DIN 2544 specifies flat plate/slip-on flanges rated at PN 25 (25 bar). The flat plate design makes it economical for medium-pressure applications. Particularly common in European waterworks, heating installations, and general industrial plant piping. Available as both plain plate and bossed (recessed bore) variants. Covers sizes DN 10 to DN 1000.
View Other Standards:
DIN 2527 Blind DIN 2543 Slip-On DIN 2545 Weld Neck EN 1092-1 BS 4504
DIN 2544 — Flat Plate Flange PN 25 PN 25
DIN 2544 specifies flat plate/slip-on flanges rated at PN 25 (25 bar). The flat plate design is economical for medium-pressure applications and is particularly common in European waterworks, heating installations, and general industrial plant piping.
Key Specifications
Type: Flat Plate / Slip-On
Pressure: PN 25 (25 bar / 363 psi)
Size Range: DN 10 – DN 1000
Face Type: Raised Face (RF)
RF Height: 2–5 mm (increases with size)
Variant: Bossed / Plain Bore
DIN 2544 PN 25 — Full Dimension Table
| DN |
ISO Pipe OD (mm) |
DIN Pipe OD (mm) |
Bore d₄ (mm) |
Flange OD D (mm) |
Thickness t (mm) |
RF Height f (mm) |
Bolt Circle k (mm) |
Bolt Holes |
Hole d₂ (mm) |
Weight (kg/pc) |
| 10 |
17.2 |
14 |
40 |
90 |
— |
2 |
60 |
4 |
14 |
0.72 |
| 15 |
21.3 |
20 |
45 |
95 |
16 |
2 |
65 |
4 |
14 |
0.81 |
| 20 |
26.9 |
25 |
58 |
105 |
18 |
2 |
75 |
4 |
14 |
1.24 |
| 25 |
33.7 |
30 |
68 |
115 |
18 |
2 |
85 |
4 |
14 |
1.38 |
| 32 |
42.4 |
38 |
78 |
140 |
18 |
2 |
100 |
4 |
18 |
2.03 |
| 40 |
48.3 |
44.5 |
88 |
150 |
18 |
3 |
110 |
4 |
18 |
2.35 |
| 50 |
60.3 |
57 |
102 |
165 |
20 |
3 |
125 |
4 |
18 |
3.20 |
| 65 |
76.1 |
— |
122 |
185 |
22 |
3 |
145 |
4 |
18 |
4.29 |
| 80 |
88.9 |
— |
138 |
200 |
24 |
3 |
160 |
8 |
18 |
5.88 |
| 100 |
114.3 |
108 |
162 |
235 |
24 |
3 |
190 |
8 |
23 |
7.54 |
| 125 |
139.7 |
133 |
188 |
270 |
26 |
3 |
220 |
8 |
27 |
10.80 |
| 150 |
168.3 |
159 |
218 |
300 |
28 |
3 |
250 |
8 |
27 |
14.50 |
| 200 |
219.1 |
216 |
278 |
360 |
30 |
3 |
310 |
12 |
27 |
22.30 |
| 250 |
273 |
267 |
335 |
425 |
32 |
3 |
370 |
12 |
30 |
33.50 |
| 300 |
323.9 |
318 |
395 |
485 |
34 |
4 |
430 |
16 |
30 |
46.30 |
| 350 |
355.6 |
368 |
450 |
555 |
38 |
4 |
490 |
16 |
33 |
68.00 |
| 400 |
406.4 |
419 |
505 |
620 |
40 |
4 |
550 |
16 |
36 |
89.70 |
| 500 |
508 |
521 |
615 |
730 |
44 |
4 |
660 |
20 |
36 |
138.0 |
| 600 |
609.6 |
622 |
720 |
845 |
— |
5 |
770 |
20 |
39 |
— |
| 700 |
711.2 |
720 |
820 |
960 |
— |
5 |
870 |
24 |
42 |
— |
| 800 |
812.8 |
820 |
930 |
1085 |
— |
5 |
990 |
24 |
48 |
— |
| 900 |
914.4 |
920 |
1030 |
1185 |
— |
5 |
1090 |
28 |
48 |
— |
| 1000 |
1016 |
1020 |
1140 |
1320 |
— |
5 |
1210 |
28 |
56 |
— |
Table 1: DIN 2544 PN 25 Flat Plate Flange Dimensions. "—" indicates data not published in standard tables. ISO Pipe OD per ISO-R64; DIN Pipe OD per DIN 2448. Full table DN 10–DN 1000.
RF Height Progression
| DN Range |
RF Height f |
| DN 10 – DN 40 |
2 mm |
| DN 50 – DN 300 |
3 mm |
| DN 350 – DN 500 |
4 mm |
| DN 600 – DN 1000 |
5 mm |
Table 2: DIN 2544 Raised Face (RF) height by DN size range.
Applications
Industrial waterworks and municipal water distribution
Heating systems and heat exchangers
Mining support structures
Fire protection systems
Petrochemical plant piping
Food and beverage processing (with appropriate material)
Flange Material Selection Guide
| Material |
Grade |
Max Temp |
Key Application |
| Carbon Steel |
ASTM A105 |
425°C |
Steam, water, air, oil |
| Stainless Steel 316 |
A182 F316 |
400°C |
Chemical, food, pharma |
| Stainless Steel 316L |
A182 F316L |
400°C |
Weld-intensive fabrication |
| Duplex 2205 |
A182 F51 / S31803 |
300°C |
Offshore, seawater |
| Alloy Steel F22 |
A182 F22 (2¼CrMo) |
550°C |
Power plant, refineries |
Table 3: Material selection guide for DIN 2544 flat plate flanges. Verify material compatibility with process media and operating temperature.
PN Class vs ANSI/ASME Pressure Equivalent
| PN Class |
Max Pressure (bar) |
ANSI/ASME Equivalent |
| PN 10 |
10 bar |
Class 150 |
| PN 16 |
16 bar |
Class 150–300 |
| PN 25 |
25 bar |
Class 300 |
| PN 40 |
40 bar |
Class 300–600 |
Table 4: PN pressure class vs ANSI/ASME equivalent. Approximate equivalencies only.
HT PIPE manufactures DIN 2544 flat plate flanges in carbon steel, stainless steel, and duplex materials. All flanges supplied with EN 10204 3.1 material test reports and dimensional inspection certificates.
