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
Elliptical Cap
Torispherical Cap
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.