Maxon 250SMA11AA11BB22A0 Gas Valve

The Maxon 250SMA11AA11BB22A0 is a high-performance 2 1/2" ANSI threaded gas valve designed for critical industrial fuel shut-off applications. Engineered as a normally closed safety shut-off valve, this cast iron body unit features an auto-reset electromechanical actuator with a 6-second motor timing for controlled opening and instantaneous closing upon power loss. This standard port flow capacity valve is built for natural gas service and general-purpose environments, utilizing a durable Buna body O-ring and bumper set for reliable sealing. With a NEMA 4 enclosure rating, the assembly is protected against dust and water, ensuring longevity in demanding mechanical rooms. The integrated VOS2/VCS2 switch options provide precise valve position feedback (Proof of Closure and Proof of Open), which is essential for meeting modern safety shut-off valve interlocking requirements. Operating on 115Vac 60Hz for both the solenoid and motor, this Maxon Series 5000 valve is the industry standard for contractors requiring industrial gas valve replacement and dependable automatic gas shut-off performance. Key Benefits

• Enhanced Safety Monitoring: Features VOS2/VCS2 proof-of-closure switches to verify the valve’s state within the safety limit string.
• Rugged Construction: The cast iron body and Internal Trim Package 1 provide superior durability for commercial HVAC gas valve applications.
• Reliable Sealed Design: High-grade Buna-N O-rings ensure tight shut-off and prevent external leakage during operation.
• Weatherproof Protection: The NEMA 4 rating allows for installation in areas exposed to moisture or debris without compromising the motor.
• Standardized Compatibility: Features a 2.5-inch NPT threaded connection for straightforward integration into existing gas manifolds.

Common Questions

What is the purpose of the VOS2 and VCS2 switches?
These are auxiliary signal switches used for "Proof of Open" (VOS2) and "Proof of Closure" (VCS2). They allow the burner management system to confirm the valve’s position before it proceeds to the next step of the ignition sequence.

Can this valve be used for hazardous locations?
This specific model is rated for General Purpose (GP) areas with a NEMA 4 enclosure. If your site requires Class I, Division 2 certification, you must verify if a hazardous-rated model (such as the SMA12 series) is required for your specific zone.

Does the valve close immediately when power is cut?
Yes. While the motor takes 6 seconds to open the valve, the internal spring return mechanism ensures the valve trips to the closed position in less than one second when the safety circuit is interrupted.

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.