JPH026014B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for testing the operation of air valves.

Air valves are installed in pipes that allow water to flow through them, such as water pipes and penstocks. For example, as shown in FIG. 5, in a piping system in which water 22 flowing into a head tank 21 from a reservoir flows out to a water wheel 25 via a penstock 24 by opening an inlet valve or a water gate 23, Air valve 26 on the top side
is provided. The purpose of providing this air valve 26 is to
This is activated when air enters and exits the pipe during filling and draining, and when a pressure difference occurs between the inner and outer surfaces of the pipe to prevent large negative pressure from occurring within the pipe. In other words, when the water in the penstock 24 is drained when the inlet valve 23 is closed, or when a sudden pressure fluctuation occurs while the pipe is in use (the pipe is full of water) and the pressure inside the pipe becomes lower than atmospheric pressure. At this time, a large negative pressure is generated within the pipe, and this negative pressure causes the tube body to collapse, but at this time, the opening of the air valve 26 prevents the generation of large negative pressure. In addition, in order to smoothly fill the pipe with water, the air inside the pipe is discharged through the air valve 26, and when the pipe is filled with water, the air valve 26
is closed and the valve is operated to shut off water. Therefore, the air valve 26 is generally designed with a float type valve body so that it operates reliably when filling and discharging water in the pipe, and the float is configured to move up and down due to the buoyancy of the water in the valve box.

Conventionally, the operation of such air valves was only tested by moving the valve body by hand to see if it moved lightly, but the test method involves generating negative pressure in the air valve and operating it at a specified differential pressure. I stopped talking. Therefore, accurate test results under various conditions could not be obtained. For example, as shown in Japanese Utility Model Application Publication No. 56-142219, a cap with a spring-biased pressure valve or negative pressure valve is set in the opening of the sample tank, and air is introduced into the sample tank. Cap operating pressure testing equipment is available that pressurizes the test tank by pressurizing it, or deaerates the test tank to create a negative pressure. It is not possible to perform an operation test under the same conditions where a float-type air valve that is closed due to water is opened by drainage.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for testing the operation of a pneumatic valve, which allows an operation test to be performed under the same conditions as during use, and which allows accurate test results to be obtained.

In order to achieve this objective, the air valve operation test method of the present invention provides a top plate at the top of a cylindrical valve box and a mounting flange at the bottom, which can freely abut against the bottom surface of the top plate inside the valve box. A method for testing the operation of an air valve, in which a floating type valve body is provided, and a rod integrated with the valve body is passed through an air inlet/outlet formed in a top plate, the method comprising: attaching a pipe to the mounting flange; Connect the air valve, place the air valve in the water tank so that this pipe is at the bottom, and fill the inside of the air valve with water by injecting water into the tank and press the valve body against the bottom surface of the top plate. The water in the water tank is drained until the distance between the valves reaches a predetermined pressure difference, and then the valve body is confirmed to have been lowered.

According to this configuration of the present invention, the valve body can be brought into contact with the lower surface of the top plate by injecting water into the inside of the air valve from the pipe,
By further injecting water to fill the tank with water, the valve body with increased buoyancy can be brought into pressure contact with the lower surface of the top plate. When the water is drained from the tank in this state, the water level in the valve box also tends to fall, but at this time, as mentioned above, the valve body, which has increased buoyancy, is brought into pressure contact. The upper part of the valve body is in a sealed state, so during the first stage of water removal, a negative pressure is generated at the upper part of the valve body so that the increased buoyancy is gradually reduced (for example, in the reverse direction shown in Figure 4). (same principle as that in which negative pressure is generated at the top of test tube B). While the water in the water tank is being drained until a predetermined pressure difference is reached, the valve body separates from the bottom of the top plate due to the decrease in increased buoyancy or negative pressure, causing the rod to descend, causing the air valve to open. You can check at what level it is operating normally. In other words, using this principle, if the inside of the valve box is filled with water and the water level in the water tank is lowered, the pressure inside the valve box becomes lower than atmospheric pressure and becomes a negative pressure state, and when the air valve operates, the valve box and water tank The water pressure corresponding to the height of the water surface becomes the operating negative pressure of the air valve. Further, if the rod does not descend even after reaching a predetermined pressure difference, an abnormality has been detected.

Hereinafter, one embodiment of the present invention will be described based on the drawings. First, the details of the air valve 1 will be described based on FIG. Reference numeral 2 denotes a cylindrical valve box, the upper part of which is closed with a top plate 3, and the lower part of which is provided with a ring-shaped mounting flange 4. A floating type valve body 6 is disposed in the space 5 in the valve box 2, and a packing 7 is provided between the upper surface of the valve body 6 and the lower surface of the top plate 3.
is provided. An air inlet/outlet 8 is formed in the center of the top plate 3, and a rod 9 passing through the air inlet/outlet 8 is erected from the upper surface of the valve body 6.

First, a pipe 10 is connected to the air valve 1 having the above configuration via a mounting flange 4, as shown in FIG. Then, the air valve 1 is placed in the water tank 11 so that the pipe 10 is at the bottom. This water tank 11 has a drain port 12 at the bottom. Next, when water is injected into the water tank 11, the valve body 6 can be brought into contact with the packing 7 by injecting water from the pipe 10 into the space 5 of the air valve 1. By further injecting water to fill the inside of the pipe 10 and the space 5, the valve body 6 with increased buoyancy is packed 7.
It can be pressed against. At this time, the water level A of the water tank 11 is set to the level of the top plate 3. When water is drained from the water tank 11 in this state, the water level in the valve box 2 tends to drop accordingly, but at this time, as described above, the valve body 6, which has increased buoyancy, is brought into pressure contact. Therefore, the upper part of the valve body 2 is in a closed state, and therefore, at the initial stage of water removal, a negative pressure is generated in the upper part of the valve body 2 so that the increased buoyancy is gradually reduced. While the water in the water tank is being drained until a predetermined differential pressure is reached, the valve body 6 separates from the packing 7 due to a decrease in increased buoyancy or negative pressure, causing the rod 9 to descend. It is possible to check at what level the valve 1 has operated normally. Further, if the rod 9 does not descend even when a predetermined differential pressure is reached, an abnormality has been detected.

In this way, as shown in FIG. 3, the water in the water tank 11 is drained through the drain port 12 until the distance l between the water tank water level a and the air valve 1 reaches a predetermined pressure difference. The rod 9 can be lowered by generating a negative pressure and operating the air valve 1 at a specified differential pressure. Therefore, by pressing the rod 9, it can be confirmed that the valve body 6 has come down.

An operating rod is attached to the rod 9 side, and a switch is provided on the top plate 3. When the rod 9 is lowered, the operating rod operates the switch, and a buzzer sounds, for example, to confirm the operation. You may also do so. Further, the rods 9 may be color-coded or marked with scales.

According to the air valve operation test method of the present invention having the above configuration, the valve body can be brought into contact with the bottom surface of the top plate by injecting water from the pipe into the inside of the air valve, and by further injecting water to fill the water, the buoyancy can be increased. The valve body can be pressed against the bottom surface of the top plate. When the water is drained from the tank in this state, the water level in the valve box also tends to fall, but at this time, as mentioned above, the valve body, which has increased buoyancy, is brought into pressure contact. The upper part of the valve body can be sealed, so that during the initial stage of draining, a negative pressure can be generated in the upper part within the valve body so that the increased buoyancy is gradually reduced. While the water in the water tank is being drained until a predetermined pressure difference is reached, the valve body separates from the bottom of the top plate due to the decrease in increased buoyancy or negative pressure, causing the rod to descend, causing the air valve to open. You can check at what level the system is operating normally. Further, if the rod does not descend even after reaching a predetermined pressure difference, an abnormality has been detected.

As described above, according to the present invention, it is possible to generate negative pressure in the air valve and operate the air valve at a specified differential pressure, and the operating state can be confirmed by moving the rod.
Therefore, accurate test results can be obtained under the same conditions as when used.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a vertical sectional front view of the air valve, Figs. 2 and 3 are front views showing the operating state, Fig. 4 is a diagram explaining the principle, and Fig. 5 is the use. It is an explanatory diagram of an example. 1... Air valve, 2... Valve box, 3... Top plate, 4... Mounting flange, 5... Space, 6... Valve body, 7... Packing, 8... Air inlet/outlet, 9... Rod, 10... Pipe, 1
1...Aquarium, 12...Drain port, A, a...Aquarium water level, l
…distance.

Claims (1)

[Claims] 1 A top plate is provided at the top of the cylindrical valve box, and a mounting flange is provided at the bottom, and a float-type valve body that can freely come into contact with the bottom surface of the top plate is disposed inside the valve box, and the valve body is integrated with the valve body. A method for testing the operation of an air valve, in which a rod is passed through an air inlet/outlet formed in a top plate, a pipe is connected to the mounting flange, and the air valve is placed in a water tank with this pipe at the bottom. Then, pour water into the water tank to fill the inside of the air valve with water and press the valve body against the bottom surface of the top plate, then drain the water in the water tank until the distance between the water tank water level and the air valve reaches a predetermined differential pressure. An operation test method for air valves that confirms that the valve body has lowered by lowering the rod.