Maxitrol M420H-1/2 Modulator Valve for Atmospheric Burners with 1/2 PSI Inlet Pressure Max for Liquid Propane Gas Applications

The Maxitrol M420H Valves are used for indirect fired atmospheric burner applications where outlet pressure is greater than 7" W.C.  This model can modulate in a span of as much as 10" W.C.   For applications with a total modulation span of less than 7" W.C. it is not recommendable to use these models which can cause hunting to occur when the sensitivity of outlet pressure change relative to voltage change.

A pressure adjustment spring has been factory set to obtain an outlet pressure slightly above atmospheric pressure (0.1" W.C.) with the bypass closed and zero voltage is applied. The minimum flow rate is now adjusted through the bypass.

NOTE: Minimum outlet pressure is always above 0.2" W.C — maximum outlet pressure is 7.0" W.C.  They can be driven by the A1094 and AD1094 Amplifiers or SC10 Signal Conditioner.