 Mpa OK
Moment between Rafters Forces is Mi
Mi =(H*R/2)*(1/α -1/tanα) 3E+05 N-mm
Tension in Ring is "Ni" = H/2 *(1/tan α) 30669 N
Mi/6.6288115 N/mm^2
Ni/ 9.2937299 N/mm^2
Total Tension/compression Stresses in Ring = Mi/Z +Ni /A = 15.9 Mpa OK
Weight of Crown Ring 166.1 kg
Design of curb Section
As per Sec. 5.5.3
A tension or compression ring is often required to resist the circumferential forces
generated by the discontinous membrane forces.
S = F / (AL + 0.78 (Rt)0.5)
Provided size of curb angle 150 X 150 x 15
w/r AL = provided area of curb angle, in in² = 4275 mm^2
= 6.626263 in²
Ap= participating area of the shell 0.78 (Rt)0.5 , in in² = 2.73 in²
Ø = angle between horizontal and roof = 9.470 deg
F = dead load + live load on the curb angle, in lb. = 8047 lb
R = radius of exterior surface of the shell, in in. = 287.40 in
t = thickness of the top shell course, in in. = 0.043 in
S = actual stress at the curb angle = 860 psi
Sa= all. stress for tension and comp.rings (table 4 and 5) = 15000 psi
Safe
Curb Section having multiple equispace Stress anaylysis
(Reff. Roark 5 th eddition table 17 case 7)

No.of equispaced loads acting on Curb Sec 14.00

Section size Area(A) x Ax Ax2 Ig =bh3/12
b-cm x h- cm Cm2 Cm Cm3 Cm4 Cm4
1 1.5 x 15 22.5 7.5 168.75 1265.63 421.875
2 15 X 1.5 22.5 0.75 16.875 12.6563 4.21875
3 14 X 0.8 11.2 0.4 4.48 1.792 0.5973333

∑ (total) ### 190.105 1280 426.6911

Xg =∑Ax /∑A = 3.383 cm
C =∑LT -Xg = 11.62 cm
IX = ∑ Ig +∑ AX2 -[ (∑AX)2 /∑A ] = 1063.705 Cm4
Zx = Ix / C = 91.5618 Cm4
Curb section Radius Corroded ,R 10069.5 mm 10.0695 m
ψ = Angle Between Raters 25.714 °
α = 1/2 Angle between Rafters 12.857 °
1/α =360 /(2∏*α) 4.456 radians
1/sin α 4.494
1/Tanα 4.381
Horiz.Load on Ring "H" =C *cos(Θ) 7.0 KN
C.S.A OF Corroded Crown Ring ,A = 5620 mm^2 0.00562 m 2
Section Modulus ,Zyy 91561.8 mm3
Moment Between Loads"H" "Mo"
Mo = (H *R/2)*(1/sin α -1/α) 1327360.99665 N-mm
Compression in Ring is "No"= H /2 *(1/sinα) 15746.4346577 N
Mo/Z 14.49689 N/mm2
No/A 2.801857 N/mm2
Total Comp.Stress in Ring =Mo/Z +No/A 17.29874 N/mm2
Design Allowable stress 160.8 Mpa OK
Moment under load "H" Mi

Mi =(H*R/2)*(1/α -1/tanα) 2648037 N-mm

Tension in Ring is "Ni" = H/2 *(1/tan α) 15351.64 N
Mi/Z = 28.92 N/mm 2
Ni/A = 2.732 N/mm 2
Total Tension/compression Stresses in Ring = Mi/Z +N 31.7 Mpa OK

Deflection in the Ring due to Load From Rafters

Radial Displacement at each load point

1/sin 2α = 20.20 sin α = 0.222521

α = 0.2244 cosα = 0.974928
1/2α = 0.1122 1/2 sin α.cosα = 0.108471
E = 2E+06 N/mm2 1/α = 4.456338
I = 1E+07 mm4
Radial displacement at each Load (outwards) 0.04 mm
L spacing between Rafters 1638 mm
Acceptable displacement =L/300 = 8.19 mm OK

Radial displacement at each Load (inwards)

Radial displacement between each load point

2/α 8.9127
1/sinα 4.494
cosα 0.9749
sin2α 0.0495
α *(cosα/sin2α) 4.4183
Radial displacement between each load point (inwards) 0.04 mm OK

Structure 4,607.7 kg
Curb section 2,791.22 kg
Total Weight of strcture 7,398.92 kg
Plates 6,946.4 kg
6 .0 WIND LOAD CALCULATION (OVERTURNING STABILITY)
6 .1 WIND DESIGN CALCULATION
Internal design pressure, Pi ( @ 0.0 mbarg. ) = 0 N/mm²
Insulation thickness, ti = 0 mm
Nominal diameter of tank, D = 14,610 mm
Tank height , Hs = 9,750 mm
Roof slope, ß° = 9.470 °
Roof height, Hr = 1,218 mm
Height from tank bottom to shell centre, Ls = 4,875 mm
Height from tank bottom to roof centre,Lr = 10,156 mm
Min. depth of product (always present in tank) , Hw = 400 mm
Weight of tank, (corroded condition) Wt 54,716 kg ) = 536,763 N
Weight of Remining product Ww ------------------ = 177,373 N
Weight of shell @ Attachements(corroded) , WDL (@ 25,354 kg ) = 248,723 N
Wind Speed = 150 kmph
6 .2 WIND FORCE CALCULATION
As per API 650 clause 5.2.1(j), the wind pressure are as follows:-
Wind pressure on conical surfaces , wr (@ 30.00 psf ) = 0.0014369 N/mm²
Wind pressure on cylindrical surfaces, ws (@ 18.00 psf ) = 0.0008621 N/mm²
Wind correction factor, kw (= V /190)² = 4.00
Projected area of roof, Ar ( = 0.5..Do.Hr ) = 8,906,833 mm²
Projected area of shell, As ( = .Do.(Hs +6000) = 230,265,000 mm²
Total wind load exerted on roof, ( = wr.kw.Ar ) = 51,193 N
Total wind load exerted on shell,( = ws.kw.As ) = 794,082 N
Wind shear Force acting on the Tank = 845,275 N
Total wind moment on tank, Mw ( = Fr.Lr + Fs.Ls ) = 4,391,071,423 Nmm
6 .3 OVERTURNING STABILITY AGAINST WIND LOADING

Wind Uplift Load

Internal Pressure Load

D/2

Wind lo H
shell, FS

H/2 Momment about

shell to bottom joint

Dead Load (WDL)

Liquid hold down weight (wa)
 For tank to be structurally stable without anchorage, the following uplift criteria shall satisfy:

Criteri0.6 Mw + Mpi < MDL / 1.5

CriteriMw + 0.4 Mpi < (MDL +MF) / 2

where:

Mpi = Moment about the shell-to-bottom joint from design internal pressure
= Uplift thrust on roof due to internal pressure x 1/2 tank diameter
= ( 1/4 p. D2. Pi ). 1/2. D = 0 Nmm

Mw = Overturning moment about the shell-to-bottom joint from horizontal

plus vertical wind pressure
= Total wind moment on tank, ( = Fr.Lr + Fs.Ls ) = 4,391,071,423 Nmm

MDL = Moment about the shell-to-bottom joint from the weight of the
shell and the roof supported by the shell.
= 0.5. D. WDL = 1,816,921,473 Nmm

MF = Moment about the shell-to-bottom joint from liquid weight (wa) = 18,204,227,853 Nmm
= (wa. p D). D
1000 2

wa = Weight of liquid = 70 tb Fby. H = 54,294.01 N/m

H = Design liquid height = 9.4 m
tb = Thickness of Bottom plate under the shell = 16 mm
Fby = Minimum specified yeid stress of the bottom plate under the shell = 250 N/m2

FOR CRITERIA 1 0.6 Mw + Mpi < MDL / 1.5

0.6 Mw + Mpi = 2,634,642,854 Nmm
MDL / 1.5 = 1,211,280,982 Nmm
Not satisfactory

FOR CRITERIA 2 Mw + 0.4 Mpi < (MDL +MF) / 2

Mw + 0.4 Mpi = 4,391,071,423 Nmm
(MDL +MF) / 2 = 10,010,574,663 Nmm
Satisfactory
Since,
0.6 Mw+ Mpi > MDL/1.5, and
Mw+0.4 Mpi < 1/2 (MDL+ MF)

* The tank anchorage is …. Required.

7 .0 SEISMIC FORCE CALCULATION
7 .1 SEISMIC LOADS DESIGN
7 .1.1GEOMETRIC DATA
Seismic peak ground acceleration, Sp = 0.1 g
Importance factor, I = 1.15
Site Class = E

Nominal diameter of tank, D = 14,600 mm

Total height of tank shell, Ht = 9,750 mm
Ht.from bottom shell to COG of shell,Xs = 4,875 mm
Maximum design liquid level, H = 9,400 mm
Ht.from bottom shell to COG of roof,Xr = 10,566 mm
Design specific gravity of liquid, G = 1

Total weight of tank shell , W (@ 54,716 kg ) = 536,763 N

Weight of tank roof plates., Wr (@ 0 kg ) = 0N
Weight of tank contents , Wp (@ 1,573,705 kg ) = 15,438,050 N
Weight of tank bottom, , W (@ 22,089 kg ) = 216,697 N

7 .1.2DESIGN SPECTRAL RESPONSE ACCELERATIONS

Impulsive spectral acceleration parameter, Ai

I
Ai = 2.5 Q Fa So = 0.12
Rwi

Convective spectral acceleration parameter, Ac

When Tc ≤ TL
Ts I
c= 2.5 K Q Fa So ≤ Ai = -
Tc Rwc

When Tc > TL
Ts .TL I
c= 2.5 K Q Fa So ≤ Ai = 0.41772593824
Tc 2
Rwc

where
Q = Scaling factor = 1
K = Coefficient to adjust the spectral damping from 5% - 0.5% = 1.5
Fa = Acceleration based site coefficient as per Table E-1 = 1.7
Fv = Velocity-based site coefficient as per Table E-2 = 2.8
So = Substitution for seismic peak ground acceleration Sp = 0.1
Rwi = Force reduction coefficient for impulsive mode as per Table E-4= 4
Rwc = Force reduction coefficient for convective mode as per Table E-= 2
TL = Regional dependent transition period for longer period = 4s
ground motion
Tc = First mode sloshing wave period for convective mode = 4.01 s
Ts = Fv. S1/ Fa. Ss = 4.58
7 .1.3CONVECTIVE (SLOSHING ) PERIOD
The first mode sloshing wave period,

Tc = 1.8 Ks √ D = 4.01 s

where,
Ks = sloshing period coefficient

0.578
Ks = 3.68 H = 0.58
tanh
D

Fv . S1
Ts =
Fa . Ss
= 4.58
where,
Fa = Acceleration based site coefficient (at 0.2 sec perios)
as per Table E-1 = 1.2
Fv = Velocity-based site coefficient (at 1 sec. period) as per Table E- = 1.6800

S1 = Maximum considered earthquake, 5% damped, spectral response

acceleration parameter at the period of one second, %g
Ss = Maximum considered earthquake, 5% damped, spectral response
acceleration parameter at shorts period of 0.2 second, %g

For regions outside USA, sites not defined by ASCE 7 method,

S1 = 1.25 Sp = 0.36
Ss = 2.5 Sp = 0.11

Since Tc > TL , the convective spectral acceleration parameter Ac = 0.42

and the impulsive spectral acceleration parameter Ai = 0.12

7 .2 OVERTURNING STABILITY AGAINST SEISMIC LOADING

7 .2.1EFFECTIVE MASS OF TANK CONTENTS
Effective impulsive portion of the liquid weight,

For D/H ≥ 1.333,

tanh (0.866.D/H)
Wi = . Wp = 10018569 N
0.866. D/H

For D/H < 1.333,

D
Wi = 1.0 - 0.218 . Wp = - N
H

Since /H > 1.333 , effective impulsive portion of the liquid weight, Wi = 10018569 N

Effective convective weight,

D 3.67H
Wc = 0.230 tanh . Wp = 5,418,085.94 N
H D
7 .2.2CENTER OF ACTION FOR EFFECTIVE LATERAL FORCES
The height from the bottom of the Tank Shell to the center of action of the lateral
seismic forces related to the impulsive liquid force for ringwall moment,

For D/H ≥ 1.333,

Xi = 0.375H = 3525 mm

For D/H < 1.333,

D
Xi = 0.5 - 0.094 .H = - mm
H

Since /H > 1.333 , Xi = 3,525.00 mm

The height from the bottom of the Tank Shell to the center of action of the lateral
seismic forces related to the convective liquid force for ringwall moment,

3.67 H
cosh -1
D
c = 1.0 - .H = 6,106.43 mm
3.67H 3.67 H
sinh
D D

7 .2.3OVERTURNING MOMENT
The seismic overturning moment at the base of the tank shell shall be the SRSS summation of the impulsive
and convective components multiplied by the respective moment arms to the center of action of the forces.

Ringwall moment,

Mrw = [Ai ( Wi. Xi + Ws. Xs + Wr. Xr)]2 + [Ac (Wc. Xc)]2 = 14,576,991,752 Nmm

= 14576991.7518 Nm

7 .2.4SHEAR FORCE
The seismic base shear shall be defined as the SRSS combination of the impulsive and convective components.

V= Vi2 + Vc2 = 2,618,170.22 N

where, Vi = Ai (Ws + Wr +Wf + Wi) = 1,316,207.21 N

Vc = Ac. Wc = 2,263,275.03 N
7 .3 RESISTANCE TO OVERTURNING
7 .3.1THICKNESS OF THE BOTTOM PLATE UNDER THE SHELL & ITS RADIAL WIDTH
Bottom/Annular plate thickness , ta = 16.00 mm
Thickness of bottom shell course, ts = 10.00 mm
Bottom/Annular plate radial width, Ls = 700.0 mm
Min. specified yield strength of bottom annulus, Fy = 250.0 N/mm2
Min. specified yield strength of bottom shell course, Fty = 250.0 N/mm2

Anchorage Ratio, J

Mrw
J= = 1.86
D ( Wt (1 - 0.4 Av) + Wa )
2

where,
Av = Vertical earthquake acceleration coefficient = 2
Wt = Tank and roof weight acting at base of shell = 11.70 N/mm
wa = Resisting force of the annulus = 34.34 N/mm

Weight of tank shell and portion of roof supported by the shell,

Ws
Wt = + wrs = 11.70 N/mm
p. D

wrs = Roof load acting on the shell, including 10% of specified

= 0.00 N/mm
snow load. ( Zero for floating roof)

The resisting force of the annulus,

wa = 99 ta Fy. H. Ge ≤ 196. H. D. Ge = 34,340.30 N/m

wa < 196.H.D.Ge = 5,379,808,000.00

Ge = Effective specific gravity including vertical seismic effect

= G. (1 - 0.4 Av) = 0.2

The Tank is not stable and cannot be self -Anchorage J > 1.54

7 .3.2ANNULAR PLATE REQUIREMENT

If the thickness of the bottom plate under the shell is thicker than the remainder
of the bottom, then the minimum radial width of the bottom plate,

Fy
L= 0.01723 ta = 3,179.04 mm
H. Ge

The maximum width of annulus for determining the resisting force, 0.035 = 511.00 mm

Since L < 0.035 D, the minimum radial width should be = 3,179.04 mm

And,
Since Ls < L, the bottom/ annular plate width is Satisfactory.
7 .3.3SHELL COMPRESSION
MECHANICALLY-ANCHORED TANKS

Maximum longitudinal shell compression,

1.273 Mrw 1
sc = wt ( 1 + 0.4 Av) +
D 2
ts = 10.81 N/mm

7 .3.4MAXIMUM ALLOWABLE SHELL COMPRESSION

GHD² ( D in m ) = 20.037 m³/mm²

A=
ts²

For GHD²/(ts²) < 44 m³/mm²,

83.ts
Fc = + 7.5{G.H}½
2.5D = 45.73 N/mm²

For GHD²/(ts²) ³ 44 m³/mm²,

83.ts = - N/mm²
Fc =
D

Therefore, Fa ( < 0.5Fty ) = 45.73 N/mm²

Since sc < Fc, therefore the tank is structurally Stable.

7 .4 FREE BOARD FOR SLOSHING WAVE HEIGHT

Sloshing wave height above the product design height,

d s = 0.5 D. Af = 5,303.30 mm

where:
For SUG I and II,
When Tc ≤ 4
1 Ts
Af = K. SD1. I. =2.5 K Q Fa So = 0.84
Tc Tc

When Tc > 4
4 4Ts
Af = K. SD1. I. =2.5 K Q Fa So = 0.84
Tc 2 Tc 2

For SUG III

When Tc ≤ TL
1 Ts
Af = K. SD1 =2.5 K Q Fa So = 0.73
Tc Tc

When Tc > TL
TL Ts. TL
Af = K. SD1 =2.5 K Q Fa So = 0.73
Tc 2 Tc 2

Since SUG is II and Tc > TL , Af = 0.73

For SDS = Q Fa Ss = 0.187 < 0.33g,
Minimum required freeboard, d( as per Table E-7) = 5,303.30 mm

7 .5 TANK ANCHORAGE
7 .5.1GEOMETRIC DATA
Number of bolts , N = 12
Dia. of anchor bolt, d = 36 mm
Dia. of anchor bolt,d.corr (less 3.000 mm) (min.size.25.4 mm ) = 30 mm
Bolts circle diameter, Da = 14,800 mm
Root area of each hold down bolt, Ab = 707 mm²
Spacing between anchor bolts, Sp = 3,875 mm

7 .5.2MATERIAL & MECHANICAL PROPERTIES

Material used : SA293 GR B7/2H
Specific minimum yield stress, Sy = 723.9495 N/mm²
Allowable tensile strength, St.all ( 0.80Sy ) ( Table 5-21a ) = 579.16 N/mm²

Uplift force due to seismic loading,

1.273 Mrw = 3,885,592 N
WAB = - wt ( 1 - 0.4 Av) + wint
Dc²
where
Mrw = Overturing moment due to seismic = 14576991752 Nmm
Dc = Nominal diameter of tank = 14,600 mm
wt = Tank and roof weight acting at base of shell, = 11.70 N/mm
Av = Vertical earthquake acceleration coefficient = 2.00
wint = Uplift thrust due to internal pressure = 0 N/mm
Tensile stress,
sb = WAB / N.Ab = 458.08 N/mm²
Since sb < St.all,therefore the anchor bolt size is Satisfactory.
8 0 ANCHOR CHAIR DESIGN

d b
twdt

a e

h hg tm

g ta

8 1 ANCHOR CHAIR DESIGN

AISI 'Steel Plate Engr Data' Dec. 92, Vol. 2, Part VII

Thickness of Gusset Plates j = 12 mm

Width of Gussets at Top Plate twdt = 230 mm
Width of Gussets at Base Plate bwdt = 180 mm
Height of Gussets hg = 274 mm
Height of Chair h = 292 mm
Top plate thickness c = 18 mm
Distance between Gussets g = 132 mm
Circumferential width of Top plate a = 180 mm
Radial width of top plate b = 250 mm
Anchor Bolts No. Nb = 12 Nos.
Distance from Bolt Center to Gusset cg = 90 mm
External corrosion allowance for chairs ca* = 0 mm
Top Plate Allowable stress σ all. = 160000 kpa
No.of Gussets per Bolt NG = 2 Nos.
Bottom plates shell course thickness ts = 10.00 mm
Shell course corrosion allowance ca = 0.00 mm
Bottom plates shell course thickness (corroded) tsc = 10.00 mm
Thickness of Annular ring ta = 16.00 mm
Bolt eccentricity e = 70 mm
Bolt diameter d = 36 mm
Allowable Bending stress = σ all.*1.5 σ all. = 240000 kpa
Bolt Load P = 323799 N
Tank radius R = 14600 mm
Average thickness of bottom shell course+pad (cotm = 20.00 mm
Stress due to Top plate thickness
Stress in the Top plate at Given thickness
σ top =P(0.375*b -0.22*d )/e/(c-ca*)2 σ tc = 22056.9 kpa pass
Gusset plate thickness as per AISI
Gusset plate thickness = MAX.(12 mm , 0.04 hg j = 12 mm
With the following condtion must be pass
J+tm >P/1000/25 32.00 > 12.952 pass

stresses at the Top Plate including axial stress due to chair height as per AISI
Top Plate stress =P*e/ tm 2 *K
where K= 1.32 * Z / [(1.43*a*h2 / R*tm ) +(4*a*h2)0.333] + 0.031/(R*tm)0.5
Z = 1/ [ 0.1777*a*ta / (R*tm )0.5 + (ta /tm )2 +1]

Z = 0.38654
K = 0.00115
Top Plate stress σ th = 65.1214 kpa pass

Anchor chairs weight

Top plate weight = 6.3585 kg
Gusset plates weight = 10.5824 kg
Pad plate = 6.17481 kg
Total weight od chair = 23.1157 kg
Total weight od chairs = 277.389 kg
6 8 VENT CALCULATION

Check for venting capacity

Capacity of the tank, C = 1,632 m³
= 10,267 barrel
pumping out rate, Re = 524 m³/hr
= 3,297 barrel/hr
pumping in rate , Rf = 524 m³/hr
= 3,297 barrel/hr
Inbreathing (Vacuum Relief)
As per clause 4.3.2.1.1 of API 2000
Due to maximum movement out of tank, Q1 = 18,461 SCFH
As per clause 4.3.2.1.2 of API 2000
Due to thermal inbreathing, Q2 10,000 SCFH
VENT SIZE CALC. & EMERGENCY VENT = 28,461 SCFH
Out breathing (Pressure Relief) =
As per clause 4.3.2.2.1 of API 2000
Due to maximum movement into tank , Q1 = 10,000 SCFH
As per clause 4.3.2.2.2 of API 2000
Due to thermal out breathing , Q2 = 10,000 SCFH
Total pressure relief required = 20,000 SCFH
Maximum relief required = 28,461 SCFH
We Assume the is fully air tighted and there is must be created apressure in the tank during the filling of liquid
.since the tank is fully closed.this pressure might be caused to lift the roof plate from tank
so we consider to provide engough vent opening so that the pressure inside tank would be lesser than of roof acting
Dead Load acting on roof plate
Thickness of plates ( 0.24 ) in = 6 mm
DL. Acting on Roof ( 0.07 ) PSI = 47.1 kg/m2
So we consider Set Pressure 3.04615 in water pressure
Considering 3.04615 inches of water pressure, for above capacity size
of the free vent required (attached Mushroom (free) vents chart) is=
Total pressure relief required 3.2399 in water
Provided free vent size (N5-Nozzle) = 1 pcs. SAFE
6"Ø
14 WEIGHT ANALYSIS

ITEM : QP10-Q-6764_TypicalSteelWaterTower1500m³

1 GENERAL
Design Type of roof
code : API 650 11th Edition fixed
: conical w/col,s
Inside Tank height
diameter : 14,600 mm : 9,750 mm
Steel density Roof plates lapping Annular/Bottom plates lapping
Shell / Btm : 7,850 kg/m³ factor : 25mm factor : 25 mm
Roof : 7,850 kg/m³
2 SHELL COURSES

ONE - FOOT METHOD Y

Course No. Material Thickness Width Weight
(mm) (mm) (kg)
1 A36 10.00 1,980 7,134
2 A36 8.00 1,980 5,706
3 A36 6.00 1,980 4,279
4 A36 6.00 1,950 4,214
5 A36 6.00 1,860 4,020
6 0 0.00 0 0
7 0 0.00 0 0
8 0 0.00 0 0
9 0 0.00 0 0
10 0 0.00 0 0
11 0 0.00 0 0

Total weight of shell plates = 25,354 kg

3 BOTTOM PLATES
ANNULAR RING Y
Material Thickness Width Weight
(mm) (mm) (kg)
A36 16.00 700 3,961 = 3,961 kg
BOTTOM PLATES
Material Thickness Outside Dia. Weight
(mm) (mm) (kg)
A36 16.00 13,390 18,128.6 = 18,129 kg

4 TOP CURB ANGLE Y

Material Size Length Unit Weight Weight
BIULT UP SEC. (mm) (kg/m) (kg)
A36 L100X100X15 46,181 = 1,021 kg

5 WIND GIRDERS N
Material Size Qty Length Unit Weight Weight
BIULT UP SEC. (mm) (kg/m) (kg)
A36 Err:509 1 - - - = - kg

7 NOZZLES N
Total weight of nozzles 1,000 = 0 kg

8 NOZZLES ,PIPES SUPPORTES AND OTHER MISC. Y

Assuming 5.00 % of total weight 1,268 = 1,268 kg
10 LADDER Y
Stair weight 918.00 Kg 918 = 918 kg

12 ROOF HANDRAILS
Handrails weig 760.14 Kg 760 = 760 kg

13 ROOF STRUCTURE `
Material Weight
(kg)
ASTM A36 0 = 0 kg
14 ROOF PLATES
Material Thickness Weight
(mm) (kg)
A36 5.00 0 = 0 kg
15 MANHOLES ( FABRICATED PLATES) Y Weight
Material QTY (kg)
A36 1 275 275 kg
16 BOLTS Y
Material QTY (kg)
ASTM A 193GR B7 /A194 GR 2H H.D 1000 0.25 250 kg
20 ANCHOR BLOTS QTY Y (kg)
12 0.25 3 kg

21 ANCHOR CHAIRS QTY Y (kg)

12 23.12 277 kg
22 SUMP DRAIN N
QTY (kg)
1 450.00 - kg
23 EXTERNAL PIPES (INTAK & OVER FLOW) Y
(kg)
2,500 2,500 kg

24 Hydrostatic water height (@ 9,750 mm ) = 1,632,301 kg

ERECTION WEIGHT
OPERATING WEIGHT 54,716 kg
= 1,628,421
FIELD HYDROSTATIC TEST WEIGHT = 1,687,017 kg
 15 BOTTOM
(i) EVALUATION OF BOTTOM PLATE THICKNESS

BULT UP SEC 0.5 m

2.43 m
We Consider SEC-A as basic Calculation
From ROARK,S STRESS STRAIN FORMULA 7ED.TABLE 11.4
Rectnagular Plte all edges simply supported unifrom load over entirenplate

a 2430 mm 95.669 in
b 500 mm 19.685 in
a/b 4.9
α 0.1417
β
= 0.7476
γ 0.501

Material A36
Design stress 160 Mpa = 23200 psi
Modulus of Elasticity 2E+11 psi
Water Load(q) 92214 N/m2 13.3745 PSI

t =b *( β *q/s)0.5 =0.408663 in10.21659 mm

Provided thickness 16 mm 0.64 in
Max.deflection (α q b )/Et
4 3
0.00001 in 0.0001 mm
Allowable deflection =0.5 Nom.thk. Of Plate 8 mm Acceptable

Max.bending stress,Sb =(β *q*b 2/t 2

) 9459.3149 PSI
65.2196779 Mpa Acceptable
(II) STIFFENERS DESIGN
Load of stiffener ,U 9.4 Ton/m2 224080 N/m
L 2.43 m
b 0.5 m
S, Design stress 160 Mpa 160000000 N/m2
Zreq. 0.1284 *L*b*U/S 218 cm3
We Provided Profile IPE 30z 533 cm3 Acceptable