Flowmeter

摘要

A flowmeter has a main body having fluid inlet and outlet passages and a vertical fluid channel formed in the main body and having one end communicating with the inlet passage and the other end communicating with the outlet passage. The vertical fluid channel has a first passage and a second passage having a cross-sectional area larger than that of the first passage. The first passage has therein a float for regulating a flow rate of the fluid flowing therethrough, and is tapered to have a cross-sectional area increasing from the inlet passage side toward the outlet passage side such that the float remains in position when the fluid passes through the first passage. The second passage has therein a valve for opening the second passage when the fluid is to flow therethrough and for closing the second passage when the fluid is not to flow therethrough. The valve has a projection for moving the float toward the inlet passage when the second passage is closed. The float and the valve have specific gravities larger or smaller than that of the fluid.