JP7292738B2 - Valve device and pressure reducing valve using the same - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve device that is provided in a fluid passage and adjusts the pressure of the passage by opening and closing the passage, and a pressure reducing valve using the same.

Various valve devices are arranged in the fluid passages to regulate the pressure in the passages (eg, US Pat. A direct-acting pressure reducing valve such as that disclosed in Patent Document 1 is opened and closed by one main valve, and a pilot-operated pressure reducing valve 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 replacement and cleaning of the valve. If regular maintenance is not performed, scale builds up on the valve, which can lead to steam leaks and the possibility of not being able to adjust the pressure on the secondary side.

JP 2020-029872 A

However, maintenance requires disassembly of the device, which means that the device must be stopped. Therefore, it leads to opportunity loss, which is not preferable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a valve device and a pressure reducing valve using the valve device that allows maintenance of the valve without disassembling the device.

In order to achieve the above object, the valve device of the present invention comprises a valve body that opens and closes between a fluid inflow path and a fluid outflow path, and a first spring body that causes the valve body to be seated on a valve seat by a spring force. a shaft member for pressing the valve body in the valve-opening direction to separate it from the valve seat; and a valve replacement mechanism for ejecting the valve body in use and installing a new valve body.

According to this configuration, the valve replacement mechanism allows the valve body in use to be discharged and a new valve body to be installed. As a result, maintenance such as replacement and cleaning of the valve body can be performed without disassembling the device.

In the present invention, the valve replacement mechanism includes a cylindrical slide member that accommodates the valve body therein and is slidable in the axial direction of the shaft member, and the valve body in use is attached to the outer peripheral wall of the slide member. and an insertion hole for inserting the new valve body may be formed. According to this configuration, by sliding the slide member in the axial direction, the valve body in use can be discharged from the discharge hole and a new valve body can be inserted from the insertion hole.

When the valve replacement mechanism has the slide member, the discharge hole and the insertion hole may be formed on opposite sides of the slide member with respect to the axis of the slide member. In this case, the discharge hole may open on the lower surface of the slide member, and the insertion hole may open on the upper surface of the slide member. According to this configuration, the valve body in use can be discharged and the new valve body inserted smoothly.

When the valve replacement mechanism has the slide member, the slide member has a locking portion that locks onto the first spring body and slides to apply and cut off the spring force to the valve body. may According to this configuration, since the biasing force of the first spring can be received by the locking portion, the valve in use can be smoothly discharged and the new valve can be inserted.

When the valve replacement mechanism has the slide member, the valve replacement mechanism may have a slide mechanism for moving the slide member in the axial direction, and an operation section for operating the slide mechanism. According to this configuration, the user can easily move the slide member via the slide mechanism by operating the operation unit. Therefore, replacement of the valve body is easy.

In the present invention, the valve replacement mechanism may have a spare valve body storage section for storing a plurality of replacement valve bodies. According to this configuration, since a plurality of valve bodies for replacement can be stocked in the spare valve body storage section, there is no need to prepare a valve body each time maintenance is performed, resulting in good workability.

A pressure reducing valve according to the present invention is a pressure reducing valve that is arranged in a main fluid passage and reduces the pressure on the primary side to the pressure on the secondary side. and a pilot valve unit for opening and closing. The pilot valve unit has 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 drive unit includes a second spring body that advances and presses the shaft member in the valve opening direction, and a spring force that receives the pressure from the secondary side and presses the second spring body. and a valve-closing force applying member that is retracted in the valve-closing direction against the valve-closing force applying member. Further, a second valve driving portion is provided for receiving the pressure of the outflow passage to open the main valve body, and the inflow passage of the valve device communicates with the primary side of the main passage.

According to this configuration, the valve replacement mechanism allows the valve body in use to be discharged and a new valve body to be installed, so maintenance of the valve body can be performed without disassembling the device.

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.

1 is a longitudinal sectional view showing the basic configuration of a pressure reducing valve, which is the object of the present invention; FIG. It is a longitudinal cross-sectional view which shows typically the state before pressure_reduction|reduced_pressure of the same pressure-reduction valve. It is a longitudinal cross-sectional view which shows typically the pressure adjustment state of the same pressure-reduction valve. It is a longitudinal cross-sectional view which shows typically the pressure reduction holding state of the same pressure-reduction valve. 1 is a vertical cross-sectional view showing a main part of a valve device according to a first embodiment of the invention; FIG. It is a longitudinal cross-sectional view which shows the state which discharged the valve body in the same valve apparatus. It is a longitudinal cross-sectional view which shows the state which injected the valve body in the same valve apparatus. It is the back view which looked at the same valve apparatus from the back.

Prior to describing embodiments of the present invention, a pressure reducing valve used in a steam passage will be described. In various industries, steam is used as a heat carrier from the viewpoint of cost, convenience and safety. The greatest advantage is that the latent heat per unit weight is large, and the temperature can be kept constant by controlling the pressure.

When using steam, instead of generating steam at each required pressure, a boiler generates high-pressure steam, and the steam is lowered to the required pressure according to the product or application. In that case, the automatic valve that keeps the steam pressure substantially constant is the pressure reducing valve. The purpose of lowering the pressure is to lower the steam temperature and keep it at the desired heating temperature.

The basic principle of decompression is called the throttling phenomenon. When steam flows through a pipe, if the passage through which the steam flows is throttled, the steam pressure on the downstream side becomes lower than the throttled point. This is the decompression of steam. If it is just to throttle, there is a method of 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 primary pressure (upstream pressure of the throttling point) changes, the secondary pressure (downstream pressure of the throttling point) does not fluctuate. A pressure reducing valve is a valve that is set to automatically change the valve opening by directly using .

Preferred embodiments of the present invention will be described below 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, which is the subject of the present invention. In FIG. 1, the pressure reducing valve is arranged in a main passage 1 through which steam S, which is a type of fluid, flows. A casing 2 of the pressure reducing valve PRV is formed by connecting a body case 4, an upper case 6 and a lower case 8. As shown in FIG. A primary side passage 10 , a secondary side passage 12 , and a valve chamber 14 therebetween are formed inside the body case 4 . The primary passage 10 and the secondary passage 12 form part of the main passage 1 through which the steam S flows. A valve holder 16 and a main valve element 18 that slides inside the valve holder 16 are arranged in the valve chamber 14 . The upper portion of the valve holder 16 is supported by the main body case 4 by screw connection.

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

A pilot valve unit 30 is arranged above the upper case 6 . That is, the upper case 6 forms a casing of the pilot valve unit 30. As shown in FIG. The pilot valve unit 30 has a valve device 34 including a valve element 32 and a pilot valve driving section 36 for opening and closing the valve device 34 . In this embodiment, the valve body 32 is ball-shaped (sphere), 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 opening 41 that is opened and closed by the valve body 32 is opened in the central portion 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 portion 42a of the shaft member 42 contacts the valve body 32, and a rear end portion 42b faces a tip plate 38 of the pilot valve drive portion 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 bearing 48 provided on the upper case 6 .

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

The pilot valve driving section 36 has pressure adjusting means 49 . The pressure adjusting means 49 has the tip plate 38 and the bellows 43, and retracts the second spring body 54 in the valve closing direction (rightward direction). That is, the pressure adjusting means 49 constitutes a valve closing force applying member that retracts the second spring body 54 in the valve closing direction against the spring force.

A distal end portion 43 a of a bellows 43 is connected to the distal end plate 38 , and a proximal end portion 43 b 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 screws.

A pilot chamber 62 that houses the first spring body 44 is arranged on the front side (left side) of the valve device 34 . The pilot chamber 62 communicates with the primary side passage 10 via a primary conduction passage 64 . A screen 66 for removing foreign matter is arranged in the pilot chamber 62 . A through passage 68 communicating with the valve port 41 is formed downstream 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 secondary passage 12 communicates with the pressure introduction chamber 70 housing the pressure application means 49 via the secondary conduit 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, in which the main valve body 18 is in the closed state. When the steam S is passed through the pressure reducing valve, the steam S reaches the pilot chamber 62 from the primary passage 10 through the primary conduit 64 .

[Pressure adjustment]
When the adjustment handle 52 is rotated in the pressure reducing direction (counterclockwise), the push rod 60 of the pressure application means 49 moves forward (leftward) as shown in FIG. As a result, the bellows 43 expands and the tip plate 38 moves the shaft member 42 forward (to the left) to open the valve body 32 . As a result, the steam S flows into the outflow passage (through passage) 68 and pushes down the piston 26 to open 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 . By opening the main valve body 18, the steam S in the primary side passage 10 flows into the secondary side passage 12 and is decompressed.

[Holding of reduced pressure]
Part of the steam S that has flowed into the secondary passage 12 reaches the pressure introduction chamber 70 through the secondary conduit 72 as shown in FIG. The bellows 43 of the pressure application means 49 is compressed by the steam pressure in the pressure introduction chamber 70, and the tip plate 38 retreats rightward. As a result, the shaft member 42 is allowed to move rearward (rightward), and the valve body 32 is moved in the valve closing direction. By adjusting the pressure in the main valve drive chamber 27 in this manner, the degree of opening of the main valve 18 is adjusted, and the pressure in the secondary passage 12 is kept constant.

Next, the valve device 34, which is the essential part of the first embodiment of the present invention, will be described with reference to FIGS. The valve device 34 of this embodiment includes a valve replacement mechanism 80 . The valve replacement mechanism 80 ejects the valve body 32 in use and installs a new valve body 32A. 5 to 8 denotes scale (scale) attached to the ball 32, which is drawn larger than it actually is for convenience of explanation.

The valve replacement mechanism 80 includes a slide member 82, a slide mechanism 84 that moves the slide member 82 in the axial direction AX, an operation portion 86 that operates the slide mechanism 84, and a spare valve body that houses the replacement valve body 32A. and a storage portion 88 . The slide member 82 has a tubular shape, and is supported by the valve seat block 37 so as to be slidable in the axial direction AX (left and right direction in FIG. 5). A valve body is positioned inside the cylindrical slide member 82 . That is, the valve body 32 is covered with the outer peripheral wall of the slide member 82 .

The outer peripheral surface (peripheral wall) of the slide member 82 is formed with a discharge hole 90 for discharging the used valve body 32 and an insertion hole 92 for inserting a new valve body 32A. The discharge hole 90 and the insertion hole 92 are formed on opposite sides of the slide member 82 with the axis AX interposed therebetween. In this embodiment, the discharge hole 90 is formed in the lower surface (lower wall) of the slide member 82 and the insertion hole 92 is formed in the upper surface (upper wall) of the slide member 82 . However, the positions of the discharge hole 90 and the injection hole 92 are not limited to this.

In this embodiment, the discharge hole 90 and the injection hole 92 are formed to have the same size and shape. The hole diameters of the discharge hole 90 and the injection hole 92 are slightly larger than the diameter of the valve body 32 . Further, the axis A1 of the discharge hole 90 and the axis A2 of the insertion hole 92 are offset in the direction of the axis AX of the slide member 82 . Specifically, the axis A1 of the discharge hole 90 is positioned forward (to the left in FIG. 5) of the axis A2 of the insertion hole 92 . However, the sizes and shapes of the discharge hole 90 and the injection hole 92 may be different, and the axial centers A1 and A2 of both 90 and 92 may be the same.

A locking portion 94 is formed at the front end portion (the left end portion in FIG. 5) of the slide member 82 . The locking portion 94 is formed so as to protrude radially inward from the front end portion of the slide member 82 and is formed so as to be capable of being locked to the first spring body 44 . In this embodiment, the locking portion 94 is formed on the upper portion of the front end portion of the slide member 82 .

A valve body discharge passage 96 is formed below the discharge hole 90 . As shown in FIG. 8, the valve body discharge passage 96 extends downward, then curves in the left-right direction (right side in FIG. 8) and opens to the outside of the device. The opening of the valve body discharge passage 96 is closed by a lid member 98, and by removing the lid member 98, the valve body 32 can be taken out.

A spare valve body housing portion 88 is provided above the injection hole 92 shown in FIG. A plurality of replacement valve bodies 32A are housed inside the spare valve body housing portion 88 . In this embodiment, five replacement valve bodies 32A are stored. The number of stored valve bodies 32A is not limited to this.

The spare valve body storage part 88 of this embodiment has a chimney shape extending in the vertical direction, and a plurality of replacement valve bodies 32A are stored side by side in the vertical direction. The upper end of the spare valve body housing portion 88 is closed by a detachable closing member 99 . By removing the closing member 99, the replacement valve body 32A can be replenished from the upper end opening of the spare valve body accommodating portion 88. As shown in FIG.

A lower end portion of the spare valve body accommodating portion 88 is bent in the axial direction of the slide member 82, which is the right side in FIG. 5 in this embodiment, backward. Specifically, among the plurality of replacement valve bodies 32A housed in the spare valve body housing portion 88, the lowermost valve body 32A is displaced in the axial direction of the slide member 82 from the other upper valve bodies 32A. placed in position. This makes it easier to insert the valve bodies 32A one by one.

The operating portion 86 operates the slide member 82 via the slide mechanism 84 . The operation unit 86 is exposed to the outside of the apparatus and is a part operated by the user. The operation unit 86 has push buttons 85 operated by the user. A spring body 87 applies an upward spring force to the push button 85 . A connecting portion 85 a to which the slide mechanism 84 is connected is formed on the lower surface of the push button 85 .

The slide mechanism 84 axially moves the slide member 82 and has a first link piece 100 and a second link piece 102 . The first link piece 100 connects the slide member 82 and the second link piece 102 . On the other hand, the second link piece 101 connects the second link piece 102 and the operating portion 86 . Specifically, one end of the first link piece 100 is connected to the rear end of the slide member 82 (right end in FIG. 5). More specifically, one end of the first link piece 100 is supported around the first shaft support member 104 by a first shaft support member 104 such as a connecting pin extending in the left-right direction (direction perpendicular to the plane of FIG. 5). is rotatably connected to the slide member 82 .

Also, the other end of the first link piece 100 is connected to the lower end of a vertically extending second link piece 102 . Specifically, the other end of the first link piece 100 is supported around the second shaft support member 106 by a second shaft support member 106 such as a connecting pin extending in the left-right direction (direction perpendicular to the plane of FIG. 5). is rotatably connected to the lower end of the second link piece 102 .

Further, the upper end of the second link piece 102 is connected to the connecting portion 85a of the push button 85 of the operating portion 86. As shown in FIG. Specifically, the upper end of the second link piece 102 is rotated around the third shaft support member 108 by a third shaft support member 108 such as a connecting pin extending in the left-right direction (direction perpendicular to the plane of FIG. 5). It is rotatably connected to the connecting portion 85a of the push button 85. As shown in FIG. The lower portions of the first link piece 100 and the second link piece 102 are arranged in the through passage 68, and are moved rearward (to the right in FIG. 5) by the rear surface of the through passage 68 (left end surface in FIG. 5). is regulated.

Next, a replacement procedure for the valve body 32 of the valve device 34 of this embodiment will be described. In the operating state of FIG. 5, if scale Sc adheres to the valve body 32, it may cause malfunction, so maintenance (replacement, cleaning) of the valve body 32 is required periodically. In the state of FIG. 5, the center P1 of the valve body 32 in use and the axis A1 of the discharge hole 90 are displaced in the axial direction AX. Since the core A2 is displaced in the axial direction AX, each valve element 32, 32A does not pass through the discharge hole 90 and the injection hole 92.

To maintain the valve body 32, first, the push button 85 is pushed in the direction of the arrow AR1 (downward) shown in FIG. The pressing force of this push button 85 is transmitted to the slide member 82 via the slide mechanism 84 connected to the push button 85 . Specifically, the pressing force of the push button 85 causes the second link piece 102 of the slide mechanism 84 to move downward. Since the rearward movement of the second link piece 102 is restricted by the rear surface of the through passage 68 , the second link piece 102 moves downward along the front end surface of the valve seat block 37 .

At this time, the first link piece 100 rotates around the first and second pivot members 104 and 106 and assumes a posture extending in the front-rear direction (left-right direction in FIG. 6). As a result, the slide member 82 moves in the direction of the arrow AR2 (forward). At this time, the locking portion 94 of the slide member 82 also pushes the first spring body 44 in the direction of the arrow AR3 (forward). As a result, the spring force of the first spring body 44 is no longer applied to the valve body 32, and the valve body 32 becomes movable.

When the slide member 82 moves forward, first, the center P1 (FIG. 5) of the valve body 32 in use and the axis A1 (FIG. 5) of the discharge hole 90 are aligned, and the valve body 32 moves toward the discharge hole 90 by its own weight. to the valve body discharge passage 96 (arrow AR4). Further, when the slide member 82 moves forward, the center P2 of the replacement valve body 32A and the axis A2 of the insertion hole 92 are aligned, and the valve body 32A is inserted into the valve chamber through the insertion hole 92 by its own weight (arrow AR5).

When the push button 85 is released, the spring force of the spring body 87 returns the push button 85 in the direction of the arrow AR6 in FIG. 7 (upward). As a result, the second link piece 102 of the slide mechanism 84 moves upward, and the first link piece 100 rotates around the first and second shaft support members 104 and 106, thereby moving the slide member 82 to the position indicated by the arrow. Move in the direction of AR7 (backward). As a result, the spring force of the first spring body 44 is applied in the direction of arrow AR8 (backward), and the valve body 32 is pressed against the valve seat 41 . Replacement of the valve body 32 is thus completed.

The valve body 32B discharged from the valve body discharge passage 96 can be taken out of the device by removing the lid member 98 shown in FIG. After being cleaned, the removed valve body 32B is supplied to the spare valve body housing portion 88 . If the valve body 32 is heavily soiled or damaged and cleaning is difficult, a new valve body 32 is supplied to the spare valve body housing portion 88 . Replenishment to the spare valve body housing portion 88 is performed by removing the closing member 99 .

According to the above configuration, the valve replacement mechanism 80 shown in FIG. 5 allows the valve body 32 in use to be discharged and a new valve body 32A to be installed. As a result, maintenance such as replacement and cleaning of the valve body 32 can be performed without disassembling the device.

Further, by moving the slide member 82, the valve body 32 in use can be discharged and the replacement valve body 32A can be loaded by its own weight, so that the valve body 32 in use and the new valve body 32A can be loaded smoothly. And the structure is simple. Furthermore, by moving the slide member 82, the engaging portion 94 provided on the sliding member 82 can prevent the biasing force of the first spring body 44 from being applied to the valve body 32, so that the valve body 32 in use can be prevented from being applied. is smoothly discharged and the new valve body 32A is introduced.

Since the user simply presses the push button 85 provided outside the device, replacement of the valve body 32 is easy. Since the spare valve housing part 88 for housing a plurality of replacement valve bodies 32A is provided, there is no need to prepare the valve bodies 32 each time maintenance is performed, and workability is good.

The present invention is not limited to the above embodiments, and various additions, changes, or deletions are possible without departing from the scope of the present invention. The valve replacement mechanism 80 is not limited to the structure of the above embodiment as long as the valve body 32 can be replaced without disassembling the device. Accordingly, such are also included within the scope of this 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 valve device 36 pilot valve driving section (first valve driving section)
37 valve seat block 40 valve seat 42 shaft member 44 first spring body 49 pressure adjusting means (valve closing force applying member)
54 Second spring body 62 Pilot chamber (inflow path)
68 through passage (outflow passage)
80 Valve exchange mechanism 82 Slide member 84 Slide mechanism 86 Operation part 88 Spare valve body storage part 90 Discharge hole 92 Input hole 94 Locking part PRV Pressure reducing valve S Steam (fluid)

Claims (7)

a valve body that opens and closes between the inflow path and the outflow path of the fluid;
a first spring body that causes the valve body to be seated on the 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;
Equipped with a valve replacement mechanism that discharges the valve body in use and installs a new valve body,
The valve replacement mechanism includes a cylindrical slide member that accommodates the valve body therein and is slidable in the axial direction of the shaft member,
A valve device in which a discharge hole for discharging the valve body in use and a loading hole for loading a new valve body are formed in the outer peripheral wall of the slide member. 2. The valve device according to claim 1 , wherein said discharge hole and said insertion hole are formed on opposite sides of said slide member with respect to the axial center thereof. 3. The valve device according to claim 2 , wherein said discharge hole opens to the lower surface of said slide member, and said insertion hole opens to the upper surface of said slide member. 4. The valve device according to any one of claims 1 to 3 , wherein the slide member engages with the first spring body and slides to apply and block the spring force to the valve body. A valve device having a section. 5. The valve device according to claim 1 , wherein the valve replacement mechanism has a slide mechanism that moves the slide member in the axial direction, and an operating portion that operates the slide mechanism. valve device. a valve body that opens and closes between the inflow path and the outflow path of the fluid;
a first spring body that causes the valve body to be seated on the 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;
Equipped with a valve replacement mechanism that discharges the valve body in use and installs a new valve body,
The valve device, wherein the valve replacement mechanism has a spare valve housing section for housing a plurality of replacement valve bodies. A pressure reducing valve arranged in a main fluid passage to reduce the pressure on the primary side to the pressure on the secondary side,
a main valve body that opens and closes the main passage;
and a pilot valve unit that opens and closes the main valve body,
wherein the pilot valve unit is the valve device according to any one of claims 1 to 6 ;
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 drive unit includes a second spring body that advances and pushes the shaft member in the valve opening direction, and a spring force that receives the pressure from the secondary side and presses the second spring body. a valve-closing force applying member that retracts in the valve-closing direction against the
Furthermore, a second valve drive section is provided for receiving the pressure of the outflow passage and opening the main valve body,
A pressure reducing valve in which the inflow passage of the valve device communicates with the primary side of the main passage.

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