Abstract: A double casing water meter includes a casing having an inlet port, a water chamber in fluid communication with the inlet port, an outlet port and a water discharging chamber in fluid communication with the outlet port. An inner casing has a bottom plate defining at least one water inflow passage extending between the water chamber and the water discharging chamber, and a water inflow tube opening at its opposed ends respectively into the water inflow passage and the water chamber and inclined relative to the bottom plate. A vane wheel is supported for rotation in the casing upon issuance of water from the water inflow passage and has individual vanes successively disposed in intersecting relation to the longitudinal axis of the tube in the course of the vane wheel rotation.

Abstract: An improved magnetic rotor type water meter having an anti-reverse-rotation device for preventing the reverse rotation of the pointer driving gear of the water meter, although the rotor or impeller of the water meter is rotated in the reverse direction by a counterflow from the outlet or by any type of fluid pressures applied to the outlet.

Abstract: A vane wheel water meter having a vane wheel disposed in a vane chamber located between an inlet and an outlet with the meter body being positioned above the vane chamber. The vane wheel has a body with several vanes extending outwardly perpendicular to the vane axis. Stepped back stops are provided on the upper surface of the vane wheel body which gradually incline downwardly in the normal rotational direction of the vane wheel relative to the inlet. Stop pins are mounted within respective cylinders provided in meter body for coacting with the back stops to stop the vane wheel from rotating in the reverse rotational direction. The vane wheel body can be shaped like a truncate cone.