Magnetic Drive Positive Displacement Disk Meters are available in bronze and ductile iron bodies. They are for the measurement of cold water for residential, commercial and industrial applications where water volumes are low, and low flow sensitivity is important.
Meters consist of three basic parts: maincase; measuring chamber; and permanently sealed register. The maincase and topcase are made of bronze. The measuring chamber, nutating disc and strainer are made of thermoplastic, which is dimensionally stable and will not corrode. A test port in the body permits in-line testing. Register box and lid are available in plastic or bronze.
The permanently sealed register has a unique seal and heat-treated glass to eliminate dirt, moisture infiltration and lens fogging. An integral tamper-proof locking feature is provided to resist tampering with the register. The totalizing register has a straight-reading odometer type display, a 360º test circle with center sweep hand and a low flow (leak) detector. Standard gearing is used, making registers interchangeable by size.
Water flows through the meter’s strainer where any debris that could adversely affect meter accuracy or free operation is screened out. As the water enters, it fills a known volume of the measuring chamber on one or the other side of a movable disc that separates the chamber into two sections. As water enters it moves the disc (nutates), forcing a known volume of water out of the meter from the opposite side of the disc. The process repeats as the sections refill and empty in turn. The nutating action of the disc is coupled magnetically to the register to indicate the volume of water that passes through the meter. The large
measuring chamber requires fewer nutations of the disc for each gallon measured, which helps to limit wear, reduce pressure loss and extend the life of the meter.
