Cubic Foot Registers (Small Meters)
The majority of water meters used in our system are 5/8 x 3/4” positive displacement types with cubic foot registers. Water flowing through the meter causes a measuring element known as a nutating disc to displace a set amount of water from the measuring chamber. The water displaced by the disc during each cycle will be constant in volume. The movement of the disc is transferred to the register gear train which turns the dials. All of our meters are factory tested prior to shipment. Once a meter is assembled with the correct register for the size of the meter it cannot over-register, but will under-register over the course of time.
Other types of meters used in our system include turbine meters and compound meters. These meters are generally used by commercial customers with substantial water demand. Turbine meters use propeller-like rotors to measure water velocity and are used in applications where the flow rate is moderate to high. Compound meters house two types of metering chambers within one casing, a turbine and a positive displacement type, and usually have two registers. They are used when flow rates fluctuate considerably; the low side (positive displacement) will register water flow up to a specific crossover point, after which the high side (turbine) will begin to register the heavier demand.
One of the most important things to know with regards to water conservation and detecting leaks is to learn to read your water meter. Most of the water meters for El Paso city residential and commercial accounts have registers similar to the one pictured here from a 5/8 x 3/4” meter. It is labeled as “Cubic Feet”. Each numeric indicator around the face of the register indicates a tenth of a cubic foot and the sweep hand measures one cubic foot for each complete revolution. The register has odometer type dials that total all of the water that has passed though the meter. The two dials on the right are known as “dead zeroes” and are not used when we read meters for billing purposes.
Since EPWU bills in hundred cubic foot (Ccf) increments we only read up to the thousand foot dial ( the last dial that has a black digit against a white background), which increases by one every time a hundred cubic feet of water passes through the meter.
The small red triangular dial near the center of the register is a flow or leak indicator and it will turn counterclockwise with the slightest amount of water that flows through the meter, even a dripping faucet. However, a slight back and forth movement may occur if the pressure from the main line is fluctuating somewhat, and is not significant.