EN 13480-3 Application

Pressure Piping Calculations, Design & Compliance Made Easy

Comprehensive Component Coverage: Perform precise calculations for straight pipes, bends (elbows), miter bends, branch connections (tees), and reducers. Includes both standard methods and advanced, more accurate calculations like Annex B for bends (Premium Feature).
Integrated Material Database: Access a robust database of standard EN 13480-3 materials. Premium users can further enhance their workflow by adding and managing custom materials.
Dynamic Unit Conversion: Seamlessly switch between metric (MPa, °C, mm) and imperial (psig, °F, in) unit systems. All inputs and outputs are automatically converted, eliminating manual errors.
Intelligent Temperature Validation: The system automatically checks the suitability of your selected material for the specified design temperature, flagging potential issues proactively.

Note on Temperature: Negative values can be entered for the design temperature. However, in such cases, the nominal design stress (`f`) of the material will automatically be considered for the lowest defined material temperature in your database (typically 20 °C / 68 °F), where the design stress values are typically available.

Clear & Detailed Results: Obtain transparent calculation results, including analysis thickness, minimum required thickness, Stress Intensification Factor (SIF), Maximum Allowable Working Pressure (MAWP), and clear pass/fail condition statements.
Professional PDF Reports: Generate high-quality, printable PDF reports of your calculations for comprehensive documentation and record-keeping.
Efficient Session Management: Your input data is intelligently saved within your session, allowing you to navigate between different component calculations without losing your progress.

By leveraging this comprehensive EN 13480-3 app, you can efficiently perform complex calculations, ensuring the safety, reliability, and full compliance of your piping designs in accordance with the European standard EN 13480-3.

How to Use the EN 13480-3 App?

Our intuitive interface guides you through each step of the calculation process. Follow these general steps to perform your analysis:

Select Component: Navigate using the sidebar to choose the specific piping component you need to analyze (e.g., 'Straight Pipes', 'Bends').
Project Information: Begin by entering general project details such as the project name, component identifier, drawing number, designer, revision, and the current date.
Design Conditions: Input your design pressure and temperature. Then, select the appropriate material from the dropdown list. The system will automatically validate if the chosen material is suitable for your specified temperature range.
Component Geometry: Provide the specific dimensions relevant to your selected component. Visual SVG diagrams are provided alongside the input fields to clarify each parameter.
Factors/Tolerances: Enter values for critical factors such as the weld joint coefficient, corrosion allowance, manufacturer's thickness tolerance, and thinning allowance.
Calculate: Click the 'Calculate' button to initiate the analysis.
Review Results: The output section will instantly display detailed results, including calculated thicknesses, Stress Intensification Factor (SIF), Maximum Allowable Working Pressure (MAWP), and a clear condition statement (e.g., "Valid" or "Not valid").
Manage & Document: You have options to save your calculation (Premium Feature), reset the form for a new entry, or generate a professional PDF report of your results.

Calculation Guides

1. Straight Pipes

This section is dedicated to calculating the required wall thickness and the maximum allowable working pressure for straight pipe sections subjected to internal pressure (EN 13480-3 par. 6.1). These calculations are fundamental for ensuring the safe operation of piping systems.

Key Inputs

Project Information

Project Name: Required. This name is used to identify your project and will appear in the PDF report.
Component, Revision, Date, etc.: Optional. These fields are for your reference and for populating the PDF report. They do not influence the calculation results.

Design Conditions

Design Pressure (p_c): Required. The internal pressure the pipe is designed to withstand.
Design Temperature (T): Required. The operating temperature that determines the material's allowable stress.
Material: Required. Select a material from the database. The system validates its suitability for the design temperature.

Geometry

Outside Diameter (D_o): Required. The external diameter of the pipe.
Ordered Wall Thickness (e_ord): Required. The nominal wall thickness as specified by the manufacturer before any allowances are applied.

Allowances & Factors

Weld Joint Coefficient (z): Required. A factor representing the quality and strength of the weld.
Corrosion Allowance (c₀): Required. The expected reduction in thickness due to corrosion over the component's lifespan.
Manufacturer's Tolerance (c₁): Required. The permissible negative tolerance on wall thickness, expressed as a percentage (Example: 12.5%).
Thinning Allowance (c₂): Required. Additional thickness reduction allowance due to manufacturing processes.

Calculations Performed

Analysis Thickness ($e_a$)

The analysis thickness represents the effective wall thickness available for pressure containment after accounting for various allowances.

$$ e_a = e_{ord} - c_0 - \left(e_{ord} \cdot \frac{c_1}{100}\right) - c_2 $$

$e_{ord}$

Ordered (nominal) wall thickness

$c_0$

Corrosion allowance

$c_1$

Manufacturer's thickness tolerance (as a percentage)

$c_2$

Thinning allowance

Minimum Required Thickness ($e$)

The minimum required thickness is determined by the design pressure and material properties. EN 13480-3 provides two main formulas depending on the diameter-to-thickness ratio.

$D_o/D_i \le 1.7$ $$ e = \frac{p_c \cdot D_o}{2 \cdot f \cdot z + p_c} $$ $D_o/D_i > 1.7$ $$ e = 0.5 \cdot D_o \left(1 - \sqrt{\frac{f \cdot z - p_c}{f \cdot z + p_c}}\right) $$

$p_c$

Design pressure

$D_o$

Outside diameter

$f$

Nominal design stress

$z$

Weld joint coefficient

Condition: The pipe is considered valid if the analysis thickness is greater than or equal to the minimum required thickness: $e_a \ge e$.

Maximum Allowable Working Pressure (MAWP)

The MAWP is the highest internal pressure the pipe can safely operate under, considering its dimensions and material properties. It is derived from the same principles as the required thickness, but solved for pressure.

$D_o/D_i \le 1.7$ $$P_{max}(MAWP) = \frac{2 \cdot e_a \cdot f \cdot z}{D_o - e_a} $$ $D_o/D_i > 1.7$ $$P_{max}(MAWP) = f \cdot z \cdot \frac{D_o^2 - (D_o - 2e_a)^2}{D_o^2 + (D_o - 2e_a)^2} $$

$e_a$

Analysis thickness

$D_o$

Outside diameter

$f$

Nominal design stress

$z$

Weld joint coefficient

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2. Bends (Elbows)

This section provides a detailed analysis (EN 13480-3 par. 6.2) for pipe bends (elbows), accounting for the complex stress intensification effects that occur at both the intrados (inner curve) and extrados (outer curve). Bends are critical components where stress concentrations can significantly impact the integrity of the piping system.

Premium Feature: Annex B Calculation

In addition to the standard method (par. 6.2), this calculator now offers a more accurate calculation for bends and elbows according to Annex B of EN 13480-3. This premium feature allows for a less conservative design by performing detailed stress calculations for the intrados and extrados.

You can select the "Annex B" option in the calculator to use this advanced method.

Key Inputs

Project Information

Project Name: Required. This name is used to identify your project and will appear in the PDF report.
Component, Revision, Date, etc.: Optional. These fields are for your reference and for populating the PDF report.

Design Conditions

Design Pressure (p_c): Required. The internal pressure the bend is designed to withstand.
Design Temperature (T): Required. The operating temperature for material stress evaluation.
Material: Required. Select a suitable material from the database.

Geometry

Outside Diameter (D_o): Required. The external diameter of the bend.
Ordered Wall Thickness at Intrados (e_ord,int): Required. The nominal thickness at the inner curve of the bend.
Ordered Wall Thickness at Extrados (e_ord,ext): Required. The nominal thickness at the outer curve of the bend.
Bend Radius (R): Required. The radius of the bend's centerline.

Allowances & Factors

Weld Joint Coefficient (z): Required. Factor for weld quality (1.0 for seamless).
Corrosion Allowance (c₀): Required. Expected thickness loss from corrosion.
Manufacturer's Tolerance (c₁): Required. Permissible negative tolerance on wall thickness (%).
Thinning Allowance (c₂): Required. Thickness reduction from the manufacturing process.

Calculations Performed

Analysis Thickness ($e_a$)

The analysis thickness is calculated separately for the intrados and extrados, considering their respective ordered thicknesses and allowances.

$$ e_{a,int} = e_{ord,int} - c_0 - \left(e_{ord,int} \cdot \frac{c_1}{100}\right) - c_2 $$ $$ e_{a,ext} = e_{ord,ext} - c_0 - \left(e_{ord,ext} \cdot \frac{c_1}{100}\right) - c_2 $$

$e_{ord,int}$

Ordered (nominal) wall thickness at intrados

$e_{ord,ext}$

Ordered (nominal) wall thickness at extrados

$c_0$

Corrosion allowance

$c_1$

Manufacturer's thickness tolerance (as a percentage)

$c_2$

Thinning allowance

Minimum Required Thickness ($e_{int}, e_{ext}$)

The minimum required thicknesses for intrados and extrados are calculated by applying the intensification factors to the base required thickness for a straight pipe:

$$ e_{int} = e_{base} \cdot I_{int} $$ $$ e_{ext} = e_{base} \cdot I_{ext} $$

$e_{base}$

Required thickness for a straight pipe (from par. 6.1)

$I_{int/ext}$

Intensification factor

Conditions:

Intrados: $e_{a,int} \ge e_{int}$
Extrados: $e_{a,ext} \ge e_{ext}$

Both conditions must be met for the bend to be considered valid.

Maximum Allowable Working Pressure (MAWP)

The MAWP for the bend is determined by considering the minimum of the MAWPs calculated for both the intrados and extrados, using adapted formulas from straight pipe calculations and the intensification factors.

$D_o/D_i \le 1.7$ $$ P_{max,int} = \frac{2 \cdot e_{a,int} \cdot f \cdot z}{D_o \cdot I_{int} - e_{a,int}} $$ $$ P_{max,ext} = \frac{2 \cdot e_{a,ext} \cdot f \cdot z}{D_o \cdot I_{ext} - e_{a,ext}} $$ $D_o/D_i > 1.7$ $$ P_{max,int} = f \cdot z \cdot \frac{D_o^2 - (D_o - 2e_{a,int}/I_{int})^2}{D_o^2 + (D_o - 2e_{a,int}/I_{int})^2} $$ $$ P_{max,ext} = f \cdot z \cdot \frac{D_o^2 - (D_o - 2e_{a,ext}/I_{ext})^2}{D_o^2 + (D_o - 2e_{a,ext}/I_{ext})^2} $$

$e_{a,int/ext}$

Analysis thickness

$I_{int/ext}$

Intensification factor

$D_o$

Outside diameter

$f$

Nominal design stress

$z$

Weld joint coefficient

Condition: The overall MAWP is the minimum of $P_{max,int}$ and $P_{max,ext}$.

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3. Miter Bends

This section focuses on the strength calculations for miter bends (EN 13480-3 par. 6.3), which are typically fabricated from straight pipe sections by welding them together at angles. Miter bends are often used as an economical alternative to forged elbows, especially for large diameters or low pressures.

Key Inputs

Project Information

Project Name: Required. This name is used to identify your project and will appear in the PDF report.
Component, Revision, Date, etc.: Optional. These fields are for your reference and for populating the PDF report.

Design Conditions

Design Pressure (p_c): Required. The internal design pressure.
Design Temperature (T): Required. The operating temperature for material stress evaluation.
Material: Required. Select a suitable material from the database.

Geometry

Outside Diameter (D_o): Required. The external diameter of the miter bend sections.
Ordered Wall Thickness (e_ord): Required. The nominal wall thickness of the pipe sections.
Number of Miter Cuts (N): Required. The total number of cuts used to form the bend.
Mean Radius of Miter Bend (R): Required. The mean radius of the completed miter bend.

Allowances & Factors

Weld Joint Coefficient (z): Required. Factor for weld quality (1.0 for seamless).
Corrosion Allowance (c₀): Required. Expected thickness loss from corrosion.
Manufacturer's Tolerance (c₁): Required. Permissible negative tolerance on wall thickness (%).
Thinning Allowance (c₂): Required. Thickness reduction from the manufacturing process.

Calculations Performed

Analysis Thickness ($e_a$)

Similar to straight pipes, the analysis thickness for miter bends accounts for allowances.

$$ e_a = e_{ord} - c_0 - \left(e_{ord} \cdot \frac{c_1}{100}\right) - c_2 $$

$e_{ord}$

Ordered (nominal) wall thickness

$c_0$

Corrosion allowance

$c_1$

Manufacturer's thickness tolerance (as a percentage)

$c_2$

Thinning allowance

Maximum Allowable Working Pressure (MAWP)

The MAWP for miter bends is complex and depends on the number of cuts and the miter angle. Different formulas apply based on these conditions.

$$ P_{base} = \frac{2 \cdot f \cdot z \cdot e_a}{D_m} $$ For $N = 1$ and $\theta > 22.5°$ $$ P_{max} = P_{base} \cdot \frac{e_a}{e_a + 1.25 \cdot \tan(\theta) \cdot \sqrt{0.5 \cdot D_m \cdot e_a}} $$ For $N \ge 1$ and $\theta \le 22.5°$ $$ P_{max} = \min \left( P_{base} \cdot \frac{e_a}{e_a + 0.643 \cdot \tan(\theta) \cdot \sqrt{0.5 \cdot D_m \cdot e_a}}, P_{base} \cdot \frac{R - 0.5 \cdot D_m}{R - 0.25 \cdot D_m} \right) $$

$P_{base}$

Pressure

$e_a$

Analysis thickness

$f$

Nominal design stress

$z$

Weld joint coefficient

$D_m$

Mean diameter

$R$

Min. radius

$N$

Number of miter cuts

$\theta$

Miter cut angle

Note: Combinations of $N > 1$ and $\theta > 22.5$ degrees are generally not covered by the standard and may require more advanced analysis.

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4. Branch (Tees)

This section performs crucial area replacement calculations for welded branch connections (tees) to ensure that adequate reinforcement is provided around the opening (EN 13480-3 par. 8.4.3 a), b)). This method verifies that the material removed for the branch opening is sufficiently compensated by available material in the pipe, branch, and any reinforcing pads.

Key Inputs

Project Information

Project Name: Required. This name is used to identify your project and will appear in the PDF report.
Component, Revision, Date, etc.: Optional. These fields are for your reference and for populating the PDF report.

Design Conditions

Design Pressure (p_c): Required. The internal design pressure.
Design Temperature (T): Required. The operating temperature for material stress evaluation.
Material: Required. Select a suitable material from the database.

Geometry (Header & Branch)

Header Outside Diameter (D_o): Required. The outside diameter of the main (header) pipe.
Header Ordered Wall Thickness (e_ord,s): Required. The nominal wall thickness of the header pipe.
Branch Outside Diameter (d_o): Required. The outside diameter of the branch pipe.
Branch Ordered Wall Thickness (e_ord,b): Required. The nominal wall thickness of the branch pipe.

Reinforcement (Optional)

Reinforcing Pad Thickness (e_pl): Optional. The thickness of any additional reinforcing pad. Leave as 0 if not used.
Reinforcing Pad Width (l_pl): Optional. The width of the reinforcing pad. Leave as 0 if not used.

Allowances & Factors

Corrosion Allowance (c₀): Required. Expected thickness loss from corrosion.
Manufacturer's Tolerance (c₁): Required. Permissible negative tolerance on wall thickness (%).
Thinning Allowance (c₂): Required. Thickness reduction from manufacturing.

Note: The weld joint coefficient (z) is not a direct input for this area replacement calculation as per the standard's methodology.

Calculations Performed

Analysis Thicknesses ($e_{a,s}, e_{a,b}$)

The analysis thicknesses for the header (shell) and branch are calculated by deducting allowances from their respective ordered thicknesses.

$$ e_{a,s} = e_{ord,s} - c_0 - \left(e_{ord,s} \cdot \frac{c_1}{100}\right) - c_2 $$ $$ e_{a,b} = e_{ord,b} - c_0 - \left(e_{ord,b} \cdot \frac{c_1}{100}\right) - c_2 $$

$e_{ord,s}$

Ordered (nominal) wall thickness of the shell (header)

$e_{ord,b}$

Ordered (nominal) wall thickness of the branch

$c_0$

Corrosion allowance

$c_1$

Manufacturer's thickness tolerance (as a percentage)

$c_2$

Thinning allowance

Effective Cross-Sectional Areas ($A_{fs}, A_{fb}, A_{fpl}$)

These areas quantify the material available for reinforcement.

$$ A_{fs} = e_{a,s} \cdot (l_s + e_{a,b}) $$ $$ A_{fb} = e_{a,b} \cdot l_b $$ $$ A_{fpl} = e_{pl} \cdot l_{pl} $$

$e_{a,s}$

Pipe analysis thickness

$e_{a,b}$

Branch analysis thickness

$e_{pl}$

Reinforcement thickness

$l_{s}$

Pipe reinforcing length

$l_{b}$

Branch reinforcing length

$l_{pl}$

Reinforcement width

Pressured Area ($A_p$)

This is the area under pressure that needs to be compensated by reinforcement.

$$ A_p = (0.5 \cdot D_o - e_{a,s}) \cdot (l_s + e_{a,b}) + (0.5 \cdot d_o - e_{a,b}) \cdot (l_b + 0.5 \cdot D_o) $$

$e_{a,s}$

Pipe analysis thickness

$e_{a,b}$

Branch analysis thickness

$l_{s}$

Pipe reinforcing length

$l_{b}$

Branch reinforcing length

$D_{o}$

Pipe outside diameter

$d_{o}$

Branch outside diameter

Percentage Area Replacement

The percentage area replacement is a critical metric to determine if the branch connection is adequately reinforced.

$$ \text{Area Replacement} = \frac{(f - p_c/2) \cdot (A_{fs} + A_{fb} + A_{fpl})}{p_c \cdot A_p} \cdot 100\% $$

$f$

Nominal design stress

$p_c$

Design pressure

Condition: If the Percentage Area Replacement is less than or equal to 100%, additional reinforcement is required. Otherwise, no additional reinforcement is needed.

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5. Reducers

This section enables the calculation of strength for both concentric and eccentric reducers (EN 13480-3 par. 6.4.4), ensuring their suitability for the specified operating conditions. Reducers are components that transition between different pipe diameters, and their design must account for potential stress concentrations.

Key Inputs

Project Information

Project Name: Required. This name is used to identify your project and will appear in the PDF report.
Component, Revision, Date, etc.: Optional. These fields are for your reference and for populating the PDF report.

Design Conditions

Design Pressure (p_c): Required. The internal design pressure.
Design Temperature (T): Required. The operating temperature for material stress evaluation.
Material: Required. Select a suitable material from the database.

Geometry

Reducer Type: Required. Select either "Concentric" or "Eccentric" to match your component.
Large End Diameter (D₁): Required. The outside diameter of the larger end of the reducer.
Small End Diameter (D₂): Required. The outside diameter of the smaller end of the reducer.
Ordered Wall Thickness (e_ord): Required. The nominal wall thickness of the reducer.
Length (L): Required. The overall length of the reducer (end-to-end).
Analysis Point (x): Required. The specific distance from the large end where the analysis is to be performed.

Allowances & Factors

Weld Joint Coefficient (z): Required. Factor for weld quality (1.0 for seamless).
Corrosion Allowance (c₀): Required. Expected thickness loss from corrosion.
Manufacturer's Tolerance (c₁): Required. Permissible negative tolerance on wall thickness (%).
Thinning Allowance (c₂): Required. Thickness reduction from the manufacturing process.

Calculations Performed

Analysis Thickness ($e_a$)

The analysis thickness at the point of interest is calculated by deducting allowances from the ordered thickness.

$$ e_a = e_{ord} - c_0 - \left(e_{ord} \cdot \frac{c_1}{100}\right) - c_2 $$

$e_{ord}$

Ordered (nominal) wall thickness

$c_0$

Corrosion allowance

$c_1$

Manufacturer's thickness tolerance (as a percentage)

$c_2$

Thinning allowance

Minimum Required Thickness ($e(x)$)

The minimum required thickness at the analysis point $x$.

$$ e(x) = \frac{p_c \cdot D_x}{\cos(\alpha) \cdot (2 \cdot f \cdot z + p_c)} $$

$p_c$

Design pressure

$D_x$

Diameter (outer) at the analysis point (x)

$\alpha$

Half apex-angle of the con

$f$

Nominal design stress

$z$

Weld joint coefficient

Condition: The reducer is considered valid at the analysis point if the analysis thickness is greater than or equal to the minimum required thickness: $e_a \ge e(x)$.

Maximum Allowable Working Pressure (MAWP(x))

The MAWP at the analysis point $x$ is the maximum pressure the reducer can safely withstand at that specific location.

$$ P_{max}(x) = \frac{2 \cdot e_a \cdot f \cdot z \cdot \cos(\alpha)}{D_x - e_a \cdot \cos(\alpha)} $$

$e_a$

Analysis thickness

$D_x$

Diameter (outer) at the analysis point (x)

$\alpha$

Half apex-angle of the con

$f$

Nominal design stress

$z$

Weld joint coefficient

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Note on Documentation

The equations and guidelines presented in this documentation are based on the EN 13480-3 standard and are provided for informational purposes. They are not intended to serve as a replacement for the official standard document.