Honeywell PP901A1004 Pressure Reducing Valve 45-150 PSI Inlet 0-25 PSI Outlet

The Honeywell PP901A1004 is a pressure-reducing valve designed to regulate water pressure in various HVAC applications, including hydronic heating systems, boilers, and chilled water systems. It functions by automatically reducing incoming high-pressure water to a constant, lower pressure adjustable between 45 and 150 PSI delivered to the system. This regulated pressure ensures optimal performance and protects equipment from damage caused by excessive pressure fluctuations. The Honeywell PP901A1004 operates through a spring-loaded mechanism. When the incoming pressure exceeds the desired setting, the spring compresses, allowing a portion of the water to bypass the valve, maintaining the downstream pressure at a consistent level.