DIN 2527 specifies blind flanges (also called blank flanges) for welding neck pipe connections. A blind flange seals the end of a pipe system and is used for pressure testing, system isolation, or future extension points. It has no bore — the entire flange face is solid plate. Available in pressure ratings from PN 6 to PN 40 and sizes from DN 10 to DN 1000.
View Other Standards:
DIN 2543 Slip-On DIN 2544 Flat Plate DIN 2545 Weld Neck EN 1092-1 JIS B2220 BS 4504
DIN 2527 — Blind Flange PN 6 – PN 40
DIN 2527 specifies blind flanges (blank flanges) for welding neck pipe connections. A blind flange seals the end of a pipe system and is used for pressure testing, system isolation, or future extension points. It has no bore — the entire flange face is solid plate.
Key Specifications
Type: Blind / Blank
Pressure: PN 6 / 10 / 16 / 25 / 40
Size Range: DN 10 – DN 1000
Face Type: Flat Face (FF) / Raised Face (RF)
Temperature: −10°C to +300°C (varies by material)
Connection: Weld-on / Slip-on
DIN 2527 PN 16 — Dimension Table (Selected Sizes)
| DN |
Flange OD D (mm) |
Bolt Circle k (mm) |
Bolt Holes |
Bolt Hole d (mm) |
Thickness t (mm) |
Raised Face d4 (mm) |
Approx. Weight (kg) |
| 10 |
90 |
60 |
4 |
14 |
14 |
40 |
0.55 |
| 15 |
95 |
65 |
4 |
14 |
14 |
45 |
0.66 |
| 20 |
105 |
75 |
4 |
14 |
16 |
58 |
0.98 |
| 25 |
115 |
85 |
4 |
14 |
16 |
68 |
1.30 |
| 32 |
140 |
100 |
4 |
18 |
16 |
78 |
1.90 |
| 40 |
150 |
110 |
4 |
18 |
16 |
88 |
2.24 |
| 50 |
165 |
125 |
4 |
18 |
18 |
102 |
3.10 |
| 65 |
185 |
145 |
4 |
18 |
18 |
122 |
4.18 |
| 80 |
200 |
160 |
8 |
18 |
20 |
138 |
5.42 |
| 100 |
220 |
180 |
8 |
18 |
20 |
158 |
6.85 |
| 125 |
250 |
210 |
8 |
18 |
22 |
188 |
9.85 |
| 150 |
285 |
240 |
8 |
22 |
22 |
212 |
12.90 |
| 200 |
340 |
295 |
12 |
22 |
24 |
268 |
20.80 |
| 250 |
405 |
355 |
12 |
26 |
26 |
320 |
33.50 |
| 300 |
460 |
410 |
12 |
26 |
28 |
378 |
46.20 |
| 400 |
580 |
525 |
16 |
30 |
32 |
490 |
84.50 |
| 500 |
715 |
650 |
20 |
33 |
36 |
610 |
143.0 |
| 600 |
840 |
770 |
20 |
36 |
40 |
725 |
222.0 |
Table 1: DIN 2527 PN 16 Blind Flange Dimensions. Reference temperature 20°C. For PN 6/10/25/40 dimensions, refer to specific DIN 2527 PN tables or contact HT PIPE engineering.
Pressure Ratings — All DIN 2527 PN Classes
| PN Class |
Max Pressure (bar) at 20°C |
Max Pressure (psi) |
Typical DN Range |
Common Applications |
| PN 6 |
6 bar |
87 psi |
DN 10 – DN 1000 |
Low-pressure water, air, HVAC |
| PN 10 |
10 bar |
145 psi |
DN 10 – DN 1000 |
Water distribution, irrigation |
| PN 16 |
16 bar |
232 psi |
DN 10 – DN 600 |
General industrial, water pipelines |
| PN 25 |
25 bar |
363 psi |
DN 10 – DN 400 |
Steam, gas, chemical processing |
| PN 40 |
40 bar |
580 psi |
DN 10 – DN 300 |
High-pressure steam, oil & gas |
Table 2: DIN 2527 Blind Flange pressure ratings by PN class. All pressure ratings per EN 1092-1 / ISO 7005 reference temperature of 20°C.
PN 10 vs PN 16 vs PN 25 — Dimension Comparison
| DN |
PN 6 D (mm) |
PN 10 D (mm) |
PN 16 D (mm) |
PN 25 D (mm) |
PN 40 D (mm) |
PN 16 k (mm) |
PN 40 k (mm) |
| 10 |
75 |
90 |
90 |
90 |
90 |
60 |
60 |
| 20 |
95 |
105 |
105 |
105 |
105 |
75 |
75 |
| 40 |
130 |
150 |
150 |
150 |
150 |
110 |
110 |
| 80 |
180 |
200 |
200 |
200 |
200 |
160 |
160 |
| 100 |
200 |
220 |
220 |
235 |
235 |
180 |
190 |
| 150 |
265 |
285 |
285 |
300 |
300 |
240 |
250 |
| 200 |
320 |
340 |
340 |
360 |
375 |
295 |
320 |
| 300 |
435 |
445 |
460 |
485 |
515 |
410 |
450 |
| 400 |
535 |
565 |
580 |
620 |
660 |
525 |
585 |
Table 3: DIN 2527 Blind Flange OD (D) comparison across PN classes for selected sizes. Bolt circle (k) increases with PN class. Full dimensional tables available on request from HT PIPE.
Materials
Carbon Steel: ASTM A105, A350 LF2/LF3
Stainless Steel: ASTM A182 F304, F304L, F316, F316L, F321
Duplex: S31803 (F51), S32750 (F53), S32760 (F55)
Alloy Steel: ASTM A182 F5, F9, F11, F12, F22, F91
Inconel: 600, 625, 718, 800, 825
Hastelloy: C276, B2, B3, C2000
Monel: 400, K500
Applications
End-of-line closures and system isolation
Pressure testing of pipe systems
Manway covers on vessels and tanks
Future extension preparation points
Oil, gas, and petrochemical process lines
DIN 2527 blind flanges should be installed with a full-face or spiral-wound gasket on the raised face (if RF type). Bolt torque shall follow the flange manufacturer's gasket stress recommendations. For high-pressure steam service above PN 40, consider EN 1092-1 Type 05 blind flanges or weld-end closures per ASME B16.5.
PN Class vs ANSI/ASME Equivalent
| PN Class (DIN/EN) |
ASME/ANSI Equivalent |
Max Pressure (bar) |
Max Pressure (psi) |
| PN 6 |
— |
6 bar |
87 psi |
| PN 10 |
Class 150 |
10 bar |
145 psi |
| PN 16 |
Class 150–300 |
16 bar |
232 psi |
| PN 25 |
Class 300 |
25 bar |
363 psi |
| PN 40 |
Class 300–600 |
40 bar |
580 psi |
Table 4: DIN 2527 PN class vs. ANSI/ASME equivalent pressure classes. Approximate equivalencies only — always verify dimensional compatibility before mixing standards.
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 |
| Super Duplex 2507 |
A182 F53 / S32750 |
300°C |
Harsh chemical, subsea |
| Alloy Steel F22 |
A182 F22 (2¼CrMo) |
550°C |
Power plant, refineries |
| Inconel 625 |
UNS N06625 |
700°C |
Aerospace, marine |
Table 5: Material selection guide for DIN 2527 blind flanges. Maximum temperatures are approximate; verify with material datasheet and applicable code.
HT PIPE manufactures DIN 2527 blind flanges in carbon steel, stainless steel, duplex, and special alloys. All flanges supplied with EN 10204 3.1 material test reports and dimensional inspection certificates. Contact our engineering team for specific quotation requests.
