Input variables

Generic variables

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

Location – Location
The physical location of the component
Test medium – Test medium
The medium used to test the component
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.

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 – A
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.
Radius miter bend – R
Radius of the miter bend from the origin of curvature and perpendicular to the neutral axis of the bend. The neutral axis follows the centerlines of the segments.
Total deflection angle miter bend – Angle
The angle of the total deflection the miter bend makes, i.e. the angle between the centerlines of the attached pipes.
Number of Segments – NoS
The number of segments in which the bend is divided.
Miter Bend
Miter Bend
Miter Bend
Miter Bend Widely Spaced
Miter Bend
Miter Bend Closely Spaced

Calculated Values

Minimum yield strength at 20 °C – Symin
Stress in the component at which the component starts to plastically deform at 20 °C ambient temperature.
Design factor – F
Factor for the allowable stress when considering underthickness tolerance and maximum allowable depth of imperfections.
Test design factor – Ft
Factor for the allowable stress when considering underthickness tolerance and maximum allowable depth of imperfections.
Allowable Operating Hoop Stress – Sh
Stress in the component at which it is still allowed (without failure) to use the component.
Miter bend cut angle – θ
Cutting angle between the different segments.
Deflection angle per miter segment – α = 2θ
The total angle of deflection per miter segment.
Minimum inside crotch length – Lc min
The minimum length of a miter bend segment measured at the inside.
Inside crotch length – Lc
The length of a miter bend segment at the inside.
Mean segment radius using nominal wall thickness – r
(Outside Diameter − 2 × Thickness)/2
Segment length at centerline – s
Length of the segment measured at the centerline.
Segment length limit at centerline – slim
Limit of segment length at centerline for widely or closely segment spacing.
Widely/Closely segment spacing
When the length measured at the centerline is beyond or below the segment length limit, the miter bend does not completely follow the curvature of a circle. When beyond the limit, the miter bend is widely spaced and the segments are longer (extra straight pipe) and the distance from the centerline to the center point of deflection is larger than the bend radius. Below the limit, the miter bend is closely spaced and the segments are shorter (missing straight pipe) and the distance from the centerline to the center point of deflection is smaller than the radius.
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.
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
Test pressure factor – FPt
Factor for maximum test pressure
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 (paragraph 437.4.1)

Scope errors

Temperature is out of scope: minimum temperature = -30 °C
This code determines a minimum temperature.
Temperature is out of scope: maximum temperature = 120 °C
This code determines a maximum temperature.
Number of segments is out of scope: required is NoS ≥ 2
A miterbend has at least 2 segments.
Inside crotch length is out of scope: required is Lc ≥ pipe O.D.
This code determines a minimum length.
No calculation required when deflection angle per miter α ≤ 3°
This code determines a minimum angle of miter cut θ. Decrease the number of miter segments or increase the total deflection angle of the miterbend.
Deflection angle per miter α is out of scope: maximum angle = 90°
This code determines a maximum angle of deflection.

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 wall thickness
Wall thickness is insufficient to bear the applied loads. Increase the wall thickness.

Remarks

Angle of miter deflection α > 12.5°.
When a segment of the miterbend has an angle larger than this limit, the maximum allowable pressure shall be limited.

Calculation errors

Can't calculate maximum hoop stress. Please check miter deflection angle.
The miter deflection angle determines the maximum allowable hoop stress.