The ZW209BP Pilot Operated Pressure Reducing Valve or Automatic Control Valve (ACV) with low flow bypass is utilized in multiple residential and commercial applications where steady downstream pressure is required, and prevents chattering of the main valve from 0 to 10 GPM. The ZW209BP pilot assembly allows the main valve to modulate between closed and open for a constant downstream pressure, and seals shut after reaching the pilot setting to prevent possible downstream damage. Internal and external epoxy coating offers corrosion-resistance, while the isolation valves and pressure gauges provide easy setup, maintenance and repair.