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Vessel - Hemi-Spherical Head Thickness Calculator

General Design Data

Hemi-Spherical Head Data

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General Notes:

Note: Refer to the "Terms and Conditions" in the 'About' section before using the software.

1) Vessel Shell / Head Thickness Calculator is a software program that can be used to determine the wall thickness of cylindrical shells and 2:1 Semi-ellipsoidal and hemi-spherical heads based on internal pressure.

2) By verifying the calculated thickness and choosing the appropriate thickness for the selected shell or head diameter, material, design temperature etc., the user can determine if the selected wall thickness is suitable for the internal pressure considered. Calculations presented are based on the listed version of ASME Sec VIII Div 1 Boiler and Pressure Vessel code.

3) A number of different material types and grades (steel) are available for use. The materials and their properties presented, are taken from the listed version of ASME Sec II Part D code. Additional materials may be added on request.

4) Equations used :-
Cylindrical Shells:
Based on Circumferential Stress (Longitudinal Joints):
t = (P*R) / ( S*E - 0.6*P) ;
Based on Longitudinal Stress (Circumferential Joints):
t = (P*R) / (2*S*E + 0.4*P) ;
Semi-Ellipsoidal Heads:
t = (P*D) / (2*S*E - 0.2*P) ;
Hemispherical Heads:
t = (P*L) / (2*S*E - 0.2*P) ;
Definitions of the terms used are given in the code sections.

5) Pressure calculations are based on internal pressure only. When external pressure / other loadings need to be considered, the user needs to consult appropriate code sections.

6) Minimum Design Metal Temperature (MDMT) needs to be verified in accordance with the code section by the user.

7) The Program is based on ASME Sec VIII Div 1 Boiler and Pressure Vessel Code - 2019 Ed. and ASME Sec II Part D code - 2019 Ed.

8) If you notice any error, please let us know, so that can be rectified.

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