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Engineering Tools > Head Wall Thickness		  
 
Type of shell    
Design pressure Pd N/mm2 ( = 1 MPa = 10 Bar )
Design temperature Td 0C  
Material description  
Select yield stress and specific gravity from material database >
Yield stress, design temperature Re(Td) N/mm2  
Specific gravity kg/m3  
Outside diameter De mm  
Nominal wall thickness dn mm  
Inside radius knuckle nominal ri1n mm only for torisph.
Inside radius dish nominal ri2n mm only for torisph.
Corrosion allowance Ca mm  
Tolerance tol mm  
Strength reduction coëfficient z -  
Design Code (ASME, Dutch R., PED)
       
   
  Note: Without warranty and for estimating purposes only. Results should be checked and approved by qualified engineer.
     
     
 
Wall thickness calculation of Ellipsoidal head
according Dutch Rules
  
     
  Calculation thickness d = dn - Ca - tol = 8.2 - 1 - 0 = 7.20 mm  
  (ellipsoidal only) k1 = 2*(he-dn) / (De-2*dn) = (with he = De/4) 0.4595  
  Inside radius knuckle nom. ri1n = 0.25 * (De-2*dn) * (1+k12 - (1-k1) * (1+k12) =    
    ==> 0.25 * ( 0.00) * (1+ 0.45952 - (1- 0.4595) * (1+ 0.45952) = 31.24 mm  
  Inside radius dish nominal ri2n = 1/(4*k1) * (De-2*dn) * (1+k12 + (1-k1) * (1+k12) =    
    ==> 1/(4* 0.4595)*( 0.00)*(1+ 0.45952+(1- 0.4595)*(1+ 0.45952)= 199.15 mm 
  Inside radius knuckle ri1 = ri1n + Ca + tol = 31.24 + 1.00 + 0.00 = 32.24 mm  
  Inside radius dish ri2 = ri2n + Ca + tol = 199.15 + 1.00 + 0.00 = 200.15 mm  
           
  Ellipsoidal head:        
           
  (Constant 1) C1 = 101.125*(1.6-log(100*(ri1/ri2)))*(1-(d/(1.1*ri1))) =    
    ==> 101.125*(1.6-log(100*( 32.24/ 200.15)))*(1-( 7.20/(1.1* 32.24))) = 2.25  
  (Constant 2) C2 = 1 + 0.306*ln(1+(d/ri1)) + 0.1574*ln2(1+(d/ri1)) =    
    ==> 1 + 0.306*ln(1+( 7.20/ 32.24)) + 0.1574*ln2(1+( 7.20/ 32.24))= 1.07  
  (Constant 3) C3 = min (C1, 2) = min ( 2.25, 2) = 1.50  
           
  Allowable stress knuckle fe = C3 * Re(Td) = 1.50 * 175.20 = 262.85 N/mm2  
  Allowable stress dish f2 = 0.67 * Re(Td) = 0.67 * 175.20 = 117.38 N/mm2  
           
  Required wall thickn. knuckle
drk =
Pd*De*C1*C2

(2*z*fe)
=
0.50* 219.10* 2.25* 1.07

(2* 1.00* 262.85)
=
0.50 mm  
  Nominal required thickness k. drkn = drk + Ca + tol = 0.50 + 1 + 0 = 1.50 mm  
  Required strength reduction kn.
zmin,k =
Pd*De*C1*C2

(2*drk*fe)
=
0.50* 219.10* 2.25* 1.07

(2* 7.20* 262.85)
=
0.070  
  Required wall thickn. dish
drd =
2*Pd*ri2

(4*z*f2 - Pd)
=
2* 0.50* 200.15

(4* 1.00* 117.38 - 0.50)
=
0.43 mm  
  Nominal required thickness d. drdn = drd + Ca + tol = 0.43 + 1 + 0 = 1.43 mm  
  Required strength reduct. dish
zmin,d =
Pd*(2*ri2 + d)

(4*d*f2)
=
0.50*(2* 200.15 + 7.20)

(4* 7.20* 117.38)
=
0.060  
  Analysis, z > zmin,k and zmin,d ? dn = 8.2 mm is OK      
  Stability analysis required ? No    
           
  Weight     2.94 kg  
  Enclosed volume     0.001 m3