JP7349739B2 - Valve device and pressure reducing valve using it - Google Patents

Description

The present invention relates to a valve device that is provided in a fluid passage and adjusts the pressure in the passage by opening and closing the passage, and a pressure reducing valve using the same.

Various valve devices are arranged in the fluid passageway to adjust the pressure within the passageway (for example, Patent Document 1). A direct-acting pressure reducing valve is opened and closed by one main valve, and a pilot-operated pressure reducing valve as disclosed in Patent Document 1 is opened and closed by one main valve and one pilot valve. Therefore, it is necessary to periodically disassemble the valve and perform maintenance such as replacing the valve and cleaning it. If regular maintenance is not performed, scale may accumulate on the valve, causing steam leakage, and it may become impossible to adjust the pressure on the secondary side.

Japanese Unexamined Patent Publication No. 62-103717

However, since maintenance requires disassembling the device, the device must be stopped. This leads to opportunity loss, which is not desirable.

An object of the present invention is to provide a valve device that allows maintenance of the valve without disassembling the device, and a pressure reducing valve using the same.

In order to achieve the above object, the valve device of the present invention includes a valve body that opens and closes between a fluid inflow path and a fluid outflow path, and a first spring body that seats the valve body on a valve seat by a spring force. , a shaft member that presses the valve body in a valve opening direction to separate it from the valve seat, and a valve replacement unit that discharges the valve body that is in use and installs a new valve body in a use position. . The valve replacement unit includes a plurality of valve body storage parts that store a valve body and a first spring body, and a valve body switching mechanism that switches between the plurality of valve body storage parts and moves the valve body to the use position. have.

According to this configuration, the valve replacement unit can discharge the valve body in use and install a new valve body. Thereby, maintenance such as replacing the valve body and cleaning can be performed without disassembling the device. Further, when the valve body moves, the valve body rotates due to friction. As a result, the position where the valve body is seated on the valve seat changes, so that it is possible to prevent scale from accumulating at a specific location on the valve body. As a result, the valve body can be replaced without discarding the valve body.

In the present invention, the plurality of valve body housing portions may be spaced apart from each other in the circumferential direction of the rotation axis. According to this configuration, a plurality of valve bodies can be accommodated within a limited space.

In the present invention, the valve replacement unit may have a cleaning area that comes into contact with and cleans the valve body when the valve body is moved. According to this configuration, it is possible to replace and clean the used valve body without discarding it.

The pressure reducing valve of the present invention is a pressure reducing valve that is disposed in a main passage of fluid and reduces the pressure on the primary side to the pressure on the secondary side, and includes a main valve body that opens and closes the main passage, and a main valve body that opens and closes the main passage. It is equipped with a pilot valve unit that opens and closes. The pilot valve unit includes the valve device of the present invention and a first valve drive section that presses the shaft member of the valve device in a valve opening direction to separate the valve body from the valve seat. . The first valve driving section includes a second spring body that moves forward and presses the shaft member in the valve opening direction, and a second spring body that receives pressure from the secondary side and applies the spring force to the second spring body. and a valve-closing force applying member that resists the valve-closing force and causes the valve to retreat in the valve-closing direction. Further, a second valve drive unit is provided that opens the main valve body in response to pressure in the outflow passage, and the inflow passage of the valve device communicates with the primary side of the main passage.

According to this configuration, since the valve replacement unit can discharge the valve body in use and install a new valve body, maintenance of the valve body can be performed without disassembling the device. Further, when the valve body moves, the valve body rotates due to friction. As a result, the position where the valve body is seated on the valve seat changes, so that it is possible to prevent scale from accumulating at a specific location on the valve body. As a result, the valve body can be replaced without discarding the valve body.

According to the valve device and pressure reducing valve of the present invention, maintenance of the valve body can be performed without disassembling the device, and the valve body can be replaced without discarding the valve body.

1 is a longitudinal cross-sectional view showing the basic configuration of a pressure reducing valve that is a subject of the present invention. FIG. 3 is a longitudinal sectional view schematically showing the state of the pressure reducing valve before pressure reduction. FIG. 3 is a vertical cross-sectional view schematically showing the pressure adjustment state of the pressure reducing valve. FIG. 3 is a vertical cross-sectional view schematically showing a reduced pressure holding state of the pressure reducing valve. FIG. 1 is a longitudinal sectional view showing a main part of a valve device according to a first embodiment of the present invention. FIG. 7 is a longitudinal cross-sectional view showing another state of the main part of the valve device. (A) to (D) are front views showing the procedure for replacing the valve body of the valve replacement unit of the same valve device. FIG. 3 is a side view showing a turning drive unit when a valve body of the valve device is used. It is a longitudinal cross-sectional view showing the main part of the valve device concerning a 2nd embodiment of the present invention. FIG. 3 is a front view showing a cleaning area of the valve device. It is a perspective view showing how a valve body moves in the same cleaning area. FIG. 7 is a front view showing a modification of the cleaning area of the valve device.

Prior to describing embodiments of the present invention, a pressure reducing valve used in a steam passage will be described. Steam is used as a heat medium in various industries due to cost, convenience, and safety considerations. Its biggest advantages are that it has a large amount of latent heat per unit weight, and that it can maintain a constant temperature by controlling the pressure.

When using steam, instead of generating steam at each required pressure, high-pressure steam is generated in a boiler and then used by lowering the pressure to the required level depending on the product or application. In that case, a pressure reducing valve is an automatic valve that keeps the steam pressure almost constant. The purpose of lowering the pressure is to lower the steam temperature and maintain it at the desired heating temperature.

The basic principle of pressure reduction is called the throttling phenomenon. When steam flows through a pipe, if the passage through which the steam flows is constricted, the steam pressure downstream of the constricted area will be lower. This is steam depressurization. To simply throttle the valve, there are methods such as fixing the valve at an intermediate opening or providing an orifice plate, but this method has the problem that the pressure also changes when the flow rate changes. Therefore, even if the flow rate or the pressure on the primary side (pressure on the upstream side of the throttle point) changes, the energy of the fluid passing through the valve is A pressure reducing valve is a valve that is set to automatically change the valve opening by directly utilizing the

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the basic configuration of a pilot-operated pressure reducing valve, which is a type of pressure reducing valve using a valve device that is the object of the present invention. In FIG. 1, a pressure reducing valve is arranged in a main passage 1 through which steam S, which is a type of fluid, flows. The casing 2 of the pressure reducing valve PRV is formed by connecting a main body case 4, an upper case 6, and a lower case 8. A primary side passage 10, a secondary side passage 12, and a valve chamber 14 located therebetween are formed inside the main body case 4. The primary passage 10 and the secondary passage 12 form a part of the main passage 1 through which the steam S flows. A valve holder 16 and a main valve body 18 that slides inside the valve holder 16 are arranged in the valve chamber 14 . The upper part of the valve holder 16 is supported by the main body case 4 by screw connection.

A spring force is applied to the main valve body 18 by a main spring body 20 made of a coil spring in a direction in which the main valve body 18 contacts a main valve seat 22 formed on the valve holder 16 and closes the valve. A main valve drive section 24 that drives the main valve body 18 is arranged above the valve chamber 14 . In the main valve drive section 24, a piston 26 that contacts the main valve body 18 is slidably inserted into a cylinder 28 supported by the main body case 4. Above the piston 26 is a main valve element drive chamber 27, which will be described later. The piston 26 is provided with a relief hole 29 for releasing the pressure in the main valve element drive chamber 27.

A pilot valve unit 30 is arranged at the top of the upper case 6. That is, the upper case 6 forms the casing of the pilot valve unit 30. This pilot valve unit 30 has a valve device 34 including a valve body 32, and a pilot valve drive section 36 that opens and closes this valve device 34. The valve body 32 is, for example, ball-shaped (spherical), but is not limited to this. The valve device 34 has a valve seat block 37, and a valve seat 40 is formed at its tip (left end in FIG. 1). A valve port 41 that is opened and closed by the valve body 32 is opened in the center of the valve seat 40 .

A shaft member 42 is inserted through the valve seat block 37 in the front-rear direction (left-right direction in FIG. 1). A tip end 42a of the shaft member 42 contacts the valve body 32, and a rear end 42b faces a tip plate 38 of the pilot valve driving section 36, which will be described later. The valve body 32 is pressed against the valve seat 40 by a first spring body 44 made of a coil spring. The first spring body 44 is interposed between a first spring receiver 48 provided on the upper case 6.

In the pilot valve drive unit 36, a tip plate 38 at the tip (left end in FIG. 1) is connected to a second spring body made of a coil spring from the rear (right side in FIG. 1) to the front (left side in FIG. 1). 54. The second spring body 54 is interposed between a tip member 56 that contacts the tip plate 38 and a second spring receiver 58 arranged inside the cover member 50. The cover member 50 is screwed to the upper case 6 (casing). A push rod 60 is disposed between the cover member 50 and the tip member 56, and this push rod 60 passes through the inner space of the second spring body 54.

The pilot valve drive section 36 has a pressure adjustment means 49. The pressure adjustment means 49 includes the tip plate 38 and the bellows 43, and causes the second spring body 54 to retreat in the valve closing direction (rightward direction). In other words, the pressure adjustment means 49 constitutes a valve-closing force applying member that causes the second spring body 54 to retreat in the valve-closing direction against the spring force.

A tip end 43a of a bellows 43 is connected to the tip plate 38, and a base end 43b of the bellows 43 is fixedly supported between the upper case 6 and the cover member 50. An adjustment handle 52 for adjusting pressure is rotatably connected to the cover member 50 by a screw.

A pilot chamber 62 that accommodates the first spring body 44 is arranged on the front side (left side) of the valve device 34 . A primary passage 10 communicates with this pilot chamber 62 via a primary conduction passage 64 . A screen 66 for removing foreign matter is arranged in the pilot chamber 62. Further, a through passage 68 communicating with the valve port 41 is formed on the downstream side of the valve body 32 in the valve device 34 . The pilot chamber 62 and the through passage 68 form an inflow passage and an outflow passage for the pilot valve unit 30, respectively. On the other hand, the pressure introducing chamber 70 in which the pressure applying means 49 is housed is communicated with the secondary side passage 12 via a secondary conduction passage 72 .

Next, the operation of the above configuration will be explained.
[Before decompression]
FIG. 2 shows the state before the start of the pressure reducing operation, and the main valve body 18 is in a closed state. When the steam S is vented to this pressure reducing valve, the steam S passes through the primary passage 64 from the primary passage 10 and reaches the pilot chamber 62 .

[Pressure adjustment]
When the adjustment handle 52 is rotated in the pressure reducing direction (counterclockwise), the push rod 60 of the pressure applying means 49 moves forward (leftward) as shown in FIG. Accordingly, the bellows 43 expands and the tip plate 38 moves the shaft member 42 forward (to the left), opening the valve body 32. As a result, the steam S flows into the outflow path (through path) 68, pushing down the piston 26 and opening the main valve body 18. At this time, a slight gap G exists between the pressing plate 38 at the tip of the pressure applying means 49 and the back surface of the valve seat block 37. When the main valve body 18 is opened, the steam S in the primary passage 10 flows into the secondary passage 12 and is depressurized.

[Maintaining reduced pressure]
A part of the steam S flowing into the secondary passage 12 passes through the secondary conduit passage 72 and reaches the pressure introduction chamber 70, as shown in FIG. The bellows 43 of the pressure applying means 49 is compressed by the steam pressure in the pressure introduction chamber 70, and the tip plate 38 is retreated to the right. This allows the shaft member 42 to move rearward (rightward) and moves the valve body 32 in the valve closing direction. By adjusting the pressure in the main valve element drive chamber 27 in this way, the opening degree of the main valve element 18 is adjusted, and the pressure in the secondary passage 12 is kept constant.

Next, the valve device 34, which is a main part of the first embodiment of the present invention, will be explained with reference to FIGS. 5 to 8. The valve device 34 shown in FIG. 5 includes a valve replacement unit 80. The valve replacement unit 80 discharges the valve body 32 in use and installs a new valve body 32 in the use position.

The valve replacement unit 80 has a plurality of valve body housing parts 82 that house the valve bodies 32. In this embodiment, the first spring body 44 is housed in the valve body storage section 82 in addition to the valve body 32 .

As shown in FIG. 7, in this embodiment, six valve body storage parts 82 are provided at intervals in the circumferential direction of the rotation axis AX. Specifically, the valve replacement unit 80 includes a cylindrical cylinder 86 centered on the rotation axis AX, and a shaft body 88 having the rotation axis AX. Six circular through holes are formed spaced apart in the circumferential direction. The space formed by this through hole constitutes the valve body housing portion 82. However, the number and arrangement of the valve body housing sections 82 are not limited to this. As shown in FIG. 5, the through hole constituting each valve body storage portion 82 is stepped, and the stepped portion 82a serves as a spring receiver for the first spring body 44.

The valve replacement unit 80 further includes a valve body switching mechanism 84 that switches the valve body storage portion 82. The valve body switching mechanism 84 of this embodiment switches the valve body 32 (valve body storage portion 82) by rotating the cylinder 86 around the rotation axis AX.

Specifically, the valve body switching mechanism 84 includes a swing drive section 90 that rotates the cylinder 86, an operation section 92 that is operated by the user, and an operation force transmission section 94 that transmits the operating force of the operation section 92 to the swing drive section 90. It has

The operating section 92 operates the swing drive section 90 via the operating force transmitting section 94. The operation unit 92 is exposed to the outside of the device and is operated by the user. The operation unit 92 has a push button 96 operated by the user. A spring force is applied upward to the push button 96 by a spring body 98 . A connecting portion 92a to which the operating force transmitting portion 94 is connected is formed on the lower surface of the push button 96.

The operating force transmitting unit 94 includes a first link piece 100 extending in the vertical direction from the operating unit 92, a second link piece 102 extending in the front-back direction (horizontal direction in FIG. 5) from the first link piece 100, and a second link piece 102 extending in the front-rear direction (horizontal direction in FIG. The third link piece 104 extends from the second link piece 102 in the vertical direction.

The upper end 100a of the first link piece 100 is connected to the connecting part 92a of the operating part 92 by a first shaft supporting member 95 such as a connecting pin extending in the left-right direction (direction perpendicular to the paper surface of FIG. 5). There is. A tooth portion (gear portion) 100b is formed on the rear surface (right side in FIG. 5) of the first link piece 100.

The second link piece 102 has teeth portions (gear portions) 102a and 102b formed on its upper and lower surfaces, respectively. The front end (left side in FIG. 5) of the second link piece 102 is connected to the lower part of the first link piece 100 by a first gear 106.

The first gear 106 is a cylindrical gear connected to a shaft body 106a having a rotation axis in the left-right direction (direction perpendicular to the paper surface of FIG. 5), and has a tooth portion (gear portion) 106b on its outer peripheral surface. It is formed. The teeth 100b of the first link piece 100 and the teeth 102a on the upper surface of the second link piece 102 mesh with the teeth 106b of the first gear 106, so that the first link piece 100 and the second link Pieces 102 are connected. That is, the first gear 106 converts vertical movement of the first link piece 100 into movement of the second link piece 102 in the front-rear direction (left-right direction in FIG. 5).

The third link piece 104 has a tooth portion (gear portion) 104a formed on its front surface (right side in FIG. 5). The upper end of the third link piece 104 is connected to the rear end (left end in FIG. 5) of the second link piece 102 by a second gear 108. Further, the lower end portion 104b of the third link piece 104 is connected to the swing drive unit 90, which will be described later, by a second shaft supporting member 105 such as a connecting pin extending in the left-right direction (direction perpendicular to the paper surface of FIG. 5). ing.

The second gear 108 is a cylindrical gear connected to a shaft body 108a having a rotation axis in the front-rear direction (direction perpendicular to the plane of the paper in FIG. 5), and has a tooth portion (gear portion) 108b on its outer peripheral surface. It is formed. The lower tooth portion 102b of the second link piece 102 and the tooth portion 104a of the third link piece 104 mesh with the tooth portion 108b of the second gear 108, so that the second link piece 102 and the third link piece 102 are connected to each other. Link pieces 104 are connected. That is, the second gear 108 converts the movement of the second link piece 102 in the front-rear direction (the left-right direction in FIG. 5) into the movement of the third link piece 104 in the up-down direction.

The swing drive section 90 includes a locking pawl 110 shown in FIG. 6 supported by the third link piece 104 of the operating force transmission section 94, and a third gear 112 supported by the shaft body 88. The locking pawl 110 is rod-shaped, and its upper end is connected to the lower end 104b of the third link piece 104. The lower end portion of the locking pawl 110 in FIG. 5 is bent rearward (to the left in FIG. 5) to form a pawl portion 110a.

The third gear 112 is fitted onto the shaft body 88 at the center of the cylinder 86, as shown in FIG. That is, the third gear 112 rotates together with the cylinder 86 around the axis AX of the shaft body 88. A gear 112a is formed on the outer peripheral surface of the third gear 112. The same number of gears 112a as the valve body housing portions 82, six in this embodiment, are provided. The claw portion 110a of the locking claw 110 shown in FIG. 5 engages with this gear 112a.

Next, a procedure for replacing the valve body 32 of the valve device 34 of this embodiment will be explained using FIGS. 5 to 8. In FIGS. 7(A) to (D), the valve body accommodating part 82 in which the valve body 32 in the used state is stored is referred to as a first valve body accommodating part 82-1, and The second to sixth valve body housing sections 82-2 to 82-6 are arranged clockwise.

First, the push button 96 of the operating section 92 in FIG. 5 is operated downward (in the direction of arrow A1). As a result, the first link piece 100 of the operating force transmission section 94 moves downward, the second link piece 102 moves rearward (to the right in FIG. 5) via the first gear 106, and the second link piece 102 moves backward (to the right in FIG. The third link piece 104 moves downward via. As the third link piece 104 moves downward, the locking pawl 110 of the swing drive section 90 moves downward.

FIG. 7A shows the state of FIG. When the locking claw 110 of the swing drive section 90 moves downward, the gear 112a of the third gear 112 of the swing drive section 90 is pushed by the locking claw 110, and the cylinder 86 rotates in the A2 direction (clockwise). (FIG. 7(B)), the second valve body storage portion 82-2 moves to the use position (lowest position) (FIG. 7(C)). When the locking pawl 110 moves further downward, the locking pawl 110 separates from the gear 112a of the third gear 112 (FIG. 7(D)). FIG. 7(D) shows the state of FIG. 6.

When the push button 96 in FIG. 5 is released, the spring force of the spring body 98 causes the push button 96 to return upward (in the direction of arrow A3). As a result, the first link piece 100 of the operating force transmitting section 94 moves upward, the second link piece 102 moves forward (to the left in FIG. 5) via the first gear 106, and the second link piece 108 moves forward (to the left in FIG. 5). The third link piece 104 moves upward via. As a result, as shown in FIG. 8, the locking pawl 110 moves forward (to the left in FIG. 8) around the second shaft supporting member 105 along the relief surface 112b formed on the gear 112a of the third gear 112. It rotates, detaches from the gear 112a, and moves upward.

Through the above steps, the state returns to the state shown in FIG. 7(A). However, instead of the first valve body housing part 82-1, the second valve body housing part 82-2 is located at the use position (lowest position). From then on, when replacing the valve body 32, by repeating the above-mentioned operation, the third valve body storage part 82-3, the fourth valve body storage part 82-4, the fifth valve body storage part 82-5, and the third valve body storage part 82-5 are replaced. The valve body housing parts 82 installed in the use position are changed in the order of the six valve body housing parts 82-6, and the valve bodies 32 are replaced.

According to the above configuration, the valve replacement unit 80 can discharge the valve body 32 in use and install a new valve body 32. Thereby, maintenance such as replacing the valve body 32 can be performed without disassembling the device. Further, in addition to the valve body 32, a first spring body 44 is housed in the valve body storage portion 82. Therefore, when the cylinder 86 of the valve replacement unit 80 rotates and the valve body 32 moves (revolutions), the spring force of the first spring body 44 causes the valve body 32 to move toward the valve receiving surface of the casing (upper case) 6. It is pressed against 6a and rolls (rotates). The valve receiving surface 6a is a moderately rough surface. As a result, the position where the valve body 32 is seated on the valve seat 41 changes, so that it is possible to prevent scale from accumulating at a specific location on the valve body 32. As a result, the valve body 32 can be replaced without discarding the valve body 32.

A plurality of valve body housing parts 82 are arranged to be spaced apart in the circumferential direction of the rotation axis AX. Thereby, the valve replacement unit 80 having a plurality of valve bodies 32 can be installed within a limited space.

A valve device 34A according to a second embodiment of the present invention will be explained with reference to FIGS. 9 to 12. In the valve device 34A of the second embodiment, the valve replacement unit 80A has a cleaning area 114 that cleans the valve body 32 when the valve body 32 is moved. The other configurations are the same as the valve device 34 of the first embodiment. Components similar to those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The cleaning area 114, which is different from the first embodiment, will be explained below.

The cleaning area 114 is provided in the casing (upper case) 6 of the pilot valve unit 30. As shown in FIGS. 10 and 11, the cleaning area 114 is formed in an arc shape along the trajectory of the valve body 32. As shown in FIGS. The cleaning area 114 is, for example, a resin brush or sponge. However, the cleaning area 114 is not limited to these. When the valve body 32 is replaced by the valve replacement unit 80A (FIG. 9), the valve body 32 is cleaned by the cleaning area 114.

According to the configuration of the second embodiment, similarly to the first embodiment, maintenance such as replacing the valve body 32 can be performed without disassembling the device, and also without discarding the valve body 32. The valve body 32 can be replaced.

Furthermore, since the valve replacement unit 80A has a cleaning area 114 that comes into contact with and cleans the valve body 32 when the valve body 32 is moved, the valve exchange unit 80A automatically cleans the valve body 32 when replacing the used valve body 32. 32 cleanings can be performed.

FIG. 12 shows a modification of the cleaning area 114. The cleaning area 114A of the modified example is divided into a plurality of regions 124 along the trajectory of the valve body 32. In the modification shown in FIG. 12, five areas 124-1 to 124-5 are provided corresponding to the five valve body storage parts 82 in which valve bodies 32 that are not in use are stored. The cleaning area 114A may have a plurality of areas 124, and is not limited to the modified example shown in FIG. 12.

By providing a plurality of areas 124 in the cleaning area 114A, for example, the roughness of the brush, sponge, etc. can be changed for each area 124, or a cleaning area 124 and a non-cleaning area 124 can be provided, depending on the usage situation. A cleaning area 114A may be provided.

The present invention is not limited to the above-described embodiments, and various additions, changes, or deletions can be made without departing from the gist of the present invention. For example, in the above embodiment, a pilot-operated pressure reducing valve has been described, but the valve replacement mechanism of the present invention can also be applied to a direct-acting pressure reducing valve that does not have a pilot valve. In addition, the valve replacement units 80 and 80A of the above embodiments switch the valve body housing section 82 by rotating with respect to the rotation axis AX, but by sliding the valve body housing section 82 in a direction perpendicular to the rotation axis AX. The body storage section 82 may be switched. Therefore, such materials are also included within the scope of the present invention.

1 Main passage 18 Main valve body 24 Main valve drive section (second valve drive section)
30 Pilot valve unit 32 Valve body 34, 34A Valve device 36 Pilot valve drive section (first valve drive section)
37 Valve seat block 40 Valve seat 42 Shaft member 44 First spring body 49 Pressure adjustment means (valve closing force applying member)
54 Second spring body 62 Pilot chamber (inflow path)
68 Penetration path (outflow path)
80, 80A Valve replacement unit 82 Valve body storage section 84 Valve body switching mechanism 114, 114A Cleaning area AX Rotation axis PRV Pressure reducing valve S Steam (fluid)

Claims (3)

a valve body that opens and closes between a fluid inflow path and an outflow path;
a first spring body that seats the valve body on a valve seat by a spring force;
a shaft member that presses the valve body in a valve opening direction to separate it from the valve seat;
and a valve replacement unit for discharging the valve body in use and installing a new valve body in the use position,
The valve replacement unit includes a plurality of valve body storage parts that house the valve body and the first spring body, and a valve body switching unit that switches between the plurality of valve body storage parts and moves the valve body to the use position. It has a mechanism,
The valve replacement unit is a valve device having a cleaning area that comes into contact with and cleans the valve body when the valve body is moved . The valve device according to claim 1, wherein the plurality of valve body storage portions are spaced apart from each other in the circumferential direction of the rotation axis. A pressure reducing valve disposed in a main passage of fluid to reduce pressure on the primary side to pressure on the secondary side,
a main valve body that opens and closes the main passage;
a pilot valve unit that opens and closes the main valve body,
The pilot valve unit includes the valve device according to claim 1 or 2 ,
a first valve drive unit that presses the shaft member of the valve device in a valve opening direction to separate the valve body from the valve seat;
The first valve driving section includes a second spring body that moves forward and presses the shaft member in the valve opening direction, and a second spring body that receives pressure from the secondary side and applies the spring force to the second spring body. and a valve-closing force applying member that resists and retreats in the valve-closing direction,
Furthermore, a second valve drive unit is provided that opens the main valve body in response to pressure in the outflow path,
A pressure reducing valve in which the inflow path of the valve device communicates with the primary side of the main passage.

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