PN10
GESTRA RK 41 is a versatile wafer-type non-return valve designed for sandwiching between flanges according to DIN, BS, and ASME standards. This high-performance check valve is suitable for liquid, gas, and steam media, providing reliable backflow prevention in industrial piping systems. For units equipped with a spring, installation is possible in any position; units without a spring are restricted to vertical pipes with an upward flow direction.
Pressure and Temperature Ratings
| Model | Temperature [°C] | -10 | 120 | 150 | 180 | 200 | 250 | 300 | Design |
|---|---|---|---|---|---|---|---|---|---|
| DN 15-100 | Pressure [barg] | 16.0 | 16.0 | 16.0 | 16.0 | 13.5 | - | - | Metal-to-metal |
| DN 125-200 | Pressure [barg] | 16.0 | 16.0 | 14.4 | 13.4 | 12.8 | 11.2 | 9.6 | Metal-to-metal |
Material Specification
| Component | DN 15 – 100 (½ – 4") | DN 125 - 200 (5 – 8") |
|---|---|---|
| Body | Brass (CW617N) | Grey cast iron (5.1301) |
| Valve Disc/Cone | Stainless steel (1.4571) | Chromium steel (1.4006) |
| Spring | Stainless steel (1.4571) | Stainless steel (1.4571) |
| Guide/Seat | Brass (CW617N) | Chromium steel (1.4107) |
Valve Seat Variants
- Metal-to-Metal: Standard for steam, liquid, and gas. Leakage rate D (EN 12266-1).
- EPDM: Suitable for water, condensate, and steam up to 150°C. Leakage rate A.
- FPM: Suitable for air and non-hazardous gases up to 200°C. Leakage rate A.
Opening Pressures
| DN [mm] | Without Spring (↑) | With Spring (↑) | With Spring (→) | With Spring (↓) |
|---|---|---|---|---|
| 15-25 | 2.5 mbar | 10.0 mbar | 7.5 mbar | 5.0 mbar |
| 50 | 4.5 mbar | 14.0 mbar | 9.5 mbar | 5.0 mbar |
| 100 | 6.5 mbar | 18.0 mbar | 11.5 mbar | 5.0 mbar |
| 200 | 11.2 mbar | 32.4 mbar | 22.2 mbar | 10.0 mbar |
Special Springs
Custom springs for specific opening pressures (20 to 1000 mbar) are available upon request for special process requirements.
Flow Dynamics
To ensure stable operation, the minimum volume flowrate must be sufficient to keep the valve disc in the open position. Consult the "Full opening/stable range" section of the pressure drop chart for your specific fluid density (ρ) and operating state.
Installation Guidance
- Centring: DN 15-100 models feature a spiral centring ring for precise alignment. DN 125-200 models use a self-centring body diameter.
- Orientation: Ensure the flow arrow on the body matches the actual pipe flow. For horizontal pipes, the valve disk must lie evenly on the guide rails.
- Eyebolts: Larger units (DN 125-200) include eyebolts to simplify positioning during installation between flanges.
