HYDRAULIC TESTING METHOD AND DEVICE

Even if test pipes have a wide range of sizes, a water hydraulic test on each of the test pipes is conducted accurately, efficiently, and economically. Such an object is achieved by using a plurality of booster cylinders 41 arranged in parallel with respect to a test pipe and having respective boosting ratios increasing in stages. A plurality of servo motor driven pumps 51 arranged in parallel is used as a drive source for the plurality of booster cylinders 41. Before a water pressure on an output side of the booster cylinder 41 reaches a pressure near a test pressure, the plurality of servo motor driven pumps 51 operates simultaneously. Then, the plurality of servo motor driven pumps 51 stops operating except one and the water pressure on the output side of the booster cylinder 41 is increased to the test pressure by the one servo motor driven pump 51. During pressure increase, the plurality of booster cylinders 41 is used in turn in order of increasing boosting ratio.