Meters American Water College 1 American Water CollegeDistribution ReviewWater Meters American Water CollegeWater Meter Training ObjectivesTo gain an understanding of:The construction and operation of the different types of water metersThe normal application of the various water meters American Water CollegeWater MetersTypes:Positive-displacementCompoundCurrentProportionalVenturi OrificeMagneticSonicMeters American Water College 2 American Water CollegePositive Displacement Water MeterMost common type of meterTwo types:Pistonpiston moves back and forth as water passesa known volume is measure for each cyclemotion is transmitted to the register througha magnetic drive and gearsNutating-discmeasuring chamber contains flat discwater flow causes disc to wobble and rotaterotation is transmitted to register which records volume that passed through American Water CollegePositive Displacement Water MeterUsed for residential meteringNot intended for continuous flowAs positive displacement meters age and wear, they will measure less flow than actually passes through the meter.They should be calibrated on a 10 year cycle. American Water CollegePositive Displacement Water MeterNutating DiscMeters American Water College 3 American Water CollegePositive Displacement Water MeterPiston type Picture from Water Distribution System Operation and MaintenanceFourth Edition published by the Office of Water Programs, CSUS. American Water CollegeCurrent Water MetersUsed for large industrial customersCommonly called velocity metersThree main types:turbinerotors turned by flow revolutions are proportional to flowmulti-jetsimilar to turbine but has multi-blade rotorpropellerpropeller turned by flowrevolutions are proportional to flow American Water CollegeCurrent Water MetersPicture from Water Distribution System Operation and MaintenanceFourth Edition published by the Office of Water Programs, CSUS.Propeller Meter Turbine MeterMeters American Water College 4 American Water CollegeCompound Water MetersUsed for customers with wide variations in flowAccurate over a wide range of flowThree main parts:turbine meterpositive displacement meterautomatic valve arrangementDuring periods of low flow, water flows through positive displacement meterAs flow increases, the valve opens and allows flow through turbine meter American Water CollegeCompound Water MetersPicture from Water Distribution System Operation and MaintenanceFourth Edition published by the Office of Water Programs, CSUS. American Water CollegeProportional Water MetersPrinciple of operation:Proportional meters have an orifice which restricts flow and forces a portion of flow through the meterTotal flow is determined by reading the meter and multiplying the reading by a factor.Meters American Water College 5 American Water CollegeProportional Water Meters American Water CollegeVenturi Water MetersPrinciple of operationCross sectional area of flow path is reducedVelocity increases while pressure goes downPressure is measured at two pointsprior to reduction in areaat the throat of the venturi (narrow point)Differential pressure is proportional to flow American Water CollegeVenturi Water MetersHigher PressureLower PressureMeters American Water College 6 American Water CollegeOrifice Water MetersPrinciple of operation:Orifice plate is inserted into the pipePressure is measured on both sides of the orificePressure difference is proportional to the flowCauses high head loss American Water CollegeOrifice Water Meters American Water CollegeMagnetic Water MetersPrinciple of operation:A conductive material flowing through a magnetic field will induce a voltageA magnetic field is established across the pipeThe higher the flow, the higher the voltageVoltage is proportional to flowOften used in dirty or corrosive applicationsMeters American Water College 7 American Water CollegeMagnetic Water MetersIn Line Meter Insertion type Meter American Water CollegeSonic Water MetersPrinciple of operation:Ultrasonic sound waves are transmitted through the pipe and across the flowing water.Doppler effect caused by the flowing water is measured and is proportional to the flow. American Water CollegeReview the lecture handout and then complete the quiz. This will help you remember the information we just covered.