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Flange Tables, Bolt Sizing
and Gasket Materials
V2.14
1
Contents
Flange Identification
….
Page 3
Flange Type Codes
….
Page 3
Flange Face Types
….
Page 4
DN Explanation
….
Page 4
Flange PCD
….
Page 4
Pressure Rating
….
Page 4
Gasket Materials
….
Page 5
….
….
Page
Page
Page
Page
CESWI 7 Compliance
….
Page 11
Bolt, Flange and Coupling Coatings
….
Page 12
Flange Tables for the Heating and
Ventilating Industry
BS10 and BS1560 (ANSI B16.5)
Temperature Pressure Ratings
BS4504
Approx. Bolting Torque
….
….
7
8
9
10
2
Flange Tables, Bolt Sizing and Gasket Materials
There are many different standards relating to the sizing and specification of
flange & bolt sets world-wide, common ones include ASA / ANSI / ASME (USA), PN /
DIN (EU), BS10 / BS4504 (British), and JIS / KS (Japanese / Korean).
The British standards relate to metric sizing in the case of BS 4504 and imperial sizing for BS10.
The American standard, ANSI is also used in Britain.
Flange Identification:
BS4504 / 111 / B – PN16 – DN400 - B4 - XXXX - 654321
Casting Number
Manufacturer
Material Designation
Nominal Diameter
Nominal Pressure
Flange Face Type
Flange Code Number
British Standard
Flange Type Codes
101 – Plate flange for welding
102 – Loose plate flange with weld on plate collar
104 – Loose plate flange with weld-nut collar
105 – Blank flange
111 – Weld neck flange
112 – Hubbed slip-on flange for welding
113 – Hubbed threaded flange
121 – Integral flange
3
Flange Face Types

Type A : Flat Face

Type D: Grooved Face

Type G: Ring Recess

Type B: Raised Face

Type E: Spigot

Type H: O-Ring
Groove

Type C: Tongue Face

Type F: Recess
Nominal Diameter (DN)
DN stands for ‘Diameter Nominale’, it is a translation between imperial and metric sizing, though not exact.
1/2”
3/4”
1”
1 1/4”
1 1/2”
2”
DN15
DN20
DN25
DN32
DN40
DN50
2 1/2”
3”
4”
5”
6”
8”
DN65
DN80
DN100
DN125
DN150
DN200
10”
12”
14”
16”
18”
20”
DN250
DN300
DN350
DN400
DN450
DN500
Flange PCD
“PCD” – Pitch Circle Diameter. Diameter described between centre of bolt holes.
Pressure Rating
‘PN’ stands for Pressure Nominale and prefixes the pressure rating, e.g. a PN16 flange is designed to operate up to 16 bar. Typical ratings include
PN6, PN10, PN16, PN25, PN40, PN64, PN100.
The American ANSI standard refers instead to a pressure / temperature rating termed ‘Class’.
4
Gasket Materials
EDPM
Effective for: hydraulic fluids, ketones, hot and cold water, and alkalis, heat, ozone and weather resistance.
Not for: most oils, gasoline, kerosene, aromatic and aliphatic hydrocarbons, halogenated solvents and concentrated acids.
Temp Range: -40 oC to +120 oC
Natural Rubber / SBR
Effective for: Acids & Bases, abrasion resistance
Not for: Oils, oxidisaing agents, aromatics, hydrocarbons, sunlight, ozone, oxygen
Temp Range: -40 oC to +80 oC
Neoprene
Effective for: weathering resistance, ozone, low gas permeability, seawater applications
Not For: Low temperature operations
Temp Range: -20 oC to +100 oC
Nitrile
Effective for: oils, hot oils, animal fats, acids & bases, heat and resistance to abrasion, gas.
Not For: nozone, sunlight, or weather resistance
Temp Range: -20 oC to +110 oC
Butyl
Effective for: Ozone, weathering, general chemical resistance, low gas & moisture permeability
Not For: Oils, fuels, fats
Temp Range: -40 oC to +100 oC
5
Viton
Effective For: high temperatures, solvents, oils
Not For: acetone, esters, ketones, low temperature applications or steam
Temp Range: -10 oC to +250 oC
Silicone
Effective For: high and low temperatures, electrically insulating
Temp Range: -60 oC to +220 oC
Nitrile Bonded Cork
Effective For: Thermal insulation, fuels, oils, refrigerants, solvents, vibration suppression
Temp Range: -30 oC to +125 oC
Fibre Paper
Effective For: vegetable oils, fuel, petrol, petroleum distillates
Temp Range: -20 oC to +120 oC
6
Flange Tables for the Heating and Ventilating Industry
BS10 and BS1560 (ANSI B16.5)



Bolts lengths are approx. for flange – flange duty assuming one 1/16” gasket and one washer
Flange thickness shown are the greatest thickness for any given rating
BS10 are available are forged bossed or flat plate as standard, BS1560 are normally forged flanges
Nominal Bore
BS10 Table D
Flange Dimensions
In.
1/2
3/4
1
1 1/4
1 1/2
2
2 1/2
3
4
5
6
7
8
9
10
12
14
15
16
18
20
24
Dia. In.
3 3/4
4
4 1/2
4 3/4
5 1/4
6
6 1/2
7 1/4
8 1/2
10
11
12
13 1/4
14 1/2
16
18
20 3/4
21 3/4
22 3/4
25 1/4
27 3/4
32 1/2
Thick In.
3/16
3/16
3/16
1/4
1/4
5/16
5/16
3/8
3/8
1/2
1/2
1/2
1/2
5/8
5/8
3/4
7/8
7/8
7/8
1
1 1/8
1 1/4
PCD In.
2 5/8
2 7/8
3 1/4
3 7/16
3 7/8
4 1/2
5
5 3/4
7
8 1/4
9 1/4
10 1/4
11 1/2
12 3/4
14
16
18 1/2
19 1/2
20 1/2
23
25 1/4
29 3/4
No.
Holes
4
4
4
4
4
4
4
4
4
8
8
8
8
8
8
12
12
12
12
12
16
16
Dia &
Length
Bolts
M12.25
M12.25
M12.25
M12.30
M12.30
M16.40
M16.40
M16.45
M16.45
M16.45
M16.50
M16.50
M16.50
M16.55
M20.55
M20.65
M22.70
M22.70
M22.70
M22.75
M22.80
M24.90
BS10 Table E
Flange Dimensions
Dia. In.
3 3/4
4
4 1/2
4 3/4
5 1/4
6
6 1/2
7 1/4
8 1/2
10
11
12
13 1/4
14 1/2
16
18
20 3/4
21 3/4
22 3/4
25 1/4
27 3/4
32 1/2
Thick In.
1/4
1/4
9/32
5/16
11/32
3/8
13/32
7/16
1/2
9/16
11/16
3/4
3/4
13/16
7/8
1
1 1/8
1 1/4
1 1/4
1 3/8
1 1/2
1 7/8
PCD In.
2 5/8
2 7/8
3 1/4
3 7/16
3 7/8
4 1/2
5
5 3/4
7
8 1/4
9 1/4
10 1/4
11 1/2
12 3/4
14
16
18 1/2
19 1/2
20 1/2
23
25 1/4
29 3/4
No. Holes
4
4
4
4
4
4
4
4
8
8
8
8
8
12
12
12
12
12
12
16
16
16
Dia &
Length
Bolts
M12.30
M12.30
M12.30
M12.40
M12.40
M16.45
M16.45
M16.45
M16.50
M16.50
M20.65
M20.65
M20.65
M20.70
M20.70
M22.80
M22.80
M22.90
M22.90
M22.100
M22.105
M27.120
BS10 Table F
Flange Dimensions
Dia. In.
3 3/4
4
4 3/4
5 1/4
5 1/2
6 1/2
7 1/4
8
9
11
12
13 1/4
14 1/2
16
17
19 1/4
21 3/4
22 3/4
24
26 1/2
29
33 1/2
Thick In.
3/8
3/8
3/8
1/2
1/2
5/8
5/8
5/8
3/4
7/8
7/8
7/8
1
1 1/8
1 1/8
1 1/4
1 3/8
1 1/2
1 5/8
1 3/4
2
2 1/4
PCD In.
2 5/8
2 7/8
3 7/16
3 7/8
4 1/8
5
5 3/4
6 1/2
7 1/2
9 1/4
10 1/4
11 1/2
12 3/4
14
15
17 1/4
19 1/2
20 1/2
21 3/4
24
26 1/2
30 3/4
No. Holes
4
4
4
4
4
4
8
8
8
8
12
12
12
12
12
16
16
16
20
20
24
24
Dia &
Length
Bolts
M12.40
M12.40
M16.45
M16.45
M16.50
M16.55
M16.55
M16.55
M16.65
M20.70
M20.70
M20.70
M20.75
M22.80
M22.80
M22.90
M24.100
M24.105
M24.110
M27.120
M27.130
M30.150
7
Hex Round Hex (HRH) Bolts to
BS4190
1/2"
Standard Bolt Sizes
M12
1"
5/8"
3/4"
M16
M20
1 1/4"
M24
M30
Nominal Bore
BS10 Table H
Flange Dimensions
In.
1/2
3/4
1
1 1/4
1 1/2
2
2 1/2
3
4
5
6
7
8
9
10
12
14
15
16
Dia. In.
4 1/2
4 1/2
4 3/4
5 1/4
5 1/2
6 1/2
7 1/4
8
9
11
12
13 1/4
14 1/2
16
17
19 1/4
21 3/4
22 3/4
24
Thick In.
1/2
1/2
9/16
11/16
11/16
3/4
3/4
7/8
1
1 1/8
1 1/8
1 1/4
1 1/4
1 3/8
1 3/8
1 5/8
1 7/8
2
2 1/8
PCD In.
3 1/4
3 1/4
3 7/16
3 7/8
4 1/8
5
5 3/4
6 1/2
7 1/2
9 1/4
10 1/4
11 1/2
12 3/8
14
15
17 1/4
19 1/2
20 1/2
21 3/4
No.
Holes
4
4
4
4
4
4
8
8
8
8
12
12
12
12
12
16
16
16
20
Dia &
Length
Bolts
M16.50
M16.50
M16.50
M16.55
M16.55
M16.55
M16.65
M16.70
M16.75
M20.80
M20.80
M20.90
M20.90
M22.100
M22.100
M22.105
M24.120
M24.130
M24.140
18
20
24
26 1/2
29
33 1/2
2 3/8
2 5/8
3
24
26 1/2
30 3/4
20
24
24
M27.150
M27.170
M30.200
BS1560 ANSI B16.5 Class 150
Flange Dimensions
Dia. In.
3 1/2
3 7/8
4 1/4
4 5/8
5
6
7
7 1/2
9
10
11
13 1/2
16
19
21
23 1/2
Thick In.
7/16
1/2
9/16
5/8
11/16
3/4
7/8
15/16
15/16
15/16
1
1 1/8
1 3/16
1 1/4
1 3/8
1 7/16
PCD In.
2 3/8
2 3/4
3 1/8
3 1/2
3 7/8
4 3/4
5 1/2
6
7 1/2
8 1/2
9 1/2
11 3/4
14 1/4
17
1 3/8
21 1/4
25
27 1/2
32
1 9/16
1 11/16
1 7/8
22 3/4
25
29 1/2
BS1560 ANSI B16.5 Class 300
Flange Dimensions
No. Holes
4
4
4
4
4
4
4
4
8
8
8
8
12
12
12
16
Dia &
Length
Bolts
M12.45
M12.50
M12.50
M12.55
M12.55
M16.70
M16.75
M16.75
M16.75
M20.80
M20.80
M20.90
M22.95
M22.100
M24.105
M24.105
Dia. In.
3 3/4
4 5/8
4 7/8
5 1/4
6 1/8
6 1/2
7 1/2
8 1/4
10
11
12 1/2
15
17 1/2
20 1/2
23
15 1/2
Thick In.
9/16
5/8
11/16
3/4
13/16
7/8
1
1 1/8
1 1/4
1 3/8
1 7/16
1 5/8
1 7/8
2
2 1/8
2 1/4
PCD In.
2 5/8
3 1/4
3 1/2
3 7/8
4 1/2
5
5 7/8
6 5/8
7 7/8
9 1/4
10 5/8
13
15 1/4
17 3/4
20 1/4
22 1/2
No. Holes
4
4
4
4
4
8
8
8
8
8
12
12
16
16
20
20
Dia &
Length
Bolts
M12.50
M16.65
M16.65
M16.70
M16.75
M20.75
M20.80
M20.90
M20.95
M20.100
M20.105
M22.105
M24.120
M27.130
M27.140
M30.150
16
20
20
M27.110
M27.120
M30.120
28
30 1/2
36
2 3/8
2 1/2
2 3/4
24 3/4
27
32
24
24
24
M30.150
M30.160
M36.180
8
Flange Tables for the Heating and Ventilating Industry
BS4504



Bolts lengths are approx. for flange – flange duty assuming one 1/16” gasket and one washer
Flange thickness shown are the greatest thickness for any given rating
BS4504 (Metric) flanges are available as forged, bossed or plate flanges as standard
Nominal
Bore
mm
15
20
25
32
40
50
65
80
100
125
150
175
200
250
300
350
400
450
500
600
BS 4504 Table 6
Flange Dimensions
Dia.
(mm)
80
90
100
120
130
140
160
190
210
240
265
320
375
440
490
540
595
645
755
Thick
(mm)
12
14
14
16
16
16
16
18
18
20
20
22
24
24
26
28
30
30
32
PCD
(mm)
55
65
75
90
100
110
130
150
170
200
225
280
335
395
445
495
550
600
705
No.
Holes
4
4
4
4
4
4
4
4
4
8
8
8
12
12
12
16
16
20
20
BS 4504 Table 10
Flange Dimensions
Dia. & Length
Bolts
M10 .45
M10. 50
M10 .50
M12 .55
M12 .55
M12 .55
M12 .55
M16 .65
M16 .65
M16 .70
M16 .70
M16 .70
M16 .70
M20 .70
M20 .80
M20 .80
M20 .90
M20 .90
M24 .90
Dia.
(mm)
95
105
115
140
150
165
185
200
220
250
285
315
340
395
445
505
565
615
670
780
Thick
(mm)
14
16
16
16
16
18
18
20
20
22
22
24
24
26
26
28
32
36
38
42
PCD
(mm)
65
75
85
100
110
125
145
160
180
210
240
270
295
350
400
460
515
565
620
725
No.
Holes
4
4
4
4
4
4
4
8
8
8
8
8
8
12
12
16
16
20
20
20
BS 4504 Table 16
Flange Dimensions
Dia. & Length
Bolts
M12 .50
M12 .55
M12 .55
M16 .55
M16 .55
M16 .65
M16 .65
M16 .70
M16 .70
M16 .70
M20 .70
M20 .75
M20 .75
M20 .80
M20 .80
M20 .80
M24 .90
M24 .105
M24 .105
M27 .120
Dia.
(mm)
95
105
115
140
150
165
185
200
220
250
285
315
340
405
460
520
580
640
715
840
Thick
(mm)
14
16
16
16
16
18
18
20
20
22
22
24
24
26
28
32
36
40
44
52
PCD
(mm)
65
75
85
100
110
125
145
160
180
210
240
270
295
355
410
470
525
585
650
770
No.
Holes
4
4
4
4
4
4
4
8
8
8
8
8
12
12
12
16
16
20
20
20
Dia. & Length
Bolts
M12 .50
M12.55
M12 .55
M16 .55
M16 .55
M16 .65
M16 .65
M16 .70
M16 .70
M16 .70
M20 .70
M20 .75
M20 .75
M24 .80
M24 .80
M24 .90
M27 .100
M27 .120
M30 .125
M33 .140
Hex Round Hex (HRH) Bolts to BS 4190
Standard Bolt Sizes
1/2” M12
1” M24
5/8” M16
1 1/4” M30
3/4” M20
9
Nominal Bore
80
100
150
200
250
300
350
400
450
500
600
Nominal
Bore
mm
To Seal @ 10 bar
70
75
115
110
155
165
160
200
195
240
305
15
20
25
32
40
50
65
80
100
125
150
175
200
250
300
350
400
Dia.
(mm)
95
105
115
140
150
165
185
200
235
270
300
330
360
425
485
555
620
450
500
600
670
730
845
Approx. Bolting Torque (Nm)
To Seal @ 16 bar To Seal @ 20 bar
70
75
80
80
120
125
115
120
165
175
180
190
175
185
220
235
215
230
270
295
365
425
BS 4504 Table 25
Flange Dimensions
Thick
PCD
No.
(mm)
(mm)
Holes
16
65
4
18
75
4
18
85
4
18
100
4
20
110
4
20
125
4
22
145
8
24
160
8
26
190
8
28
220
8
30
250
8
28
280
12
30
310
12
40
370
12
38
430
16
42
490
16
46
550
16
52
58
66
600
660
770
20
20
20
Dia. &
Length Bolts
To Seal @ 25 bar
75
80
135
130
180
210
200
270
260
345
505
M12 .55
M12 .65
M12 .65
M12 .65
M16 .65
M16 .70
M16 .70
M16 .70
M16 .75
M20 .80
M24 .80
M24 .90
M24 .80
M24 .90
M27 .110
M30 .125
M33 .140
Dia.
(mm)
95
105
115
140
150
165
185
200
235
270
300
350
375
450
515
580
660
M33 .140
M33 .155
M36 .165
685
755
-
B20S 4504 Table 40
Flange18 Dimensions
Thick18
PCD
No.
(mm18)
(mm)
Holes
16
65
4
18
75
4
18
85
4
18
100
4
20
110
4
20
125
4
22
145
8
24
160
8
26
190
8
28
220
8
30
250
8
32
295
12
34
320
12
42
385
12
50
450
16
55
510
16
64
585
16
68
72
-
610
670
-
20
20
-
Dia. &
Length Bolts
M12 .55
M12 .65
M12 .65
M16 .65
M16. 70
M16 .70
M16 .70
M16 .75
M20 .80
M24 .80
M24 .90
M27 .90
M27 .90
M30 .120
M30 .140
M33 .150
M36 .160
Dia.
(mm)
105
130
140
155
170
180
205
215
250
295
345
375
415
470
530
600
670
M36 .170
M39 .180
-
-
BS 4504 Table 64
Flange Dimensions
Thick
PCD
No.
(mm)
(mm)
Holes
20
75
4
22
90
4
24
100
4
24
110
4
26
125
4
26
135
4
26
160
8
30
170
8
32
200
8
34
240
8
36
280
8
40
310
12
46
345
12
54
400
12
62
460
16
72
525
16
78
585
16
-
-
-
Dia. &
Length Bolts
M12 .70
M16 .70
M16 .75
M20 .75
M20 .80
M20 .80
M20 .80
M20 .90
M24 .90
M27 .100
M30 .105
M30 .120
M33 .130
M33 .150
M33 .160
M39 .180
M39 .200
-
10
CESWI 7 Compliance
The Civil Engineering Specification for Water Industry (CESWI), 7th edition, is now the standards document for all civil engineering works. The
document stipulates that the bolts in flange joint sets must be of sufficient length to ensure that nuts are fully threaded when tightened with
at least two threads showing when in their final tightened position. Also that washers must be used both under the head of the bolt, and
under the nut.
fwb stock and supply CESWI 7 compliant sets containing appropriate bolt lengths, each with two washers. Typical sizes would include:
Nominal
Diameter
(DN)
80
100
150
200
250
300
350
400
Bolt Size
Length
Diameter
(mm)
70
M16
70
M16
80
M20
80
M20
90
M24
100
M24
100
M24
100
M27
Number
of bolts
8
8
8
12
12
12
16
16
Nominal
Diameter
(DN)
450
500
600
700
800
900
1000
1200
Bolt Size
Length
(mm)
110
115
130
135
155
155
165
190
Number
of Bolts
Diameter
M27
M30
M33
M33
M36
M36
M39
M45
20
20
20
24
24
28
28
32
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Bolt, Flange and Coupling Coatings

Galvanised
 Rilsan Coatings
In production since 1947 polyamide-11 or Rilsan is conceptually similar to nylon and perlon and comes from the same chemical family as other
leading materials such as Kevlar and Nomex.
Powdered Rilsan coatings are ideal for use in the water industry, it offers:
o UV resistance
o Compliance with all standards (AWAA, EEC, French, Germany, Belgium, Australian, Italian, Dutch, Japanese, British etc.)
o High levels of corrosion resistance
o High resistance to abrasion and impact damage
 Sheraplex Coatings
Sheraplex is a viable alternative to Rilsan. The Sheraplex process is a Duplex system which provides excellent corrosion
protection provided by a Sherardizing process combined with an organic barrier layer.
o A more consistent “Torque/load” ratio can be achieved
o Sheraplex coating does not gall when re-used, meaning nuts & bolts can be used repeatedly
o Long term vibration testing has shown difference in the performance of Sheraplex compared to Rilsan
o The coating process is considered by some to be more environmentally friendly than others
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