Input variables
Generic variables
These variables can be found in almost all reports as input variables.
Design Pressure – Pc
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 – Do
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 disk, knuckle – en, ekn
Thickness ‘as is’, meaning it is the design thickness taking into account corrosion and tolerance.
Nominal Inside Dish Radius – Rin
Nominal inside radius of the dish (large radius). Custom defined size for torispherical and estimated size for elliptical.
Nominal Inside Knuckle Radius – rin
Nominal inside radius of the knuckle (small radius). Custom defined size for torispherical and estimated size for elliptical.
Corrosion – c0
Amount of thickness that accounts for the possible effects of corrosions.
Tolerance – c1
Tolerance in thickness for production
Joint coefficient – z
Effectiveness of the strength, depending on whether joints are seamless, welded, or expected to perform worse than the base material properties
Calculated Values
Allowable Stress at Temperature – f
Stress in the component at which it is still allowed (without failure) to use the component
Allowable Buckling Stress at Temperature – fb
Buckling stress in the component at which it is still allowed (without structural failure) to use the component
Allowable stress at 20 °C – ft
Stress in the component at which it is still allowed (without failure) to use the component at testing condition
Allowable buckling stress at 20 °C – fbt
Buckling stress in the component at which it is still allowed (without structural failure) to use the component at testing condition
Nominal Required Thickness dish, knuckle – esrn, ekrn
Based on the input, this is the calculated thickness that is required to sustain the loads. The nominal value should be smaller than the nominal design thickness.
Maximum Allowable Working Pressure – MAWP
The maximum pressure at which the component can be used in operation. This value should be larger than the design pressure.
Design margin – Pc/MAWP
Ratio of the design pressure to MAWP
Maximum Allowable Test Pressure – MATP
The maximum pressure at which the component should be tested and survive.
Scope errors
Ellipsoidal end factor K is out of scope: required 1.7 < K < 2.2
The calculation takes a default value K = 2
Joint coefficient z is out of scope: required z = 1.0
This code determines a specific joint coefficient.
Internal knuckle radius is out of scope: required ri ≤ 0.2 Di, ri ≥ 0.06 Di and ri ≥ 3 e
This code determines a minimum and maximum knuckle radius.
Internal dish radius is out of scope: required Ri ≤ Do
This code determines a maximum dish radius.
Required thickness is out of scope: required 0.001 Di ≤ e ≤ 0.08 Di
This code determines a minimum and maximum required thickness
For e < 0.003 Di the material must be 'Carbon Steel' or 'Austenitic' and T ≤ 100 °C
This code determines specific material and a maximum temperature for (very) thin walled heads.
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.
Insufficient dish thickness.
Wall thickness is insufficient to bear the applied loads. Increase the wall thickness.
Insufficient knuckle thickness.
Wall thickness is insufficient to bear the applied loads. Increase the wall thickness.
Calculation errors
Can't calculate required knuckle thickness ey. Please check input data.
An error occured in the calculation for the required thickness.
Can't calculate required knuckle thickness eb. Please check input data.
An error occured in the calculation for the required thickness.