Dwyer Series HF in-Line Flow Monitors, 1/4"Female NPT, 2-12 Air SCFM, 3.32 psid Max. Pressure Drop

Series HF Flow Monitors combine the simplicity of a sharp edged orifice disk with a variable area flow monitor to provide a low cost way to measure flow at high pressures. These monitors are tubular, with all internal wetted parts sealed within the body casing. Running through the body is a tapered shaft which is centered in the bore by pilot disks at each end. Surrounding the shaft are a sharp-edged floating orifice disk, a transfer magnet and return spring. The disk and transfer magnet are held in the €œno flow€ position by a biased return spring. As flow moves through the monitor, it creates a differential pressure at the orifice disk forcing the disk and transfer magnet against the return spring. As flow increases, the differential pressure at the disk increases, forcing the disk and transfer magnet to move along the tapered center shaft. As flow decreases, the biased return spring forces the disk and transfer magnet down the center shaft, returning to the €œno flow€ position. In metal casing monitors, disk and magnet movement are not visible so a magnet follower is located outside the body casing, magnetically coupled to the internal transfer magnet. As flow increases, motion of the internal magnet moves the magnet follower outside the body casing, under the scale.