Maintaining consistent temperatures is no longer a problem. The unique Modulator or Modulator / Regulator valve, the heart of the Selectra Electronic Gas Flame Modulating System, provides precise, non-fluctuating, instantaneous temperature control without requiring any motor or mechanically driven butterfly valve. Whether your needs are for problem-free stabilized area heating, elevated heating, consistent higher baking/drying temperatures or other process applications.

These valves are designed exclusively for negative pressure (pull through) applications. They use a counter spring to keep the valve in the closed position despite the downward pull of negative pressure. M411, M511, and M611 valves are set for applications up to 1.5" w.c. and are not adjustable. MR212 valves are factory set for applications up to -1.5" w.c. and are field adjustable for up to -3.5" w.c. With the main valve closed an adjustable bypass provides a minimum firing rate to the burner whenever the safety shut-off valve(s) is open. This is low fire to the heater. Since the pressure regulator maintains a constant supply pressure, the minimum firing rate is also held constant. The MR212's regulator is an integral component while a separate upstream pressure regulator is required for the M411, M511, and M611.