Compound Water Meters

Compound meters combine positive displacement and turbine (velocity) measuring technologies to capture accurate measurements in applications that experience rapid and wide fluctuations in water demands.

Water flows directly into the single compound meter housing. If the water is flowing through the meter in a high flow condition, the pressure differential causes the spring-loaded valve assembly to open. It flows past the straightening vanes at the entrance to the measuring element, helping to condition the water flow. As the water flows into the element, it comes in contact with the rotor, which lifts into a floating position and begins to spin. A right-angle worm gear couples the rotor to a vertical spindle, which, in turn, drives the gearset that rotates a coupled magnet on the wet side of the meter. The rotor’s revolutions are then transmitted via this coupling, through the cover plate, to the register. Finally, the water flows into the downstream side of the meter’s housing, where the valve assembly resides. The water then exits through the outlet.

For billing purposes, with compound meters, two sets of meter readings are taken – a larger meter for the high flows (the "high side") and another, smaller meter, for the low flows (the "low side"). The usages are then added together and the customer is billed for the combined usage.

Size Flow Range
2"     0.5 to 200 gpm
3"     0.5 to 450 gpm
4"     0.75 to 1,000 gpm
6"     0.75 to 2,000 gpm
8"     2.5 to 4,500 gpm

*Propeller* Water flowing through a pipe turns a propeller. Those turns, or revolutions, equate to flow rate and volume over time. The speed of the propeller revolutions correlated with the inside diameter of the pipe, calculating flow rate and totalization. Totalization and flow rate are indicated on a meter’s register.