Gestra BK46 is a bimetallic steam trap equipped with a Thermovit bimetallic regulator, suitable for PN 40 and Class 150/300 pressure ratings. The body and cover are manufactured from 1.5415/A182 F1 material, with a maximum permissible differential pressure of 32 bar. Flanged, threaded, socket-weld, and butt-weld connection options are available. It is primarily used in steam pipelines and related steam systems to automatically discharge air and non-condensable gases during start-up and operation through thermostatic air venting.
Gestra BK46 bimetallic steam trap, three-quarter product image
1 / 1
BK46 Bimetallic Steam Trap | Gestra
Thermovit bimetallic regulating steam trap for venting air from steam lines during startup and operation, available with flanged, threaded, butt-weld and socket-weld connections.
Genuine product assurance
We can help verify product data and purchasing details.
Model confirmation
Confirm model, connection and key options before ordering.
After-sales support
After-sales communication support is provided according to the order agreement.
Specifications
- Regulator type
- Thermovit bimetallic regulator (stainless-steel bimetal strip)
- Standard regulator subcooling
- Δt approx. 15 K
- Maximum permissible differential pressure
- 32 bar
- Pressure ratings
- PN 40 / Class 150 / Class 300
- Pressure-temperature rating (PN 40 flange)
- PMA 40.0 bar g at 20°C; 39.0 bar g at 250°C; 34.2 bar g at 300°C; 32.3 bar g at 350°C; 29.9 bar g at 400°C; 27.6 bar g at 450°C
- Pressure-temperature rating (Class 150 flange)
- PMA 20.0 bar g at -10/50°C; 14.0 bar g at 200°C; 10.2 bar g at 300°C; 8.4 bar g at 350°C; 6.5 bar g at 400°C; 4.7 bar g at 450°C
- Nominal sizes
- DN15, DN20, DN25 (1/2", 3/4", 1")
- Connection types
- DIN/ANSI flanges, threaded sockets, NPT threaded sockets, socket-weld ends, butt-weld ends
- Flange standards
- EN 1092-1 PN 40; ASME B16.5 Class 150 / Class 300
- Butt-weld end standards
- EN 12627; ASME B16.25 / ASME B36.10
- Socket-weld end standards
- EN 12760; ASME B16.11 Class 3000
- Thread standards
- BSP ISO 228-1; NPT ASME B16.11
- Body and cover materials
- DIN/EN 1.5415 (ASME equivalent material A182 F1)
- Sealing materials
- Graphite/CrNi
- Automatic air venting function
- Automatic air venting during start-up and operation; suitable for thermostatic air venting in steam systems
- PED applicable media
- Group 2 fluids
Application scenarios
Automatic air venting in steam systems
Used to automatically discharge air and non-condensable gases from steam pipelines and related steam systems during start-up and operation. Product documentation explicitly supports this automatic air venting function.
Installation & maintenance notes
Verify the pressure-temperature rating range
Before installation and operation, verify that the system pressure and temperature are within the rating range corresponding to the BK46 and the selected connection or flange class. Exceeding the rated parameters may cause seal failure or reduced equipment performance.
FAQ
How does the BK46 bimetallic steam trap work?
The BK46 uses a stepped-nozzle design actuated by bimetallic strips. During start-up, the valve is fully open to discharge condensate and air. As the temperature rises, the bimetallic strips bend and close the stepped nozzle. The valve orifice closes rapidly at a temperature slightly below the saturation temperature, thereby providing condensate drainage and air venting for steam systems.
What connection options are available for the BK46?
The BK46 supports multiple end connections, including DIN/ANSI flanges, threaded connections, NPT threaded connections, socket-weld ends, and butt-weld ends, accommodating different piping-system designs and on-site installation requirements.
What are the body material and sealing design of the BK46?
The valve body is made of structural steel 1.5415. The valve-seat sealing uses graphite/CrNi, and the internal components include a stainless-steel bimetallic regulator, ensuring good sealing performance and durability during start-up and operation.
What BK46 models are available, and what are their weights and nominal sizes?
The available models are BK46-15, BK46-20, and BK46-25, with nominal sizes DN15/20/25 and a pressure rating of PN40. Their respective weights are 4.00, 4.00, and 5.00 kg. Detailed flange and end-connection parameters for each model are subject to the applicable model table.
Which key parameters should be considered when selecting the BK46?
When selecting the BK46, consider the system pressure and temperature conditions, verify the DN/PN ratings and connection type, check the maximum allowable differential pressure and air-venting requirements, and confirm the applicable model against the technical documentation.