Flange - Pipe Index

BS EN 1092-1 PN 40 Dimensions


DN = Nominal size, D = Outside Diameter, A = Outside Dia of Neck , B1 = Bore of Type 01 & 12 Flange, C1 = Thickness of Plate Flange,
C2 = Thickness of Weld_Neck and Boss Flange , N1 = Dia of Weld Neck , N2 = Dia of Boss ,R = corner Radius, H1 = Length of Boss Flange,
H2 = Length of Weld Neck Flange, H3 = Length of Neck : : S = neck thickness

Note: The flange types shown are only a small part of the range covered in BS EN 1092-1.
  • type 05 is a blank flange
  • type13 is a screwed boss flange
  • type 02 is a loose plate flange used with either
      a type 32 weld on plate collar or
      a type 33 lapped pipe end
  • a type 04 flange is a loose flange for use with a
       type 34 a weld-neck collar
  • type 21 is an integral flange
The Facings shown are type B (Raised Face).  Other Facings include:
Type A..Flat:  Type C..Tongue:   Type D..Groove   Type E..Spigot:  :Type F..Recess:   Type G..O-ring Spigot:  Type H.,0-ring Groove:

A typical designation for a flange would be BS EN 1092-1/01B/DN150/PN40/ */S235JR
Key: = Standard No/Flange Type & Face Type / Nominal Size/ Pressure Rating/*/ Material Designation.
* Normally not used.   * for type 11 and 31 the neck thickness (S) is specified here.


This is an extremely simplified note.   To obtain a comprehensive description with the various variations the standards must be used.

Note : All Dimensions in mm

DN D C1 C2 H1 H2 H3 R A N1 N2 B1 d1 f1 S
10 90 14 14 20 35 6 4 17,2 28 30 18 40 2 1,8
15 95 14 14 20 35 6 4 21,3 32 35 22 45 2 2,0
20 105 14 14 24 38 6 4 26,9 39 45 27,5 58 2 2,3
25 115 16 16 24 38 6 4 33,7 46 52 34,5 68 2 2,6
32 140 18 16 26 40 6 6 42,4 56 60 43,5 78 2 2,6
40 150 18 16 26 42 7 6 48,3 64 70 49,5 88 2 2,6
50 165 20 20 34 48 8 6 60,3 75 84 61,5 102 2 2,9
65 185 22 22 38 52 10 6 76,1 90 104 77,5 122 2 2,9
80 200 24 24 40 58 12 8 88,9 105 118 90,5 138 2 3,2
100 235 26 24 44 65 12 8 114,3 134 145 116 162 2 3,6
125 270 28 26 48 68 12 10 139,7 162 170 141,5 188 2 4,2
150 300 30 28 52 75 12 10 168,3 192 200 170,5 218 2 4,5
200 375 36 34 52 88 16 10 219,1 244 260 221,5 285 2 6,3
250 450 42 38 60 105 18 12 273 306 312 276,5 345 2 7,1
300 515 48 42 67 115 18 12 323,9 362 380 327,5 410 2 8,0
350 580 54 46 72 125 20 12 355,6 408 424 359,5 465 2 8,8
400 660 60 50 78 135 20 12 406,4 462 478 411,0 535 2 11,0
450 685 66 57 84 135 20 12 457,0 500 522 462,0 560 2 12,5
500 755 72 57 90 140 20 12 508,0 562 576 513,5 615 2 14,2
600 890 84 72 100 150 20 12 610,0 666 686 616,5 735 2 16,0
DN D C1 C2 H1 H2 H3 R A N1 N2 B1 d1 f1 S
Note: in BS EN 1092-1:2002   f1= 2 for all sizes.
In the latest versions of the relevant DIN standard. f1 varies as follow
(DN =< 32 f1 = 1-2, DN 32->250(inc) f1= 1-3, DN 250->500(inc) f1= 1-4, Dn >500 f1= 1-5 )..

Flange Bolting

K = Bolt Circle Diameter, L = Dia Of Bolt Hole,
No = Number of Holes , Size = Size of Bolts

DN K L No Size
mm mm mm - mm
10 60 14 4 M12
15 65 14 4 M12
20 75 14 4 M12
25 85 14 4 M12
32 100 18 4 M16
40 110 18 4 M16
50 125 18 4 M16
65 145 18 8 M16
80 160 18 8 M16
100 190 22 8 M20
125 220 26 8 M24
150 250 26 8 M24
200 320 30 12 M27
250 385 33 12 M30
300 450 33 16 M30
350 510 36 16 M33
400 585 39 16 M36
450 610 39 20 M36
500 670 42 20 M39
600 795 48 20 M45
Steel Flange Index