Linepipe Tools

This module provides the core class and functions for representing and calculating the main geometric and material properties of pipeline sections.

Features:

• The Pipe class encapsulates the geometry and material characteristics of a pipeline section, supporting both scalar and array-based calculations for batch processing.

• Methods for computing inner/outer diameters, areas, steel and coating cross-sections, stiffness, and moments of inertia.

• Designed for use in subsea pipeline and riser engineering, but general enough for any pipeline property calculations.

All calculations are vectorized using NumPy for efficiency and flexibility.

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class refpy.linepipe_tools.Pipe(*, outer_diameter=0.0, wall_thickness=0.0, coating_thickness=0.0, corrosion_allowance=0.0, youngs_modulus=0.0)

Bases: object

Class representing a pipeline section with geometric and material properties. Supports both scalar and array inputs for calculations.

Parameters:

• outer_diameter (float or array-like, optional) – Outer diameter of the pipe (m). Default is 0.

• wall_thickness (float or array-like, optional) – Wall thickness of the pipe (m). Default is 0.

• coating_thickness (float or array-like, optional) – Coating wall thickness (m). Default is 0.

• corrosion_allowance (float or array-like, optional) – Corrosion allowance (m). Default is 0.

• youngs_modulus (float or array-like, optional) – Young’s modulus of the material (Pa). Default is 0.

wall_thickness_corroded()

Calculate the corroded wall thickness.

Returns:

corroded_wall_thickness – Corroded wall thickness of the pipe.

Return type:

np.ndarray

Examples

>>> wall_thickness = [0.0127, 0.0159]
>>> corrosion_allowance = [0.003, 0.003]
>>> pipe = Pipe(
...     wall_thickness=wall_thickness,
...     corrosion_allowance=corrosion_allowance
... )
>>> pipe.wall_thickness_corroded()
array([0.0097, 0.0129])

inner_diameter()

Calculate the pipe inner diameter.

Returns:

inner_diameter – Inner diameter of the pipe.

Return type:

np.ndarray

Examples

>>> outer_diameter = [0.2731, 0.3239]
>>> wall_thickness = [0.0127, 0.0159]
>>> pipe = Pipe(
...     outer_diameter=outer_diameter,
...     wall_thickness=wall_thickness
... )
>>> pipe.inner_diameter()
array([0.2477, 0.2921])

inner_area()

Calculate the pipe inner area.

Returns:

inner_area – Inner area of the pipe.

Return type:

np.ndarray

Examples

>>> outer_diameter = [0.2731, 0.3239]
>>> wall_thickness = [0.0127, 0.0159]
>>> pipe = Pipe(
...     outer_diameter=outer_diameter,
...     wall_thickness=wall_thickness
... )
>>> pipe.inner_area()
array([0.04818833, 0.06701206])

outer_area()

Calculate the pipe outer area.

Returns:

outer_area – Outer area of the pipe.

Return type:

np.ndarray

Examples

>>> outer_diameter = [0.2731, 0.3239]
>>> pipe = Pipe(
...     outer_diameter=outer_diameter
... )
>>> pipe.outer_area()
array([0.05857783, 0.08239707])

steel_area()

Calculate the steel cross-sectional area.

Returns:

steel_area – Steel cross-sectional area.

Return type:

np.ndarray

Examples

>>> outer_diameter = [0.2731, 0.3239]
>>> wall_thickness = [0.0127, 0.0159]
>>> pipe = Pipe(
...     outer_diameter=outer_diameter,
...     wall_thickness=wall_thickness
... )
>>> pipe.steel_area()
array([0.0103895 , 0.01538501])

total_outer_diameter()

Calculate the total outer diameter of steel and coating.

Returns:

total_outer_diameter – Total outer diameter of steel and coating.

Return type:

np.ndarray

Examples

>>> outer_diameter = [0.2731, 0.3239]
>>> coating_thickness = [0.003, 0.003]
>>> pipe = Pipe(
...     outer_diameter=outer_diameter,
...     coating_thickness=coating_thickness
... )
>>> pipe.total_outer_diameter()
array([0.2791, 0.3299])

total_outer_area()

Calculate the outer area of steel and coating.

Returns:

total_outer_area – Outer area of steel and coating.

Return type:

np.ndarray

Examples

>>> outer_diameter = [0.2731, 0.3239]
>>> coating_thickness = [0.003, 0.003]
>>> pipe = Pipe(
...     outer_diameter=outer_diameter,
...     coating_thickness=coating_thickness
... )
>>> pipe.total_outer_area()
array([0.06118001, 0.08547803])

coating_area()

Calculate the coating cross-sectional area.

Returns:

coating_area – Coating cross-sectional area.

Return type:

np.ndarray

Examples

>>> outer_diameter = [0.2731, 0.3239]
>>> coating_thickness = [0.003, 0.003]
>>> pipe = Pipe(
...     outer_diameter=outer_diameter,
...     coating_thickness=coating_thickness
... )
>>> pipe.coating_area()
array([0.00260218, 0.00308096])

axial_stiffness()

Calculate the axial stiffness.

Returns:

axial_stiffness – Axial stiffness of the pipe.

Return type:

np.ndarray

Examples

>>> outer_diameter = [0.2731, 0.3239]
>>> wall_thickness = [0.0127, 0.0159]
>>> youngs_modulus = [207.0e+09, 207.0e+09]
>>> pipe = Pipe(
...     outer_diameter=outer_diameter,
...     wall_thickness=wall_thickness,
...     youngs_modulus=youngs_modulus
... )
>>> pipe.axial_stiffness()
array([2.15062613e+09, 3.18469656e+09])

area_moment_inertia()

Calculate the area moment inertia.

Returns:

area_moment_inertia – Area moment inertia.

Return type:

np.ndarray

Examples

>>> outer_diameter = [0.2731, 0.3239]
>>> wall_thickness = [0.0127, 0.0159]
>>> pipe = Pipe(
...     outer_diameter=outer_diameter,
...     wall_thickness=wall_thickness
... )
>>> pipe.area_moment_inertia()
array([8.82710601e-05, 1.82921605e-04])

bending_stiffness()

Calculate the bending stiffness.

Returns:

bending_stiffness – Bending stiffness.

Return type:

np.ndarray

Examples

>>> outer_diameter = [0.2731, 0.3239]
>>> wall_thickness = [0.0127, 0.0159]
>>> youngs_modulus = [207.0e+09, 207.0e+09]
>>> pipe = Pipe(
...     outer_diameter=outer_diameter,
...     wall_thickness=wall_thickness,
...     youngs_modulus=youngs_modulus
... )
>>> pipe.bending_stiffness()
array([18272109.437121..., 37864772.21769765])