Subject
A pressure vessel is a container that can hold a pressurised fluid without leakage.
A safe pressure vessel is one that behaves predictably, i.e. the material from which it is manufactured behaves according to Hooke's law and the construction methods are tried and tested.
As pressure vessel failure is particularly dangerous, strict control of their design is very important and because ASME VIII is the world’s most recognised design code it has been selected for the basis of CalQlata’s pressure vessel calculator.
Pressure Vessels calculates the minimum required wall thickness or maximum permissible pressure of stiffened or unstiffened pressure vessels (and their heads) exposed to internal or external pressure according to ASME VIII design criteria.
The pressure vessel calculator includes spheres and cylinders along with hemispherical, ellipsoidal, torispherical, conical and toriconical heads and also provides their internal and external volumes. Subtract the internal volume from the external volume and you will have the volume of material required to manufacture the component (vessel or head).
The ASME VIII design code includes about 260 plots within 60 charts (Fig5UCD to UNF) used to determine the strength factors and elastic moduli for various materials in externally pressurised vessels. CalQlata has mathematically modelled each and every individual plot on all of these charts and Pressure Vessels interpolates for intermediate temperatures.
The pressure vessel calculator not only graphically reproduces these plots for cylindrical and spherical pressure vessels, it also provides coordinate listings for each modelled plot to enable you to verify its accuracy (against those published in Appendix 5 of the ASME design code).
Note: This calculator has not been officially endorsed by the ASME. It is CalQlata’s interpretation of the design code
For help using this calculator, including its plot verification, see Technical Help
Pressure Vessels Calculator  Options
Cylinders and Spheres (internal pressure)
The minimum permissible wall thickness for internally pressurised cylinders or spheres.
You enter: 
and the pressure vessel calculator will provide: 


Minimum wall thickness

Internal volume

External volume

Heads (internally pressurised)
The minimum permissible wall thickness for internally pressurised hemispherical, torispherical, ellipsoidal, conical and toriconical heads for capping cylindrical pressure vessels.
You enter: 
and the pressure vessel calculator will provide: 


Ellipsoidal wall thickness

Ellipsoidal internal volume

Ellipsoidal external volume

Torispherical wall thickness

Torispherical internal volume

Torispherical external volume

Hemispherical wall thickness

Hemispherical internal volume

Hemispherical external volume

Conical wall thickness

Conical internal volume

Conical external volume

Knuckle thickness

Cylinders and Spheres (external pressure)
The maximum permissible pressure for externally pressurised cylinders or spheres.
You enter: 
and the pressure vessel calculator will provide: 


Max pressure

Internal volume

External volume

Factor A

Factor B

Young's modulus Fig 5

Yield stress Fig 5

Wall thickness with rings (cylinders only)

Ring 2nd moment of area (cylinders only)

Verification plot coordinate listings

Heads (internally pressurised)
The maximum permissible pressure for externally pressurised hemispherical, torispherical, ellipsoidal, conical and toriconical heads for capping cylindrical pressure vessels.
You enter: 
and the pressure vessel calculator will provide: 


Max pressure ellipsoidal

Ellipsoidal internal volume

Ellipsoidal external volume

Max pressure torispherical

Torispherical internal volume

Torispherical external volume

Max pressure hemispherical

Hemispherical internal volume

Hemispherical external volume

Max pressure conical

Conical internal volume

Conical external volume

Factor A

Factor B

Young's modulus Fig 5

Yield stress Fig 5

Verification plot coordinate listings

Check minimum system requirements