EN 1092-1 Type 11 is the European standard welding neck flange—the equivalent of the ASME B16.5 weld neck flange in the EN 1092-1 system. It has a tapered hub that is butt-welded to the pipe, providing excellent stress distribution for high-pressure, high-temperature, and cyclic-loading applications. Type 11 is the most specified EN flange type for process piping in Europe, the Middle East, and Africa.
Key Specifications
Property Detail Standard EN 1092-1 Type designation Type 11 (welding neck) Size range DN 10 to DN 600 (higher with EN 1092-1 Annex A) Pressure ratings PN 2.5, 6, 10, 16, 25, 40, 63, 100, 160, 250, 320, 400 Face types Raised face (Form B1), flat face (Form A), tongue and groove (Form D/E) Materials P250GH, P280GH (CS); 1.4301, 1.4404 (SS); 1.4462 (duplex) per EN 10222 Dimensions Metric (mm) Bolt sizing Metric (M12, M16, M20, M24, M27, M30, M33, M36)
EN 1092-1 Flange Types
Type Number Description ASME B16.5 Equivalent Type 01 Plate flange (flat) No direct equivalent Type 02 Loose plate flange with weld-on ring Lap joint (conceptual) Type 05 Blind flange Blind flange Type 11 Welding neck flange Weld neck flange Type 12 Hubbed slip-on flange Slip-on flange Type 13 Hubbed threaded flange Threaded flange
EN 1092-1 Type 11 flanges use metric bolt holes and metric bolt sizes. They are NOT interchangeable with ASME B16.5 weld neck flanges of similar nominal size. Even where OD and bolt circle dimensions appear close (e.g., DN 150/NPS 6), the bolt hole diameters, bolt threading, and RF height differ. See the ASME vs EN comparison for details.
Dimensional Example: DN 150
Parameter EN 1092-1 Type 11 PN 40 ASME B16.5 WN Class 300 Flange OD 285 mm 279.4 mm Bolt circle 240 mm 241.3 mm Number of bolts 8 12 Bolt size M24 3/4 in (19.05 mm) Bolt hole diameter 26 mm 22.4 mm RF height 2 mm 1.6 mm
Note the different bolt count (8 vs 12) and bolt size despite similar OD and bolt circle.
When ordering EN 1092-1 Type 11 flanges, specify: DN size, PN rating, face form (B1 for RF is standard), material designation per EN 10222, and any additional requirements such as NACE MR0175 compliance or specific NDE requirements . Example: “DN 150 PN 40 Type 11 Form B1 P250GH per EN 1092-1.”
Read the full guide to flanges
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