Maxitrol M520R-3/4 Valve

The Maxitrol M520R-3/4 is a precision-engineered NPT modulating gas valve designed for integration with Series 94 and A200 Selectra electronic gas flame modulation systems. Built for atmospheric burners, this 3/4-inch valve handles a maximum inlet pressure of 1/2 PSI, providing continuous, non-fluctuating fuel regulation without the need for mechanical butterfly valves or mod motors. This "R" configuration features a right-side outlet and a dedicated low-fire bypass adjustment screw, allowing technicians to fine-tune the minimum firing rate for stable ignition and consistent temperature control in indirect-fired applications.

Ruggedly constructed for industrial environments, the M520R-3/4 modulator valve utilizes a 24VDC solenoid to provide proportional gas flow based on amplifier signals. This ensures high-accuracy gas flow modulation for makeup air units and space heating systems. When installing, ensure the valve is paired with a separate upstream pressure regulator, as this Maxitrol modulating valve focuses exclusively on signal-driven flow control rather than primary pressure regulation. Its compact footprint and 3/4 inch NPT threading simplify field replacements in existing HVACR control systems.

• Precise Modulation: Delivers infinite, instantaneous flame adjustment for superior temperature stability in atmospheric burner systems.
• Simplified Setup: Includes a low-fire bypass adjustment on the right side for easy field calibration of the minimum heat output.
• Durable Design: Engineered for industrial-grade gas flow modulation in demanding makeup air and process heating applications.
• High Compatibility: Seamlessly replaces or integrates into Selectra Series 94 or A200 modulation circuits using 3/4 inch NPT piping.

Can the M520R-3/4 be used as a standalone pressure regulator?
No, this is a modulating gas valve designed to work in tandem with a modulation amplifier. It requires a separate upstream pressure regulator to manage the primary inlet pressure of 1/2 PSI.

Where is the bypass adjustment located for this specific model?
The "R" in the Maxitrol M520R-3/4 model number signifies that the low-fire bypass adjustment is located on the right side of the valve body for convenient access during service.

What systems is this NPT modulating gas valve compatible with?
It is primarily designed for use with Maxitrol Selectra systems, including the Series 94 and A200, which are common in indirect-fired heating units.

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.