EN 1092-1 · Standard reference
EN 1092-1 flange types and facings
EN 1092-1 identifies the shape of a flange or collar with a two-digit type number, from 01 to 37. Table 6 lists the 14 types covered: eight flanges (01, 02, 04, 05, 11, 12, 13 and 21) and six collars (32, 33, 34, 35, 36 and 37) that are used with the loose plate flanges type 02 and type 04. The numbers are not consecutive, which leaves room for future additions.
Which DN and PN combinations exist for each type is set out in the synoptic Table 7 (pp. 28–33); dimensions then come from Table 8 and Tables 10 to 21, with the calculation basis in Annexes E and F. Table 1 shows which manufacturing routes the standard permits for each type — forged, cast, machined from bar, from flat product, bent and electric welded, or pressed.
The second half of the topic covers facings. Figure 3 defines eight facing types (A to H), Table 8 carries their dimensions, and Table 2 specifies the jointing-face surface finish as Ra and Rz ranges matched to reference specimens. Unless the purchaser agrees otherwise, most flanges are supplied with a B1 raised face, while type 01 and blind flanges up to PN 40 and all collars (except types 33, 36 and 37) get a type A flat face.
- Type numbers
- 01 to 37 (14 types)
- Flange types
- 01, 02, 04, 05, 11, 12, 13, 21
- Collar types
- 32, 33, 34, 35, 36, 37
- Facing types
- A to H
- Default facing
- B1 raised face (type A for 01/05 ≤ PN 40)
- Dimensions
- Table 8, Tables 10–21
Type numbers and descriptions (Table 6, p. 26)
EN 1092-1 · EN 1092-1:2018
| Type No. | Description | Kind | Use / note |
|---|---|---|---|
| 01 | Plate flange for welding | Flange | — |
| 02 | Loose plate flange with weld-on plate collar or for lapped pipe end | Flange | Used with collars 32, 33, 35, 36 or 37 |
| 04 | Loose plate flange with weld-neck collar | Flange | Used with collar 34 |
| 05 | Blind flange | Flange | — |
| 11 | Weld-neck flange | Flange | — |
| 12 | Hubbed slip-on flange for welding | Flange | — |
| 13 | Hubbed threaded flange | Flange | — |
| 21 | Integral flange | Flange | Part of pressure equipment or a component (footnote a) |
| 32 | Weld-on plate collar | Collar | For type 02 flanges (footnote b) |
| 33 | Lapped pipe end | Collar | For type 02 flanges (footnote b) |
| 34 | Weld-neck collar | Collar | For type 04 flanges (footnote b) |
| 35 | Welding neck | Collar | For type 02 flanges (footnote b) |
| 36 | Pressed collar with long neck | Collar | For type 02 flanges (footnote b) |
| 37 | Pressed collar | Collar | For type 02 flanges (footnote b) |
- a An integral flange is part of the pressure equipment or component itself.
- b Collar types are used together with the loose plate flange stated.
Type numbers are deliberately non-consecutive so that future types can be added. Types 32, 33, 35, 36 and 37 are collars used with type 02 loose plate flanges; type 34 is a collar used with type 04.
Permitted methods of manufacture (Table 1, p. 14)
Not every type may be made every way. Table 1 is the reference used when a purchase order specifies forging, casting, plate or welded construction.
EN 1092-1 · EN 1092-1:2018
| Type No. | Forged a | Cast | Made from flat products (plates) | Machined from rolled or forged bars and forged sectional steel | Bent and electric welded form bars, sectional steel or strip | Pressed from welded or seamless pipes or flat products |
|---|---|---|---|---|---|---|
| 01 | yes | no | yes | yes | yes | no |
| 02 | yes | no | yes | yes | yes | no |
| 04 | yes | no | yes | yes | yes | no |
| 05 | yes | no | yes | yes | no | no |
| 11 | yes | no | no | yes | yes, for ≥ DN 700 | no |
| 12 | yes | no | no | yes | no | no |
| 13 | yes | no | no | yes | no | no |
| 21 | yes | yes | no | yes | no | no |
| 32 | yes | no | yes | yes | yes | no |
| 33 | yes | no | yes | no | yes | yes |
| 34 | yes | yes | no | yes | yes | no |
| 35 | yes | no | yes | yes | yes | no |
| 36 | yes | no | no | no | yes | yes |
| 37 | yes | no | yes | yes | yes | yes |
- a Seamless rolled, pressed or forged.
- b Only one radial weld is permitted below DN 1800; strip grain direction rules apply to types 11 and 34.
- c For welding, see §5.11.
- d Welded flanges are permitted only up to 370 °C under EN 13480-3:2002, D.4.4.
- e Cold forming can reduce elongation and impact energy unless the part is subsequently heat treated.
yes / no as printed in the standard. The type 11 entry for bent and electric welded manufacture is limited to DN 700 and above.
Facing types (Figure 3, p. 27)
EN 1092-1 · EN 1092-1:2018
| Facing | Description | Note |
|---|---|---|
| A | Flat face | — |
| B | Raised face | Two variants, B1 and B2, with different specified surface roughness (see Table 2) |
| C | Tongue | — |
| D | Groove | — |
| E | Spigot | — |
| F | Recess | — |
| G | O-ring spigot | — |
| H | O-ring groove | — |
Facing dimensions are given in Figure 4 and Table 8. For facing types B, D, F and G the transition from the edge of the raised face to the flange face may be a radius or a chamfer, at the manufacturer's choice.
Jointing-face surface finish (Table 2, p. 17)
Facing types A, B1, E and F are turned with a round-nosed tool of at least 1,0 mm radius and finish in the Ra 3,2–12,5 µm / Rz 12,5–50 µm band. Facing types B2, C, D, G and H take the finer Ra 0,8–3,2 µm / Rz 3,2–12,5 µm band; B2 is available only by agreement.
Unless otherwise agreed, type 01 and type 05 flanges up to PN 40, and collars other than types 33, 36 and 37, are supplied with type A flat facing; all other flanges are supplied with the standard B1 raised facing for every PN.
EN 1092-1 · EN 1092-1:2018
| Facing types | Method of machining | Radius of round-nosed tool min. mm | Ra min. µm | Ra max. µm | Rz min. µm | Rz max. µm |
|---|---|---|---|---|---|---|
| A, B1, E, F | Turning c | 1,0 | 3,2 | 12,5 | 12,5 | 50 |
| B2, C, D, G, H | Turning c | — | 0,8 | 3,2 | 3,2 | 12,5 |
- a Ra and Rz are defined in EN ISO 4287.
- b B1 and B2 are both raised face (type B) but with different specified roughness: B1 is the standard facing for all PN numbers; B2 only if agreed between purchaser and manufacturer.
- c Turning includes any machining method producing serrated concentric or serrated spiral grooves.
Ra and Rz are in µm. The facing types are compared with reference specimens by visual or tactile means rather than by instrument measurement on the face itself.
EN 1092-1 flange types — questions
What is an EN 1092-1 type 11 flange?
Type 11 is the weld-neck flange: a flange with a tapered hub and a butt-weld end for connection to pipe. It is the standard European choice for process and utility piping and is made in PN 2,5 to PN 400.
What are EN 1092-1 types 32 to 37?
They are collars, not flanges. Types 32, 33, 35, 36 and 37 are used with type 02 loose plate flanges, and type 34 with type 04. The plate flange is bolted and the collar forms the hub or the lapped pipe end behind it.
Which facing is standard on an EN 1092-1 flange?
B1 raised face is standard for most flanges at all PN numbers. Type 01 plate flanges and type 05 blind flanges up to PN 40, and collars other than types 33, 36 and 37, are supplied with a type A flat face unless the purchaser agrees otherwise.
What is the difference between B1 and B2 facing?
Both are raised face (type B), but Table 2 gives them different roughness bands: B1 uses Ra 3,2–12,5 µm / Rz 12,5–50 µm and is the standard facing, while B2 uses the finer Ra 0,8–3,2 µm / Rz 3,2–12,5 µm and is supplied only if agreed between purchaser and manufacturer.