Gestra UNA27h is a high-pressure float and thermostatic steam trap featuring a rolling ball valve design. It uses a high-strength G20Mo5 body material, supports a maximum allowable pressure of up to 63 bar g, and is available in DN25 to DN50 sizes with flanged or welded connections. Duplex automatic air venting or Simplex manual air venting configurations are available. The product is designed for high-temperature, high-pressure steam systems and provides reliable condensate drainage from steam lines and associated equipment.
Product photo of Gestra UNA27h high-pressure steam trap, three-quarter view
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UNA27h Ball Float Steam Trap | Gestra
High-pressure ball float steam trap with rolling ball valve, DN25 to DN50, available with Duplex or Simplex air venting.
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Specifications
- Steam trap type
- Float and thermostatic steam trap with a rolling ball valve design
- Control device
- Duplex control device with a thermostatic bellows automatic air vent or Simplex control device with manual air venting
- Nominal size
- DN25, DN40, DN50
- Maximum allowable pressure and temperature
- 63 bar g at 250°C; 56 bar g at 300°C; 47 bar g at 400°C; 45 bar g at 450°C
- Maximum allowable differential pressure
- 45 bar (650 psi); optional special orifices for 28 bar (405 psi) or 16 bar (230 psi)
- Flow coefficient
- DN25: KvS 0.31 (0 45), 0.38 (0 28), 0.44 m3/h (0 16); DN40/DN50: KvS 1.1 (0 45), 1.5 (0 28), 2.1 m3/h (0 16)
- Orifice diameter
- DN25: 3, 3.5, 4.1 mm; DN40/DN50: 6.5, 7, 8.5 mm
- Connection type
- DIN/ANSI flanges, socket-weld ends or butt-weld ends
- Flange standards
- DIN 2546 PN63 (Type E); ASME B16.5 Class 300, Class 400/600
- Weld-end standards
- DIN 3239 Class 3000 socket-weld ends; DIN 3239-2-R3 butt-weld ends with DIN 2559 Type 22 bevel
- Body material
- G20Mo5 (GS 22Mo4) (1.5419), approximately equivalent to ASTM A217 WC1
- Sealing material
- Graphite/CrNi
- Seat material
- X8CrNiS18-9 / X80CrSiMoW15-2 (1.4305 / 1.4732), approximately equivalent to AISI 303 / Stellite
- Float material
- X6CrNiMoTi17-12-2 (1.4571), approximately equivalent to ASTM A182 F316
- Air venting method
- Automatic air venting for Duplex version; manual air venting for Simplex version
Application scenarios
Condensate drainage in high-temperature, high-pressure steam systems
For condensate drainage from high-temperature, high-pressure steam lines and associated steam equipment. UNA27h is a float and thermostatic steam trap available in DN25, DN40 and DN50 sizes. It can operate within the specified pressure and temperature ranges and can be equipped with automatic or manual air venting devices.
Installation & maintenance notes
Observe temperature, pressure, and differential-pressure limits
During operation and commissioning, observe the applicable maximum allowable pressure limits according to the medium temperature: 63 bar g at 250°C, 56 bar g at 300°C, 47 bar g at 400°C, and 45 bar g at 450°C. The maximum allowable differential pressure specified for the applicable orifice must also not be exceeded. The default upper limit is 45 bar; the upper limit for special orifices is 28 bar or 16 bar.
FAQ
What is the core operating principle of the UNA27h high-pressure steam trap?
The UNA27h operates on the principle of a float-operated steam trap. The float-operated lifting mechanism controls the opening and closing of the valve seat to discharge condensate from the steam system while preventing steam loss. A dual or single control unit enables automatic or manual discharge, ensuring rapid removal of large volumes of condensate and safe system operation.
What are the main applications of this valve?
It is used for drainage and condensate removal in steam and condensate systems, particularly in applications requiring the discharge of large volumes of condensate under high-pressure conditions. The integrated check valve and drain plug provide stable discharge and prevent backflow.
What connection options does the UNA27h support?
The UNA27h supports various connection options, including DIN/ANSI flanges, socket-weld ends, and butt-weld ends, allowing selection for different piping layouts and international standards.
What are the key materials used in the UNA27h?
The valve body is made of stainless steel G20Mo5 (GS22Mo4, 1.5419), and the valve seat sealing uses graphite/CrNi. Other internal components are manufactured from suitable highly corrosion-resistant materials to ensure reliable operation in high-pressure, high-temperature steam environments. For specific material details, refer to the actual factory-supplied model.
How should the valve be selected and verified?
When selecting the valve, specify the inlet pressure, outlet pressure, condensate flow rate to be discharged, design configuration, orifice size, and other application information, then verify the applicable model against the technical documentation;