A 3-inch fire hydrant meter combines metering ability with a newly designed backflow preventer. The product, called the Fire Hydrant Reduced Pressure Backflow Preventer Meter (BPM), is a result of two companies? efforts.
Both Badger Meter and the Ames Co. will sell the combination product, which combines the 3-inch Turbo Series Fire Hydrant Meter with an Ames reduced pressure zone (RPZ) backflow preventer. This new product is intended to provide the most accurate, shortest length and lightest weight assembly available in the market. It is the only reduced pressure backflow preventer meter available.
The new BPM is designed to protect the potable water system by preventing a backflow condition from occurring through fire hydrants. The new BPM works just like a fire hydrant meter. It simply attaches to a fire hydrant?s hose connection with standard connections. The assembly is supported by a stainless steel support bar that rests against the base of the fire hydrant.
The fire hydrant meter uses an inlet strainer made of a double-walled stainless steel plate. It uses the same measuring element found in the three-inch Turbo Series meter.
Water flows through the meter?s measuring element and is measured on the local register. Measurements are taken by means of rotor revolutions transmitted by magnetic drive coupling through the meter?s cover plate to the sealed register. Magnetic drive is achieved by a right-angle worm drive, coupling the rotor to the vertical transmission spindle. A ceramic magnet on the spindle rotates around the vertical axis. Through the magnetic coupling, rotor rotation is transmitted to a follower magnet which transmits rotation to the register gearing.
The backflow preventer consists of two independently operating, spring loaded cam-check valves with a hydraulically operated differential pressure relief valve located between and below the cam checks. The check valves are mounted in a 300 series stainless steel housing. Each is internally loaded and provides a positive drip-tight closure against reverse flow. The cam checks include a stainless steel cam arm and spring, rubber faced disc and a replaceable seat.
When normal flow exists, both checks arc open and the pressure in the area between the checks (called the zone) is at least 2 psi lower than the inlet pressure. If normal flow stops, the differential pressure relief valve, located at the bottom of the BPM, automatically opens and discharges to atmosphere.
A permanent orifice, positioned in the outlet side of the meter housing, limits the maximum flow of water through the meter. This is provided to protect the measuring element from overspeeding when the meter discharges to atmosphere.
The standard register consists of a straight-reading odometer-type totalization display, 360-degree test circle with center sweep hand, and flow finder to detect leaks. Register gearing consists of self-lubricating thermoplastic gears to minimize friction and provide long life.
The Badger Recordall Turbo Series fire hydrant backflow preventer meters meet or exceed registration accuracy for low flow rate, normal operating flow rate, and maximum continuous operation flow rate as stated in AWWA Standard C701.
