DIN 2565 DIN 2566 DIN 2567 DIN 2568 DIN 2569
This series of standards specifies threaded neck flanges (also called screwed flanges or TH flanges) with an integral tapered BSPT (British Standard Pipe Thread) connection on the bore. They require no welding for assembly — the pipe threads directly into the flange. This makes them ideal for temporary connections, explosive atmospheres, or locations where welding is impractical. Covers DN 10 to DN 150 across PN 6 to PN 100.
View Other Standards:
DIN 2527 Blind DIN 2543 Slip-On DIN 2545 Weld Neck EN 1092-1 JIS B2220
DIN 2565–2569 — Threaded Neck Flanges PN 6 – PN 100
Threaded neck flanges feature an integral BSPT (ISO 7-1) tapered thread on the bore, allowing direct threaded connection to the pipe without welding. This zero-heat assembly method is critical for hazardous area installations, temporary connections, or locations where welding is impractical.
Overview — Pressure Ratings by Standard
| Standard |
Pressure Rating |
Max Pressure (bar) |
Max Pressure (psi) |
Typical Service |
| DIN 2565 |
PN 6 |
6 bar |
87 psi |
Low-pressure water, air, HVAC |
| DIN 2566 |
PN 16 |
16 bar |
232 psi |
Water pipelines, light industrial |
| DIN 2567 |
PN 25 & PN 40 |
25 / 40 bar |
363 / 580 psi |
Steam, gas, chemical |
| DIN 2568 |
PN 64 |
64 bar |
928 psi |
Medium-pressure process lines |
| DIN 2569 |
PN 100 |
100 bar |
1,450 psi |
High-pressure steam, oil & chemical |
Table 1: Threaded Neck Flange series — DIN 2565 to DIN 2569. All PN ratings reference 20°C. Seal face: Raised Face (RF) standard for PN 16 and above; Flat Face (FF) for PN 6.
Thread Specifications
| DN |
BSPT Thread Size |
Thread Type |
Reference Standard |
| DN 10 |
Rp 3/8 / NPT 1/2 |
Tapered BSPT / NPT |
ISO 7-1 / ANSI B1.20.1 |
| DN 15 |
Rp 1/2 / NPT 1/2 |
Tapered BSPT / NPT |
ISO 7-1 / ANSI B1.20.1 |
| DN 20 |
Rp 3/4 / NPT 3/4 |
Tapered BSPT / NPT |
ISO 7-1 / ANSI B1.20.1 |
| DN 25 |
Rp 1 / NPT 1 |
Tapered BSPT / NPT |
ISO 7-1 / ANSI B1.20.1 |
| DN 32 |
Rp 1¼ / NPT 1¼ |
Tapered BSPT / NPT |
ISO 7-1 / ANSI B1.20.1 |
| DN 40 |
Rp 1½ / NPT 1½ |
Tapered BSPT / NPT |
ISO 7-1 / ANSI B1.20.1 |
| DN 50 |
Rp 2 / NPT 2 |
Tapered BSPT / NPT |
ISO 7-1 / ANSI B1.20.1 |
| DN 65–DN 150 |
Rp 2½ – Rp 6 |
Tapered BSPT |
ISO 7-1 |
Table 2: DIN 2565–2569 Threaded Neck Flange BSPT thread sizes by DN. BSPT (Rp) per ISO 7-1; NPT per ANSI B1.20.1. Thread sealing requires appropriate compound or PTFE tape.
Key Design Features
Thread: BSPT tapered (ISO 7-1) or NPT (ANSI B1.20.1)
Seal Face: RF standard (PN 16+); FF optional (PN 6)
No Welding: Zero-heat assembly
Size Range: DN 10 – DN 150 (typical); larger on request
Temperature Limit: −30°C to +300°C (by material)
Explosion-Proof: Suitable for hazardous areas
PN Class vs ANSI/ASME Pressure Equivalent
| PN Class |
Max Pressure (bar) |
ANSI/ASME Equivalent |
| PN 6 |
6 bar |
— |
| PN 16 |
16 bar |
Class 150–300 |
| PN 25 |
25 bar |
Class 300 |
| PN 40 |
40 bar |
Class 300–600 |
| PN 64 |
64 bar |
Class 600 |
| PN 100 |
100 bar |
Class 600–900 |
Table 3: DIN 2565–2569 PN class vs ANSI/ASME equivalent. Approximate equivalencies only.
Materials
Carbon Steel: ASTM A105, A350 LF2
Stainless Steel: ASTM A182 F304, F316 (cast CF8/CF8M)
Duplex: ASTM A182 F51 (S31803)
Super Duplex: ASTM A182 F53 (S32750), F55 (S32760)
Inconel: 600, 625
Monel: 400
Titanium: Grade 2, Grade 5
Applications
Explosive or flammable gas service (no welding)
Temporary or test connections
Instrumentation and sampling lines
Chemical process plants (corrosive media)
Steam and condensate systems (PN 25–40)
Offshore platforms and marine piping
Retrofit installations where pipe alignment is difficult
Note: Threaded connections in high-pressure steam service (PN 40+) should be inspected periodically for thread degradation. For critical service above PN 64, welding neck flanges (EN 1092-1 Type 11) are generally preferred over threaded types.
Flange Material Selection Guide
| Material |
Grade |
Max Temp |
Key Application |
| Carbon Steel |
A105 |
425°C |
Steam, water, air, oil |
| Stainless Steel 316 |
A182 F316 / CF8M |
400°C |
Chemical, food, pharma |
| Duplex 2205 |
A182 F51 / S31803 |
300°C |
Offshore, seawater |
| Super Duplex 2507 |
A182 F53 / S32750 |
300°C |
Harsh chemical, subsea |
| Inconel 625 |
UNS N06625 |
700°C |
Aerospace, marine |
Table 4: Material selection guide for DIN 2565–2569 threaded neck flanges.
HT PIPE manufactures DIN 2565–2569 threaded neck flanges in carbon steel, stainless steel, duplex, and special alloys. All flanges supplied with EN 10204 3.1 material test reports. Contact our engineering team for quotation.
