| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas meter equipped with a selector valve with improved responsiveness to a rapid increase in the amount of gas used without causing hunting. SOLUTION: In this gas meter 20, a large-flow measuring means 24 is put in a first passage 23 causing a supply port 21 to communicate with a discharge port 22, and the selector valve 25 is put in the first passage 23 on the upstream side of the measuring means 24. A small-flow measuring means 27 is put in a second passage 26 connected to the first passage 23 so as to bypass the selector valve 25. The selector valve 25 has a valve element 33 making opening/ closing motion by being angularly displaced relative to a valve seat 32. A pair of opposite diaphragms 30, 31 are provided above the selector valve 25. The diaphragms 30, 31 are displaced toward or away from each other correspondently to a pressure loss in the measuring means 27, and the displacement is transmitted to the valve element 33 of the selector valve 25. The diaphragms 30, 31 are each provided with a valve opening setting means 80 equipped with a permanent magnet piece 83 or 84.
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