PURPOSE: To provide such a measuring device acting as a shut-off value between its assigned measurement missions in such a way that accurate measurement is possible by rapid injection for federating nearly continuos flow and constituted in an extremely simple structure which a small number of working portions so as to be easily arranged on the distribution ends of a pressurized transfer device of liquid and gas and generation of flow surge in front of a measuring device at the starting time of stalled steam static pressure behind the measuring device may by prevented.

CONSTITUTION: The measuring device is provided with a housing 1 on which at least one inlet port 2 and at least one outlet 3 are formed and at least one piece of rotatable ball 4 driven by a shaft 5, and this ball has a lateral hole 9 housing a shuttle ball 10 and the ball 10 makes straight line motion inside of a lateral hole between two seats 11, 12, and on the other hand, makes seal of the other seat. The ball 4 is caught between seats so as to pressurize to seal an outlet seat 8.