Technical standards of the EN 12516 series: regulations for valve strength
The EN 12516 standard is a fundamental document for the design and assessment of the structural integrity of industrial valve bodies. EV Group China experts utilize these standards to ensure the safety and durability of the supplied equipment operating under high pressure.
EN 12516-1 – Tabular method for assessing the strength of steel bodies
Scope and technical parameters
The first part of the standard establishes a tabulation methodology for determining the wall thickness of circular cross-section valve bodies and bonnets made of cast, forged, or welded steel. For products with non-circular or oval sections, section 8.6 of this standard should be followed.
The tabular values for wall thickness cover the following pressure classes:
- PN: 2.5, 6, 10, 16, 25, 40, 63, 100, 160, 250, 320, 400.
- Class: 150, 300, 600, 900, 1500, 2500, 4500.
EV Group China emphasizes that the standard defines non-destructive testing protocols and acceptance criteria necessary for operation under specific pressure and temperature regimes. For small diameters (up to DN65), alternative requirements (“Limited Class”) are provided.
Limitations of the scope:
- Threaded valves: DN80 and above, pressure exceeding CL2500, temperature above 540°C.
- Socket weld valves: diameters DN80 and larger.
EN 12516-2 – Calculation method for body design
Calculation methodology
This part of the standard describes engineering approaches for calculating the strength of valve bodies under internal overpressure. The methodology is based on mathematical modeling of the stress-strain state of the metal.
EN 12516-3 – Experimental strength verification
Testing requirements
The third section regulates the performance of full-scale tests on representative samples of bodies and connecting elements. The method is applicable to valves made of steel, cast iron, and copper alloys, confirming the design’s ability to withstand the design pressure with a specified safety factor.
Important note: The standard does not cover equipment subject to material creep or cyclic fatigue loading. According to the PED (97/23/EC) regulation, the method is valid without additional calculations if the product of PS (max. pressure at room temperature) and DN is less than 3000 bar.
EN 12516-4 – Calculation of bodies made of non-ferrous metals and alloys
Design for non-steel materials
The fourth part of the standard establishes calculation algorithms for valve bodies made of materials other than steel. Design is conducted taking into account loads similar to the requirements of EN 12516-2, ensuring a unified engineering basis for all types of metal products supplied by EV Group China.