Reference tables are transcribed from EN 1092-1:2018; table numbers, printed page numbers and cell values keep the standard's original wording.
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 numbers01 to 37 (14 types)
Flange types01, 02, 04, 05, 11, 12, 13, 21
Collar types32, 33, 34, 35, 36, 37
Facing typesA to H
Default facingB1 raised face (type A for 01/05 ≤ PN 40)
DimensionsTable 8, Tables 10–21
Type numbers and descriptions (Table 6, p. 26)
Table 6 (p. 26) — types of steel flanges and collars
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)
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.
aAn integral flange is part of the pressure equipment or component itself.
bCollar types are used together with the loose plate flange stated.
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.
Table 1 (p. 14) — permitted methods of manufacture by flange and collar type
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
yes / no as printed in the standard. The type 11 entry for bent and electric welded manufacture is limited to DN 700 and above.
aSeamless rolled, pressed or forged.
bOnly one radial weld is permitted below DN 1800; strip grain direction rules apply to types 11 and 34.
cFor welding, see §5.11.
dWelded flanges are permitted only up to 370 °C under EN 13480-3:2002, D.4.4.
eCold forming can reduce elongation and impact energy unless the part is subsequently heat treated.
Facing types (Figure 3, p. 27)
Figure 3 (p. 27) — flange facing types
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.
Table 2 (p. 17) — surface finish for jointing faces
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
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.
aRa and Rz are defined in EN ISO 4287.
bB1 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.
cTurning includes any machining method producing serrated concentric or serrated spiral grooves.
FAQ
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.
Sources
EN 1092-1:2018, Table 1 — Methods of manufacture (p. 14)
EN 1092-1:2018, §5.6 — Dimensions (pp. 15–16)
EN 1092-1:2018, Table 6 — Types of steel flanges and collars (p. 26)
EN 1092-1:2018, §5.7 — Facings (pp. 16–17)
EN 1092-1:2018, Figure 3 — Flange facing types (p. 27)
EN 1092-1:2018, Table 2 — Surface finish for jointing faces (p. 17)
EN 1092-1:2018, Table 7 — Synoptic table (pp. 28–33)