Pressure Vessel (ASME VIII) Calculator v1

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 (Fig-5-UCD 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 co-ordinate 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:
Fluid pressure Weld-joint-factor Allowable stress Inside diameter	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:
Fluid pressure Weld-joint-factor Allowable stress Inside diameter Half conical angle Knuckle inside radius	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:
Wall thickness Weld-joint-factor Allowable stress Inside diameter Operating temperature Ring section area (cylinders only) Number of rings (cylinders only) Vessel length (cylinders only)	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 co-ordinate 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:

Wall thickness Weld-joint-factor Allowable stress Inside diameter Operating temperature Half conical angle Knuckle inside radius

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 co-ordinate listings

Check minimum system requirements