Design of Atmospheric Storage Tanks by API Std 650    
     
  Calculation of Thicknesses by The Variable-Design-Point Method (5.6.4)    
                                                   
  Tables y Standards    
  - API Std 650 Welded Tanks for oil Storage, para. 5.6.4                
  - Minimum Plate Thickness by API Std 650 (5.6.1.1)                
  - Plate Thickness by ASME / ASTM                
  - Tables 5-2a and 5-2b Allowable stress for design & Hydrostatic Test conditions                
                                                   
  VARIABLE-DESIGN-POINT METHOD    
  (Enter values in yellow cells for calculations)    
  DATA INPUT    
Capacity (Barrels)
m³
G (Fluid Specific Gravity)
    Fluid Density, r (g/cm³) (1) Note (1): (Consider r ≥ 1 g/cm³ for the Hmáx calculation)         
Ground Resistance, Ps (Kg/cm²)
    Outage (m) (2) Note (2): (Distance from the maximum level to the upper edge)        
 
Course
    Plate  Specification
     
Plate Width, E (m)
Hydrostatic Test Stress, St (Mpa)
Product Design Stress, Sd (Mpa)
Corrosion Allowance, CA (mm)
Hmáx = 1000*Ps/ρ
 cm          = m
    Htank ≤ Hmáx                m                  
h = Htank-outage
 m
    D = (V 4/πh)⁰∙⁵                m           =  m³         =  barrels According to API Std 650    
Dtank
 m           =  m³         =  barrels
No. of Courses = Htank/E
                                                   
                                                   
  OUTPUT tmin & SELECTION tuse              
  Courses Design Condition td
(mm) 		Hidrostatic Test Condition tt
(mm) 		tmin
(mm) 		tuse (*)
(mm) 		             
  t1              
  t2              
  t3              
  t4              
  t5              
  t6              
  t7              
  t8              
    Notes:                                    
    - Dimensions in mm                                    
- (*) Verified Minimum Thickness by API Std 650 (5.6.1.1)
                                                   
  CALCULATING THE THICKNESS OF THE 1ST SHELL COURSE (N=1)              
N
    H = Htank - (N-1)E                 m                  
DESIGN CONDITIONS
tpd = 4.9D(H-0.3)G + CA
mm
    Sd                                    
    t1d = [ 1.06 -  0.0696D ( HG ) 0,5 ] ( 4.9HDG ) + CA mm                  
H Sd
Sd
    t1d need not be greater than tpd                                    
Lower between tpd y t1d
    HYDROSTATIC TEST CONDITIONS              
    tpt = 4.9D(H-0.3)                   mm                  
    St                                        
    t1t = [ 1.06 -  0.0696D ( H ) 0,5 ] ( 4.9HD )   mm                  
H St
St
    t1t need not be greater than tpt                                      
Lower between tpt y t1t
    THICKNESS OF THE FIRST COURSE              
Higher between t1d y t1t (t1min)
mm
    t1use                 mm t1use> t1min                
                                                   
                                                   
    Verify L/H ≤ 1000/6                                    
    t = t1use - CA                 mm                  
    L = (500 D t)⁰∙⁵                                    
    H = Htank - (N-1)E                                    
                                                   
    L/H =                                    
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 2ND SHELL COURSE (N=2)      
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t2a = tdx-CA)          
CALCULATE THE RATIO R
    t1 = t1use - CA                   mm                  
h1
m mm
r
m mm
R = h1
(r  t1)⁰∙⁵
                                                   
R ≤ 1.375 →
    R ≥ 2.625 →                                    
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h1 mm h1 mm h1 mm h1 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
Sd MPa Sd MPa Sd MPa Sd MPa
CA mm CA mm CA mm CA mm
    t1d = t1use mm t1d = t1use mm t1d = t1use mm t1d = t1use mm
tpd - CA= 4.9D(H-0.3)G
mm tdx-CA mm tdx1-CA mm tdx2-CA mm
Sd
tL = t1use - CA
mm tL = t1use-CA mm tL = t1use-CA mm tL = t1use-CA mm
tu = tpd-CA
mm tu = tdx-CA mm tu = tdx1-CA mm tu = tdx2-CA mm
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
                                                   
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 4.9D(H-X/1000)G
mm tdx1-CA mm tdx2-CA mm tdx3-CA mm
    Sd                                        
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
 tu-(tdx1-CA) =
 tu-(tdx2-CA) =
 tu-(tdx3-CA) =
    t2a = tdx-CA                   mm                  
        mm                  
t2d = t2 + CA
mm
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t2a = ttx)          
CALCULATE THE RATIO R
t₁ = t1use
mm
h1
m mm
r
m mm
R = h1
(r x t1)⁰∙⁵
R ≤ 1.375 →
    R ≥ 2.625 →                                    
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h1 mm h1 mm h1 mm h1 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
St MPa St MPa St MPa St MPa
CA mm CA mm CA mm CA mm
    t1t = [ 1.06 -  0.0696D ( H ) 0,5 ] ( 4.9HD )   mm t1t mm t1t mm t1t mm
H St
St
tpt = 4.9D(H-0.3)
mm ttx mm ttx1 mm ttx2 mm
    St                                        
tL = t1t
mm tL = t1t mm tL = t1t mm tL = t1t mm
tu = tpt
mm tu = ttx mm tu = ttx₁ mm tu = ttx2 mm
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 4.9D(H-X/1000)
mm ttx1 mm ttx2 mm ttx3 mm
    St                                        
Verify tu-ttx. Repeat using the calculated value of ttx until there is little difference between the calculated values of tu and ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t₂ₐ = ttx
mm
mm
t₂t = t₂
mm
THICKNESS OF THE SECOND COURSE
t2min is the higher value between t2d & t2t
mm
t2use
mm (The additional thickness will not be used for subsequent calculations)
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 3RD SHELL COURSE (N=3)          
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t3a = tdx-CA)          
CALCULATE THE RATIO R
t2 = t2min-CA
mm
h2
m mm
r
m mm
R = h2
(r x t2)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h2 mm h2 mm h2 mm h2 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
Sd MPa Sd MPa Sd MPa Sd MPa
CA mm CA mm CA mm CA mm
tpd - CA= 4.9D(H-0.3)G
mm tdx-CA mm tdx1-CA mm tdx2-CA mm
    Sd                                        
tL = t2d-CA
mm tL = t2d-CA mm tL = t2d-CA mm tL = t2d-CA mm
tu = tpd-CA
mm tu = tdx-CA mm tu = tdx1-CA mm tu = tdx2-CA mm
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 4.9D(H-X/1000)G
mm tdx1-CA mm tdx2-CA mm tdx3-CA mm
    Sd                                        
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
tu-(tdx1-CA) =
tu-(tdx2-CA) =
tu-(tdx3-CA) =
    t3a = tdx-CA                   mm                  
        mm                  
t3d = t3 + CA
mm
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t3a = ttx)          
CALCULATE THE RATIO R
t2 = t2min
mm
h2
m mm
r
m mm
R = h2
(r x t2)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h2 mm h2 mm h2 mm h2 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
St MPa St MPa St MPa St MPa
CA mm CA mm CA mm CA mm
t2t = t2
mm t2t = t2 mm t2t = t2 mm t2t = t2 mm
    tpt = 4.9D(H-0.3)                   mm ttx mm ttx1 mm ttx2 mm
    St                                        
tL = t2t
mm tL = t2t mm tL = t2t mm tL = t2t mm
tu = tpt
mm tu = ttx mm tu = ttx1 mm tu = ttx2 mm
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 4.9D(H-X/1000)
mm ttx1 mm ttx2 mm ttx3 mm
    St                                        
Verify tu-ttx. Repeat using the calculated value of ttx until there is little difference between the calculated values of tu and ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t3a = ttx
mm
        mm                  
t3t = t3
mm
THICKNESS OF THE THIRD COURSE
t3min is the higher value between t3d & t3t
mm
t3use
mm
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 4TH SHELL COURSE (N=4)          
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t4a = tdx-CA)          
CALCULATE THE RATIO R
t3 = t3min-CA
mm
h3
m mm
r
m mm
R = h3
(r x t3)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h3 mm h3 mm h3 mm h3 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
Sd MPa Sd MPa Sd MPa Sd MPa
CA mm CA mm CA mm CA mm
tpd - CA= 4.9D(H-0.3)G
mm tdx-CA mm tdx1-CA mm tdx2-CA mm
    Sd                                        
tL = t3d-CA
mm tL = t3d-CA mm tL = t3d-CA mm tL = t3d-CA mm
tu = tpd-CA
mm tu = tdx-CA mm tu = tdx1-CA mm tu = tdx2-CA mm
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 4.9D(H-X/1000)G
mm tdx1-CA mm tdx2-CA mm tdx3-CA mm
    Sd                                        
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
tu-(tdx1-CA) =
tu-(tdx2-CA) =
tu-(tdx3-CA) =
t4a = tdx-CA
mm
        mm                  
t4d = t4 + CA
mm
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t4a = ttx)          
CALCULATE THE RATIO R
t3 = t3min
mm
h3
m mm
r
m mm
R = h3
(r x t3)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h3 mm h3 mm h3 mm h3 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
St MPa St MPa St MPa St MPa
CA mm CA mm CA mm CA mm
t3t = t3
mm t3t = t3 mm t3t = t3 mm t3t = t3 mm
    tpt = 4.9D(H-0.3)                   mm ttx mm ttx1 mm ttx2 mm
    St                                        
tL = t3t
mm tL = t3t mm tL = t3t mm tL = t3t mm
tu = tpt
mm tu = ttx mm tu = ttx1 mm tu = ttx2 mm
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 4.9D(H-X/1000)
mm ttx1 mm ttx2 mm ttx3 mm
    St                                        
Verify tu-ttx. Repeat using the calculated value of ttx until there is little difference between the calculated values of tu and ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t4a = ttx
mm
        mm                  
t4t = t4
mm
THICKNESS OF THE FOURTH COURSE
t4min is the higher value between t4d & t4t
mm
t4use
mm
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 5TH SHELL COURSE (N=5)          
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t5a = tdx-CA)          
CALCULATE THE RATIO R
t4 = t4min-CA
mm
h4
m mm
r
m mm
R = h4
(r x t4)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h4 mm h4 mm h4 mm h4 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
Sd MPa Sd MPa Sd MPa Sd MPa
CA mm CA mm CA mm CA mm
tpd - CA= 4.9D(H-0.3)G
mm tdx-CA mm tdx1-CA mm tdx2-CA mm
    Sd                                        
tL = t4d-CA
mm tL = t4d-CA mm tL = t4d-CA mm tL = t4d-CA mm
tu = tpd-CA
mm tu = tdx-CA mm tu = tdx1-CA mm tu = tdx2-CA mm
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 4.9D(H-X/1000)G
mm tdx1-CA mm tdx2-CA mm tdx3-CA mm
Sd
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
tu-(tdx1-CA) =
tu-(tdx2-CA) =
tu-(tdx3-CA) =
t5a = tdx-CA
mm
        mm                  
t5d = t5 + CA
mm
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t5a = ttx)          
CALCULATE THE RATIO R
t4 = t4min
mm
h4
m mm
r
m mm
R = h4
(r x t4)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h4 mm h4 mm h4 mm h4 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
St MPa St MPa St MPa St MPa
CA mm CA mm CA mm CA mm
t4t = t4
mm t4t = t4 mm t4t = t4 mm t4t = t4 mm
    tpt = 4.9D(H-0.3)                   mm ttx mm ttx1 mm ttx2 mm
    St                                        
tL = t4t
mm tL = t4t mm tL = t4t mm tL = t4t mm
tu = tpt
mm tu = ttx mm tu = ttx1 mm tu = ttx2 mm
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 4.9D(H-X/1000)
mm ttx1 mm ttx2 mm ttx3 mm
    St                                        
Verify tu-ttx. Repeat using the calculated value of ttx until there is little difference between the calculated values of tu and ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t5a = ttx
mm
        mm                  
t5t = t5
mm
THICKNESS OF THE FIFTH COURSE
t5min is the higher value between t5d & t5t
mm
t5use
mm
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 6TH SHELL COURSE (N=6)          
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t6a = tdx-CA)          
CALCULATE THE RATIO R
t5 = t5min-CA
mm
h5
m mm
r
m mm
R = h5
(r x t5)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h5 mm h5 mm h5 mm h5 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
Sd MPa Sd MPa Sd MPa Sd MPa
CA mm CA mm CA mm CA mm
tpd - CA= 4.9D(H-0.3)G
mm tdx-CA mm tdx1-CA mm tdx2-CA mm
    Sd                                        
tL = t5d-CA
mm tL = t5d-CA mm tL = t5d-CA mm tL = t5d-CA mm
tu = tpd-CA
mm tu = tdx-CA mm tu = tdx1-CA mm tu = tdx2-CA mm
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 4.9D(H-X/1000)G
mm tdx1-CA mm tdx2-CA mm tdx3-CA mm
    Sd                                        
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
tu-(tdx1-CA) =
tu-(tdx2-CA) =
tu-(tdx3-CA) =
t6a = tdx-CA
mm
        mm                  
t6d = t6 + CA
mm
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t6a = ttx)          
CALCULATE THE RATIO R
t5 = t5min
mm
h5
m mm
r
m mm
R = h5
(r x t5)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h5 mm h5 mm h5 mm h5 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
St MPa St MPa St MPa St MPa
CA mm CA mm CA mm CA mm
t5t = t5
mm t5t = t5 mm t5t = t5 mm t5t = t5 mm
    tpt = 4.9D(H-0.3)                   mm ttx mm ttx1 mm ttx2 mm
    St                                        
tL = t5t
mm tL = t5t mm tL = t5t mm tL = t5t mm
tu = tpt
mm tu = ttx mm tu = ttx1 mm tu = ttx2 mm
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 4.9D(H-X/1000)
mm ttx1 mm ttx2 mm ttx3 mm
    St                                        
Verify tu-ttx. Repeat using the calculated value of ttx until there is little difference between the calculated values of tu and ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t6a = ttx
mm
        mm                  
t6t = t6
mm
THICKNESS OF THE SIXTH COURSE
t6min is the higher value between t6d & t6t
mm
t6use
mm
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 7TH SHELL COURSE (N=7)          
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t7a = tdx-CA)          
CALCULATE THE RATIO R
t6 = t6min-CA
mm
h6
m mm
r
m mm
R = h6
(r x t6)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h6 mm h6 mm h6 mm h6 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
Sd MPa Sd MPa Sd MPa Sd MPa
CA mm CA mm CA mm CA mm
tpd - CA= 4.9D(H-0.3)G
mm tdx-CA mm tdx1-CA mm tdx2-CA mm
    Sd                                        
tL = t6d-CA
mm tL = t6d-CA mm tL = t6d-CA mm tL = t6d-CA mm
tu = tpd-CA
mm tu = tdx-CA mm tu = tdx1-CA mm tu = tdx2-CA mm
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 4.9D(H-X/1000)G
mm tdx1-CA mm tdx2-CA mm tdx3-CA mm
    Sd                                        
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
tu-(tdx1-CA) =
tu-(tdx2-CA) =
tu-(tdx3-CA) =
t7a = tdx-CA
mm
        mm                  
t7d = t7 + CA
mm
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t7a = ttx)          
CALCULATE THE RATIO R
t6 = t6min
mm
h6
m mm
r
m mm
R = h6
(r x t6)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h6 mm h6 mm h6 mm h6 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
St MPa St MPa St MPa St MPa
CA mm CA mm CA mm CA mm
t6t = t6
mm t6t = t6 mm t6t = t6 mm t6t = t6 mm
    tpt = 4.9D(H-0.3)                   mm ttx mm ttx1 mm ttx2 mm
    St                                        
tL = t6t
mm tL = t6t mm tL = t6t mm tL = t6t mm
tu = tpt
mm tu = ttx mm tu = ttx1 mm tu = ttx2 mm
    K = tL/tu                     K   K   K  
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 4.9D(H-X/1000)
mm ttx1 mm ttx2 mm ttx3 mm
    St                                        
Verify tu-ttx. Repeat using the calculated value of ttx until there is little difference between the calculated values of tu and ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t7a = ttx
mm
        mm                  
t7t = t7
mm
THICKNESS OF THE SEVENTH COURSE
t7min is the higher value between t7d & t7t
mm
t7use
mm
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 8TH SHELL COURSE (N=8)          
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t8a = tdx-CA)          
CALCULATE THE RATIO R
t7 = t7min-CA
mm
h7
m mm
r
m mm
R = h7
(r x t7)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h7 mm h7 mm h7 mm h7 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
Sd MPa Sd MPa Sd MPa Sd MPa
CA mm CA mm CA mm CA mm
tpd - CA= 4.9D(H-0.3)G
mm tdx-CA mm tdx1-CA mm tdx2-CA mm
    Sd                                        
tL = t7d-CA
mm tL = t7d-CA mm tL = t7d-CA mm tL = t7d-CA mm
tu = tpd-CA
mm tu = tdx-CA mm tu = tdx1-CA mm tu = tdx2-CA mm
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 4.9D(H-X/1000)G
mm tdx1-CA mm tdx2-CA mm tdx3-CA mm
    Sd                                        
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
tu-(tdx1-CA) =
tu-(tdx2-CA) =
tu-(tdx3-CA) =
t8a = tdx-CA
mm
        mm                  
t8d = t8 + CA
mm
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t8a = ttx)          
CALCULATE THE RATIO R
t7 = t7min
mm
h7
m mm
r
m mm
R = h7
(r x t7)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R =  →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank m Dtank m Dtank m Dtank m
h7 mm h7 mm h7 mm h7 mm
r mm r mm r mm r mm
E m E m E m E m
Htank m Htank m Htank m Htank m
H = Htank - (N-1)*E (Lower) m H (Lower) m H (Lower) m H (Lower) m
H = Htank - (N-1)*E (In Analysis) m H (Analysis) m H (Analysis) m H (Analysis) m
G
G
G
G
St MPa St MPa St MPa St MPa
CA mm CA mm CA mm CA mm
t7t = t7
mm t7t = t7 mm t7t = t7 mm t7t = t7 mm
    tpt = 4.9D(H-0.3)                   mm ttx mm ttx1 mm ttx2 mm
    St                                        
tL = t7t
mm tL = t7t mm tL = t7t mm tL = t7t mm
tu = tpt
mm tu = ttx mm tu = ttx1 mm tu = ttx2 mm
    K = tL/tu                     K   K   K  
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(320CH)                     X₁   X₁   X₁  
X₂ = 1000CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 4.9D(H-X/1000)
mm ttx1 mm ttx2 mm ttx3 mm
    St                                        
Verify tu-ttx. Repeat using the calculated value of ttx until there is little difference between the calculated values of tu and ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t8a = ttx
mm
        mm                  
t8t = t8
mm
THICKNESS OF THE EIGHTH COURSE
t8min is the higher value between t8d & t8t
mm
t8use
mm
                                                   
  Design of Atmospheric Storage Tanks by API Std 650    
     
  Calculation of Thicknesses by The Variable-Design-Point Method (5.6.4)    
                                                   
  Tables y Standards    
  - API Std 650 Welded Tanks for oil Storage, para. 5.6.4                
  - Minimum Plate Thickness by API Std 650 (5.6.1.1)                
  - Plate Thickness by ASME / ASTM                
  - Tables 5-2a and 5-2b Allowable stress for design & Hydrostatic Test conditions                
                                                   
  VARIABLE-DESIGN-POINT METHOD    
  (Enter values in yellow cells for calculations)    
  DATA INPUT    
Capacity (Barrels)
ft³
G (Fluid Specific Gravity)
    Fluid Density, r (Lb/ft³) (1) Note (1): (Consider r ≥ 62,43 Lb/ft³ for the Hmáx calculation)         
Ground Resistance, Ps (Lb/in²)
    Outage (ft) (2) Note (2): (Distance from the maximum level to the upper edge)        
 
Course
    Plate  Specification      
Plate Width, E (ft)
Hydrostatic Test Stress, St (psi)
Product Design Stress, Sd (psi)
Corrosion Allowance, CA (in.)
Hmáx = 1728*Ps/ρ
in.          = ft
    Htank ≤ Hmáx                 ft                  
h = Htank-outage
ft
    D = (V 4/πh)⁰∙⁵                 ft            = ft³          = barrels According to API Std 650    
Dtank
ft            = ft³          = barrels
No. of Courses = Htank/E
                                                   
                                                   
  OUTPUT tmin & SELECTION tuse              
  Courses Design Condition td
(in.) 		Hidrostatic Test Condition tt
(in.) 		tmin
(in.) 		tuse (*)
(in.) 		             
  t1              
  t2              
  t3              
  t4              
  t5              
  t6              
  t7              
  t8              
    Notes:                                    
    - Dimensions in inches.                                    
- (*) Verified Minimum Thickness by API Std 650 (5.6.1.1)
                                                   
  CALCULATING THE THICKNESS OF THE 1ST SHELL COURSE (N=1)              
N
    H = Htank - (N-1)E                 ft                  
DESIGN CONDITIONS
tpd = 2.6D(H-1)G + CA
in.
    Sd                                    
    t1d = [ 1.06 -  0.463D ( HG ) 0,5 ] ( 2.6HDG ) + CA in.                  
H Sd
Sd
    t1d need not be greater than tpd                                    
Lower between tpd y t1d
    HYDROSTATIC TEST CONDITIONS              
    tpt = 2.6D(H-1)                   in.                  
St
    t1t = [ 1.06 -  0.463D ( H ) 0,5 ] ( 2.6HD )   in.                  
H St
St
    t1t need not be greater than tpt                                    
Lower between tpt y t1t
    THICKNESS OF THE FIRST COURSE              
Higher between t1d y t1t (t1min)
in.
    t1use                 in. t1use> t1min                
                                                   
                                                   
    Verify L/H ≤ 2                                    
    t = t1use - CA                 in.                  
    L = (6 D t)⁰∙⁵                                    
    H = Htank - (N-1)E                                    
                                                   
    L/H =                                    
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 2ND SHELL COURSE (N=2)      
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t2a = tdx-CA)          
CALCULATE THE RATIO R
    t1 = t1use - CA                   in.                  
h1
ft in.
r
ft in.
R = h1
(r  t1)⁰∙⁵
                                                   
R ≤ 1.375 →
    R ≥ 2.625 →                                    
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank ft Dtank ft
h1 in. h1 in. h1 in. h1 in.
r in. r in. r in. r in.
E ft E ft E ft E ft
Htank ft Htank ft Htank ft Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower) ft H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis) ft H (Analysis) ft
G
G
G
G
Sd psi Sd psi Sd psi Sd psi
CA in. CA in. CA in. CA in.
    t1d = t1use in. t1d = t1use in. t1d = t1use in. t1d = t1use in.
tpd - CA= 2.6D(H-1)G
in. tdx-CA in. tdx1-CA in. tdx2-CA in.
Sd
    tL = t1use - CA                 in. tL = t1use-CA in. tL = t1use-CA in. tL = t1use-CA in.
tu = tpd-CA
in. tu = tdx-CA in. tu = tdx1-CA in. tu = tdx2-CA in.
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
                                                   
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 2.6D(H-X/12)G
in. tdx1-CA in. tdx2-CA in. tdx3-CA in.
    Sd                                        
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
 tu-(tdx1-CA) =
 tu-(tdx2-CA) =
 tu-(tdx3-CA) =
    t2a = tdx-CA                   in.                  
        in.                  
t2d = t2 + CA
in.
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t2a = ttx)          
CALCULATE THE RATIO R
t₁ = t1use
in.
h1
ft in.
r
ft in.
R = h1
(r x t1)⁰∙⁵
R ≤ 1.375 →
    R ≥ 2.625 →                                    
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank
Dtank ft
h1 in. h1 in. h1
h1 in.
r in. r in. r
r in.
E ft E ft E
E ft
Htank ft Htank ft Htank
Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower)
H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis)
H (Analysis) ft
G
G
G
G
St psi St psi St
St psi
CA in. CA in. CA
CA in.
    t1t = [ 1.06 -  0.463D ( H ) 0,5 ] ( 2.6HD )   in. t1t in. t1t   t1t in.
H St
St
tpt = 2.6D(H-1)
in. ttx in. ttx1
ttx2 in.
    St                                        
tL = t1t
in. tL = t1t in. tL = t1t
tL = t1t in.
tu = tpt
in. tu = ttx in. tu = ttx₁
tu = ttx2 in.
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 2.6D(H-X/12)
in. ttx1 in. ttx2
ttx3 in.
    St                                        
Verificar tu-ttx. Repetir usando el valor calculado de ttx hasta que haya poca diferencia entre los valores calculados de tu y ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t₂ₐ = ttx
in.
in.
t₂t = t₂
in.
THICKNESS OF THE SECOND COURSE
t2min is the higher value between t2d y t2t
in.
t2use
in. (The additional thickness will not be used for subsequent calculations)
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 3RD SHELL COURSE (N=3)          
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t3a = tdx-CA)          
CALCULATE THE RATIO R
t2 = t2min-CA
in.
h2
ft in.
r
ft in.
R = h2
(r x t2)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank
Dtank ft
h2 in. h2 in. h2
h2 in.
r in. r in. r
r in.
E ft E ft E
E ft
Htank ft Htank ft Htank
Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower)
H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis)
H (Analysis) ft
G
G
G
G
Sd psi Sd psi Sd
Sd psi
CA in. CA in. CA
CA in.
tpd - CA= 2.6D(H-1)G
in. tdx-CA in. tdx1-CA
tdx2-CA in.
    Sd                                        
tL = t2d-CA
in. tL = t2d-CA in. tL = t2d-CA
tL = t2d-CA in.
tu = tpd-CA
in. tu = tdx-CA in. tu = tdx1-CA
tu = tdx2-CA in.
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 2.6D(H-X/12)G
in. tdx1-CA in. tdx2-CA
tdx3-CA in.
    Sd                                        
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
tu-(tdx1-CA) =
tu-(tdx2-CA) =
tu-(tdx3-CA) =
    t3a = tdx-CA                   in.                  
        in.                  
t3d = t3 + CA
in.
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t3a = ttx)          
CALCULATE THE RATIO R
t2 = t2min
in.
h2
ft in.
r
ft in.
R = h2
(r x t2)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank
Dtank ft
h2 in. h2 in. h2
h2 in.
r in. r in. r
r in.
E ft E ft E
E ft
Htank ft Htank ft Htank
Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower)
H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis)
H (Analysis) ft
G
G
G
G
St psi St psi St
St psi
CA in. CA in. CA
CA in.
t2t = t2
in. t2t = t2 in. t2t = t2
t2t = t2 in.
tpt = 2.6D(H-1)
in. ttx in. ttx1
ttx2 in.
    St                                        
tL = t2t
in. tL = t2t in. tL = t2t
tL = t2t in.
tu = tpt
in. tu = ttx in. tu = ttx1
tu = ttx2 in.
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 2.6D(H-X/12)
in. ttx1 in. ttx2
ttx3 in.
    St                                        
Verificar tu-ttx. Repetir usando el valor calculado de ttx hasta que haya poca diferencia entre los valores calculados de tu y ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t3a = ttx
in.
        in.                  
t3t = t3
in.
THICKNESS OF THE THIRD COURSE
t3min is the higher value between t3d y t3t
in.
t3use
in.
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 4TH SHELL COURSE (N=4)          
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t4a = tdx-CA)          
CALCULATE THE RATIO R
t3 = t3min-CA
in.
h3
ft in.
r
ft in.
R = h3
(r x t3)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank
Dtank ft
h3 in. h3 in. h3
h3 in.
r in. r in. r
r in.
E ft E ft E
E ft
Htank ft Htank ft Htank
Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower)
H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis)
H (Analysis) ft
G
G
G
G
Sd psi Sd psi Sd
Sd psi
CA in. CA in. CA
CA in.
tpd - CA= 2.6D(H-1)G
in. tdx-CA in. tdx1-CA
tdx2-CA in.
    Sd                                        
tL = t3d-CA
in. tL = t3d-CA in. tL = t3d-CA
tL = t3d-CA in.
tu = tpd-CA
in. tu = tdx-CA in. tu = tdx1-CA
tu = tdx2-CA in.
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 2.6D(H-X/12)G
in. tdx1-CA in. tdx2-CA
tdx3-CA in.
    Sd                                        
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
tu-(tdx1-CA) =
tu-(tdx2-CA) =
tu-(tdx3-CA) =
t4a = tdx-CA
in.
        in.                  
t4d = t4 + CA
in.
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t4a = ttx)          
CALCULATE THE RATIO R
t3 = t3min
in.
h3
ft in.
r
ft in.
R = h3
(r x t3)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank
Dtank ft
h3 in. h3 in. h3
h3 in.
r in. r in. r
r in.
E ft E ft E
E ft
Htank ft Htank ft Htank
Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower)
H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis)
H (Analysis) ft
G
G
G
G
St psi St psi St
St psi
CA in. CA in. CA
CA in.
t3t = t3
in. t3t = t3 in. t3t = t3
t3t = t3 in.
    tpt = 2.6D(H-1)                   in. ttx in. ttx1   ttx2 in.
    St                                        
tL = t3t
in. tL = t3t in. tL = t3t
tL = t3t in.
tu = tpt
in. tu = ttx in. tu = ttx1
tu = ttx2 in.
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 2.6D(H-X/12)
in. ttx1 in. ttx2
ttx3 in.
    St                                        
Verificar tu-ttx. Repetir usando el valor calculado de ttx hasta que haya poca diferencia entre los valores calculados de tu y ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t4a = ttx
in.
        in.                  
t4t = t4
in.
THICKNESS OF THE FOURTH COURSE
t4min is the higher value between t4d y t4t
in.
t4use
in.
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 5TH SHELL COURSE (N=5)          
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t5a = tdx-CA)          
CALCULATE THE RATIO R
t4 = t4min-CA
in.
h4
ft in.
r
ft in.
R = h4
(r x t4)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank
Dtank ft
h4 in. h4 in. h4
h4 in.
r in. r in. r
r in.
E ft E ft E
E ft
Htank ft Htank ft Htank
Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower)
H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis)
H (Analysis) ft
G
G
G
G
Sd psi Sd psi Sd
Sd psi
CA in. CA in. CA
CA in.
tpd - CA= 2.6D(H-1)G
in. tdx-CA in. tdx1-CA
tdx2-CA in.
    Sd                                        
tL = t4d-CA
in. tL = t4d-CA in. tL = t4d-CA
tL = t4d-CA in.
tu = tpd-CA
in. tu = tdx-CA in. tu = tdx1-CA
tu = tdx2-CA in.
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 2.6D(H-X/12)G
in. tdx1-CA in. tdx2-CA
tdx3-CA in.
Sd
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
tu-(tdx1-CA) =
tu-(tdx2-CA) =
tu-(tdx3-CA) =
t5a = tdx-CA
in.
        in.                  
t5d = t5 + CA
in.
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t5a = ttx)          
CALCULATE THE RATIO R
t4 = t4min
in.
h4
ft in.
r
ft in.
R = h4
(r x t4)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank
Dtank ft
h4 in. h4 in. h4
h4 in.
r in. r in. r
r in.
E ft E ft E
E ft
Htank ft Htank ft Htank
Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower)
H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis)
H (Analysis) ft
G
G
G
G
St psi St psi St
St psi
CA in. CA in. CA
CA in.
t4t = t4
in. t4t = t4 in. t4t = t4
t4t = t4 in.
tpt = 2.6D(H-1)
in. ttx in. ttx1
ttx2 in.
    St                                        
tL = t4t
in. tL = t4t in. tL = t4t
tL = t4t in.
tu = tpt
in. tu = ttx in. tu = ttx1
tu = ttx2 in.
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 2.6D(H-X/12)
in. ttx1 in. ttx2
ttx3 in.
    St                                        
Verificar tu-ttx. Repetir usando el valor calculado de ttx hasta que haya poca diferencia entre los valores calculados de tu y ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t5a = ttx
in.
        in.                  
t5t = t5
in.
THICKNESS OF THE FIFTH COURSE
t5min is the higher value between t5d y t5t
in.
t5use
in.
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 6TH SHELL COURSE (N=6)          
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t6a = tdx-CA)          
CALCULATE THE RATIO R
t5 = t5min-CA
in.
h5
ft in.
r
ft in.
R = h5
(r x t5)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank
Dtank ft
h5 in. h5 in. h5
h5 in.
r in. r in. r
r in.
E ft E ft E
E ft
Htank ft Htank ft Htank
Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower)
H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis)
H (Analysis) ft
G
G
G
G
Sd psi Sd psi Sd
Sd psi
CA in. CA in. CA
CA in.
tpd - CA= 2.6D(H-1)G
in. tdx-CA in. tdx1-CA
tdx2-CA in.
    Sd                                        
tL = t5d-CA
in. tL = t5d-CA in. tL = t5d-CA
tL = t5d-CA in.
tu = tpd-CA
in. tu = tdx-CA in. tu = tdx1-CA
tu = tdx2-CA in.
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 2.6D(H-X/12)G
in. tdx1-CA in. tdx2-CA
tdx3-CA in.
    Sd                                        
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
tu-(tdx1-CA) =
tu-(tdx2-CA) =
tu-(tdx3-CA) =
t6a = tdx-CA
in.
        in.                  
t6d = t6 + CA
in.
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t6a = ttx)          
CALCULATE THE RATIO R
t5 = t5min
in.
h5
ft in.
r
ft in.
R = h5
(r x t5)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank
Dtank ft
h5 in. h5 in. h5
h5 in.
r in. r in. r
r in.
E ft E ft E
E ft
Htank ft Htank ft Htank
Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower)
H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis)
H (Analysis) ft
G
G
G
G
St psi St psi St
St psi
CA in. CA in. CA
CA in.
t5t = t5
in. t5t = t5 in. t5t = t5
t5t = t5 in.
tpt = 2.6D(H-1)
in. ttx in. ttx1
ttx2 in.
    St                                        
tL = t5t
in. tL = t5t in. tL = t5t
tL = t5t in.
tu = tpt
in. tu = ttx in. tu = ttx1
tu = ttx2 in.
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 2.6D(H-X/12)
in. ttx1 in. ttx2
ttx3 in.
    St                                        
Verify tu-ttx. Repeat using the calculated value of ttx until there is little difference between the calculated values of tu and ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t6a = ttx
in.
        in.                  
t6t = t6
in.
THICKNESS OF THE SIXTH COURSE
t6min is the higher value between t6d y t6t
in.
t6use
in.
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 7TH SHELL COURSE (N=7)          
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t7a = tdx-CA)          
CALCULATE THE RATIO R
t6 = t6min-CA
in.
h6
ft in.
r
ft in.
R = h6
(r x t6)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank
Dtank ft
h6 in. h6 in. h6
h6 in.
r in. r in. r
r in.
E ft E ft E
E ft
Htank ft Htank ft Htank
Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower)
H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis)
H (Analysis) ft
G
G
G
G
Sd psi Sd psi Sd
Sd psi
CA in. CA in. CA
CA in.
tpd - CA= 2.6D(H-1)G
in. tdx-CA in. tdx1-CA
tdx2-CA in.
    Sd                                        
tL = t6d-CA
in. tL = t6d-CA in. tL = t6d-CA
tL = t6d-CA in.
tu = tpd-CA
in. tu = tdx-CA in. tu = tdx1-CA
tu = tdx2-CA in.
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 2.6D(H-X/12)G
in. tdx1-CA in. tdx2-CA
tdx3-CA in.
    Sd                                        
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
tu-(tdx1-CA) =
tu-(tdx2-CA) =
tu-(tdx3-CA) =
t7a = tdx-CA
in.
        in.                  
t7d = t7 + CA
in.
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t7a = ttx)          
CALCULATE THE RATIO R
t6 = t6min
in.
h6
ft in.
r
ft in.
R = h6
(r x t6)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank
Dtank ft
h6 in. h6 in. h6
h6 in.
r in. r in. r
r in.
E ft E ft E
E ft
Htank ft Htank ft Htank
Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower)
H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis)
H (Analysis) ft
G
G
G
G
St psi St psi St
St psi
CA in. CA in. CA
CA in.
t6t = t6
in. t6t = t6 in. t6t = t6
t6t = t6 in.
tpt = 2.6D(H-1)
in. ttx in. ttx1
ttx2 in.
    St                                        
tL = t6t
in. tL = t6t in. tL = t6t
tL = t6t in.
tu = tpt
in. tu = ttx in. tu = ttx1
tu = ttx2 in.
    K = tL/tu                     K   K   K  
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 2.6D(H-X/12)
in. ttx1 in. ttx2
ttx3 in.
    St                                        
Verify tu-ttx. Repeat using the calculated value of ttx until there is little difference between the calculated values of tu and ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t7a = ttx
in.
        in.                  
t7t = t7
in.
THICKNESS OF THE SEVENTH COURSE
t7min is the higher value between t7d y t7t
in.
t7use
in.
                                                   
                                                   
  CALCULATING THE THICKNESS OF THE 8TH SHELL COURSE (N=8)          
    UPPER-COURSE METHOD FOR  DESIGN CONDITIONS (t8a = tdx-CA)          
CALCULATE THE RATIO R
t7 = t7min-CA
in.
h7
ft in.
r
ft in.
R = h7
(r x t7)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank
Dtank ft
h7 in. h7 in. h7
h7 in.
r in. r in. r
r in.
E ft E ft E
E ft
Htank ft Htank ft Htank
Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower)
H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis)
H (Analysis) ft
G
G
G
G
Sd psi Sd psi Sd
Sd psi
CA in. CA in. CA
CA in.
tpd - CA= 2.6D(H-1)G
in. tdx-CA in. tdx1-CA
tdx2-CA in.
    Sd                                        
tL = t7d-CA
in. tL = t7d-CA in. tL = t7d-CA
tL = t7d-CA in.
tu = tpd-CA
in. tu = tdx-CA in. tu = tdx1-CA
tu = tdx2-CA in.
K = tL/tu
K
K
K
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
tdx - CA= 2.6D(H-X/12)G
in. tdx1-CA in. tdx2-CA
tdx3-CA in.
    Sd                                        
Verify tu- (tdx-CA). Repeat using the calculated value of tdx-CA until there is little difference between the calculated values of tu and tdx-CA
tu-(tdx-CA) =
tu-(tdx1-CA) =
tu-(tdx2-CA) =
tu-(tdx3-CA) =
t8a = tdx-CA
in.
        in.                  
t8d = t8 + CA
in.
    UPPER-COURSE METHOD FOR  HYDROSTATIC TEST CONDITIONS (t8a = ttx)          
CALCULATE THE RATIO R
t7 = t7min
in.
h7
ft in.
r
ft in.
R = h7
(r x t7)⁰∙⁵
R ≤ 1.375 →
R ≥ 2.625 →
1.375 < R < 2.625 →
How R = →
1st Iteration
2nd Iteration
3th Iteration
N (Lower Course)
N (Lower)
N (Lower)
N (Lower)
N (Course in Analysis)
N (Analysis)
N (Analysis)
N (Analysis)
Dtank ft Dtank ft Dtank
Dtank ft
h7 in. h7 in. h7
h7 in.
r in. r in. r
r in.
E ft E ft E
E ft
Htank ft Htank ft Htank
Htank ft
H = Htank - (N-1)*E (Lower) ft H (Lower) ft H (Lower)
H (Lower) ft
H = Htank - (N-1)*E (In Analysis) ft H (Analysis) ft H (Analysis)
H (Analysis) ft
G
G
G
G
St psi St psi St
St psi
CA in. CA in. CA
CA in.
t7t = t7
in. t7t = t7 in. t7t = t7
t7t = t7 in.
tpt = 2.6D(H-1)
in. ttx in. ttx1
ttx2 in.
    St                                        
tL = t7t
in. tL = t7t in. tL = t7t
tL = t7t in.
tu = tpt
in. tu = ttx in. tu = ttx1
tu = ttx2 in.
    K = tL/tu                     K   K   K  
C = [K⁰∙⁵(K-1)]/(1-K¹∙⁵)
C
C
C
    X₁ = 0.61(rtu)⁰∙⁵+(3.84CH)                     X₁   X₁   X₁  
X₂ = 12CH
X₂
X₂
X₂
X₃ = 1.22(rtu)⁰∙⁵
X₃
X₃
X₃
X
X
X
X
ttx = 2.6D(H-X/12)
in. ttx1 in. ttx2
ttx3 in.
    St                                        
Verify tu-ttx. Repeat using the calculated value of ttx until there is little difference between the calculated values of tu and ttx
tu-ttx =
tu-ttx1 =
tu-ttx2 =
tu-ttx3 =
t8a = ttx
in.
        in.                  
t8t = t8
in.
THICKNESS OF THE EIGHTH COURSE
t8min is the higher value between t8d y t8t
in.
t8use
in.
                                                   
  Minimum Plate Thickness Especified by API Std 650 (5.6.1.1)
  D  Thickness of Shell Course
  (m) (ft)  (mm)  (in)
  < 15 < 50 5 0,1875
  15 to < 36 50  to <120 6 0,25
  36 to 60 120 to 200 8 0,3125
  > 60 > 200 10 0,375
         
  Plate Thickness   
 
  Nominal Size Thickness   Nominal Size Thickness  
  (mm)   (inches)  
5
0,1875
6
0,25
8
0,3125
10
0,375
11
0,4375
12,5
0,5
14
0,5625
16
0,625
18
0,6875
19
0,75
21
0,8125
22
0,875
24
0,9375
25
1
27
1,0625
28
1,125
30
1,1875
32
1,25
33
1,3125
35
1,375
36
1,4375
38
1,5
40
1,5625
41
1,625
43
1,6875
  45   1,75  
                   
  Table 5.2a—Permissible Plate Materials and Allowable Stresses (SI)  
  Plate Material Plate  Specification Grade Nominal Plate Thickness t
mm 		Minimum Yield Strength
Mpa 		Minimum Tensile Strength
Mpa 		Product Design Stress Sd
Mpa 		Hydrostatic Test Stress St
Mpa 		 
- - - - -
A283 C
205 380
A285 C
205 380
A131 A
235 400
A131 B
235 400
A36 -
250 400
A131 EH36
360 490
A573 58
220 400
A573 65
240 450
A573 70
290 485
A516 55
205 380
A516 60
220 415
A516 65
240 450
A516 70
260 485
A662 B
275 450
A662 C
295 485
A537 1 t ≤ 65 345 485
A537 2 t ≤ 65 415 550
A633 C t ≤ 65 345 485
A633 D t ≤ 65 345 485
A678 A
345 485
A678 B
415 550
A737 B
345 485
A841 Class 1
345 485
  A841 Class 2   415 550  
 
  Table 5.2b—Permissible Plate Materials and Allowable Stresses (USC)  
  Plate Material Plate  Specification Grade Nominal Plate Thickness t
in. 		Minimum Yield Strength
psi 		Minimum Tensile Strength
psi 		Product Design Stress Sd
psi 		Hydrostatic Test Stress St
psi 		 
A283 C
30.000 55.000
A285 C
30.000 55.000
A131 A
34.000 58.000
A131 B
34.000 58.000
A36 -
36.000 58.000
A131 EH36
51.000 71.000
A573 58
32.000 58.000
A573 65
35.000 65.000
A573 70
42.000 71.000
A516 55
30.000 55.000
A516 60
32.000 60.000
A516 65
35.000 65.000
A516 70
38.000 70.000
A662 B
40.000 65.000
A662 C
43.000 70.000
A537 1 t ≤ 2-½ 50.000 70.000
A537 2 t ≤ 2-½ 60.000 80.000
A633 C t ≤ 2-½ 50.000 70.000
A633 D t ≤ 2-½ 50.000 70.000
A678 A
50.000 70.000
A678 B
60.000 80.000
A737 B
50.000 70.000
A841 Class 1
50.000 70.000
  A841 Class 2   60.000 80.000