

NORRES CONNECT STORZ DIN ALU 251
Storz coupling in forged aluminium – DIN standard for vacuum and process systems
The NORRES CONNECT STORZ DIN ALU 251 is a robust suction and pressure coupling made of forged aluminium, manufactured according to DIN 14321 / 14322 / 14323. It is designed for industrial and construction applications, including groundwater lowering and conveying of wood pellets in heating systems. Available with either a corrugated or smooth hose tail, compatible with NORRES CLAMP and CONNECT systems for secure and tight assembly.
Properties and design
- Manufactured according to DIN 14321 / DIN 14322 / DIN 14323.
- Material: forged aluminium.
- Not suitable for explosive fluids (Group 1) and not part of the pressure equipment directive.
- Complies with REACH (see technical information at manufacturer’s site).
Applications
Used for water and material transfer in groundwater lowering systems, pumping and construction sites, as well as for conveying wood pellets in automated heating systems. Compatible with CLAMP 211 and CONNECT 229 / 231 systems.
Technical note
Storz couplings are widely used in industrial and emergency systems as quick-connect fittings. Choose corrugated hose tail for spiral hoses (for use with clamp assembly) and smooth hose tail with locking ring for safety clamp systems (CONNECT 231). Ensure proper sealing and locking to prevent leakage under vacuum or pressure.
Recommended accessories
- CLAMP 211
- CONNECT 229 CLAMP ASSEMBLY
- CONNECT 231 SAFETY CLAMP ASSEMBLY
Unsure which coupling type you need?
Contact us for technical advice on correct assembly, sealing and compatibility with your NORRES hoses and fittings.
FAQ: CONNECT STORZ DIN ALU 251
What material is the coupling made of?
The coupling is made of forged aluminium according to DIN 14321 / 14322 / 14323.
What is it used for?
For vacuum and pressure hose connections in construction, water handling and pellet transport systems.
Can it be used with explosive fluids?
No, it must not be used with explosive fluids (Group 1) and is not covered by the pressure equipment directive.
Which versions are available?
With corrugated hose tail for clamp assembly (CONNECT 229), smooth hose tail with locking ring for safety clamp assembly (CONNECT 231), and spare NBR seals.
Which accessories fit?
CLAMP 211 and CONNECT 229 / 231 systems.
Related links
Technical specifications – CONNECT STORZ DIN ALU 251
With corrugated hose tail – for clamp assembly (CONNECT 229 CLAMP ASSEMBLY)
| Type | Lug spacing (mm) | Weight (kg/pcs) | Suitable for hose I.D. (mm) | Order No. |
|---|---|---|---|---|
| 52-C | 66 | 0.35 | Ø 50 | 251-0050-8012 |
| 75-B | 89 | 0.66 | Ø 75 | 251-0075-8012 |
| 110-A | 133 | 1.84 | Ø 100 | 251-0100-8012 |
With smooth hose tail + locking ring – for safety clamp assembly (CONNECT 231 SAFETY CLAMP ASSEMBLY)
| Type | Lug spacing (mm) | Weight (kg/pcs) | Suitable for hose I.D. (mm) | Order No. |
|---|---|---|---|---|
| 52-C | 66 | 0.35 | Ø 50 | 251-0050-8022 |
| 75-B | 89 | 0.66 | Ø 75 | 251-0075-8022 |
| 110-A | 133 | 1.84 | Ø 100 | 251-0100-8022 |
Spare parts – NBR seal (black)
| Type | Lug spacing (mm) | Weight (kg/pcs) | Order No. |
|---|---|---|---|
| 52-C | 66 | 0.02 | 251-0052-8068 |
| 75-B | 89 | 0.03 | 251-0075-8068 |
| 110-A | 133 | 0.05 | 251-0110-8068 |
All values determined at approx. 20 °C. Subject to technical modifications.





