PURPOSE: To detect failure of a check valve based on the flows of a fluid before and after the check valve in a system for supply water directly from a main pipe of city water to a high-rise building or the like.
CONSTITUTION: In a system for supplying a fluid after boosting through a pump P, the piping is branched 31, 32 immediately before the pump P and each branch path is provided, respectively, with a check valve 51, 52 and an ON/OFF control valve 41, 42. Sensors 61, 62 and 71, 72 are provided before and after the check valves in order to detect the pressure or flow rate of the fluid and the difference of output between both sensors is monitored constantly. Upon occurrence of abnormality, the ON/OFF control valves are operated based on an abnormality detection signal to interrupt the branch path.
TAKITA MICHIYASU
ICHIKAWA HIDEAKI
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