Magnetic Drive Positive Displacement Disc Meters
Sizes 5/8” x 1/2” and 5/8" x 3/4"
Measurement of cold water for residential and small
commercial applications where water volumes are low and low flow
sensitivity is important.
CONFORMANCE TO STANDARDS:
Hersey® Series 420 water meters comply
with the latest revision of ANSI/AWWA Standard C710. Each meter is fully
tested to ensure 100% compliance. Meters manufactured with advanced
Hersey Meters composite maincases meet the requirements of NSF
Hersey 420 Water Meters consist of three basic parts:
maincase; measuring chamber; and permanently sealed register. The
maincase is an advanced composite material designed for reduced
weight and minimal environmental impact. Stainless steel metal threads
provide corrosion resistant connections to standard bronze couplings.
Integral gaskets simplify installation for all applications.
Direction of flow arrows, model and size are molded into each maincase for
easy identification. The bottom cover is an advanced composite material
designed with a unique internal thread that enhances the structural
integrity of the meter and is sealed with an o-ring. The measuring chamber
is molded from materials specifically designed to provide reduced wear
during operation. The measuring chamber, integral strainer, nutating
disc and thrust roller are thermoplastic, which is dimensionally stable
and will not corrode. The thrust roller moves smoothly along the chamber
diaphragm to reduce friction and maintain accuracy. The register box and
lid are molded thermoplastic. The meter is designed so that the register
can be replaced without removing the meter from the service line.
The permanently sealed register has a unique seal and heattreated
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. All Hersey meter models have electronic meter reading systems
available for increased reading efficiency (see Meter Reading Systems.)
Water flows through the meter’s strainer where debris is
screened out. The incoming water fills a known volume of the measuring
chamber on one 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
highly accurate volume of water that passes through the meter.
The Hersey Series 420 Water Meter is designed and
manufactured to provide long service life with virtually no maintenance
Supplied with stainless steel metal external straight