Siemens Building Technology 257-02031 Control Valve Assembly

For veteran mechanical contractors managing commercial hydronic systems, the Siemens 257-02031 provides a reliable, field-proven solution for precise fluid regulation. As a core component of the Powermite 599 MT Series, this 2-way normally open pneumatic control valve is engineered for terminal units, hydronic heating coils, and chilled water applications. The assembly integrates a high-performance 1/2" brass globe valve with a 2-inch pneumatic actuator, calibrated for a 3–8 PSI spring range to ensure seamless integration with existing building automation systems (BAS).

The Siemens 257-02031 features a 0.4 Cv flow coefficient with a modified equal percentage characteristic, allowing for superior modulating control and improved system balance under varying load conditions. Designed for tight spaces, the 1/2" NPT internal thread by union male external thread configuration simplifies installation and serviceability. With an ANSI Class 250 rating and a forged brass body, this HVAC modulating valve maintains its structural integrity at temperatures ranging from 35°F to 250°F, providing the durability required for high-cycle industrial environments.

• Precision Modulation: The 0.4 Cv equal percentage flow characteristic ensures accurate temperature control in terminal units.
• Rugged Construction: Built with a forged brass body and brass trim to resist corrosion and handle ANSI Class 250 pressure requirements.
• Maintenance Optimized: The union male connection allows for rapid removal and replacement without cutting into the piping header.
• Pneumatic Reliability: Features a 2-inch Siemens pneumatic actuator designed for consistent response in air-driven control loops.

Is the 257-02031 compatible with 2-pipe systems?
Yes, this normally open 2-way valve is ideal for 2-pipe heating or cooling configurations where the valve must fail-safe to the open position upon loss of control signal.

What media can this Siemens valve handle?
This valve is designed for use with water or water-glycol solutions containing up to 50% antifreeze, making it suitable for both chilled water and low-pressure steam applications.

Can I replace just the actuator on this assembly?
The assembly utilizes the standard 599-01088 pneumatic actuator, which can be serviced or replaced independently of the valve body if the mechanical trim remains intact.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.