Gestra MK25-2S is a thermostatic steam trap equipped with a corrosion-resistant Hastelloy® or stainless-steel thermostatic element, available in nominal sizes DN40 and DN50. The valve features a carbon-steel or cast-steel body and bonnet, an integrated strainer, a maximum allowable differential pressure of 22 bar, and a maximum allowable inlet temperature of 450°C. It supports multiple connection options, including flanged, threaded, and welded connections. The valve complies with the PED Pressure Equipment Directive, can be installed in any position, and is suitable for condensate drainage in industrial steam networks and distribution mains.
Product image of the Gestra MK25-2S bimetallic steam trap with double flanges
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MK25-2S Bimetallic Steam Trap | Gestra
Large-bore thermostatic steam trap, DN40/DN50, with integral strainer and unrestricted mounting position.
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Specifications
- Steam Trap Type
- Thermostatic steam trap with a corrosion-resistant thermostatic element (diaphragm regulator)
- Nominal Size
- DN40, DN50
- Connection Type
- DIN PN40 flanges, ASME B16.5 Class 150/300 RF flanges, BSP threads, NPT threads, socket-weld ends, butt-weld ends
- Valve Body Material
- 1.0460 (C 22.8) / ASTM A105 steel
- Bonnet Material
- GP240GH (1.0619) / ASTM A216 Gr WCB
- Bonnet Seal
- Asbestos-free graphite / CrNi
- Thermostatic Element Material
- Hastelloy® / stainless steel
- Maximum Allowable Differential Pressure
- 22 bar (319 psig)
- Pressure-Temperature Ratings
- PN40: 40 barg at 20°C, 35 barg at 200°C, 28 barg at 300°C, 21 barg at 400°C, 14.5 barg at 450°C; Class 300: 51 barg at 20°C, 43.9 barg at 200°C, 38.9 barg at 300°C, 34.6 barg at 400°C, 20.2 barg at 450°C; Class 150: 19.7 barg at 20°C, 14 barg at 200°C, 10.2 barg at 300°C, 6.5 barg at 400°C, 4.6 barg at 450°C
- Maximum Allowable Inlet Temperature
- 450°C
- Integrated Strainer
- Yes
- Installation Position
- Can be installed in any position
- Pressure Equipment Compliance
- Complies with PED 97/23/EC; DN40 and DN50 versions bear the CE mark
- Inspection Certificates
- DIN EN 10204 2.2 and 3.1B inspection certificates are available upon request when ordering
Application scenarios
Condensate Drainage in Industrial Steam Networks and Distribution Mains
For condensate drainage in industrial steam networks or steam distribution mains. MK25-2S is a thermostatic steam trap equipped with a thermostatic element and an integrated strainer. It supports PN40 connections, has a maximum allowable differential pressure of 22 bar, and is available in DN40 and DN50 sizes.
Installation & maintenance notes
Inspection and Maintenance of the Integrated Strainer and Thermostatic Element
During maintenance and servicing, inspect the condition of the integrated strainer and thermostatic element. If contamination or wear is identified, clean or replace the components in accordance with the manufacturer's requirements.
FAQ
Which parts of a steam system are suitable for Gestra MK25-2S?
Gestra MK25-2S is a bimetallic thermostatic steam trap suitable for condensate drainage in industrial steam networks and steam distribution mains. Its DN40 and DN50 sizes can be matched to corresponding pipeline dimensions. The valve can be installed in any position, making it suitable for locations with space or piping-layout constraints.
How does the bimetallic thermostatic element in MK25-2S provide condensate drainage?
The valve uses a corrosion-resistant thermostatic element, or diaphragm regulator, available in Hastelloy® or stainless steel. Its thermostatic operating principle regulates operation according to the condensate temperature and is suitable for condensate drainage in steam systems. The valve also incorporates an integrated strainer to retain contaminants in the medium before they reach the regulating components.
Which pressure, temperature, and capacity conditions must be checked when selecting MK25-2S?
The valve has a maximum allowable differential pressure of 22 bar, meaning that the difference between inlet and outlet pressure must not exceed 22 bar. The maximum allowable inlet temperature is 450°C. Pressure-temperature ratings also depend on the connection class: PN40 is rated at 14.5 barg at 450°C, Class 300 at 20.2 barg at 450°C, and Class 150 at 4.6 barg at 450°C. Valve Cloud Warehouse recommends confirming the steam pressure, back pressure, condensate load, medium temperature, and required connection standard during selection, and verifying the operating conditions against the applicable capacity curve.
Which connection types are available for MK25-2S, and how should they be matched to existing piping standards?
MK25-2S is available with DIN PN40 flanges, ASME B16.5 Class 150/300 RF flanges, BSP threads, NPT threads, socket-weld ends, and butt-weld ends, covering flanged, threaded, and welded piping connection requirements. DN40 corresponds to 1½ inches, and DN50 corresponds to 2 inches. When ordering, specify the nominal size, connection standard, and end type to prevent incompatibility with the on-site flange class, thread standard, or weld-end dimensions.
What are the key material, compliance, and inspection-certificate considerations for MK25-2S?
The MK25-2S valve body is made of 1.0460 (C22.8) or ASTM A105 steel, and the bonnet is made of GP240GH (1.0619) or ASTM A216 Gr WCB. The bonnet seal is asbestos-free graphite / CrNi, and the internal thermostatic element is made of Hastelloy® or stainless steel. DN40 and DN50 versions comply with PED 97/23/EC and bear the CE mark. DIN EN 10204 2.2 and 3.1B inspection certificates can be requested when ordering.