Rev. A
ZENNER FHZD Fire Hydrant
Backflow Meter with RPZ
3” Model FHZD30S**-RP
U.S.A. Patent No. US 6363782 B1
U.S.A. Patent No. D560,132
INTRODUCTION: FHZD Fire Hydrant Backflow Meters,
with built-in dual check valves and RPZ dump valve, are designed to measure a wide variety of cold potable wa-
ter flows from fire hydrants where flows are in one di- rection. These Meters are light weight portable units
designed for temporary installations. The built-in dual check valves help provide a practical solution to help
prevent backflow into the primary water source. The
RPZ (Reduced Pressure Zone) Dump Valve allows this
assembly to dump to atmosphere when the check
valves are fouled.
OPERATION: Water flows through the turbine section
causing the rotor to turn proportionately to the quantity of water flowing through the meter. A drive magnet
transmits the motion of the rotor to a driven magnet
located within the hermetically sealed register. The
magnet is connected to a gear train which translates the rotations into volume totalization displayed on the regis- ter dial face.
CONSTRUCTION: FHZD Fire Hydrant Meters consist of
several basic components: light weight aluminum main
case, turbine type measuring element assembly, sealed
register, aluminum cover plate, stainless steel hardware, brass lid assembly, aluminum or brass swivel and nipple, stainless steel handles, front and rear 3” check valves, RPZ Dump Valve and adjustable support stand. The measuring element assembly includes the rotor assembly, vertical shaft and a calibration vane which eliminates the need for calibration change gears.
MAINTENANCE: FHZD Fire Hydrant Meters are engineered and manufactured to provide long-term service and operate virtually maintenance free. If maintenance is necessary the measuring element can be removed from the main case. The 3” Check Valves and RPZ can be easily serviced.
CONFORMANCE: FHZD Hydrant Meters are tested and comply with AWWA C701 Class II performance stand- ards.
STRAINERS: FHZD Fire Hydrant Meters come with a built-in 54 square inch strainer after the first check valve and in front of the Turbine Measuring Element.
CONNECTIONS: FHZD Fire Hydrant Meters are typically configured with bronze fire hose connections, alt- hough aluminum connections are available.
OPTIONS: Locking devices, special order connections, gate valves, “add-on” restrictor plates, etc.
Rev. A
MODEL FHZD30S**-RP
SIZE 3"
Flow Rate Maximum Intermittent USGPM 650
Maximum Continuous USGPM 450
Optimum Operating Flow Range USGPM 3 - 450
Low Flow rate USGPM 2-1/2
Maximum Working Pressure P.S.I. 175
Maximum Temperature Deg. F 140
Length Inches 27
Weight Pounds 52
FHZD30S**-RP
Configured with optional 2-1/2” ZHGV250
Hydrant Gate Valve (Eddy Valve)