EN 1092-1 is the European standard for circular flanges for pipes, valves, fittings, and accessories. It specifies blind flanges (type 05) across DN 10 to DN 2000 with pressure designations from PN 2.5 to PN 400. The standard defines two face types: Type A (flat collar) and Type B (raised face).
EN 1092-1 is mandatory for European Union construction projects and widely used in the Middle East, Africa, Asia-Pacific, and South America where European engineering specifications are adopted. It is the direct successor to the older DIN 2527 and DIN 2630–2633 standards, which are now considered obsolescent.
Type A vs Type B: Type A (flat collar) flanges have a flat, smooth bore matching the pipe bore. Type B (raised face) flanges have a raised collar/face around the bore that serves as the gasket seating surface. In practice, Type B (raised face) is more commonly specified in modern European projects. Always confirm which type is required by project specifications.
PN Pressure Ratings — Reference Chart
PN Designation
Max Pressure (bar) at 120°C
Approx. ASME Class Equivalent
Typical Application
PN 2.5
2.5 bar
— (very low pressure)
Low-pressure air, drainage, HVAC
PN 6
6 bar
~Class 150 (low)
General utility, water distribution
PN 10
10 bar
~Class 150
Water supply, municipal piping, fire systems
PN 16
16 bar
~Class 150 (higher)
Water treatment, industrial process
PN 25
25 bar
~Class 300 (lower)
Higher pressure water, district heating
PN 40
40 bar
~Class 300
Process industry, steam, chemical
PN 63
63 bar
~Class 400
High-pressure process, refinery
PN 100
100 bar
~Class 600
Oil & gas, high-pressure steam
PN 160
160 bar
~Class 900
Very high pressure, cracking units
PN 250
250 bar
~Class 1500
Critical process, catalyst reactors
PN 320
320 bar
—
Ultra-high pressure specialty
PN 400
400 bar
~Class 2500
Ultra-high pressure, specialized chemical
PN vs Class: PN and Class ratings are not directly equivalent. PN values are nominal pressure ratings (in bar) that vary with temperature per EN 1092-1 Annex A pressure-temperature tables. ASME Class values are based on a different reference temperature (38°C / 100°F). For critical service, always perform a formal pressure-temperature rating comparison using both standards.
PN 10 / PN 16 Blind Flange Dimensions PN 10PN 16
PN 10 and PN 16 are the most commonly specified European flange ratings for water, HVAC, and general industrial applications. For DN 300 and below, PN 10 and PN 16 have identical dimensions in most flange types. Divergences appear above DN 350.
DN
Pipe
OD (mm)
O (mm)
PN10 / PN16
C (mm)
PN10 / PN16
W (mm)
PN10 / PN16
dh (mm)
PN10 / PN16
n
PN10 / PN16
Weight
PN16 (kg)
10
17.2
90
90
14
14
60
60
14
14
4
4
0.5
15
21.3
95
95
14
14
65
65
14
14
4
4
0.6
20
26.9
105
105
14
14
75
75
14
14
4
4
0.8
25
33.7
115
115
14
14
85
85
14
14
4
4
1.0
32
42.4
140
140
14
14
100
100
18
18
4
4
1.5
40
48.3
150
150
14
14
110
110
18
18
4
4
1.7
50
60.3
165
165
14
14
125
125
18
18
4
4
2.1
65
76.1
185
185
14
14
145
145
18
18
4
4
2.8
80
88.9
200
200
16
16
160
160
18
18
8
8
3.6
100
114.3
220
220
16
16
180
180
18
18
8
8
4.5
125
139.7
250
250
16
16
210
210
18
18
8
8
6.1
150
168.3
285
285
16
16
240
240
22
22
8
8
8.0
200
219.1
340
340
18
18
295
295
22
22
8
8
12.8
250
273.0
395
405
20
22
350
355
22
26
12
12
21
300
323.9
445
460
20
22
400
410
22
26
12
12
28
350
355.6
505
520
22
24
460
470
22
26
16
16
41
400
406.4
565
580
22
26
515
525
26
30
16
16
52
500
508.0
670
715
24
28
620
650
26
33
20
20
84
600
610.0
780
840
26
32
725
770
30
36
20
20
122
700
711.0
895
910
26
32
840
840
30
36
24
24
152
800
813.0
1015
1025
28
36
950
950
33
39
24
24
205
900
914.0
1115
1125
30
40
1050
1050
33
39
28
28
270
1000
1016.0
1230
1255
30
44
1160
1170
36
42
28
28
328
PN 40 Blind Flange Dimensions PN 40
PN 40 is the most common higher-pressure rating in European process industry specifications. It is equivalent to approximately ASME Class 300. PN 40 is widely used in chemical plants, refineries, and steam systems.
