| 摘要 |
Irrigation valves for channels and for irrigation tanks are of three types. All are activated by a pair of tilting float arms to which a pair of floats are attached. One type is a T-shaped duct with a cylindrical valve disposed at 90 degrees to the part that is connected to the incoming flow. The floats rotate the valve. The second type has the same construction as the first type, thereby giving flow control but additionally has a rise and fall gate in the duct part that is connected to the incoming flow. The gate acts as a stop valve. The third type has a cylindrical duct connectable to the incoming flow but no valve and provides both flow control and stop valve facilities through a rise and fall gate actuated by the tilting of the float arms. |
