What is BS EN 10253-4:2025 - Butt-welding stainless steel pipe fittings with specific inspection requirements about?
The fourth and final standard in a four-part series on butt-welding pipe fittings, BS EN 10253-4 details the latest technical requirements for fittings made of austenitic and austenitic-ferritic (duplex) stainless steel in two test categories.
The other standards in the series are:
- BS EN 10253-1 Wrought carbon steel for general use and without specific inspection requirements;
- BS EN 10253-2 Non alloy and ferritic alloy steels with specific inspection requirements; and
- BS EN 10253-3 Wrought austenitic and austenitic-ferritic (duplex) stainless steels without specific inspection requirements.
Who is BS EN 10253-4:2025 - Butt-welding stainless steel pipe fittings with specific inspection requirements for?
BS EN 10253-4 is applicable to the following users:
- engineering services;
- special trade contractors;
- certification services;
- iron and steel forgings;
- fabricated metal products;
- fabricated plate work (boiler shops);
- metals services centres and offices;
- steel pipe and tubes;
- oil and gas field services;
- plumbing and heating equipment and supplies (hydronics);
- plumbing, heating and air-conditioning;
- installation or erection of building equipment; and
- universities/students.
What does BS EN 10253-4:2025 - Butt-welding stainless steel pipe fittings with specific inspection requirements cover?
BS EN 10253-4 specifies the technical delivery requirements for seamless and welded butt-welding fittings (elbows, concentric and eccentric reducers, equal and reducing tees, caps) made of austenitic and austenitic-ferritic (duplex) stainless steel in two test-categories which are intended for pressure purposes at room temperature, at low temperature or at elevated temperatures, and for the transmission and distribution of fluids and gases.
BS EN 10253-4:2025 specifies:
- type of fittings;
- type A: butt-welding fittings with reduced pressure factor;
- type B: butt-welding fittings for use at full service pressure;
- steel grades and their chemical compositions;
- mechanical properties;
- dimensions and tolerances;
- requirements for inspection and testing;
- inspection documents;
- marking; and
- protection and packaging.
Why should you use BS EN 10253-4:2025 - Butt-welding stainless steel pipe fittings with specific inspection requirements?
This standard is one voluntary means of conforming to essential requirements of the New Approach Pressure Equipment Directive 2014/68/EU. The directive provides essential safety requirements that pressure equipment shall satisfy. Using BS EN 10253-4:2025 will guarantee that the required chemical composite and mechanical properties are met.
BS EN 10253-4:2025 also ensures that welds are strong, fatigue and corrosion resistant, resistant to high temperatures and will perform in high pressure environments.
What has changed?
BS EN 10253-4:2025 will supersede BS EN 10253-4:2008. In comparison with the previous edition, the following technical modifications have been made:
- concretization of the scope;
- restructuring of BS EN 10253-2 and BS EN 10253-4 and ensuring they align with each other;
- update of technical requirements and dimensions to reflect current market standards;
- correction of identical construction dimensions within the BS EN 10253 series;
- introduction of additional wall thickness and diameter values;
- introduction of test concept TC2 analogous to pipe standards;
- rewording of some options and new numbering;
- modification of test lot sizes;
- update of contents for ultrasonic testing;
- update to the contents of welding chapters;
- revision of figures;
- update of the terms and definitions;
- update of normative references;
- editorial revision to follow the latest design rules;
- revision of mechanical properties; and
- update of metric elbows dimensions table.
