IV
DESIGN OF SINGLE DECK FLOATING ROOF FOR A STORAGE TANK 75 1 64
Top pontoon plt
8 Rafter
Outer Rim
975
Post Btm Angle Bulkhead
198
2181 20604 Shell I.D
21000
( All dimensions in mm unless other 1
TANK GEOMETRY DATA Inside diameter , Di ( corroded ) (@ Tank height (tan/tan), H Material of Construction Specific Minimum Yield Stress, Sy Modulus of Elasticity Density of Material, (plate) Corrosion Allowance Min. Specific Gravity of product Max. Specific Gravity of product
2
GEOMETRY DATA Outer Rim Height, Hor Inner Rim Height, Hir Pontoon width, w Rim Gap Outer Rim Extend above pontoon, Hext No. of Pontoons, N Outer Rim Diameter, Øor Inner Rim Diameter, Øir Bulkhead Outer heigh, Boh Bulkhead Inner heigh, Bih Bulkhead Width, wb
3
MEMBER SIZE & PROPERTIES Outer Rim Thk, Tor Inner Rim Thk, Tir
21,000
mm )
Top Pontoon Thk, Ttp Btm Pontoon Thk, Tbp Bulkheads Thk, Tb Deck Plate Thickness, Td Circumferential Truss Plates Rafter Posts
44 Nos. of 44 Nos. of
L 75 x 75 x 6 L 75 x 75 x 6
@ unit weight of @ unit weight of
4 4.1
4.2
4.3
ROOF SUPPORT LEG PONTOON LEG No. of Pontoon Leg, Np Pontoon Leg Size Pontoon Leg Housing Pontoon Leg length Pontoon Leg Housing length DECK LEG No. of Deck Leg, Nd Deck Leg Size Deck Leg Housing Deck Leg length Deck Leg Housing length
( Refer to Design of Supporting Legs)
3" pipe x Sch. 4" pipe x Sch.
(Area od deck / 30m² / leg ) 3" pipe x Sch. 4" pipe x Sch.
80 80
80 80
WEIGHT CALCULATION Top Pontoon Bottom Pontoon
=
/4 x( Øor² - Øir²) x Ttp x (plate) /4 x( Øor² - Øir²) x Tbp x (plate)
Inner Rim Outer Rim
= =
x Øir x Hir x Tir x x Øor x Hor x Tor x
Bulkheads
=
1/2 x (Boh - Bih)x wb x Tb x x N
Deck Plate
=
/4 x Øir x Td x
Pontoon Legs Pontoon Legs housing Deck Legs Deck Legs housing TOTAL WEIGHT Pontoon Components: (Wpontoon) Deck Components: (Wdeck) Total Weight of Floating Roof, (Wroof)
5
PONTOON VOLUME O. Rim Ø
20604
mm
I. Rim Ø + 2 x 2/3 w h3 = 0.03
3 I. Rim Ø 2
h2 = 0.53 h1 = 0.35
1 2
Volume 1
Volume 2 Volume 3 Total Pontoon Volume, Vol(pontoon)
6 6.1
SETTING DECK LEVEL OPERATION FLOATATION LEVEL - DECK Deck Floatation Depth Deck Thk
Density of Deck Density of Product
=
(deck) (product)
Floatation Depth, D(deck) =
6.2
x Td
OPERATION FLOATATION LEVEL - PONTOON Buoyant Force, FB x Vdisplacement x g
Fpontoon W (Pontoon) x g
= =
Pontoon Weight, W(pontoon) (product)
Product Displacement, Vdisplacement =
To find Floatation Depth of Pontoon from Inner Corner of Pontoon, D(pontoon) =
Vol. Displacement above Inner corner of Pontoon Pontoon Cross Area in Vol. 2 Vdisplacement - Vbackslope (Vol.1) 1/4 x x (Øor² - Øir²)
D(pontoon) =
3 89.71
2 459.08 1 The Deck is set at the difference of floation depth in Pontoon & Deck, D(deck) - D(pontoon) 6.3
=
369 mm
NORMAL OPERATION FLOATATION LEVEL FOR ROOF - PONTOON & DECK
Actual Product Level
97.51 m³
Deck Level
H, Floatation Height Above Deck Total Volume Displaced by the roof = Volume Displaced by the Backslope, V1 +
Partial Volume Displaced in Pontoon below the deck level, Va + Volume Displaced by the Deck, Vb Total Volume Displaced by the roof, Vdisplacement (roof): Vdisplacement (roof) =
Roof Total Weight, W(roof) (product)
i)
Volume Displaced by the Backslope, Volume 1
ii)
Partial Volume Displaced in Pontoon below the deck level: Deck level Height, h Bulk head outer height, Bih
iii)
x
Vol. 2
Volume Displaced by the Deck: Area of Deck Plate x Floatation Height Above Deck /4 x Øir2 x H
Hence, The Floatation Height Above Deck, H
6.4
FLOATATION LEVEL FOR ROOF - PONTOON & DECK FOR 10" (254MM) OF ACCUMULATED RAIN WATER For deck to support 10" (254mm) of rain water: Volume of rain water collected at the deck, Vrain = Vrain = Adeck x Hrain where Adeck = Hrain =
Area of deck = Rain accumulation of 10"
/4 x Øir2
Total Volume Displaced by the roof with the 10" of rain water accumulation, Vdisplacement (rain): W(roof) + Wt(rain) Vdisplacement (rain) = (product) where W(roof) =
Total weight of roof
Wt(rain) =
Weight of 10" rain water
Floatation Height above Deck, Vdisplacement (rain) - Vol.1 - partial of Vol.2 (ii) H(rain) = Area of roof 7 7.1
CHECKING THE STRESSES AND DEFLECTION IN THE CENTRE DECK (Ref. to Roark's Formulas For Stress And Strain, 7th Edition) CASE 1: NORMAL CASE - NO PONTOON PUNCTURED
q 4 K1 Et 4
y K2 t
y t
3
y K4 t
y t
2
Et
2 2
K3
Where: t= = q= = y= b d v= E=
Plate thickness, Deck (mm) Outer radius of the deck plate Unit lateral pressure (equiv. weight of deck that float on product) Td x ( (plate) - (product) ) Maximum deflection bending stress diaphragm stress b + d = Maximum stress due to flexure and diaphragm tension combined Poisson's ratio Modulus of Elasticity
= =
The deck plate is fixed and held at its outer edge by the pontoon, hence condition is consider as: Fixed and Held. Uniform pressure q over entire plate (Case 3 in Roark's Formulas) 5.33 1 - 2 2.6 1 - 2
K1 = K2 = At the Centre,
K3 =
2 1-
K4 At the edge, K3 =
4 1 - 2
K4
q α4 Et4
For
And
y t
K1
+ K2
y t
y
q α4 Et4
3
= =
216 mm
Solving equation 11.11.2 σα² E. t 2
=
K3
y t = =
At Deck Center,
At Deck Edge,
+
K4
y t
2
787.3494954301 1377.567314837
σtotal σbending σdiaphgram σtotal σbending σdiaphgram
It is the diaphragm stress at the edge which causes the tension at the outer edge of the Deck. Hence, the radial force on the inner rim, Rh = σ diaphgram x deck thickness
7.2 PONTOON STRESS DESIGN - CASE 1 7.2.1 PONTOON PROPERTIES Nominal diameter of Inner Rim, Øir Pontoon Inside Width Inner Rim Thickness, Tir Outer Rim Thickness, Tor Top Pontoon Thk, Ttp Btm Pontoon Thk, Tbp
2 2160 525 4 900
2187 3
Top Pontoon slope angle @ 1 :
A (mm²) 1 6300 2 17282 3 17494 4 8100 TOTAL 49,176 Neutral axis of combined section, C1
Y (mm) 6 1092 1092 2177
AY (mm³) 37,800 18,872,063 19,103,800 17,629,650 55,643,313
Backslope angle,
h (mm) 1,126 40 40 1,045 16,880,189,001
Moment of inertia of section , Ix-x Section modulus available, Za 7.2.2 MATERIAL PROPERTIES Material Properties Specified minimum yield stress, Sy Yield strength reduction factor, k ( Table M-1 ) Allowable stress reduction factor ( App. M.3.5 ), Ks ( = k.Sy/206.7 ) Allowable bending stress, Fb Allowable compressive stress, Fc 7.2.3 PONTOON RING DESIGN The uniform radial force acting on the Inner Rim is modelled as load point at each mm of circumference, with a very small angle between load point approximtaed to uniform distributed load in the circular ring design. Rh
Number of load point @ each Nlp = Angle° = Radial load on rim, Rh
° Mid Point
(Reference to Roark's Formulas For Stress and Strain, 7th Edition, Table 9.2 Case 7) At Mid-Point, Bending moment, Mm
Circ. tensile force, Rh.Do
1
4
sin
=
At Reaction-Point, Bending moment,
1 -
Tm
Circ. tensile force,
=
Rh.Do Mr
=-
1
1 -
tan 4 ( Do= Qir, nonimial diamter of inner ring)
Tr
=
7.2.4 RESULT RING STABILITY CHECK
7.3
MID-POINT
LOAD-POIN
Bending Moment Circumferential force Bending Stress Circumferential stress
( Nmm ) (N) ( N/mm² ) ( N/mm² )
85 16,589,319 0.0000032 337
-170 16,589,319 -0.000006 337
Allow. bending stress Allow. axial stress Unity Check Condition
( N/mm² ) ( N/mm² )
183 165 2 Not OK !
183 165 2 Not OK !
CASE 2:
INFLUENCE OF 10" (254mm) OF RAIN ACCUMULATED ON CENTER DECK
10" Rain
For deck to support 10" (254mm) of rain water: Volume of rain water collected at the deck, Vrain = Adeck x Hrain where Adeck = Hrain =
Area of deck = Rain accumulation of 10"
/4 x Øir2
Vol.rain x rain
Weight of 10" accumulated rain water, Wrain =
Upward Bouyant Load = Deck Area x Floatation Height x Product density 2 /4 x (Øir) x H(rain) x Downward load due to deck steel and rain water, = Wdeck + Wrain Nett downward force acting on deck = (Upward bouyant load - Downward Load) = Deck Area
q 4 K1 Et 4
y K2 t
y t
3
y K4 t
y t
2
Et
2 2
K3
Where: t = Plate thickness, Deck (mm) = Outer radius of the deck plate
= =
q = Unit lateral pressure y = Maximum deflection b bending stress d diaphragm stress b + d = Maximum stress due to flexure and diaphragm tension combined v = Poisson's ratio E = Modulus of Elasticity
The deck plate is fixed and held at its outer edge by the pontoon, hence condition is consider as: Case 3 Fixed and Held. Uniform pressure q over entire plate K1 =
5.33 1 - 2
K2 =
2.6 1 - 2
K3
2 1 v
At the Centre, K3 =
2 1-
K4 At the edge, K3 =
4 1 - 2
K4
q α4 Et4
For And
y t
K1
+ K2
y t
y
q α4 Et4
3
=
214 mm
=
Solving equation 11.11.2 σα² E. t 2
=
K3
y t = =
At Deck Center,
At Deck edge,
+
y t
K4
2
777 1360
σtotal σbending σdiaphgram σtotal σbending σdiaphgram
It is the diaphragm stress at the edge which causes the tension at the outer edge of the Deck. Hence, the radial force on the inner rim, Rh = σ diaphgram x deck thickness
7.4 PONTOON STRESS DESIGN - CASE 2 7.4.1 PONTOON PROPERTIES Nominal diameter of Inner Rim, Øir Section modulus available, Za2 = Cross sectional area, Aa 7.4.2 MATERIAL PROPERTIES Material Properties Specified minimum yield stress, Sy Yield strength reduction factor, k ( Table M-1 ) Allowable stress reduction factor ( App. M.3.5 ), Ks ( = k.Sy/206.7 ) Allowable bending stress, Fb Allowable compressive stress, Fc 7.4.3 PONTOON RING DESIGN The uniform radial force acting on the Inner Rim is modelled as load point at each mm of circumference, with a very small angle between load point approximtaed to uniform distributed load in the circular ring design. Rh
Number of load point @ each Nlp = Angle° = Radial load on rim, Rh ( Note : Rh is
° Mid Point
(Reference to Roark's Formulas For Stress and Strain, 7th Edition, Table 9.2 Case 7) At Mid-Point, Bending moment, Mm
Circ. tensile force, Rh.Do
1
4
sin
Rh.Do
1
4
=
1 -
At Reaction-Point, Bending moment, Mr
Tm
=
Circ. tensile force,
=
1 -
Tr
tan
=
7.4.4 RESULT RING STABILITY CHECK
MID-POINT
LOAD-POINT
Bending Moment Circumferential force Bending Stress Circumferential stress
( Nmm ) (N) ( N/mm² ) ( N/mm² )
80 15,665,283 0.0000030 319
-161 15,665,283 -0.000006 319
Allow. bending stress Allow. axial stress Unity Check Condition
( N/mm² ) ( N/mm² )
183 165 2 Not OK !
183 165 2 Not OK !
7.4.5 STRESSES SUMMARY LOAD CASE 1
σtotal ( N/mm² ) σbending ( N/mm² ) σdiaphgram ( N/mm² )
Deck Center 160
Deck Edge 279
16
24
144
255
8
ROOF SUPPORT LEG DESIGN 22 15 10 5
8.1
GEOMETRIC DATA Support leg size Pipe outside diameter Pipe Thickness, Pipe Area, Aleg Radius of gyration, r =
I Aleg
8.2
MATERIAL PROPERTIES Material of Construction for roof support leg Specific Minimum Yield Stress, Sy Modulus of Elasticity Density of Material, (plate) Leg Material
8.3
LOADING DATA Support leg length at i) ii) iii) iv)
R1 : R2 : R3 : R4 :
Do2 - Di2 4
Lsp1 Lsp2 Lsp3 Lsp4
Deck O.D Deck Thickness, td Deck Area, Adeck Center deck weight, Wdeck Design Live Load, Llive Effective radius for area of deck supported by leg: R3eff =
1/2(Øir/2-R3) R2eff = 1/2(R3-R2) R1eff=
Area of deck supported by legs at i)
2 R1 = R1eff)
iii)
2 2 R2 = R2eff) - (R1eff) ) 2 2 R3 = R3eff) - (R2eff) )
iv)
2 2 R4 = p((Ødeck) - (R3eff) )
ii)
8.4
SUPPORT LEG AT INNER DECK R1 No. of legs at R1 Area of deck supported by legs at R1, A1 Deck area on each leg, A1' Wdeck x
Deck load on one leg =
A1' Adeck
Llive x A1'
Live load on one leg = Total load on one leg =
Deck load + Live load Total Load / Aleg
Stress on support leg at inner deck R1, P1 = 8.5
ALLOWABLE STRESS As per AISC code, Slenderness ratio, = K.Lsp1 / Rx-x where K Column slenderness ratio dividing elastic and inelastic buckling, 2²E Cc = Sy When Cc, [ 1 - ² / 2Cc² ].Sy Sc.all = (i) 5/3 + 3 /8Cc - ³/8Cc³ When Cc 120, 12²E Sc.all = (ii) 23 ² When 120 200, Smaller of (i) or (ii) Sc.all = 1.6 - /200 In this case, the allowable stress Sc.all is Since P1
8.6
<
Sc.all, the support leg at inner deck R1 is
SUPPORT LEG AT INNER DECK R2 No. of legs at R2 Area of deck supported by legs at R2, A2 Deck area on each leg, A2' Deck load on one leg = Live load on one leg = Total load on one leg =
Wdeck x
A2' Adeck
Llive x A2' Deck load + Live load
Stresses on support leg at inner deck R2, P2 =
8.7
ALLOWABLE STRESS As per AISC code, Slenderness ratio, = K.Lsp2 / Rx-x where K Column slenderness ratio dividing elastic and inelastic buckling, 2²E Cc = Sy When Cc, [ 1 - ² / 2Cc² ].Sy Sc.all = (i) 5/3 + 3 /8Cc - ³/8Cc³ When Cc 120, 12²E Sc.all = (ii) 23 ² When 120 200, Smaller of (i) or (ii) Sc.all = 1.6 - /200 In this case, the allowable stress Sc.all is Since P2
8.8
<
Sc.all, the support leg at inner deck R2 is
SUPPORT LEG AT INNER DECK R3 No. of legs at R3 Area of deck supported by legs at R3, A3 Deck area on each leg, A3' Deck load on one leg = Live load on one leg = Total load on one leg =
Wdeck x
A3' Adeck
Llive x A3' Deck load + Live load
Stresses on support leg at inner deck R3, P3 = 8.9
ALLOWABLE STRESS As per AISC code, Slenderness ratio, = K.Lsp3 / Rx-x where K Column slenderness ratio dividing elastic and inelastic buckling, 2²E Cc = Sy When Cc, [ 1 - ² / 2Cc² ].Sy Sc.all = (i) 5/3 + 3 /8Cc - ³/8Cc³ When Cc 120, 12²E
Total Load / Aleg
Sc.all
=
23 ² When 120 200, Smaller of (i) or (ii) Sc.all = 1.6 - /200 In this case, the allowable stress Sc.all is Since P3
<
(ii)
Sc.all, the support leg at inner deck R3 is
8.10 SUPPORT LEG AT PONTOON No. of legs at R4 Area of deck supported by legs at R4, A4 Deck area on each leg, A4' Wdeck x
Deck load on one leg =
A4' Adeck
Pontoon weight, Wpontoon Pontoon weight on one leg, Wpontoon' Llive x A4' Deck load + Live load + Pontoon weight
Live load on one leg = Total load on one leg =
Total Load / Aleg
Stresses on support leg at Pontoon, P4 = 8.11 ALLOWABLE STRESS As per AISC code, Slenderness ratio, = K.Lsp4 / Rx-x where K Column slenderness ratio dividing elastic and inelastic buckling, 2²E Cc = Sy When Cc, [ 1 - ² / 2Cc² ].Sy Sc.all = (i) 5/3 + 3 /8Cc - ³/8Cc³ When Cc 120, 12²E Sc.all = (ii) 23 ² When 120 200, Smaller of (i) or (ii) Sc.all = 1.6 - /200 In this case, the allowable stress Sc.all is Since P3 8.12
<
Sc.all, the support leg at inner deck R3 is
STRESSES SUMMARY
Leg at radius 4,267 8,839 13,716 18,541
No. of leg 5 10 15 22
Actual stress, Allowable stress, (N/mm2) (N/mm2) 25 25 22 31
75 75 75 75
RESULT OK OK OK OK
L 75 x 75 x 6 Inner Rim
10
Deck Plate
8
525
16242
All dimensions in mm unless otherwise stated. )
= =
21,000 mm 8,000 mm
: SA 516 Gr 65N = 275 N/mm² = 209,000 N/mm² = 7,850 kg/m³ = = =
3 mm 0.7 1
= = = = =
975 mm 525 mm 2181 mm 198 mm 75 mm
=
22
= =
20604 mm 16242 mm
= = =
884 mm 509 mm 2161 mm
= =
10 mm 10 mm
= = = = =
8 mm 8 mm 8 mm 8 mm 8 mm 7 kg/m 7 kg/m
= @ unit wt @ unit wt = =
=
22 15 kg/m 22 kg/m 2940 mm 1084 mm
= =
30 15 kg/m 22 kg/m 2,927 mm 823 mm
= =
7,927 kg 7,927 kg
= =
2,103 kg 4,954 kg
=
2,079 kg
=
13,012 kg
= = = =
988 kg 532 kg 1,341 kg 551 kg
= = =
55,248 kg 13,012 kg 68,260 kg
@ unit wt @ unit wt
19150 mm
16242 mm
=
21 m³
=
61 m³
=
2 m³
=
84 m³
=
90 mm
=
79 m³
=
459 mm
Freeboard above deck, 189 Product Level Deck Level 369 mm
Deck
=
98 m³
=
21
=
44 m³
=
207 H
=
0m 157 mm
UMULATED RAIN WATER
=
53
= =
m³
207,190,049 mm2 254 mm
=
173
= =
m³
0m 323 mm
( 11.11.1)
( 11.11.2)
Td Øir / 2
= =
8 8121
=
0.000561
N/mm2
= =
0.3 209,000
N/mm²
=
6
=
3
=
3
=
1
=
4
=
2
=
2,851
=
56,249
(at Deck Center) (at Deck Edge)
= = =
160 N/mm2 16 N/mm2 144 N/mm2
= = =
279 N/mm2 24 N/mm2 255 N/mm2
=
2043 N/mm
inal diameter of Inner Rim, Øir Pontoon Inside Width Inner Rim Thickness, Tir Outer Rim Thickness, Tor Top Pontoon Thk, Ttp Btm Pontoon Thk, Tbp
= = = = = =
16242 mm 2160 mm 12 mm 9 mm 8 8
64 = Backslope angle, =
0.02 rad 0.2 rad
A.h² (mm4) 7,980,578,762 26,969,435 27,300,602 8,845,340,202 16,880,189,001 = = =
= = = = =
I = (bd³)/12 (mm4) 75,600 6,720,924,525 6,971,562,462 54,675 13,692,617,263 1,132 mm 30,572,806,264 mm4 27,019,626 mm³
: SA 516 Gr. 65N 275 N/mm² 1 1 183 N/mm² 165 N/mm²
circumference, he circular ring design.
Number of load point @ each mm, x Øir = 51,026 1/2 x 360/ Nlp = 0.003528 ° Radial load on rim, Rh = 2043 N ( Note : Rh is negative for inward force )
Rh 2.sin
Rh 2 tan
LOAD-POINT -170 16,589,319 -0.000006 337 183 165 2 Not OK !
=
53
= =
m³
207,190,049 mm³ 254 mm =
52,626 kg
=
46,812 kg
=
65,638 kg
=
91 kg/m2
( 11.11.1)
( 11.11.2)
Td Øir / 2
= =
8 8121
=
0.000891 N/mm2
= =
0.3 200,000 N/mm²
=
6
=
3
=
3
=
1
=
4
=
2
=
4733
=
55141
(at Deck Center) (at Deck Edge)
= = =
151 N/mm2 15 N/mm2 136 N/mm2
= = =
264 N/mm2 23 N/mm3 241 N/mm4
=
1929 N/mm
=
16,242 mm =
=
= = = = =
27,019,626 mm3 49,176 mm²
: SA 516 Gr. 65N 275 N/mm² 1 1 183 N/mm² 165 N/mm²
circumference, he circular ring design.
Number of load point @ each mm, x Øir = 51,026 1/2 x 360/ Nlp = 0.003528 ° Radial load on rim, Rh = 1,929 N/ load pt ( Note : Rh is negative for inward force )
Rh 2.sin
Rh 2 tan
LOAD-POINT -161 15,665,283 -0.000006 319 183 165 2 Not OK !
LOAD CASE 2 Deck Center Deck Edge 151 264 15
23
136
241
Nos. at R4 Nos. at R3 Nos. at R2 Nos. at R1
18,541 13,716 8,839 4,267
= 3" Sch. 80 =
89 mm
=
8 mm
=
1,946 mm2
= 24.89
: SA 333 Gr 6 = 241 N/mm² = 209,000 N/mm² = 7,850 kg/m³
= = = =
2,927 2,927 2,927 2,940
mm mm mm mm
= =
34,231 mm 8 mm
= =
920,299,221 mm2 57,795 kg =
1 KN/m2
= =
15,416 11,278 6,553
=
134,905,672 mm2
1/2(R2-R1) =
=
264,648,385 mm2
=
347,030,823 mm2
=
173,714,341 mm2
=
5
=
134,905,672 mm2
=
26,981,134 mm2
=
1,694 kg
= = =
17 KN 32 KN 49 KN
=
25 N/mm2
=
118
=
1
=
131
=
75 N/mm²
=
78 N/mm²
=
74 N/mm²
=
75 N/mm²
satisfactory.
=
10
=
264,648,385 mm2
=
26,464,838 mm2
=
1,662 kg
= = =
16 KN 32 KN 48 KN
=
25 N/mm2
=
118
=
1
=
131
=
75 N/mm²
=
78 N/mm²
=
74 N/mm²
=
75 N/mm²
satisfactory.
=
15
=
347,030,823 mm2
=
23,135,388 mm2
=
1,453 kg
= = =
14 KN 28 KN 42 KN
=
22 N/mm2
=
118
=
1
=
131
=
75 N/mm²
=
78 N/mm²
=
74 N/mm²
=
75 N/mm²
satisfactory.
=
27
=
173,714,341 mm2
=
6,433,864 mm2
= = = = = = = =
404 kg 4 KN 55,248 kg 5,023 kg 49 KN 8 KN 61 KN 31 N/mm2
=
118
=
1
=
131
=
75 N/mm²
=
77 N/mm²
=
74 N/mm²
=
75 N/mm²
satisfactory.
III 1
2 2.1
2.2
3 3.1
3.2
BLEEDER VENT CALCULATION DESIGN OF AIR VENTING SYSTEM GEOMETRIC DATA Design Code Inside diameter, Di Tank height, H Nominal Capacity Design pressure, Pi Flash point (FP)/Normal boiling point (NBP) (@ Filling rate ( Pumping in/Flow rate to tank ), Vi Emptying rate ( Pumping out/Flow rate from tank ), Vo
: = =
FP
)
OPERATING VENTING NORMAL VACUUM VENTING Maximum liquid movement out of a tank Flow rate of free air, Vv1 ( = Vo/15.9 x 15.89 ) Thermal inbreathing Tank capacity, V From Table 2, column 2 (Thermal Venting Capacity Req't ), Flow rate of free air,Vv2 (@ 0
=
= ft³/hr )
=
Total vacuum flow required, Vv ( = Vv1 + Vv2 )
=
NORMAL PRESSURE VENTING Maximum liquid movement into a tank Rate of free air per 0.159m³/hr of product import rate, m Flow rate of free air, Vp1 ( = Vi/0.159 x m )
= =
Thermal outbreathing From Table 2, column 3 (Thermal Venting Capacity Req't), Flow rate of free air,Vp2 (@ 0
ft³/hr )
=
Total pressure flow required, Vp ( = Vp1 + Vp2 ) 4
= = = =
OPEN VENT SIZING ( BLEEDER VENT SIZING ) OPEN VENT SIZING CALCULATION Maximum flow, Q ( @ Vacuum flow at ( @ Q=
K. A. 2. g. H
K= A= g= H=
Discharge coefficient cross sectional area of vent acceleration due to gravity Head as measure pressure differential p H=
=
2.50
mbarg. )
=
where
=
Minimum require cross sectional area of vent, Av_req =
Q K. 2. g. H
=
Q K 2. g. p
= =
where Q=
Max. Air flow required
=
p = 5
Specific weight of Air Air density Differential pressure
=g
BLEEDER VENT SELECTED Selected bleeder vent size Number of vent, N Outside diameter of the vent, do Inside Dia. of one vent , di ( @ vent pipe thickness = 8 Total cross sectional area of vents, Av_actual Since Av_actual > Ar_gnv, therefore the nos. & size of vents is
= = =
: = mm )
= =
API STD 2000 19400 mm 9700 mm 2500 m³ 2.50 mbarg 70 °C 427 m³/hr 1,100 m³/hr
1097 m³/hr
18,034 barrels 0 m³/hr 1,097 m³/hr
0.17 m³/hr 457 m³/hr
0 m³/hr 457 m³/hr
1,097 m³/hr
0.6
21 m
0.024 m² 24,124 mm² 0.305 mm³/s
12 kg/m2s2 1.2 kg/m³ 250 N/m²
8" Sch Std 1 219 203 mm 32,251 mm² satisfactory.
V
ROOF DRAIN DESIGN Rigid Pipe
1375
Flexible pipe
225 Rigid Pipe 1GEOMETRIC DATA Tank Nominal Diameter Tank Height, Roof lowest height, H Drain outlet nozzle elevation, z Roof Deck Area
=
Design Rain Fall
=
Design drainage required, Qreq.
=
No. of Roof Drain, N Roof drain pipe size (rigid & fitting) Dain Pipe Outside Diameter, Do Drain pipe thickness
= = = =
Drain Pipe length : L1 = Rigid L2 = Flexible 2
3
= = = =
20 m x 23 m x
2 1
nos. nos.
= =
Number of Fitting & Accessories per drain pipe - 45º elbow
N45º
=
- 90º elbow - Valve - Rigid pipe - Flexible pipe
N90º Nv
= = = =
TOTAL HEAD H = h+
V2 2g
4
TOTAL HEAD LOSS OF ROOF DRAIN PIPE
h= Where H = G = K =
L' = D = 5
V2 x 2g
K L' D
Total head between the lowest position of deck and the roof drain nozzle Gravity acceleration Friction Coefficient - For rigid pipe : - For flexible pipe : Total equivalent length of drain pipe Inside Diameter of drain pipe
EQUIVALENT PIPE LENGTH OF VALVE AND FITTING Accordance to NFPA 15 Table 8.5.2.1, 45º elbow, L45º Equivalent length for 4" 90º elbow, L90º Valve, Lv
6
=
K1 K2
= = =
= = =
Total equivalent pipe length for RIGID PIPE: L1' = L1 + N45º x L45º + N90º x L90º + Nv x Lv
=
Total equivalent pipe length for Flexible PIPE: L2' = L2
=
TOTAL HEAD LOSS OF ROOF DRAIN PIPE K1 L1' V2 x + h= 2g D
K2 L2' D
H= H= 7
V2 2g
K1 L1' D
+
K2 L2' D
+ 1
FLOW VELOCITY 2gH V=
8
9
K1 L1' D
+
K2 L2' + 1 D
DRAINAGE FLOW RATE PER DRAIN PIPE Q = AREA x Velocity = /4 x D2 x V x 3600 (s/hr) MINIMUM ROOF DRAIN REQUIRED Drainage flow rate required Nreq = Actual flow rate per drain
=
=
=
MINIMUM REQUIRED
=
19,400 mm 9,700 mm 1600 mm 225 mm 920 m2 50 mm/hr 46 m3/ hr 2 4" Sch 80 102 mm 9 mm
40 m 23 m
2 1 1 2 1
1.375
m
0.0168 0.03 0.08448
m
3.1 1.2 0.6
48 m
23 m
1.2 m/s
24.2 m3 / hr
1.9
2
Page
I WEIGHT ANALYSIS
1 GENERAL Design code Inside diameter Steel density Shell / Btm Roof
:
API 650 11th Edition
:
19,400
mm
: :
7,850 7,850
kg/m³ kg/m³
2 SHELL COURSES ONE - FOOT METHOD (OUTER TANK) Course No. Material 1 2 3 4 5 6 7 8 9 10
Type of roof support : fixed Tank height : Roof plates lapping factor :
Type of roof : 9,700 mm
Annular/Bottom plates lappin factor :
Y Thickness (mm) 10 8 8 8 8 8 8 8 8 8
A 516 GR. 65N A 516 GR. 65N A 516 GR. 65N A 516 GR. 65N A 516 GR. 65N A 516 GR. 65N A 516 GR. 65N A 516 GR. 65N A 516 GR. 65N A 516 GR. 65N
Width (mm) 1,828 1,828 1,828 1,828 1,828 560 0 0 0 0
Weight (kg) 8,750 6,999 6,999 6,999 6,999 2,144 0 0 0 0 Total weight of shell plates =
3 BOTTOM PLATES Material
Y
A 516 GR. 65N 4 TOP CURB ANGLE Material A 516 GR. 65N
Outside Dia. (mm) 19,824
Length (mm) 61,000
Unit Weight (kg/m) 10
Length (mm) 61,000
Unit Weight (kg/m) 15
Length (mm) 61,000
Unit Weight (kg/m) 15
L 75 x 75 x 6
Qty 1
Size
Qty
A 516 GR. 65N
T 125 x 125 x 6 x 9
1
=
Weight (kg) 630
=
Weight (kg) 915
=
Weight (kg) 0
=
2,100
=
6,192
=
Y
6 INTERMEDIATE WIND GIRDERS Material Size T 125 x 125 x 6 x 9
Y Qty 0
7 NOZZLES Total weight of nozzles 8 MISCELLANEOUS Assuming
Weight (kg) 19,383 Y
Size
5 TOP WIND GIRDERS Material
A 516 GR. 65N
Thickness (mm) 8
Y
Y 10
9 STAIRWAY & PERIMETER PLATFORM
% of total weight Y
332937742.xlsx
Page
Platform Weight
16.19
10 OPERATING LIQUID WEIGHT Operating liquid height 11 HYDROSTATIC WATER WEIGHT Hydrostatic water height 12 ERECTION WEIGHT (Include roof) OPERATING WEIGHT FIELD HYDROSTATIC TEST WEIGHT
KN
1,650
(@ =
8,730
mm & sg @=
(@
9,700
mm )
0.87 )
=
=
= = = =
332937742.xlsx
Page
Cone-roof
/Bottom plates lapping 1
38,892 kg
19,383 kg
630 kg
915 kg
0 kg
2,100 kg
6,192 kg
332937742.xlsx
Page
1,650 kg
2,245,054 kg
2,867,247 kg 97,740 kg 2,342,794 kg 2,964,987 kg
332937742.xlsx