Design of Conical Storage Tank

OWNER : Siemens Ltd.PROJECT : 1100 MW SUGEN CCPP PROJECT CAL # A191-44-01CONSULTANT : - REV. 2PROJECT NO.: A-191 IT. NO. GHC 01/02

DATE18.07.2007

DESIGN OF STORAGE TANK :

Item No. = GHC 01 / 02

Type of Tank = Supported Roof

Quantity = 2 Nos.

Design Code = API 650 10th EDITION ADD. 2003

Applicable Appendix = APP. E

Stored Product = DM WATER

Design Pressure = Liq. Head + 0.00 mm of Water

Diameter of Tank "D" = 10.000 M

Height of Tank "H" = 11.00 M

Design Liq. Storage Ht. "Hd" = 11.00 M FOR SHELL DESIGN ONLY

Capacity - Total = 863.94 Cu.Mtr.Considering height upto = 11.00 Mtrs.

Capacity - Designed = 856.08 Cu.Mtr.Considering height upto = 10.90 Mtrs.

Capacity - Nominal = 800 Cu.Mtr.

Design Sp. Gravity "G" = 1

Product Sp. Gravity = 1

Corrosion allowance "C.A." = 2 MM FOR SHELL= 1 MM FOR ROOF= 2 MM FOR BOTTOM

Design Temp. Max. = 60.0 Deg.CMin. = 4.4 Deg.C

Joint Efficiency = AS PER CODE

DATE18.07.2007

NEWTON ENGINEERING & CHEMICALS LTD.

PREP. BYAAG ASG

CHKD. BY APPD. BYA.S.G.

file name :10MDIAX11MHT

Page 1 of 17


DATE18.07.2007

DATE18.07.2007


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Radiography = AS PER 6.1.2 OF API 650

Material of Construction =

Y.S. T.S. Sd St

Mpa Mpa Mpa Mpa1st 250 410 164.00 175.712nd 250 410 164.00 175.713rd 250 410 164.00 175.714th 250 410 164.00 175.715th 250 410 164.00 175.716th 250 410 164.00 175.717th 250 410 164.00 175.71

Temp. Correction Factor = 1 (App.M Not Applicable)

Wind Data = AS PER PROJECT SPEC. (Refer Section No. 3 )

Seismic Data = AS PER PROJECT SPEC. (Refer Section No. 8 )

Wind Velocity = 160.00 Kmph

Design Wind Pressure = 175.39 Kg./Sq.M

Shape Factor Shell = AS PER API 650Roof = AS PER API 650

Insulation Thickness (If any) = 0 MM

Filling Rate = 54 Cu.M./Hr.

Emptying Rate = 90 Cu.M./Hr.

1. DESIGN OF SHELL : (ONE FOOT METHOD)

As per API 650 Cl. 3.6.3.2, the minimum required thickness shallbe greater of the values computed by following formulae,

4.9 x D x (H - 0.3) x Gtd = ------------------------------ + C.A.

4.9 x D x (H - 0.3)tt = ------------------------

St

Sd

IS 2062 GR. AIS 2062 GR. AIS 2062 GR. AIS 2062 GR. A

IS 2062 GR. AIS 2062 GR. A

MATERIAL SPEC.

IS 2062 GR. A

Shell Course


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DATE18.07.2007

DATE18.07.2007


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Where,td = Design Shell Thickness in MMtt = Hydrostatic Test Shell Thickness in MM

Minimum Thickness of Shell as per Cl. 3.6.1.1 is = 5.00 mm

Minimum required by Client (if any) = 5.00 mm

Shell Width Tank Des.Shell Thickness RemarksNo. Height Height td+C.A. tt Provided

mm MM MM mm mm mm1st 2000 11000 11000 IS 2062 GR. A 5.197 2.98 8 Tp > Tr2nd 1500 9000 9000 IS 2062 GR. A 4.599 2.43 6 Tp > Tr3rd 1500 7500 7500 IS 2062 GR. A 4.151 2.01 5 Tp > Tr4th 1500 6000 6000 IS 2062 GR. A 3.703 1.59 5 Tp > Tr5th 1500 4500 4500 IS 2062 GR. A 3.255 1.17 5 Tp > Tr6th 1500 3000 3000 IS 2062 GR. A 2.807 0.75 5 Tp > Tr7th 1500 1500 1500 IS 2062 GR. A 2.359 0.33 5 Tp > Tr

Hence provided thickness as shown for all shell courses.

Check for Hydrostatic Stress in 1st shell course :

Hydrostatic Stress in 1st shell course is given by,

4.9 x D x (H - 0.3) x GSt = ------------------------------

tp

= 65.538 Mpa < 160.00 Mpa

LAP WELDED BOTTOM PLATES CAN BE USED, HOWEVER BUTT WELDED CONSTRUCTION IS USED

2. Design of Roof Plate Thickness :

As per API 650 Cl. 3.10.2.2, the minimum nominal thickness shall be 5 mm + C.A. for plates in contact with product

Required thickness = 6.00 MMProvided thickness = 6.00 MMRoof Slope / Angle 1 : 6 = 0.17 Rad

= 9.46 Deg.Tank Radius = 5.00 MRoof Plate Location from O/S of Shell = 15.00 mmDeveloped Diameter of Roof = 10.178 MWT. of Roof Plate = KGS.

M.O.C. OF SHELL

4024.08

Thickness Reqd.


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DATE18.07.2007

DATE18.07.2007


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Rafter Type Roof Supporting structure is provided.

3. Calculation of Wind Velocity & Wind Pressure :As per IS 875 Part 3, Basic Wind Speed Vb for this site is 44 M/Sec.

Design Wind Speed Vz is calculated as follows:

Vz = Vb x k1 x k2 x k3

As per IS 875,

k1 = 1 As per Table 1k2 = 1 As per Table 2 for Terrain Cat. 2 Cl. Ak3 = 1

Vz = 44 M/s = 98.45 MPH

= 158.4 KmphAnd,Design Wind Pressure "Pz" is calculated as follows;

Pz = 0.6 x Vz2 = 118.41 Kg/Sq.M

As per API 650, the wind velocity considered for design is,Vz = 160 Kmph

And for this velocity the design wind pressure is,

Pz = 1.72 kPaPz = 175.39 Kg/Sq.M

Wind Velocity as per site conditions 158.40 KmphWind Velocity for Design purpose 160 Kmph

Correction factor for section Modulus is 1(On velocity basis)And correction factor for Vertical Dist. H1 is 1(On velocity basis)4. Sizing of Top Curb angle:

As per API 650 Cl. 3.1.5.9.e, min. curb angle of size is L 51 x 51 x 4.8 Thk.

Provided curb angle of size L 65 x 65 x 6 Thk.


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DATE18.07.2007

DATE18.07.2007


PREP. BYAAG ASG


5. Design of Bottom Plate Thickness :

As per API 650 Cl. 3.4.1, the minimum required thickness shall be 6 mm + C.A.

Requird thickness = 8.00 MMProvided thickness = 8.00 MMBottom Slope 1 : 50 = 0.02 Rad

= 1.15 Deg.Tank Radius = 5.00 MProjection of Bottom Plate = 65.00 mmDeveloped Diameter = 10.148 MProvided Annular Plate Thickness = 0.00 MMWt. of Sketch Plate = 5079.406 KGS.Wt. of Annular Plate = 0.00 KGS.Surface Area of Bottom = 83.30873 Sq.M.

6. Check for Stability of Shell :

As per API 650 Cl. 3.9.7.1, the maximum height of unstiffened shell is100

H1 = 9.47 x t x t / D 3 x ------VZ

Where,D = Nominal Diameter of tank

= 10.008 Mtrs.H1 = Vertical distance between the intermediate

wind girder and top angle.t = As ordered thickness of the top shell

= 3 MMH1 = 4.66 Mtrs.

Calculation of Transposed Width :t uniform = 3.00 mm

Shell Shell Co. t Wtr Cumm.Course Width `W' actual Wtr

No. in MM. mm MM MM1st 2000 6 353.6 8584.262nd 1500 4 730.7 8230.713rd 1500 3 1500.0 7500.004th 1500 3 1500.0 6000.005th 1500 3 1500.0 4500.006th 1500 3 1500.0 3000.007th 1500 3 1500.0 1500.00


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DATE18.07.2007

DATE18.07.2007


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The height of transformed shell 'H'= 8.584 Mtrs.

H1<H, UNSAFE HENCE PROVIDE WIND STIFFENER AS SPECIFIED BELOW

1st Intermediate Wind Stiffener is provided at 2.75 Mtrs. From Top Curb AngleLocation of WG w.r.t. tank height 8.25 Mtrs.Thickness at WG location 3.00 mm

Shell Shell Co. t Wtr Cumm.Course Width `W' actual Wtr

No. in MM. mm MM MM1st 2000 6 353.6 5834.262nd 1500 4 730.7 5480.713rd 1500 3 1500.0 4750.004th 1500 3 1500.0 3250.005th 1500 3 1500.0 1750.006th 250 3 250.0 250.00

8250 5.834 Mtrs.Check for unstiffened height below Int. W.G. at this level

Thk. of shell at 1st wind girder = 5.000 mmThk. of shell at 1st wind girder = 3.000 mm Corroded

H2 = 4.663 Mtrs.Wtr2 = 5.834 Mtrs.

H1<H, UNSAFE HENCE PROVIDE WIND STIFFENER AS SPECIFIED BELOW

Sizing of 1st Intermediate Wind Girder :

As per API 650, Cl.3.9.7.6 the required min. section modulus is,D2 x H1 Vz

2

Zreq. = ------------- x ------17 100

H1 = Dist. of Intermediate W.G. from Top Wind Girder= 2.75 Mtrs.

Zreq. = 15.914 Cu.Cm.


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DATE18.07.2007

DATE18.07.2007


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Provided size for wind girder as below :

100 ANGLE SECTIONL 75 x 75 x 6 Thk.AREA 7.44

99 100 99 IXX 29.1d 1.81

ts ts

Shell Course thickness = 0.5 CMCorroded Thickness = 0.3 CM

PLATE FAB. GIRDERSECT. SIZE Iyy =

Width Axd2

Cm Cm Cm2 Cm Cm3 Cm4 Cm4

1 9.9 0.3 2.97 0.15 0.4455 0.07 0.02232 10 0.6 5.68 2.11 11.9848 25.29 29.13 10 0.6 6 10.6 63.6 674.16 0.18

14.65 76.0303 699.51 29.302M2

Moment of Inertia @ N.A. Inn = Iyy + Ig - -----------A

= 334.24 Cm4

Position of N.A. fm. Ref.Axis Mis given by = ----

A= 5.19 Cm. OR 5.71 Cm.

Y InnSection Modulas provided Zp = ---------

Y= 64.40 Cu.Cm. OR 58.53 Cu.Cm.

Zprovided > Zreqd.Hence Provided Section is Adquate

Thk.

PLATE FAB. GIRDER

AREA

READY MADE ANGLE SECTION

Igd M = Axd


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DATE18.07.2007

DATE18.07.2007


PREP. BYAAG ASG


7. Weight Calculation :

Thk. Thk. MM Weight in Weight inMM (CORR.) Kgs. Kgs.

Unc. Corr.1st 2 8 6 3949.00 2961.162nd 1.5 6 4 2220.87 1480.283rd 1.5 5 3 1850.54 1110.104th 1.5 5 3 1850.54 1110.105th 1.5 5 3 1850.54 1110.106th 1.5 5 3 1850.54 1110.107th 1.5 5 3 1850.54 1110.10

TOTAL : 15422.55 9991.941

1. Weight of Shell (Uncorr.) = 15422.55 Kgs 151243.6 N

2. Weight of Shell (Corr.) = 9991.94 Kgs 97987.5 N

3. Weight Wind Girder = 191 Kgs 1876.24 N

4. Weight of Staircase = 1375 Kgs 13484.14 N

5. Weight of Roof Plates = 4024.08 Kgs 39462.76 N

6. Weight of Annular Plates = 0.00 Kgs 0.00 N

7. Weight of Sketch Plates = 5079.41 Kgs 49811.96 N

8. Weight of Shell Nozzles = 500 Kgs 4903.33 N Assumed

9. Weight of Roof Nozzles = 300 Kgs 2942.00 N Assumed

10.Weight of roof structure = 1250 Kgs 12258.31 N

11. Weight of of Insulation & Accs. = 0.00 Kgs 0.00 N (includes heating coil, supports etc)Total Empty Wt (Uncorr) = 28142.36 Kgs 275982.3 NTotal Empty Wt (Corr) = 22711.75 Kgs 222726.2 N

Weight of Product = 857454.2804 Kgs 8408754.0 N

Weight of Water = 863937.9797 Kgs 8472337.4 N

WidthShell Course


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DATE18.07.2007

DATE18.07.2007


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Weight carried by shell = 7640.40 Kgs. 74926.77 Ni.e. roof plt + structure

C.G. of shell = 626.85 Cm. CorrodedFrom Top of Shell = 599.800 Cm. Uncorroded

C.G. of shell = 473.15 Cm. CorrodedFrom Bot. of Shell = 500.200 Cm. Uncorroded

Weight in Operating Condition = 885596.6 Kgs. Uncorroded

Weight in Hydrotest Condition = 892080.3 Kgs. Uncorroded

Height of Sloshing Wave = 0.096 M

8. CHECK FOR SEISMIC DESIGN AS PER APP. E OF API 650 :

Diameter of Tank "D" = Mtrs.

Max. Design Liq. Height "H" = Mtrs.

Max. Design Liq. Height "H" = Mtrs.

Total Weight of Tank Shell WS = N(Sum of Sr. 1,3,4,8 & 11)Height from Bottom of tankshell to shell C.G. XS = Mtrs.

Total Weight of Tank Roof& Imposed Loads If Any, WR = N(Sum of Sr. 5,9,10 & 12)Total Height of Tank shell HT = Mtrs.

Total Weight of Tank contentsin Product Condition WT = N

Computation of W1,W2,X1 & X2 :D

--------------- = 0.9174H

W1From Fig "E 2" --------------- = 0.80

WT

10.008

5.002

10.900

54663.06

171507.27

(Min. of Max. oper. Level or Tank Height - Sloshing Wave Height)

11.000

8408754.0

10.900


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DATE18.07.2007

DATE18.07.2007


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W2--------------- = 0.21

WT

X1From Fig "E 3" --------------- = 0.41

H

X2--------------- = 0.76

H

Weight effective mass of tank contentsthat moves in unision with the shellis determined per "E 3.2.1" W1 = 6727003.2 N

Height from the bottom of the tank shell to the centroid of lateralseismic force applied to W1 isdeterimned as per "E 3.2.2" X1 = 4.51 Mtrs.

Weight effective mass of tank contentsthat moves in the 1st sloshing modeis determined per "E 3.2.1" W2 = 1773134.92 N

Height from the bottom of the tank shell to the centroid of lateralseismic force applied to W2 isdeterimned as per "E 3.2.2" X2 = 8.27 Mtrs.

Seismic Coeff. As per IS 1893 :For Zone III Z = 0.1600Importance Factor I = 1.50Sa / g for T as calculated below = 0.41R (on the basis I/R shall not be greater than 1) = 1.50

Z I Sa /gAh = --------------- = 0.033

2 R

Seismic Coeff. for API 650 Z = 0.0750(Assumed on Safer Side)Importance Factor I = 1.00


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DATE18.07.2007

DATE18.07.2007


PREP. BYAAG ASG


Lateral Earthquake Coeff. C1 = 0.60as per "E 3.3"

C2 = As calculated below

Site Amplification Factor S = 1.50as per Table "E-3"

Factor K from Fig. "E-4" = 0.58

Natural Period T = 3.31

Therefore,C2 = 0.34

The overturning moment due to seismic forces applied to bottom of theshell is given by,

M = ZI [ C1 x WS x XS + C1 x WR x HT + C1 x W1 x X1 + C2 x W2 x X2]

M = N - Mtrs= Kg - Mtrs

Shear Force due to seismic action

Fs = ZI [ C1 x WS+ C1 x WR + C1 x W1+ C2 x W2]= N= Kg.

As per Cl. E 4.1,

wL = 99 x tb Fby x G x H

Where,wL : Maximum Wt. of tank contents that resists

the shell overturning moment in N/mtb : Thickness of bottom plate under the shell

in Corroded Condition: 6 MM

Fby : Min. Y.S. of bottom plate under the shell

: 250 Mpa

358067.991936500.30498

183960.35581804651.091


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DATE18.07.2007

DATE18.07.2007


PREP. BYAAG ASG


wL = 31007.71033 N/Mtrs 2122.18 Lb/Ft.Or

196 x G x H x D = 21364 N/Mtrs 1462.16 Lb/Ft.

However, wL shall be Min. of Above,

Therefore wL = 21364.0 N/Mtrs 1462.2 Lb/Ft.

Check for Width of Annular Plate : NOT APPLICABLE

Check for Allowable Stress :

Wt. of portion of fixed roof = 54663.06348

wt = Weight of tank shell + portion of fixed roof supported by shell.

= 7193.470531

M---------------- = 0.6309 < 0.785

D2 x ( wL + wt ) < 1.5 / 1.57

As per Cl. E.5.1, b = wt + 1.273x M /D^2

Calculating for b by substituting the values,

b = 30130 N/Mtrs.

b------------ = 5.0217 Mpa1000 x t

Maximum allowable Shell Compression : tcorr. = 6 mm

G x H x D2

------------- = 30.326 < 44t2

As per E.5.2 if,G x H x D2

------------- > 44t2


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83 x tFa (Min. of ) = ---------------- OR 0.5Fy

DG x H x D2

Else, ------------- < 44t2

83 x tFa (Min. of ) = ---------------- + 7.5 G x H or 0.5Fy

2.5 x DTherefore,

Fa (Min. of ) = 44.665 OR 125.00

= 44.665 Mpa

b/1000t < Fa HENCE SAFE

9. CHECK UPLIFT OF TANK FOR WIND LOADING :(Condition : Tank Empty)Design Wind Pressure = 175.39 Kg./Sq.M

As per Cl. 3.11.1, following wind pressures are considered.

Wind Pressure for shell = 87.70 Kg./Sq.MWind Pressure for cone roof = 73.42 Kg./Sq.M

Corrected Design Wind Pressure for shell = 85.95 Kg./Sq.MCorrected Design Wind Pressure for cone roo = 71.96 Kg./Sq.M

Correction factor for projections C.F. = 1.15

Tank Diameter D = 10.00 MetersTank Height H = 11.00 MetersRoof Height Hr = 0.83 MetersTotal Height Ht = 11.83 Meters

Total Wind Force "Fws" on Shell = C.F. x Pw x D x H= 10872.73 Kgs.

This force will act at a dist. H/2 = 5.5 Meters

Total Wind Force "Fwr" on Roof = C.F. x Pw x Projected Area= 344.80 Kgs.


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DATE18.07.2007

DATE18.07.2007


PREP. BYAAG ASG


Height at which this force acts H1 = 11 + 0.2778= 11.278 Meters

Overturning Moment due wind = Fws x H / 2 + Fwr x H1Mw = Kgs.M.

Weight of tank shell including = Kgs.weight carried by shell

Upward Force due to Int. Presure = 0 Kgs.

Net Weight resisting Uplift W = Kgs.

Resisting Moment as per 3.11.2 = 2/3 x (Ws x D / 2)of API 650

MR = Kgs.M.

Mw>MR, Provide Anchors under Wind Condition

Check for Anchor Size due to Uplift during WIND LOAD :

Provide Anchor bolts as indicated below:

No. of Anchor Bolts - Wind Cond. = 10.47 Nos.No. of Anchor Bolts - Seismic Cond. = 0.00 Nos.No. of Anchor Bolts provided = 12 Nos. SAFESize = M 30.00Root Area in Corroded Condition = 5.3 Sq.Cm.P.C.D. d = 10180 MM

= 33.40 Ft.As per Cl. 3.11 of API 650, the design Tension Load for Anchors is calculated as follows:Load per Bolt

4 x M WTB = --------------- - ---------

d N N

= 616.0544 Kgs. = 1356.6 Lbs.

Allowable stress for anchor bolts = 1072.26 Kgs. / Sq.Cm

Area of Anchor Bolt required = 0.574538 Sq.Cm.

Ap > Ar, PROVIDED SIZE & QTY. IS ADEUQATE

58774.48

17632.34

17632.34

63688.62


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DATE18.07.2007

DATE18.07.2007


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Allowable anchor bolt stress Fs = 10000 Psi

Allowable compressive stress Fc = 800 Psifor concrete

Sizing of Anchor Chairs:B(l)

A a e

R = Do/2 Tt

Dbha Tg

Ts + Tp = 6

Tbw b

Design Parameters:Width of Top Plate A = 300 mm

= 11.81 InchProjection of Top plate B (l) = 150 mm

= 5.91 InchHeight of Chair ha = 300 mm Assumed

= 11.81 Inchhp = 300 mm Provided

Height of Gusset plate hg = 284 mm= 11.18 Inch

Dist. between the gussets b = 100 mm Provided= 3.94 Inch

Projection of base plate outside w1 = 65 mm= 2.56 Inch

Projection of base plate inside w2 = 104 mm (Assumed for design)= 4.09 Inch

Width of base plate w = 169 mm= 6.65 Inch

Load / Anchor Pw = 616.0544 Kgs.= 1356.552 Lbs.

Ps = 4204.701 Kgs.= 9258.751 Lbs.

Governing Load P = 4204.701 Kgs.= 9258.751 Lbs.

d φ


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DATE18.07.2007

DATE18.07.2007


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Allow. Stress fbot = 2238.39 Kg. / Sq.Cm.(0.66 fy x 1.33) = 31836.62 PsiAllow. Stress fa = 1835.48 Kg. / Sq.Cm.(0.66 fy x 1.33) = 26106.03 PsiP.C.D. of Anchor Chairs Db = 10180 mm

400.79 InchO. D. of tank Do = 10012 mm

394.17 InchTank Shell Thickness Ts = 6 mm

0.24 InchBottom plate Thickness Tb = 6 mm

0.24 InchThickness of Gusset Plates Tg = 10 mm

= 0.39 InchEccentricity a = 84 mm

= 3.31 Inchm 2 x A = 600 mm

= 23.62 InchDiameter of hole db = 42 mm

= 1.65 Inche = 45 mm

= 1.77 InchNumber of Gusset plates n = 24 Nos.

Thickness of Tank shell required:P a 2/3

ts = 1.76 ------------------x R1/3

m h fb

= 0.2337 Inch= 5.9367 mm

Provided thickness of shell = 6.00 mmProvided thickness of pad plate = 0.00 mmTotal Thickness at anchor chair = 6.00 mm

= 0.24 InchHence Safe

Minimum Thickness of Top PlateP

tt = 0.375 b -0.22 db ------------------e fb

= 0.4508 Inch= 11.4497 mm

tp = 16 mmHence Safe


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DATE18.07.2007

DATE18.07.2007


PREP. BYAAG ASG


Check for minimum height of anchor chair:

hmin = ----------------------------------

= 10.48805 Inch= 266.3964 mm

hp = 300 mmHence Safe

Check for Gusset thickness

Load on gusset = fc x l x b

= 18600.04 Lbs.P

Thickness of Gusset = ----------------18000 x l

= 0.174978 Inch= 4.4444 mm

Provided thickness = 10.0000 mmHence Safe

0.9 P a (R ts)0.25

fb A0.5 ( ts2 + tb2)


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Documents

Design of Conical Storage Tank