| 摘要 |
PURPOSE:To enable an air valve to be tested accurately under the various conditions by generating negative pressure in the air valve section to operate the air valve by a specified differential pressure and confirm the operation through a rod. CONSTITUTION:A pipe 10 is connected to an air valve 1 having a rod 9 integral with a valve body 6 through a mounting flange 4, and the air valve 1 is arranged in a water tank 11 so as to locate the pipe 10 below. Water is poured into the water tank 11 so that the pipe 10 and a space 5 in the air valve 1 are filled with the water. The level A of water in the tank is then made the level of a roof plate 3. The water in the water tank 11 under such a condition is drawn out until a distance l between the water level in the tank and the air valve 1 reaches one corresponding to a predetermined differential pressure so that negative pressure is generated in the air valve 1 and the air valve 1 is operated by a specified differential pressure. Then the descent of the rod 9 tells the descent of the valve body 6. |
