Description
The Maxitrol MR251D-1 1/2 Modulator Regulator Valve automatically regulates and modulates gas flow to match changing burner demand while maintaining the required outlet pressure. It combines pressure regulation and modulation in a single assembly for compatible HVAC systems using atmospheric or direct-fired gas burners. This valve is installed in the gas supply line downstream of the primary controls and integrated with the associated modulation control components. Its dual-operation design allows burner input to vary smoothly with heating demand, providing responsive flame control without requiring separate regulating equipment.









