JP7843009B2 - How to clean the air valve - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Law: Eiko Co., Ltd. Kumamoto Sales Office, April 30, 2021; Eiko Co., Ltd. Kumamoto Sales Office, May 19, 2021; Kamogawa River Basin Land Improvement District, July 21, 2021; Anegawa Left Bank Land Improvement District, July 21, 2021

This invention relates to a method for cleaning an air valve that is connected to a pipe through which water flows and performs intake and exhaust functions.

Air valves have traditionally been widely used in various locations, connected to piping such as water and sewage systems, industrial water pipelines, and agricultural water pipelines. Air valves generally have both a large and a small air vent (see, for example, Patent Documents 1 and 2). The large air vent allows for intake or large-volume exhaust (rapid exhaust). When the piping switches from a water-flowing state to a water-out state, such as when the upstream pump is stopped (or the upstream valve is closed), intake allows for the rapid removal of water from the piping by drawing in air. Similarly, when the piping switches from a water-out state to a water-flowing state, such as when the upstream pump is started (or the upstream valve is opened), large-volume exhaust allows for the rapid exhaust of air (including other gases) from the piping to the outside. The small air vent allows for small-volume exhaust. Small-volume exhaust allows for the gradual removal of air that has entered the piping due to various reasons while the piping is flowing under normal pressure.

Such air valves generally comprise a valve body connected to piping, a cover with a large air vent attached to the valve body, a movable valve body positioned within the internal space between the valve body and the cover (the internal space formed by the valve body and the cover) capable of closing the large air vent in the cover depending on the water level in that internal space, and a float valve body positioned within the internal space between the valve body and the cover. Small air vents are formed in the cover (e.g., Patent Document 1) or the movable valve body (e.g., Patent Document 2). The float valve body can close the small air vents depending on the water level. The float valve body and the movable valve body have a specific gravity lower than water. Between the air valve and the piping, a shut-off valve (including so-called repair valves, etc.) can be provided to prevent water from entering the valve body (to stop water flow) for purposes such as repairing the air valve.

Large and small air vents are often arranged in parallel in a nearly horizontal direction (e.g., Patent Document 1), or the large air vent is positioned above and the small air vent below (e.g., Patent Document 2). However, designs where the large air vent is below and the small air vent is above are also known (e.g., Patent Documents 3 and 4). Patent Documents 3 and 4 disclose an air valve in which the large air vent is formed on the lower side of the cover (valve cover and lid (and the uppermost cover in Patent Document 4)) and the small air vent is formed on the cap portion of the cover. In this air valve, an annular floating valve body (an annular float with a cylindrical valve body erected on top) is positioned inside the valve body, and the float valve body (float) is positioned inside the cover. An air valve in which the large air vent is positioned below and the small air vent is positioned above allows for a wider passage between the large air vent and the water inlet of the valve body, making it possible to increase the amount of intake and exhaust per unit time.

Japanese Utility Model Publication No. 4-126076 Japanese Patent Publication No. 2009-121678 Japanese Utility Model Publication No. 55-93769 Japanese Utility Model Publication No. 3-49477

However, there are cases where more efficient intake and exhaust are desired than those disclosed in Patent Documents 1 and 2, as well as Patent Documents 3 and 4. For example, in situations such as agricultural water pipelines, where the water flow and shut-off states of the piping switch frequently (e.g., daily), more efficient intake and high-volume exhaust are desirable.

This invention has been made in view of the above circumstances, and its purpose is to provide an air valve cleaning method that enables efficient intake and exhaust.

To achieve the above objective, the air valve cleaning method described in claim 1 comprises: a first step of, with the shut-off valve closed, pressing the upper part of the pin body for the float valve body to bring its tip down to below the small air hole, poking the float valve body to open the small air hole, drawing water or air into the small air hole and discharging it to reduce the pressure inside the air valve; and a second step of, with the large air hole open, pressing the upper part of the pin body for the free-moving valve body to bring its tip down to below the large air hole, poking the free-moving valve body to open the large air hole, and then, with the large air hole open, opening the shut-off valve, raising the pin body for the free-moving valve body to discharge the large air hole and any foreign matter in its vicinity along with water or air from the large air hole before the large air hole is closed again by the free-moving valve body.

According to the air valve cleaning method of the present invention, efficient intake and exhaust of the air valve becomes possible.

This is a front view showing an air valve and a water shut-off valve according to an embodiment of the present invention. This is a plan view of the air valve shown above. This is a cross-sectional view of the same air valve (a cross-sectional view taken at the position indicated by the line A-A in Figure 2). This is a plan view showing the valve body and the free-moving valve element inside the same air valve. This is a bottom view of the cover of the air valve shown above. The image shows the cover cap portion of the air valve cover and the components attached thereto, with (a) being a side view and (b) being a bottom view. The image shows the free-moving valve body of the same air valve, with (a) being a side view and (b) being a bottom view. The image shows the float valve body of the same air valve, with (a) being a plan view, (b) a side view, and (c) a bottom view. This is a cross-sectional view of the same air valve, showing the case when the small air vent is open.

The following describes embodiments for carrying out the present invention. The air valve 1 according to the embodiment of the present invention has a large air hole 32b and a small air hole 35a, which will be described later. As shown in Figures 1, 2, and 3, the air valve 1 comprises a valve body 2, a cover 3, a floating valve body 4, and a float valve body 5.

The valve body 2 is connected to the piping and has a hollow valve body section 2a inside. The surrounding wall of the hollow valve body section 2a forms a cylindrical valve body section 21. Below the hollow valve body section 2a is a water guide section 2b with a smaller inner diameter. The valve body 2 can be made, for example, mainly of cast iron. As shown in Figures 3 and 4, a movable valve body 4, which will be described in detail later, is arranged in the hollow valve body section 2a.

The upper side of the hollow portion 2a of the valve body is open, and a valve body flange portion 22 is located around the vicinity of this upper opening. Multiple valve body fastening holes 22a (four in this embodiment) are formed in the valve body flange portion 22.

A separate shut-off valve 10 (including so-called repair valves, etc.) is usually connected between the valve body 2 and the piping to control the ingress of water into the hollow portion 2a of the valve body through the water conduit 2b (see Figure 1). Alternatively, the shut-off valve 10 may be installed in the middle of a longer water conduit 2b, rather than being a separate component.

The cover 3 is mounted on the upper side of the valve body 2 and has a hollow section 3a inside. The surrounding wall of the hollow section 3a forms a cylindrical section 31. The cylindrical section 31 can be composed of a lower cylindrical section 311 and an upper cylindrical section 312. The lower cylindrical section 311 (and the subsequent flange section 32, described later) can be made of, for example, mainly cast iron. The upper cylindrical section 312 can be made of a material that allows for easy improvement of machining accuracy (e.g., machining accuracy of the inner wall, etc.) (e.g., stainless steel, copper-based metal). As shown in Figure 3, the float valve body 5, which will be described in detail later, is positioned in the hollow section 3a.

The lower side of the hollow portion 3a of the lid is open and communicates with the hollow portion 2a of the valve body 2. The inner diameter of the lower opening 3aa is smaller than the inner diameter of the upper opening of the hollow portion 2a of the valve body.

The cover 3 has a cover flange portion 32 around the vicinity of the lower opening 3aa. Multiple cover fastening holes 32a (four in this embodiment) are formed in the cover flange portion 32. The cover flange portion 32 is fastened to the valve body flange portion 22 by multiple fasteners 3A (four in this embodiment) consisting of bolts and nuts. Specifically, the cover flange portion 32 is fastened to the valve body flange portion 22 by passing bolts through the valve body fastening holes 22a and cover fastening holes 32a of the valve body flange portion 22 and tightening the bolts and nuts.

Furthermore, the lid flange portion 32 has a portion that overlaps with the upper opening of the hollow portion 2a of the valve body 2 in a plan view, and the upper opening of the large air hole 32b is formed on the upper surface of the lid flange portion 32. The lower opening of the large air hole 32b communicates with the hollow portion 2a of the valve body 2. The large air hole 32b is also divided into a predetermined number (six in this embodiment) (see Figure 5). The large air hole 32b can be a through hole formed in the vertical direction, or, as shown in Figure 3, it can be a through hole formed diagonally in the vertical direction, such that the upper opening of the large air hole 32b is offset outward (outward with respect to the axis of the air valve 1) compared to the lower opening, and the overall outward angle increases as it goes upward.

The cover 3 has O-rings 33A and 33B on its lower surface (including the lower surface of the cover flange portion 32), on the outer and inner sides of the lower opening of the large air hole 32b. The movable valve body 4 can close the lower opening of the large air hole 32b by having its upper surface closely contact the lower surface of the cover 3 (specifically, the O-rings 33A and 33B).

The lid 3 can incorporate a separate plate 3' made of a different material (e.g., copper-based metal) on its underside, inward from the lid fastening hole 32a. This allows for precise flattening of the underside of the lid 3 and accurate formation of holes for the O-rings 33A and 33B, ensuring proper closure of the large air hole 32b by the floating valve 4.

The cover 3 has a pin body 34 for the floating valve body, which is held via an elastic body 34A such as a spring. The pin body 34 can be inserted into the large air hole 32b from above (including from diagonally above), and by pressing its upper part, it can reach the hollow portion 2a of the valve body. In this embodiment, the elastic body 34A is held by an elastic body holding cylinder 34B.

The upper side of the hollow portion 3a of the lid 3 is closed by the lid cap portion 35. The lid cap portion 35 has the small air hole 35a formed therein. In this embodiment, the small air hole 35a is formed on the central axis of the lid 3. In detail, the lid cap portion 35 has a valve seat 35b, and the small air hole 35a is formed by penetrating the valve seat 35b and the member above it vertically. The valve seat 35b is elastic, and when the float valve body 5 comes into close contact with it from below, the small air hole 35a is closed. On the lower surface of the lid cap portion 35, in the example shown in Figure 3, a recess 35c is formed below and around the valve seat 35b. In addition, an external air hole 38 is formed on the side surface of the lid cap portion 35, which conducts to the small air hole 35a through the space between them (see Figure 1). The lid cap portion 35 is removable from the lid cylindrical portion 31 (specifically, the upper lid cylindrical portion 312). Removing the lid cap portion 35 allows for cleaning of the valve seat 35b, and removal and cleaning of the float valve body 5 located in the lid hollow portion 3a.

The lid 3 has a float valve pin 36 held in place by an elastic body 36A, such as a spring, on the lid cap portion 35. The lower part (pin body portion) of the float valve pin 36 can be inserted into the small air hole 35a from above, and by pressing the upper part, it can reach below the small air hole 35a. At this time, the reaction force of the elastic body 36A allows for repeated pressing of the upper part of the float valve pin 36, making it easier to remove foreign matter from the small air hole 35a and its vicinity, as described later.

The cover 3 has a guide rod 37 extending downward from the cover cap portion 35. As described later, the guide rod 37 passes through the guide rod insertion hole 5a of the float valve body 5, and a nut is fastened to its lower part as a stopper to prevent further descent of the float valve body 5 (see Figures 3 and 6). Thus, the guide rod 37 guides the float valve body 5 as it moves up and down according to the water level.

Furthermore, the cover 3 has a float valve rotation-preventing rod 37A extending downward from the cover cap portion 35 (see Figure 6). The float valve rotation-preventing rod 37A can prevent the float valve 5 from rotating around the guide rod 37 as an axis.

The floating valve body 4 is positioned in the hollow portion 2a of the valve body 2 as described above. The floating valve body 4 can block the large air hole 32b of the cover 3 from below, depending on the water level in the hollow portion 2a of the valve body. The floating valve body 4 can be, for example, roughly disc-shaped as shown (see Figures 4 and 7). The upper end surface of the floating valve body 4 is flat so that it can closely contact the cover 3 (specifically, the O-rings 33A and 33B). The floating valve body 4 also has a central hole 4a that penetrates vertically. The floating valve body 4 has a predetermined number (three in this embodiment) of legs 41 at its lower end (see Figure 7).

The float valve body 5 is a long, roughly cylindrical object, positioned in the hollow portion 3a of the cover body 3 as described above. The float valve body 5 can block the small air vent 35a from below depending on the water level in the hollow portion 3a of the cover body.

The float valve body 5 has a guide rod insertion hole 5a through which the guide rod 37 of the cover body 3 is inserted. The guide rod insertion hole 5a is a through hole. Furthermore, the float valve body 5 has a rotation-preventing hole 5b through which the float valve body rotation-preventing rod 37A of the cover body 3 is inserted (see Figure 8).

The float valve body 5 has an upper member 51 and a lower member 52, and the upper member 51 and the lower member 52 are connected to each other so as to be tiltable by a connecting member 5c (in this embodiment, a socket head cap screw). In this embodiment, the connecting member 5c is provided near the end of the upper member 51.

In the air valve 1 described above, when the upstream pump is stopped (or the upstream valve is closed), and the piping switches from a water-flowing state to a water-off state, air is drawn in through the large air hole 32b, and the atmosphere is guided into the piping through the hollow portion of the valve body 2a and the water-conducting portion 2b (and the open shut-off valve 10). Here, since the large air hole 32b is formed in the vertical direction or at an angle in the vertical direction as described above, a large amount of atmosphere can flow smoothly into the piping through the hollow portion of the valve body 2a and the water-conducting portion 2b. Therefore, extremely efficient air intake becomes possible. In this respect, it is more preferable to form the large air hole 32b at an angle in the vertical direction as described above.

Furthermore, in the air valve 1, when the piping switches from a water-off state to a water-flow state, such as when the upstream pump is activated (or the upstream valve is opened), the shut-off valve 10 is open, and the air (including other gases) inside the piping is rapidly exhausted to the outside through the large air hole 32b (large volume exhaust). This large volume exhaust continues from the time water enters the hollow portion 2a of the valve body until the floating valve body 4 comes into close contact with the cover 3 from below, blocking the large air hole 32b. Here, since the large air hole 32b is formed either vertically or diagonally vertically as described above, the air inside the piping can be smoothly discharged in large quantities to the outside through the large air hole 32b from the water-conducting portion 2b and the hollow portion 2a of the valve body. Therefore, extremely efficient large volume exhaust becomes possible. In this regard, it is more preferable to form the large air hole 32b diagonally vertically as described above.

After the large volume of exhaust is complete, a small volume of exhaust is performed. This small volume of exhaust causes the air inside the hollow section 3a of the lid to be expelled through the small air vent 35a, gradually raising the water level. The float valve body 5 then rises along the guide rod 37. When the distance from the water level to the small air vent 35a reaches a predetermined distance, the float valve body 5 (specifically, the upper surface of the upper member 51) comes into contact with the valve seat 35b, blocking the small air vent 35a from below, and the exhaust stops.

Subsequently, as water flows normally through the pipe and air mixes with it, air enters the hollow section 3a of the lid from the pipe. As the amount of air above the water level increases and the water level drops, the small air vent 35a opens.

Here, if the small air vent 35a is formed on the central axis of the lid 3, and the connecting member 5c that connects the upper member 51 and the lower member 52 of the float valve body 5 is located near the end of the upper member 51 and at a predetermined distance from the central axis, then a moment force (moment of force) equal to approximately the downward force of the lower member 52 multiplied by that predetermined distance acts on the contact portion between the upper member 51 and the valve seat 35b. As a result, the upper surface of the upper member 51 tilts, making it easy to separate the upper member 51 and the valve seat 35b, even if they are tightly adhered together (see Figure 9).

In this way, the upper surface of the upper member 51 tilts or lowers overall, opening the small air vent 35a, and a small amount of exhaust is released again. Then, as the water level rises due to the small amount of exhaust and the distance from the water surface to the small air vent 35a reaches a predetermined distance, the float valve body 5 closes the small air vent 35a from below, and the exhaust stops.

The large air vent 32b and its vicinity can be cleaned periodically or irregularly using the floating valve pin 34 to remove foreign matter. Removing foreign matter makes it easier to maintain the operation of the floating valve 4 opening the large air vent 32b during intake and opening and closing the large air vent 32b during high-volume exhaust, thereby maintaining efficient intake and high-volume exhaust.

Specifically, cleaning the large air vent 32b and its vicinity can be performed as follows. First, as the first step, with the shut-off valve 10 closed, the upper part of the float valve pin 36 is pressed, and its tip is brought down to below the small air vent 35a, poking the float valve body 5. This tilts or lowers the upper surface of the float valve body 5, opening the small air vent 35a. This allows water or air to be drawn into and discharged through the small air vent 35a, reducing the pressure (water pressure and atmospheric pressure) inside the air valve 1 (the hollow portion of the lid 3a and the hollow portion of the valve body 2a).

Next, in the second step, the upper part of the movable valve pin 34 is pressed, and its tip is brought down to below the large air vent 32b, striking the movable valve 4. This causes the upper surface of the movable valve 4 to tilt or lower overall, opening the large air vent 32b. Then, with the large air vent 32b open, the shut-off valve 10 is opened, and the movable valve pin 34 is raised, allowing the large air vent 32b and any foreign matter in its vicinity to be discharged from the large air vent 32b along with water or air before the large air vent 32b is closed again by the movable valve 4.

Thus, by performing the first step followed by the second step, the water pressure inside the air valve 1 decreases, weakening the force pushing back against the floating valve pin 34 from the inside. This allows the tip of the floating valve pin 34 to be easily pushed down to below the large air hole 32b. Note that the first and/or second steps can be performed multiple times as needed.

Furthermore, the small air vent 35a and its vicinity can be cleaned periodically or irregularly using the float valve pin 36 to remove foreign matter. Removing foreign matter makes it easier to maintain the opening and closing operation of the small air vent 35a by the float valve pin 36 during small-volume exhaust, thereby maintaining efficient small-volume exhaust.

Specifically, cleaning the small air vent 35a and its vicinity can be performed as follows. First, with the shut-off valve 10 open, the upper part of the float valve pin 36 is pressed, and its tip is brought down to below the small air vent 35a, poking the float valve body 5. This causes the upper surface of the float valve body 5 to tilt or lower overall, opening the small air vent 35a. Then, the float valve pin 36 is raised, and foreign matter in the small air vent 35a and its vicinity is drawn into the small air vent 35a along with water or air and discharged before the small air vent 35a is closed again by the water pressure of the float valve body 5. This process (step) can be repeated multiple times as needed.

In this way, the air valve 1 (large air hole 32b, small air hole 35a, and their vicinity) can be cleaned without disassembling the air valve 1 (for example, by removing the cover 3 from the valve body 2 and/or the cover cap portion 35 from the cover 3). This cleaning is particularly useful when the air valve 1 is used in piping such as sewers, industrial water pipelines, or agricultural water pipelines, where water of inferior quality compared to tap water flows. Although the small air hole 35a is usually away from the water surface, sudden fluctuations in the water surface due to changes in water pressure within the piping (for example, due to compression of the air layer caused by the water hammer phenomenon) can often cause foreign matter to come into contact with the small air hole 35a along with the water.

Furthermore, when disassembling the air valve 1 for maintenance, before doing so, with the shut-off valve 10 closed, press the upper part of the float valve body pin 36, allowing its tip to reach below the small air hole 35a and poke the float valve body 5. This tilts or lowers the upper surface of the float valve body 5, opening the small air hole 35a. This allows water or air to be drawn into and expelled through the small air hole 35a, reducing the pressure (water pressure and atmospheric pressure) inside the air valve 1 (the hollow portion of the lid 3a and the hollow portion of the valve body 2a). This process (step) prevents water or air from gushing out when the lid 3 is subsequently removed from the valve body 2 or the lid cap portion 35 is removed from the lid 3. This maintenance ensures efficient intake and exhaust.

Although the air valve according to the embodiments of the present invention has been described above, the present invention is not limited to those described in the above embodiments, and various design modifications are possible within the scope of the claims.

1 Air valve 10 Shut-off valve 2 Valve body 2a Hollow part of valve body 2b Water guide part 21 Cylindrical part of valve body 22 Flange part of valve body 22a Valve body fastening hole 3 Cover 3' Plate 3A Fastener 3a Hollow part of cover 3aa Lower opening 31 Cylindrical part of cover 311 Lower cylindrical part of cover 312 Upper cylindrical part of cover 32 Flange part of cover 32a Fastening hole of cover 32b Large air hole 33A, 33B O-ring 34 Pin body for floating valve 34A Elastic body 34B Elastic body retaining cylinder 35 Cover cap part 35a Small air hole 35b Valve seat 35c Recess 36 Pin body for float valve 36A Elastic body 37 Guide rod 37A Float valve body rotation stopper rod 38 External air hole 4 Free-moving valve body 4a Central hole of free-moving valve body 41 Leg portion 5 Float valve body 5a Guide rod insertion hole 5b Rotation stopper hole 5c Connecting member between upper and lower member 51 Upper member 52 Lower member

Claims (1)

A method for cleaning an air valve, comprising: a first step of pressing the upper part of the pin body for the float valve body with the shut-off valve closed, bringing its tip down to below the small air vent, poking the float valve body to open the small air vent, drawing water or air into the small air vent and then expelling it to reduce the pressure inside the air valve; and a second step of pressing the upper part of the pin body for the movable valve body with its tip down to below the large air vent, poking the movable valve body to open the large air vent, and then, with the large air vent open, opening the shut-off valve, raising the pin body for the movable valve body, and expelling the large air vent and any foreign matter in its vicinity along with water or air from the large air vent before the large air vent is closed again by the movable valve body.