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Support Span Calculator

Permissible support spans for piping – manually or directly with the values from the Piping Spec Calculator.

Background, basis, prices and sources ▸

Continue with support planning

After the support spans: load per support from pipe, contents and insulation – and how far the line expands between the anchor points. Both calculate with the same piping spec and can read in a PCF if required.

Also available as a separate page: Pipe weight · Thermal expansion

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Basis & sources

What the tool calculates with, which standards and data it relies on and where its limits are. As of September 2026. For practice: Understand it and try it out.

Estimated values: dimensions, material properties, ratings and product ranges are generalized estimates from publicly available manufacturer data. They may deviate from the respective standard in individual points. The current standard and your manufacturer's data are binding. You can load your own values – e.g. from your standard – directly in the tool; they stay on your computer and are not transferred to us.
Calculation method
  1. LoadsPipe + contents + insulation + cladding per meter, point load per span
  2. Support conditionsSingle-span beam, continuous beam end span or inner span
  3. CriteriaBending stress + longitudinal stress from internal pressure ≤ allowable stress; deflection f ≤ limit value; slope
  4. ResultLargest permissible support span, rounded to the grid spacing
Standards & codes

Reference: the assistant follows Autodesk's file structure and the connection types of these standards. Standard texts and standard tables are not included.

DIN EN 13480-3allowable stress (section 5.2), as in the Piping Spec Calculator
DIN EN 13445-3, Annex OModulus of elasticity over temperature (guide values based on it)
AD 2000 B0Copper: K = Rm, S = 3.5
Data & origin
Pipe dimensions, materialsfrom the Piping Spec Calculator (same piping spec)
Strength values, modulus of elasticityEstimates from publicly available manufacturer data, generalized – as in the Piping Spec Calculator
Densities of material, medium, insulation, claddingGuide values, editable in the calculator
Assumptions & limits
  • Preliminary sizing – not a pipe stress analysis: anchor forces, friction, wind, snow, earthquakes, vibrations and impact loads are not included.
  • Design plastic and GRP pipes according to manufacturer data (time-dependent modulus of elasticity).
Standards status for this page 4 standards · researched September 2026
StandardContentsCurrent editionReplaced / successor
DIN EN 10220Seamless and welded steel tubes – General tables of dimensions and masses per unit lengthDIN EN 10220:2003-03replaces DIN V ENV 10220:1994-02; DIN 2448:1981-02; DIN 2458:1981-02
DIN EN ISO 1127Stainless steel tubes – Dimensions, tolerances and conventional masses per unit lengthDIN EN ISO 1127:2019-03replaces DIN EN ISO 1127:1997-03
AD 2000 Merkblatt B 0Calculation of pressure vesselsAD 2000 Merkblatt B 0:2025-06replaces AD 2000 Merkblatt B 0:2014-11
DIN EN 13480-3Metallic industrial piping – Part 3: Design and calculationDIN EN 13480-3:2024-12replaces DIN EN 13480-3:2017-12; DIN EN 13480-3/A1:2021-05; DIN EN 13480-3/A2:2020-12

Researched at DIN Media, ISO, IEC and ASME, as of September 2026. Before binding use, please check the current edition with the standards publisher. Overview of all standards: Plant Engineering Infobase · Standards status.

Understand it and try it out

Why can't a pipeline span any distance unsupported? It sags – and too much deflection means excessive stress, standing water at low points or leaking flanges.

The terms in five minutes

Support span
Distance between two supports.
Deflection f
How far the pipe sags in the middle. For a single-span beam f = 5 · q · L⁴ / (384 · E · I) – the support span enters to the 4th power.
Second moment of area I
How stiff the pipe cross-section is; grows strongly with diameter (roughly D³ · wall thickness). That is why large-diameter pipes can span much further.
Modulus of elasticity
Stiffness of the material: steel around 200,000 N/mm², plastic only 800 to 3,000 N/mm² – plastic pipes need many more supports.
Bending stress σ
σ = M / W with M = q · L² / 8 (single-span beam). It must not exceed the allowable stress of the material at temperature.
Slope
Lines that must drain completely must not sag between supports so much that water remains standing.

Try it out and understand it

Change one value in the calculator above and watch what happens to the others:

Try itWhat happensWhy
Calculate the same pipe empty and filled with waterThe support span gets smaller.More load q → more deflection; L decreases only with the 4th root.
Steel versus PE pipe of the same sizeThe support span shrinks to a fraction.The modulus of elasticity is around 200 times smaller.
Increase the temperatureModulus of elasticity and allowable stress decrease → shorter support span.Materials become softer when hot.

Typical mistakes

  • Taking a support span from a table for a different wall thickness or a different medium.
  • Forgetting point loads (valves, branches) between the supports.

For practice

Exercise: Why does a DN 200 pipe have a much larger permissible support span than DN 50, even though it is heavier?

Show solution

The second moment of area I (flexural rigidity E · I) grows roughly with D³, the weight per meter only roughly with D to D². With deflection f ~ q · L⁴ / (E · I), stiffness wins – which is why L can grow considerably. Calculate DN 50 and DN 200 one after the other in the Support Span Calculator.

For training and studies: this page may be shown in class. Property values are guide values; for verification, the standards and manufacturer data apply.