| 摘要 |
PURPOSE:To improve the performance of instrumental errows by mounting a valve body in the housing case of a change-over valve adapted to switch a secondary meter to a master meter under a pressure of tap water. CONSTITUTION:A valve seat 44 is provided on a rack section 42 of the change-over valve housing case 30 having an inflow port 30a and an outflow port 30b for tap water from a master meter. A valve body 46 which has a water receiving section 54 facing a pipe 38 extending a drawing tube 36 into which tap water flows from a secondary meter is mounted oscillatably on the valve seat 44 with a pin 50. With such an arrangement, tap water jets to the water receiving section 54 of the valve body 46 through the drawing tube 36 and the pipe 38 passing through the secondary meter when the flow rate is small and flows out of the outflow port 30b thereby allowing the measurement of the flow rate with the secondary meter. When the flow rate is large, the valve body 46 is forced under water pressure to restrict the flow rate from the secondary meter with the water receiving section 54 through an output 38a of the pipe 38 thereby enabling the measurement of the flow rate with the master meter. |
