Flange differences of the DIN EN 1092-1 (European Norm Euronorm) and the previous DIN norm:

Steel and Stainless Steel Flanges are installed worldwide in various industries and are essential in connecting steel and stainless steel pipes. Flange standards differ from region to region, including different identification standards within Europe. New flange standards (e.g. DIN EN 1092-1 Type 11, DIN EN 1092-1 Type 02) have been introduced and are meant to substitute the old DIN standard (e.g. DIN 2635, DIN 2633). Changing the standard of products that have been installed in many different industries for years is difficult. It has led that more than one standard are being currently used. While some DIN flange standards were substituted by the new norm (e.g. DIN 2631 PN6 DN40/44,5 x 2,6), other flange standard dimensions continue to use the previous standards (e.g. DIN2633 Form C PN16 DN150/150  x 4,5 range 2). Furthermore, some new flange dimensions can only be found in the new EN 1092-1 standard and never existed before in the old norm (e.g. EN1092-1 Type 11 PN16 15/21,3 x 2,0). The old norms (e.g. DIN 2627, DIN 2632, DIN 2633, DIN 2634, and DIN 2635 -weld neck) mainly standardize flanges using nominal pressure standards. For example, the  DIN 2635 flange will usually be used to indicate a weld neck flange dimension with a PN of 40 while DIN 2631 is used for a flange dimension with a PN 6. The DIN EN 1092-1 norm uses “Type/Typ” to indicate the various flanges. For example, the DIN 1092-1 type 11 indicates a weld neck flange dimension, while DIN 1092-1 type 05 is used for a blind flange dimension. Also, Swiss Fittings and other major flange distributors indicate whether a flange is adhering to the old “DIN” standard or according to “DIN EN 1092-1” standard or to both.

What important information does the flange name provide?

 As there are many different dimensions and grades of flanges, it can sometimes be confusing to identify a flange correctly. The name of flanges (e.g. Weld Neck Flange EN 1092-1 Type 11 / DIN2632 Form B1/C PN10 DN200/206 x 3,0, 1.4541),  usually provide the following information:

• Flange Type (Weld Neck)
• Standard (EN 1092-1 Type 11 / DIN 2632)
• Form (Form B1/C)
• Nominal Pressure (PN 10)
• Nominal Dimension (DN 200/206)
• Wall Thickness (x 3,0)
• Material Grade (1.4541) 

The most commonly installed flanges are weld neck flanges, threaded flanges, flat flanges, blind flanges and lapped flanges. The form indicates the roughness of the sealing surface which can have a raised face, (see “forms of seals” table). European flange standards cite pressure using “PN” (pressure nominal). For the North American standards, the pressure is usually indicated in “lbs.” The standard nominal pressures for flanges are PN6, PN10, PN16, PN25, PN40, PN64 and PN100. Depending on what type of flange the dimensions may have two or three values. For weld neck flanges there are usually three, in which one value indicates the wall thickness of the neck of the flange. This is directly welded to the steel pipe. The first number indicates the nominal diameter, while the second value indicates the outer mating dimensions. The last connotation in the flange name is the material in either EN (European Norm), ASTM/AISI, or UNS-Number.  

What is marked on a EN1092-1 steel and stainless steel flange?

Since it is important to correctly identify a flange, EN1092-1 flanges are marked on the side, which is visible even after the flange is installed. The EN1092-1 norm has necessary information requirements. Because there are many different flange manufacturers, such as Viraj, Starfit China, RFF, it is important to have the flange manufacturer’s name or trade mark on the flange. This is also an important indication in which country the flanges are manufactured. Swiss Fittings offers both non-European and European stainless steel flanges. In addition to identifying the manufacturer it is necessary to mark the flange standard, i.e. EN 1092-1, as well as the flange type, e.g. 11. This is usually followed by the “DN” size, and the nominal pressure designation. If the weld neck flange has non-standard neck thickness, this needs to be marked. Next comes the EN material and the melt indication cast number. An example of a marking conforming to EN1092 would be: XXX/EN1092-1/11/DN 150/PN 16/S235JR/1880

Flanges DIN EN / DIN

Flange ASME / BS / API

Abbreviations:

DN (Diameter Nominal)

According to DIN EN ISO 6708, DN is used to indicate the size of a pipe system’s outer dimension.

PN (Pressure Nominal)

According to DIN EN 1333 is used to indicate and reference, the pressure at reference temperature of 20°C. 

Forms of Seal (Forms: types of contact faces)

Surface Roughness (Finish)

What different parts of EN1092 exist?

There are 4 main parts of EN1092:

• EN1092-1 Flanges of Steel
• EN1092-2 Casted Flanges of Steel
• EN1092-3 Flanges of Galvanized Copper
• EN1092-4 Flanges of Aluminum Alloys