MODEL HM FIRE HYDRANT METER

APPLICATIONS: Recommended for measuring high-volume water usage from fire hydrants or other fire protection systems. Convenient hose connections and lightweight construction make this portable turbine meter useful for accurately measuring water used to fill street sweepers, water tankers or other equipment.

CONFORMANCE TO STANDARDS: Hersey Model HM Water Meters comply with ANSI/AWWA Standard C701 class II. Each meter is tested to ensure compliance.

CONSTRUCTION: Hersey Model HM Water Meters consist of three basic parts: D-I-M-E (Drop-In-Measuring-Element), bottom case and register. The D-I-M-E assembly contains all of the working parts inside of the meter and is easily removed from the bottom case when servicing is desired. The bottom case is constructed from cast aluminum to be lightweight and has built in carry handles for portability. The register is enclosed in a lockable bronze register box. The rotor assembly is thermoplastic which is dimensionally stable and will not corrode. The inlet connection has a 2-1/2" female national hose thread swivel adapter and the outlet connection is 2-1/2" male national hose threads. An orifice ring in the outlet connection ensures the rate of flow stays within the operating range of the measuring element for long lasting performance.

REGISTER: O-ring sealed register includes a straight-reading odometer type totalization display, and 360° test circle with center sweep hand. Change gears are available for accuracy calibration.

OPERATION: Water flows straight through the turbine section where it turns a rotor at a rate in direct proportion to the quantity of water flowing through the meter. The straight-through design allows high volumes to flow with a minimum of head loss. Retro Thrust rotor design extends the life of the meter by dividing wear between two points: during low flow the tungsten carbide thrust bearing floats against a sapphire bearing surface; during high flow the stainless steel shaft gently contacts a second sapphire bearing. During medium flow, the rotor floats between the thrust bearings without contact.

MAINTENANCE: The Hersey Model HM Meters are designed and manufactured to provide long service life with virtually no maintenance required.

INLET HUB & ROTOR INTEGRAL IN REMOVABLE TOP CASE: Can be transferred to another bottom case without recalibration. Spare unit can be put in bottom case as original is being serviced.

CONNECTIONS: Available with National Standard for fire hose coupling thread, female and male couplings.

CARRYING HANDLE: Facilitates ease of transportation.

Model Designation
HM

Sizes
3"

Maximum Working Pressure
150 PSIG

Temperature Range
33F to 130F water temperature

Operating Range
8 - 450 GPM

Meter Top Case
Bronze

Meter Bottom Case
Epoxy-coated cast aluminium

Measuring Chamber
Plastic

Register Box and Lid
Bronze

End Detail (fire hose couplings)
Inlet: 2-1/2" - 7-1/2 NPSH (National Standard for fire hose coupling thread) Female Coupling. Outlet: 2-1/2" - 7-1/2 NPSH, Male Nipple

Shafts and Bolts
Stainless steel


Toomey Water Services 2007 created and maintained by jra design