Description
The Maxitrol R400B10-412 Violet Spring is used to set controlled outlet pressure levels inside compatible gas regulators in HVAC systems. The 4-12″ WC range defines the operating pressure band that the spring maintains for stable regulation. It is commonly applied in furnaces, boilers and other heating equipment where a steady gas flow is required for consistent combustion. It is fitted inside the R400 series regulator assembly to adjust diaphragm movement and maintain steady downstream pressure during load conditions. The violet color identifies the correct calibration range during servicing and replacement work.
