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 – Td
- 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
- Weld fitting option – W
- Is the fitting welded
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 dish and knuckle – tn
- Thickness ‘as is’, meaning it is the design thickness taking into account corrosion and tolerance.
- Nominal Inside Dish Radius – Ln
- Nominal inside radius of the dish (large radius). Custom defined size for torispherical.
- Nominal Inside Knuckle Radius – rn
- Nominal inside radius of the knuckle (small radius). Custom defined size for torispherical.
- Corrosion – Ca
- Amount of thickness that accounts for the possible effects of corrosions.
- Tolerance – tol
- Tolerance in thickness for production
- Joint Efficiency – E
- Effectiveness of the strength, depending on whether joints are seamless, welded, or expected to perform worse than the base material properties
Torispherical Cap
Calculated Values
- Allowable Operating Stress – S
- 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.
- Minimum yield strength at 20 °C – Symin
- Stress in the component at which the component starts to plastically deform at 20 °C ambient temperature.
- Minimum tensile strength at 20 °C – Sumin
- Ultimate strength that the component can withstand.
- Allowable stress test – St
- Stress in the component at which it is still allowed (without failure) to use the component at testing condition.
- Weld joint strength reduction – W
- Factor by which the allowable strength is reduced in order to accommodate the reduction in strength in the welded joint.
- Limited allowable torisherical operating stress – S
- Stress in the component at which it is still allowed (without failure) to use the component.
- Torispherical factor – M
- M = 1/4 (3 + sqr(L/r))
- Nominal Required Thickness – trn
- 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.
- Minimum head thickness – ts
- Minimum specified head thickness after forming.
- 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 – P/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.
- Required Test Pressure – Pt
- Required hydrostatic pressure for testing at any point in the piping system.
Scope errors
- Head thickness is out of scope: required is t ≥ 0.002 L
- This code determines for heads a minimum thickness.
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 head thickness.
- Wall thickness is insufficient to bear the applied loads. Increase the wall thickness.
Remarks
- Su(min) is lager than 70 000 psi (500 MPa), S = 20 000 psi (150Mpa) times ratio original S/Sa
- The minimum tensile strength exceeds a limit. The allowable stress is limited by a correction factor.