{"id":32126,"date":"2026-07-16T13:00:55","date_gmt":"2026-07-16T05:00:55","guid":{"rendered":"https:\/\/alllandpipes.com\/?p=32126"},"modified":"2026-07-16T13:03:35","modified_gmt":"2026-07-16T05:03:35","slug":"en-10217-2-p235gh-p265gh-pipe-mawp-calculation","status":"publish","type":"post","link":"https:\/\/alllandpipes.com\/fr\/blogs\/en-10217-2-p235gh-p265gh-pipe-mawp-calculation.html","title":{"rendered":"Calcul de la pression de service maximale pour les tubes en acier au carbone conformes \u00e0 la norme EN 10217-2 P235GH\/P265GH : rapport entre l'\u00e9paisseur de paroi et la r\u00e9duction de capacit\u00e9 en fonction de la temp\u00e9rature"},"content":{"rendered":"\n

Introduction<\/strong><\/strong><\/h2>\n\n\n\n

Pressure piping operating above ambient temperature must be designed using reduced allowable stresses. Otherwise, the calculation of the Maximum Allowable Working Pressure (MAWP) may give rise to safety hazards. When pipes operate at high temperatures, the strength of the material undergoes predictable degradation. To determine the safe operating range, engineers must take into account both the physical and geometric parameters of the pipe and the temperature-dependent material properties. The European standard EN 10217-2 specifies the technical delivery conditions for welded steel pipes made of non-alloy and alloy steels with specific high-temperature properties, and forms an important basis for the design of pressure equipment within the framework of the EU Pressure Equipment Directive (PED) 2014\/68\/EU.<\/p>\n\n\n\n

This guide explains how engineers can calculate the maximum allowable working pressure (MAWP) of EN 10217-2 P235GH and P265GH pipes using wall thickness and temperature-dependent design stresses. Emphasis is placed on how wall thickness selections, drawn from reliable dimensional tables, interact with temperature derating factors. The aim is to deliver a transparent, code-compliant calculation path without overstating material capabilities, while keeping the discussion objective and technically accurate.<\/p>\n\n\n\n

1<\/span>Introduction<\/a><\/span><\/div>
2<\/span>Decoding EN 10217-2: Welded Steel Pipes for Pressure Purposes<\/a><\/span><\/div>
3<\/span>The Barlow\u2019s Formula Adaptation for EN 10217-2 P265GH Grade Steel<\/a><\/span><\/div>
4<\/span>Step-by-Step Calculation: Determining MAWP for DN80 Pipes<\/a><\/span><\/div>
5<\/span>How Hardness Data Correlate with High-Temperature Pressure Retention<\/a><\/span><\/div>
6<\/span>Conclusion<\/a><\/span><\/div>
7<\/span>Frequently Asked Questions<\/a><\/span><\/div><\/div><\/div>\n\n\n\n
\"en<\/div>\n\n\n\n

Decoding EN 10217-2: Welded Steel <\/strong>Pipe<\/strong>s for Pressure Purposes<\/strong><\/strong><\/h2>\n\n\n\n

EN 10217-2 specifically covers electric welded non-alloy and alloy steel pipes intended for pressure applications at room and elevated temperatures. The standard defines mandatory tests, dimensional tolerances, and technical requirements for welded steel pipe<\/strong> products used in critical service. Within this framework, grades P235GH and P265GH are widely specified.<\/p>\n\n\n\n

The designation \u201cP\u201d indicates suitability for pressure purposes. The numeric part\u2014235 or 265\u2014represents the minimum yield strength in megapascals at ambient temperature. The suffix \u201cGH\u201d denotes confirmed elevated temperature properties: the steel has been tested and validated for creep and high-temperature yield. Chemically, P235GH typically limits carbon to 0.16% and manganese to 1.20%, while P265GH allows slightly higher carbon (up to 0.20%) and manganese (up to 1.40%) to achieve its enhanced strength. Both grades offer fine-grain structure and excellent weldability, but their strength advantage diminishes as temperature rises, making temperature derating an indispensable part of pressure calculation. Reliable calculations begin with pipes that meet the specified dimensional tolerances and mechanical property requirements.<\/p>\n\n\n\n

The Barlow\u2019s Formula Adaptation for EN 10217-2 P265GH Grade Steel<\/strong><\/strong><\/h2>\n\n\n\n

The classic Barlow\u2019s formula for thin-walled cylinders, P = (2 \u00b7 S \u00b7 t) \/ D, serves as the basis, where S is allowable stress, t is wall thickness, and D is outside diameter. However, engineering codes such as EN 13480-3 (Metallic industrial piping) and ASME B31.3 refine this equation to account for weld integrity and design safety factors.<\/p>\n\n\n\n

For a straight pipe\u00a0with a longitudinal weld under internal pressure, the code-adapted formula for MAWP is generally expressed as: MAWP = [2 \u00b7 f \u00b7 z \u00b7 (t – c\u2081 – c\u2080)] \/ [D\u2092 – (t – c\u2081 – c\u2080)]<\/p>\n\n\n\n

Where:<\/p>\n\n\n\n