Input variables

Generic variables

These variables can be found in virtually all reports as input variables

Design Pressure – P
Pressure assumed to be present in the component according to the design terms
Design Temperature – T
Temperature assumed to be present in the component according to the design terms
Material
Name of selected material used for the construction of the component

Specific variables

These variables are component specific

Outside Diameter – D
Outside diameter of the attached part. The diameter runs from the outside of the wall to the opposite outside of the wall, through the center of the circle.
Nominal Thickness – tn
Thickness ‘as is’, meaning it is the design thickness taking into account corrosion and tolerance.
Corrosion – c
Amount of thickness that accounts for the possible effects of corrosions.
Tolerance – tol
Tolerance in thickness for production
Infinite length – L′
The unsupported lenght of the shell is infitely long, meaning the external pressure can not collapse the shell.
Maximum unsupported length – L
Maximum length of the straight part of the pipe that is unsupported.
Pipe
Pipe

Calculated Values

Allowable Operating Stress – So
Stress in the component at which it is still allowed (without failure) to use the component.
Allowable stress at 20 °C – Sa
Stress in the component at which it is still allowed (without failure) to use the component at 20 °C ambient temperature.
Yield strength at operating temperature – Sy
Stress in the component at which the component starts to plastically deform at operating temperature.
Allowable Operating Stress thick shells – S
Stress in the component at which it is still allowed (without failure) to use the component.
Allowable buckling stress thin walled or thick walled shell – B, B′
Maximum compressive stress causing instability in the structure.
Modulus of elasticity – E
Tendency to deform (tensile strain) along an axis when opposing forces (tensile stress) are applied along that axis.
Maximum Allowable Pressure – Pa
The maximum pressure at which the component can be used in operation. This value should be larger than the design pressure.

Scope errors

Temperature is out of scope for material
The material properties are not available at the design temperature.

Errors

Can’t find material ‘MaterialName’ in database
Material could not be found in database. Select an existing material name, or select another material via the material selection window.

Remarks

Restricted unsupported length: L = x mm
The unsupported length is restricted to a maximum: LL′
Yield strength taken as: Sy = 2 B
This is applicable for thick walled shells with unknown yield stress according ASME II part D table Y-1.

Calculation errors

Can't calculate maximum unsupported length for external pressure.
The shell has insufficient strength to determine the unsupported length.