JPH08120750A - Reversing valve and vacuum valve using same - Google Patents

Abstract

PURPOSE: To enable a return spring with an excellent fatigue characteristic to be employed so that the fatigue characteristic of a reversing valve can be enhanced by separating a valve main body from a valve operating portion, and connecting the valve main body and the valve operating portion together by means of the return spring. CONSTITUTION: When a valve operating portion 202 is displaced by not less than a predetermined amount by some external force, the valve operating portion 202 and a reversing spring 203 are reversed from a valve closing position to a valve opening position so that the valve element 201B of a valve main body can be set in the valve opening position. When the external force is eliminated, the valve operating portion 202 and the reversing spring 203 return to the valve closing position because of their tendency to return, so that the valve element 201B can be set in the valve closing position. In this reversing valve 200, the valve main body 201 and the valve operating portion 202 are separated from each other and connected together by a return spring 203. Therefore, the return spring 203 with an excellent fatigue characteristic can be easily employed, so that the fatigue strength of the reversing spring 200 can be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reversing valve suitable for use in a vacuum sewer system or the like and a vacuum valve using the same.

[0002]

2. Description of the Related Art As described in Japanese Patent Laid-Open No. 3-43527, a vacuum sewer system is designed to allow wastewater discharged from homes, factories, etc. to flow into a wastewater tank of a vacuum valve unit from a naturally flowing wastewater inflow pipe. The sewage collected in the sewage tank is collected by the vacuum sewage pipe in the water collection tank, and then sent to a sewage treatment plant by a pressure pump.

A vacuum valve is installed in the sewage tank, and the connection between the suction pipe rising from the bottom of the sewage tank and the vacuum sewer pipe communicating with the vacuum source can be opened and closed by this vacuum valve. I am trying. Then, when the water level in the dirty water tank rises above a certain level, the vacuum valve is opened, the vacuum pressure of the vacuum sewer pipe is exerted on the suction pipe, and the atmospheric pressure that acts on the water surface of the dirty water tank to pressurize the dirty water is set. The sewage in the sewage tank is sent to the water collection tank via the vacuum sewer pipe by the pressure difference from the vacuum pressure applied to the suction pipe.

At this time, the controller part of the vacuum valve has a liquid level detection diaphragm which operates in response to a predetermined liquid level in the dirty water tank and a three-way valve which switches between opening and closing of the vacuum valve. By activating the detection valve via the plunger by movement, a vacuum force is introduced from the vacuum sewer pipe to the pressure control chamber, and the three-way valve is activated by this vacuum force. The vacuum force introduced to the pressure control chamber is released to the atmosphere by the needle valve.

However, in the prior art, the following reversing valve is used as the detection valve. That is, the reversing valve includes a valve body including a valve mounting portion and a valve body portion, a tongue-shaped valve operating portion formed by bending the valve mounting portion of the valve body,
It has a reversing spring interposed between the valve body and the valve operating part, and the valve operating part is elastic (bending elastic) to the valve closing operating position.
It has a variety of restoration habits. Then, when the valve operating portion is given a displacement of a certain amount or more by the pushing external force of the plunger,
The valve operating portion and the reversing spring are reversed from the valve closing operating position side to the valve opening operating position side, so that the valve body portion of the valve body can be set to the valve opening position (position for introducing vacuum force). On the other hand, when the plunger returns and the action of the external force on the valve operating portion disappears, the valve operating portion and the reversing spring are restored to the valve closing operating position side by the restoring behavior of the valve operating portion, and the valve body of the valve body is restored. The valve can be set to the valve closed position (the position where the introduction of vacuum force is blocked).

[0006]

However, in the conventional detection valve using the reversing valve, the valve operating portion is formed by bending from the valve mounting portion of the valve body, and the valve is pushed by the pushing external force of the plunger. Maximum bending stress is generated at the base of the operating part with respect to the valve body.

The detection valve reverses the valve operating portion as described above each time the vacuum valve is opened and closed once. When the vacuum valve is repeatedly operated, the valve operating portion is fatigued by the repeated bending stress. May be destroyed. Therefore, in the vacuum valve, there is a problem that the frequency of maintenance (replacement) of the detection valve becomes high.

An object of the present invention is to improve the fatigue strength of a reversing valve used in a vacuum valve or the like.

[0009]

The present invention according to claim 1 is a valve main body comprising a valve mounting portion and a valve body portion, and a valve operating portion connected to the valve mounting portion of the valve main body. It has a reversing spring interposed between the valve body and the valve operating part, and the valve operating part has an elastic restoring behavior to the valve closing operating position. When a displacement is applied, the valve operating part and the reversing spring reverse from the valve closing operating position side to the valve opening operating position side, enabling the valve body part of the valve body to be set to the valve opening position, and to the valve operating part. When the action of the external force is eliminated, the valve operating portion and the reversing spring are restored to the valve closing operating position side by the restoring behavior of the valve operating portion, and the valve body portion of the valve body can be set to the valve closing position. In a reversing valve, the valve body and the valve operation part are separated, and the valve body and the valve operation part are connected by a restoring spring. .

According to a second aspect of the present invention, a connecting portion between a suction pipe communicating with a tank and a vacuum sewer pipe communicating with a vacuum source can be opened and closed, and a valve body for opening and closing the connecting portion, and a valve. A valve working chamber containing a plunger connected to the body,
A vacuum configured to include a closing force applying unit that is built in the valve working chamber to apply a closing force to the valve body, and a controller unit that applies a vacuum pressure to the valve working chamber to apply an opening force to the valve body. In the valve, the controller unit has a three-way valve capable of switching and connecting a vacuum passage and an atmosphere passage to a valve working chamber, a liquid level detection diaphragm that operates in response to a liquid level in a tank, and a three-way valve that is a vacuum. A pressure control chamber for applying a vacuum force to the three-way valve so as to connect the passage to the valve working chamber, a detection valve arranged in the pressure control chamber for introducing the vacuum force into the pressure control chamber, and a liquid level. While being directly driven by the detection diaphragm, it has a plunger that is inserted into the pressure control chamber and drives the detection valve, and a vacuum release valve that operates to open so as to release the vacuum force introduced into the pressure control chamber. As the detection valve,
The reversing valve according to claim 1 is used.

[0011]

According to the present invention as set forth in claim 1, the following effects are obtained. The elastic restoring behavior of the valve operating portion of the reversing valve is not based on the bending elasticity of the valve body. That is, the valve operation portion of the reversing valve has an elastic restoring behavior by the spring force of the restoring spring provided between the valve operating portion and the valve body.
Further, it is easy to adopt a restoring spring having excellent fatigue characteristics, and as a result, the fatigue strength of the reversing valve can be improved.

The present invention according to claim 2 has the following effects. The fatigue strength of the detection valve can be improved by using the above-described reversing valve as the detection valve used for the vacuum valve. Therefore, even if the valve operating portion repeats reversal every time the vacuum valve is opened and closed once, it is possible to prevent the valve operating portion from being damaged by fatigue and reduce the maintenance (replacement) frequency of the detection valve.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view showing a vacuum type waste water collecting device, FIG. 2 is a schematic view showing a vacuum valve, FIG. 3 is a sectional view showing a controller part of the vacuum valve, and FIG. 4 is a vacuum type waste water collecting system. FIG. 5 is a schematic diagram showing the operating principle of the vacuum valve, FIG. 6 is a schematic diagram showing the operating principle of the vacuum valve, FIG. 7 is a schematic diagram showing the first embodiment of the detection valve, and FIG. FIG. 9 is a schematic diagram showing an operating state, and FIG. 9 is a schematic diagram showing a second embodiment of the detection valve.

As shown in FIG. 1, the vacuum type sewage collecting apparatus 10 has a sewage tank 11 and a sewage inflow pipe 12 connected thereto.
It has a vacuum valve 15 capable of opening and closing a connecting portion between a suction pipe 13 communicating with the tank 11 and a vacuum sewer pipe 14 communicating with a vacuum source.

That is, the sewage discharged from each home or the like flows into the tank 11 through the natural-flow-type sewage inflow pipe 12. Then, when the dirty water is collected in the tank, the vacuum valve 15 is opened, and the dirty water in the tank 11 is sucked through the suction pipe 13. Then, the sewage is sucked into the vacuum sewer pipe 14 through the vacuum valve 15, collected in the water collecting tank on the vacuum pump, and then sent to the sewage treatment plant by the pressure pump.

The vacuum valve 15 connects the first and second housings 21 and 22 to the band clamp 2 as shown in FIGS.
The valve body 24, the valve working chamber 25, the spring 26, and the controller portion 27 are integrally formed.

The valve body 24 opens and closes a connecting passage 28 which constitutes a connecting portion between the suction pipe 13 and the vacuum sewer pipe 14.

The valve working chamber 25 includes a valve valve body 24 and a valve rod 29.
The cup-shaped plunger 30 connected via the is slidably accommodated.

The spring 26 is the plunger 30 of the valve working chamber 25.
It is built in the upper chamber and exerts a spring force on the plunger 30 to give a closing force to the valve body 24. In the chamber below the plunger 30 of the valve working chamber 25, the atmosphere communication pipe 43 is connected to the hose 4
It is connected via 6 and is at atmospheric pressure.

The controller unit 27 applies a vacuum pressure to the upper chamber of the valve operating chamber 25 when the level of dirty water in the tank 11 rises, and pulls up the plunger 30 by the differential pressure between the upper and lower chambers (the lower chamber is atmospheric pressure). Then, an opening force is applied to the valve valve body 24 to open the vacuum valve 15 and bring the vacuum sewer pipe 14 into conduction with the suction pipe 13.

The controller unit 27 is constructed as follows. The controller unit 27, as shown in FIG.
The fifth cylinder-shaped cases 51 to 55 are integrally formed with bolts. Normally, the fourth case 54 is integrated with the second housing 22 of the vacuum valve 15 by the band clamp 36.

The controller 27 has a liquid level detection pipe connection port 56 to which a liquid level detection pipe 37 communicating with the tank 11 is connected via a hose 38. The liquid level detection pipe connection port 56 is connected to the first case 51 via a vibration damping prevention diaphragm 59. A small through hole is provided in the diaphragm 59 to transmit pressure, and the outer peripheral portion of the diaphragm 59 is not fixed.
The air from the lower side can also pass around the diaphragm 59.

Further, the controller section 27 has a vacuum pressure connection port 57 to which the vacuum sewer pipe 14 is connected via a hose 41.
Is provided in the third case 53.

Further, the controller unit 27 has an atmospheric pressure connection port 58 to which the atmosphere communication pipe 43 is connected via a hose 44.
Is provided in the third case 53.

The first case 51 and the second case 52 are connected via a liquid level detection diaphragm 60. A push button composed of a plunger 61, a spring 63, and an elastic cover 62 is provided on the upper part of the first case 51 so that the liquid level detection diaphragm 60 can be manually displaced. The second case 52 has a plunger 65 under the diaphragm 60.
However, it is provided so as to reach the detection valve 68 installed in the third case 53. A shaft seal such as an O-ring 67 is provided around the insertion portion of the plunger 65 into the chamber 83 so as to prevent air from leaking into the upper chamber 83 as a pressure control chamber formed by the second case 52 and the third case 53. It is provided.

The detection valve 68 is arranged in the chamber 83 and is operated by the plunger 65, so that the vacuum force can be introduced into the chamber 83. That is, the third case 53 has the passage 57A communicating with the vacuum pressure connection port 57, and the detection valve 68 can open and close the opening (vacuum port) of the passage 57A to the chamber 83. Reference numeral 66 is a return spring of the plunger 65.

Valve seats 72 and 73 are provided in the fourth case 54 and the fifth case 55, and an upper chamber 85 of the fourth case 54 is provided.
Communicates with the atmosphere through the passage 92, and the fifth case 5
The lower chamber 87 of No. 5 communicates with the vacuum sewer pipe through a passage 91. The chamber 86 formed by the lower part of the fourth case 54 and the upper part of the fifth case 55 has a passage 96 in the working chamber 25 of the vacuum valve body.
Through. The valve body 71 provided between the two valve seats 72 and 73 plays a role as a three-way valve so as to guide either the atmosphere or the vacuum to the chamber 86 by sliding up and down. The valve body 71 is connected to a three-way valve diaphragm 70 provided between the third case 53 and the fourth case 54, and a compression spring 69 is provided above the diaphragm 70 and is pressed against the valve seat 73 of the fifth case 55. Has been. Third
A partition is provided in the case 53, but the communication port 8 is partially provided in the case 53.
8 is provided so that the vacuum pressure applied to the upper chamber 83 when the detection valve 68 is activated and opened is communicated to the lower chamber 84.

Further, a needle valve 74 with a diaphragm as a vacuum force release valve is provided in a passage 93 which communicates the inside and the outside of the upper chamber 83 (pressure control chamber) of the third case 53, and passes through the needle valve 74. The atmosphere is gradually coming in.

The needle valve 74, to which the diaphragm 102 is attached, maintains equilibrium by the pressure of the spring 103 and the vacuum pressure of the vacuum sewer pipe 14 communicating from the passage 95, and the needle valve 74 is placed at an appropriate position. It is designed to be displaced. That is, when the vacuum degree of the vacuum sewer pipe 14 is high, the needle valve 74 is opened greatly, and when the vacuum degree is low, the needle valve 74 is opened small.

Therefore, the vacuum valve 15 uses the reversing valve 200 shown in FIGS. 7 and 8 as the detection valve 68.

That is, the reversing valve 200 includes a valve body 201.
, Valve operating unit 202, reversing spring 203, and restoring spring 2
04 and.

The valve body 201 includes a valve mounting portion 201A mounted on the case 53 and a valve body portion 201B for opening and closing the vacuum port of the passage 57A communicating with the vacuum pressure connection port 57 by opening and closing the vacuum port. Prepare The valve body 201B has a passage 57
A seal rubber 201C capable of sealing the vacuum port A is provided.

The valve operating portion 202 is separated from the valve body 201, and the valve body 201 and the valve operating portion 202 are connected by the restoring spring 204. The restoring spring 204 is formed of a torsion coil spring, and both ends of the restoring spring 204 are a connecting hole 201D provided in the valve body 201 and a connecting hole 20 provided in the valve operating portion 202.
It is designed to be attached to 2A respectively.

The reversing spring 203 is interposed between the valve body 201 and the valve operating portion 202. The inversion spring 203 is composed of a corrugated leaf spring and has holes (203A) provided at both ends thereof.
Are engaged with the engaging piece 201E provided on the valve body 201 and the engaging piece 202B provided on the valve operating portion 202, respectively.

However, in the reversing operation unit 200, the valve operating unit 202 has an elastic restoring behavior to the valve closing operation position. The restoring behavior of the valve operating unit 202 is the restoring spring 2
This is due to the elastic restoring force generated when 04 is elastically deformed from the free state. At this time, the spring constant of the restoring spring 204 can be arbitrarily set by the spring linearity, the material, and the number of turns. Further, as the material of the restoring spring 204, one having better fatigue characteristics than the valve body 201 can be adopted. For example, phosphor bronze can be used as the valve body 201 and stainless steel can be used as the restoring spring 204.

The detecting valve 68 using the reversing valve 200 operates as follows. (1) When the valve operating portion 202 is displaced by a predetermined amount by the pushing external force of the plunger 65 (FIG. 8A), the valve operating portion 200 and the reversing spring 203 are operated to open the valve from the valve closing operating position side. Turned to the position side (Fig. 8 (B)), the valve body 2
The valve body 201B of No. 01 is set to the valve open position separating from the vacuum port of the passage 57A, and the vacuum force is introduced into the chamber 83. At this time, the restoring spring 204 is elastically deformed from the free state.

(2) The plunger 65 returns and the valve operating section 20
When the pushing external force does not act on the valve 2, the valve operating portion 2
02 and the reversing spring 203 are based on the elastic restoring characteristics of the valve operating portion 202 (based on the elastic restoring force of the restoring spring 204 from the elastically deformed state (1) above to the free state),
The valve body portion 2 of the valve body 201 is restored to the valve closing operation position side.
01B is set to the valve closed position where it closely contacts the vacuum port of the passage 57A.

The controller section 27 of the vacuum valve operates as follows. When the liquid level of the dirty water in the tank 11 rises, the air pressure of the liquid level detection diaphragm upper chamber 81 rises through the liquid level detection pipe 37, the hose 38, and the microscopic holes of the vibration damping diaphragm 59, and the lower part of the liquid level detection diaphragm. Since the chamber 82 communicates with the atmosphere, the liquid level detection diaphragm 6 that has a pressure difference
0 is displaced downward (FIG. 5 (A), (B)).

The plunger 65 provided in the lower portion of the liquid level detection diaphragm 60 is pushed by the displacement of the diaphragm 60 and is displaced downward, and the detection valve 68 provided in the upper chamber 83 of the third case 53 is pushed downward (see FIG. 5 ( B)).

When the displacement of the plunger 65 is lowered (the liquid level of the dirty water rises to a certain level), the detection valve 68 is reversed and the vacuum port of the passage 57A is opened (FIG. 5 (C)).

Due to the opening operation of the detection valve 68, the third case chambers 83 and 84 are evacuated (FIG. 5 (D)), and the lower chamber 85 of the three-way valve diaphragm 70 communicates with the atmosphere. The resulting diaphragm 70 is pulled upwards,
Along with this, the valve body 71 also rises and moves from the valve seat 73 of the fifth case 55 to the valve seat 72 of the fourth case 54, and the chamber 86 communicating with the upper chamber of the working chamber 25 of the vacuum valve body is brought into a vacuum state. (FIG. 5 (E)). As a result, the vacuum valve 15 is opened due to the pressure difference between the upper and lower chambers of the working chamber 25 (the lower chamber is atmospheric pressure) (FIG. 5 (F)), and the dirty water in the tank becomes 14 in the vacuum sewer pipe.
(FIG. 6 (A)).

When the liquid in the tank is discharged, the liquid level lowers (FIG. 6 (B)), the pressure applied to the liquid level detecting diaphragm 60 lowers, and the spring 66 provided on the plunger 65 pushes it back to control it. Air immediately escapes from the outer peripheral edge of the vibration prevention diaphragm 59 (FIG. 6C).

The detection valve 68 that had been reversed returns to the passage 5
The vacuum port of 7A is closed, and the vacuum is not introduced into the chambers 83 and 84 (FIG. 6 (D)).

The vacuum in the chamber 83 of the third case 53 depends on the degree of vacuum pressure of the vacuum sewer pipe 14 and the needle valve 7
4 maintains an appropriate opening, the passage 93, the detection diaphragm 6
In order to introduce the atmosphere through the passage 94, the lower room of 0,
There is a slight time lag, and the atmosphere is restored, the pressure difference between the two sides of the three-way valve diaphragm 70 disappears, and the spring 69 pushes the valve back to the original state (FIG. 6 (E)), and the valve element 71 also returns to the original fifth state. The valve seat 73 of the case 55 is closed (FIG. 6 (F)), and the chamber communicating with the working chamber 25 of the vacuum valve body is brought to the atmospheric state. At this time, although the atmosphere is taken in through the passage 92, the chamber below the liquid level detection diaphragm 60 is in a depressurized state through the passage 93 and the liquid level detection diaphragm 60 tries to be attracted downward, but the diaphragm 59 is attached to the valve seat 101. The liquid level detection diaphragm 6 is attracted and closes the hole of the valve seat 101 to seal the upper chamber 81 of the liquid level detection diaphragm 60.
Since 0 does not move downward, the plunger 65 located below this is not pushed down and the detection valve 68 is not activated again.

Atmosphere flows into the upper chamber of the working chamber 25 of the vacuum valve 15 through the atmospheric pressure connection port 58 of the controller 27 and the atmosphere valve passage 43, and the differential pressure between the upper and lower chambers of the working chamber 25 disappears and the vacuum valve 15 is closed (FIG. 6 (G)).

The operation of this embodiment will be described below. The elastic restoring behavior of the valve operating portion 202 of the reversing valve 200 is not based on the bending elasticity of the valve body 201. That is, the valve operating portion 202 of the reversing valve 200 has elastic restoring behavior by the spring force of the restoring spring 204 provided between the valve operating portion 202 and the valve body 201. And
It is easy to adopt a spring having excellent fatigue characteristics as the restoring spring 204, and as a result, the fatigue strength of the reversing valve 200 can be improved.

By using the reversing valve 200 as the detection valve 68 used in the vacuum valve 15, the fatigue strength of the detection valve 68 can be improved. Therefore, the vacuum valve 15
Even if the valve operating unit 202 repeats reversing every time the valve is opened and closed once, it is possible to prevent the valve operating unit 202 from being damaged by fatigue and reduce the frequency of maintenance (replacement) of the detection valve 68.

FIG. 9 shows another reversing valve 210 which can be used as the above-mentioned detection valve 68. Reversing valve 21
0 is different from the reversing valve 200 in that a restoring spring 211 that replaces the restoring spring 204 is provided between the valve body 201 and the valve operating portion 202. The restoring spring 211 is composed of a leaf spring, and both ends of the restoring spring 211 are engaged with the connecting hole 201D provided in the valve body 201 and the connecting hole 202A provided in the valve operating portion 202, respectively. Even in the reversing valve 210, the valve operating unit 2
02 has an elastic restoring behavior to the valve closing operation position, and this restoring behavior is due to the elastic restoring force generated when the restoring spring 211 elastically deforms from the free state. The material of the restoring spring 211 is the valve body 20.
It is possible to adopt the one having the fatigue property superior to that of No. 1. For example, the valve main body 201 can be made of phosphor bronze, and the restoration spring 211 can be made of phosphor bronze.

The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and changes in design within the scope not departing from the gist of the present invention can be made. Even if it exists, it is included in the present invention.

[0050]

As described above, according to the present invention, the fatigue strength of the reversing valve used in a vacuum valve or the like can be improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a vacuum type waste water collecting device.

FIG. 2 is a schematic diagram showing a vacuum valve.

FIG. 3 is a cross-sectional view showing a controller part of a vacuum valve.

FIG. 4 is a schematic view showing a vacuum type waste water collecting system.

FIG. 5 is a schematic view showing the operating principle of a vacuum valve.

FIG. 6 is a schematic diagram showing the operating principle of a vacuum valve.

FIG. 7 is a schematic view showing a first embodiment of the detection valve.

FIG. 8 is a schematic diagram showing an operating state of a detection valve.

FIG. 9 is a schematic view showing a second embodiment of the detection valve.

[Explanation of symbols]

 11 tank 13 suction pipe 14 vacuum sewer pipe 15 vacuum valve 24 valve body 25 valve working chamber 26 closing force applying spring 27 controller section 60 liquid level detection diaphragm 65 plunger 68 detection valve 71 valve body (three-way valve) 74 needle valve (Opening time adjustment valve) 83 chambers (pressure control chamber) 200, 210 Reversing operation valve 201 Valve body 201A Valve mounting portion 201B Valve body portion 202 Valve operating portion 203 Reversing spring 204, 211 Restoring spring

Claims (2)

[Claims] 1. A valve body including a valve mounting portion and a valve body portion, a valve operating portion connected to the valve mounting portion of the valve body, and interposed between the valve body and the valve operating portion. With a reversing spring, the valve operating part has an elastic restoring behavior to the valve closing operating position, and when the valve operating part is given a certain displacement or more by an external force,
The valve operating part and the reversing spring reverse from the valve closing operating position side to the valve opening operating position side so that the valve body part of the valve body can be set to the valve opening position, and the above external force does not act on the valve operating part. In the reversing valve in which the valve operating portion and the reversing spring are restored to the valve closing operation position side by the above-mentioned restoring behavior of the valve operating portion, and the valve body portion of the valve body can be set to the valve closing position, A reversing valve, characterized in that the valve main body and the valve operating portion are separated by a restoring spring. 2. A valve body for opening and closing the connecting portion between a suction pipe communicating with the tank and a vacuum sewer pipe communicating with a vacuum source, and a plunger connected to the valve body. A valve working chamber to be housed, a closing force applying unit that is built in the valve working chamber and applies a closing force to the valve body, and a controller unit that applies a vacuum pressure to the valve working chamber to apply an opening force to the valve body. In a vacuum valve configured to have the controller part, a three-way valve capable of switching and connecting a vacuum passage and an atmosphere passage to a valve working chamber, and a liquid level detection diaphragm that operates in response to a liquid level in a tank And a pressure control chamber for applying a vacuum force to the three-way valve so that the three-way valve connects the vacuum passage to the valve working chamber, and a vacuum force can be introduced into the pressure control chamber by being arranged in the pressure control chamber. Is driven directly by the detection valve and the liquid level detection diaphragm. Along with the
A plunger that is inserted into the pressure control chamber to drive the detection valve, and a vacuum release valve that opens so as to release the vacuum force introduced into the pressure control chamber are provided. A vacuum valve comprising the reversing valve described.