JP2005044278A - Pressure control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve pressure control accuracy by keeping a desired secondary pressure constant even when the flow rate of fluid varies.
A first pressure control valve A is configured such that the flow direction of a fluid passing through a throttle portion formed by a first valve body 27 and a first valve seat 25 is such that the first valve body 27 is closed. The second pressure control valve B is configured so that the flow direction of the fluid passing through the throttle portion constituted by the second valve body 47 and the second valve seat 45 is the same as that of the second valve body 47. Same as the valve opening direction.
[Selection] Figure 1

Description

  The present invention relates to a pressure control device including a pressure control valve that moves a valve body in accordance with a displacement amount of a diaphragm and changes an effective passage sectional area of a throttle portion.

As a pressure control device, for example, one described in Patent Document 1 below is known.
JP-A-8-30332

  This is because a fluid passage having an inlet portion and an outlet portion is provided inside the valve body, a throttle portion including a valve seat and a valve body is provided in the fluid passage, and each of the two diaphragm chambers partitioned by the diaphragm is mutually connected. Connect pipes to introduce different pressures. The diaphragm and the valve body are connected to each other via a valve rod, and the valve body moves in accordance with the amount of displacement of the diaphragm to change the effective cross-sectional area of the throttle portion.

  When such a pressure control device operates, the fluid enters the fluid passage from the inlet portion, moves the valve body in the valve opening direction at the throttle portion, is decompressed, and is discharged from the outlet portion. As a result, the pressure is adjusted according to the pressure acting on the diaphragm.

  In the conventional pressure control device as described above, the fluid force applied to the valve body by the fluid passing through the throttle portion becomes larger as the passage flow rate increases, so that when this influence (fluid force) increases, both sides of the diaphragm When the balance of force due to the pressure difference in the diaphragm chamber is lost and the flow rate fluctuates as a result, there is a problem that the secondary pressure after pressure adjustment deviates from a desired value.

  Accordingly, an object of the present invention is to increase the pressure control accuracy by keeping a desired secondary pressure constant even when the flow rate of the fluid fluctuates.

  In order to achieve the above object, the present invention forms a throttle portion having a valve seat and a valve body in a fluid passage between an inlet portion and an outlet portion, and is divided by a diaphragm connected to the valve body. In a pressure control apparatus comprising a pressure control valve that introduces different pressures into each of the two diaphragm chambers and moves the valve body in accordance with the displacement amount of the diaphragm to change the effective passage sectional area of the throttle portion A plurality of the pressure control valves are arranged in parallel with the fluid passage, and at least one of the plurality of pressure control valves has a flow direction of the fluid passing through the throttle portion of the valve body. It has the same component as the valve closing direction, and at least one of the other components has the same component as the valve opening direction of the valve body in the flow direction of the fluid passing through the throttle portion.

  According to this invention, when the flow rate of the fluid increases, at least one of the plurality of valve bodies moves to the valve closing side from the reference balance position by the action of fluid force, while at least one of the other valve bodies Conversely, the valve moves from the reference balance position to the valve opening side, and the influence of the fluid force can be canceled as a whole, that is, the desired secondary pressure is kept constant even when the flow rate fluctuates. As a result, the pressure control accuracy is increased.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an overall configuration diagram of a pressure control device showing a first embodiment of the present invention. The gas supplied at the pressure (primary pressure) P0 from the gas supply port 1 as the inlet is formed in parallel with each other in the body 2, and the first gas passage 3 and the second gas passage 5 as fluid passages are formed. It is discharged at a pressure (secondary pressure) P1 through the gas discharge port 7 as an outlet.

  The first gas passage 3 extends from the gas supply port 1 to the gas discharge port 7 with the first bent portion 9 upward in the left direction and in the right direction with the second bent portion 11. Are bent at an angle of 90 degrees respectively in the right horizontal direction, at the third bent portion 13 downward in the rightward view, and at the fourth bent portion 15 in the left horizontal view in the leftward view. .

  The second gas passage 5 is located at the first bent portion 17 on the downstream side of the first bent portion 9 in the first gas passage 5 between the gas supply port 1 and the gas discharge port 7. In the first gas passage 3 upward in the direction diagram, in the right horizontal direction in the diagram in the right direction at the second bent portion 19, and downward in the diagram in the right direction in the third bent portion 21. The fourth bent portion 23 upstream from the fourth bent portion 15 is bent at an angle of 90 degrees in the right horizontal direction in the drawing in the left direction.

  By making the first gas passage 3 and the second gas passage 5 bend as described above, the gas supply port 1 and the gas discharge port 7 are positioned in the same straight line.

  A first valve seat 25 is provided between the first bent portion 9 and the second bent portion 11 of the first gas passage 3, and the first valve seat 25 constitutes a throttle portion. One valve body 27 is installed so as to be able to move toward and away from the first valve seat 25 from the first bent portion 9 side. That is, the flow direction of the fluid passing through the throttle portion has the same component as the closing direction of the first valve body 27.

  The first valve body 27 is pressed in the valve closing direction by a first lower spring 29 provided between the first valve seat 25 and the gas passage inner wall on the opposite side. Further, one end of the first valve rod 31 is connected to the opposite side of the first valve body 27 to the first lower spring 29, and the other end of the first valve rod 31 is connected to the first diaphragm 33. ing.

  The first diaphragm 33 is installed in a first differential pressure chamber 35 formed in the body 2, and the first differential pressure chamber 35 is connected to the first upper portion opposite to the valve rod 31. It is divided into two spaces, a diaphragm chamber 37 and a first lower diaphragm chamber 39 on the valve rod 31 side. A pressure P0 equivalent to that of the gas supply port 1 is introduced into the first upper diaphragm chamber 37, while a pressure P1 equivalent to that of the gas discharge port 7 is introduced into the first lower diaphragm chamber 39.

  A first upper spring 41 is provided in the first upper diaphragm chamber 37 to press the first valve rod 31 in the direction in which the first valve body 27 opens. The initial set load of the first upper spring 41 and the first lower spring 29 is the first diaphragm due to the differential pressure in the first differential pressure chamber 35 according to the magnitude of the secondary pressure P1 to be set. It is set so as to balance with the force generated at 33.

  The first valve rod 31 is movably inserted in a through hole 2a formed in the body 2 between the first gas passage 3 and the first differential pressure chamber 35. Sealing materials 42 and 43 are provided in the vicinity of the first gas passage 3 and the first differential pressure chamber 35, respectively.

  A second valve seat 45 is provided between the third bent portion 21 and the fourth bent portion 23 of the second gas passage 5, and the second valve seat 45 constitutes a throttle portion. The second valve body 47 is installed so as to be movable toward and away from the second valve seat 45 from the fourth bent portion 23 side. That is, the flow direction of the fluid passing through the throttle portion has the same component as the opening direction of the second valve body 47.

  The second valve body 47 is pressed in the valve closing direction by a second lower spring 49 provided between the second valve seat 45 and the gas passage inner wall on the opposite side. In addition, one end of the second valve rod 51 is connected to the opposite side of the second valve body 47 from the second lower spring 49, and the other end of the second valve rod 51 is connected to the second diaphragm 53. ing.

  The second diaphragm 53 is installed in a second differential pressure chamber 55 formed in the body 2, and the second differential pressure chamber 55 is connected to the second upper portion opposite to the valve rod 51. The diaphragm chamber 57 is partitioned into two spaces, a second lower diaphragm chamber 59 on the valve rod 51 side. A pressure P0 equivalent to that of the gas supply port 1 is introduced into the second upper diaphragm chamber 57, while a pressure P1 equivalent to that of the gas discharge port 7 is introduced into the second lower diaphragm chamber 59.

  A second upper spring 61 is provided in the second upper diaphragm chamber 57 to press the second valve rod 51 in the direction in which the second valve body 57 opens. The initial set load of the second upper spring 61 and the second lower spring 49 is a second diaphragm due to the differential pressure in the second differential pressure chamber 55 according to the magnitude of the secondary pressure P1 to be set. The balance is set so as to balance the force generated at 53.

  The second valve rod 51 is movably inserted into a through hole 2b formed in the body 2 between the second gas passage 5 and the second differential pressure chamber 55. Sealing materials 62 and 63 are provided in the vicinity of each of the second gas passage 5 and the second differential pressure chamber 55.

  It is assumed that the first gas passage 3 is formed in the body 2 so as to avoid the second valve rod 51.

  As described above, the pressure control device according to the first embodiment includes the first pressure control valve A having the first valve body 27 and the first diaphragm 33, the second valve body 47, and the second valve body. And a second pressure control valve B having a diaphragm 53 and the like.

  Next, the operation of each of the first and second pressure control valves A and B in the first embodiment and the operation as a whole will be described.

  FIG. 2A is an operation explanatory diagram of the first pressure control valve A. FIG. Considering the balance of forces on the first valve element 27 and the first valve stem 31, a downward force in the figure generated by the pressure difference between the first upper diaphragm chamber 37 and the first lower diaphragm chamber 39 is shown. (Differential pressure) Fp, upward force (spring force) Fs in the figure generated by the initial set load of the first lower spring 29, and the gap between the first valve body 27 and the first valve seat 25 in the figure In other words, when passing through the throttle portion, there are three forces of upward force (fluid force) Fq given to the first valve element 27 in the figure.

  Of these, the fluid force Fq increases as the gas flow rate Q increases as shown in FIG. 2B, so that the first valve element 27 automatically increases the differential pressure Fp to maintain balance. In other words, the secondary pressure P1 is decreased and the differential pressure between the first upper diaphragm chamber 37 and the first lower diaphragm chamber 39 is increased. That is, the following expression (1) is established.

Fp = Fs + Fq (1)
FIG. 3A is an operation explanatory diagram of the second pressure control valve B. FIG. Similar to the first pressure control valve A described above, when considering the balance of forces on the second valve element 47 and the second valve rod 51, the second upper diaphragm chamber 57, the second lower diaphragm chamber 59, The downward force (differential pressure) Fp in the figure generated by the pressure difference between the two, the upward force (spring force) Fs in the figure generated by the initial set load of the second lower spring 49, and the gas is the second valve When passing through the gap between the body 47 and the second valve seat 45, that is, the throttle part, there are three forces of downward force (fluid force) Fq given to the second valve body 47 in the figure.

  Of these, the fluid force Fq increases as the gas flow rate Q increases, as shown in FIG. 3B, so that the second valve body 47 automatically reduces the differential pressure Fp in order to maintain balance. That is, the secondary pressure P1 is increased so that the differential pressure between the second upper diaphragm chamber 57 and the second lower diaphragm chamber 59 is reduced. That is, the following equation (2) is established.

Fp = Fs−Fq (2)
4 is combined with the force balance equation (1) of the first pressure control valve A described in FIG. 2 and the force balance equation (2) of the second pressure control valve B described in FIG. As can be seen from the graph, Fp = Fs, and the influence of the fluid force Fq on the differential pressure Fp can be canceled.

  Thus, according to the first embodiment described above, it is possible to invalidate the influence of the fluid force Fq on the differential pressure Fp, that is, even if the fluid force Fq fluctuates, The differential pressure acting on the top and bottom of each diaphragm 33, 53 can be kept constant. This means that the desired secondary pressure P2 can be kept constant even when the flow rate of the gas passing through the first and second valve bodies 27 and 47 varies, and as a result, The effect that the pressure control accuracy of the pressure control device is increased is obtained.

  FIG. 5 is an overall configuration diagram of a pressure control device showing a second embodiment of the present invention. In this embodiment, the second gas passage 50 is linear from the gas supply port 1 to the vicinity of the installation of the second valve body 47, and is directed rightward (downward in the figure) on the upstream side of the second valve body 47. ) And a second bent portion 190 that is bent in the left direction (right horizontal direction in the figure) on the downstream side of the second valve body 47, and further on the downstream side thereof. A third bent portion 210 bent in the left direction (upward in the drawing) and a fourth bent portion 230 bent in the right direction (right horizontal direction in the drawing) toward the gas discharge port 7, respectively. It is provided.

  The fourth bent portion 230 serves as a junction with the fourth bent portion 15 in the first gas passage 3. The fourth bent portion 230 communicates with the gas discharge port 7 from the junction, The vertical height position is the same as that of the first gas passage 50 in the straight line portion extending from the gas supply port 1 to the first bent portion 170.

  For this reason, the first pressure control valve A installed in the second gas passage 3 bent upward in the drawing in the left direction from the first bent portion 9 is located above the first pressure control valve B. Will be located. About another structure, it is the same as that of 1st Embodiment.

  In this second embodiment, the bending that bends at 90 degrees in each of the first and second gas passages 3 and 50 connected from the gas supply port 1 to the gas discharge port 7. The number of the parts is four from the first to the fourth, and the number of the bent parts is the same as in the first embodiment shown in FIG.

  Thus, by making the number of bent portions of the first and second gas passages 3, 50 (5) the same, no matter which gas passes through each of the gas passages 3, 50 (5). The passage resistance due to the bent portion becomes equal. Thereby, the distribution of the gas flow rate to the first and second pressure control valves A and B is equalized, the magnitude of the fluid force acting on the first and second valve bodies 27 and 47 is also equalized, Since the physical force canceling action can be realized with higher accuracy, the pressure control accuracy of the pressure control device can be further increased.

  That is, at least two of the plurality of fluid passages provided corresponding to the plurality of pressure control valves have the same total number of bent portions between the inlet portion and the outlet portion, and thus are generated by the bent portion in the middle of the gas passage. Regarding the passage resistance, the difference between the plurality of gas passages becomes minute, and the distribution of the flow rate to each pressure control valve can be made more uniform, that is, the pressure control accuracy of the pressure control device can be further increased.

  FIG. 6 is an overall configuration diagram of a pressure control device showing a third embodiment of the present invention. In this embodiment, a shutoff valve 65 for shutting off the gas flow is provided upstream of the first bent portion 17 in the second gas passage 5. The shutoff valve 65 is driven by a control signal output by the shutoff valve control circuit 67 based on a gas flow rate signal or a gas pressure signal measured by a flow meter or a differential pressure meter (not shown). Other configurations are the same as those of the first embodiment shown in FIG.

  FIG. 7 is a flowchart for controlling the movement of the shutoff valve 65 in the third embodiment, and the algorithm will be described below.

  First, the current gas flow rate Qn is measured or calculated by a flow meter or a differential pressure meter (step S1), and the magnitude relationship with a preset valve opening / closing switching flow rate Qc is compared by Qn ≧ Qc (step S2). If Qn ≧ Qc does not hold, that is, if the current gas flow rate Qn is smaller than the valve opening / closing switching flow rate Qc, the process returns to step S1 to update the gas flow rate Qn. Conversely, if Qn ≧ Qc is established, an open signal is output to the shutoff valve 65 (step S3), and pressure control using both the first and second pressure control valves A and B is started.

  Subsequently, after the current gas flow rate Qn is measured again and the gas flow rate Q is updated (step S4), the magnitude relationship with the valve opening / closing switching flow rate Qc is compared by Qn <Qc (step S5). If Qn <Qc does not hold, that is, if the current gas flow rate Qn is equal to or greater than the valve opening / closing switching flow rate Qc, the process returns to step S4 to update the gas flow rate Qn. Conversely, if Qn <Qc, a close signal is output to the shutoff valve 65 (step S6), and pressure control using only the first pressure control valve A is started.

  According to the third embodiment described above, at the time of small flow control with little influence of fluid force, the pressure control can be performed by the first pressure control valve A on only one side, that is, the passage per pressure control valve. By increasing the flow rate on average, it is not necessary to use a minute opening region of the valve body that makes pressure control difficult, and as a result, further improvement in pressure control accuracy can be expected particularly in a small flow rate region.

  That is, at least one of the plurality of fluid passages provided corresponding to the plurality of pressure control valves is provided with a shut-off valve that shuts off the flow of fluid. It is possible to control the pressure only with this valve, that is, it is not necessary to use the minute opening area of the valve body that makes pressure control difficult because the passage flow rate per pressure control valve increases on average. As a result, further improvement in pressure control accuracy can be expected particularly in a small flow rate region.

  FIG. 8 is an overall configuration diagram of a pressure control device showing a fourth embodiment of the present invention. In this embodiment, the upper ends of the first valve rod 69 and the second valve rod 71 are connected and integrated with each other by a connecting rod 73, and the upper portion of the connecting rod 73 in the longitudinal direction is connected to the connecting tool 75. To one common diaphragm 77.

  The common diaphragm 77 has a pressure P1 equivalent to that of the upper common diaphragm chamber 81 on the opposite side of the connector 75 and the gas discharge port 7 into which the pressure P0 equivalent to that of the gas supply port 1 is introduced. It is divided into two spaces, the lower common diaphragm chamber 83 on the side of the connecting tool 75 to be introduced.

  In the upper common diaphragm chamber 81, an upper common spring 85 that presses the connector 75 in the direction in which the first and second valve bodies 27 and 47 open is provided. The initial set load of the upper common spring 85 and the first lower spring 29 and the second lower spring 49 described above depends on the differential pressure in the common differential pressure chamber 79 according to the magnitude of the secondary pressure P1 to be set. The balance is set so as to balance the force generated in the common diaphragm 77.

  The upper end of the through hole 2a into which the first valve rod 69 is movably inserted and the upper end of the through hole 2b into which the second valve rod 71 is movably inserted are connected to the connecting rod moving space 2c. The connecting rod 73 protrudes and is accommodated in the connecting rod moving space 2c so as to be movable up and down. Further, a connecting tool 75 is movably inserted into a through hole 2d communicating with the connecting rod moving space 2c and the common differential pressure chamber 79, and a seal member 87 is provided in the vicinity of the common differential pressure chamber 79 of the through hole 2d. . Other configurations are the same as those of the first embodiment described above.

  According to the fourth embodiment described above, by forming the common diaphragm 77 and the common differential pressure chamber 79 by the common diaphragm 77, these can be combined into one, the entire apparatus can be simplified, maintenance and Adjustment work can be saved. Furthermore, the cost reduction effect by the number of parts reduction can also be acquired.

  That is, since at least two of the valve bodies in the plurality of pressure control valves are connected to one common diaphragm by the valve rods integrated with each other, the diaphragm and the two diaphragm chambers sandwiching the diaphragm can be simplified. A cost reduction effect due to the reduction in the number of points can also be obtained.

  FIG. 9 is an overall configuration diagram of a pressure control device showing a fifth embodiment of the present invention. In this embodiment, the first gas passage 103 and the second gas passage 105 as fluid passages formed between the gas supply port 1 and the gas discharge port 7 are arranged in the same straight line. The port 1 and the gas discharge port 7 are arranged in the vertical direction in the figure.

  That is, the first gas passage 103 has a third bent portion at the first bent portion 107 in the left direction (upward in the figure), and at the second bent portion 109 in the right direction (right horizontal direction in the drawing). The portion 111 is bent in the right direction (downward in the figure), and further in the left direction (right horizontal direction in the figure) at the fourth bent portion 113, respectively, and communicates with the gas discharge port 7.

  On the other hand, the second gas passage 105 has a third bent portion in the right direction (downward in the drawing) at the first bent portion 115, and in the left direction (right horizontal direction in the drawing) in the second bent portion 117. The portion 119 is bent leftward (upward in the drawing), and the fourth bent portion 121 is bent rightward (right horizontal in the drawing) at an angle of 90 degrees to communicate with the gas discharge port 7.

  A second valve seat 123 is provided between the third bent portion 119 and the third bent portion 121 of the second gas passage 105, and a throttle portion is configured by the second valve seat 123. The second valve body 47 is installed so as to be movable toward and away from the second valve seat 123 from the third bent portion 119 side. That is, the flow direction of the fluid passing through the throttle portion has the same component as the closing direction of the second valve body 47. The second valve body 47 is pressed in the valve closing direction by a lower spring 125 provided between the second valve seat 123 and the gas passage inner wall on the opposite side.

  On the other hand, a first valve seat 127 is provided between the third bent portion 111 and the fourth bent portion 113 of the first gas passage 103, and the first valve seat 127 is connected to the throttle portion. The first valve body 27 that constitutes the first valve body 27 is installed so as to be movable toward and away from the first valve seat 127 from the fourth bent portion 113 side. That is, the flow direction of the fluid passing through the throttle portion has the same component as the opening direction of the first valve body 27.

  The first valve body 27 and the second valve body 47 are connected to each other by a second valve rod 129, and the third bent portion 111 side of the first valve body 27 is connected to the first valve rod. The other end of the first valve rod 131 is connected to the common diaphragm 133.

  The common diaphragm 133 is installed in a common differential pressure chamber 135 formed in the body 2, and the common differential pressure chamber 135 is introduced with a pressure P 0 equivalent to that of the gas supply port 1 by the common diaphragm 133. The upper common diaphragm chamber 137 on the side opposite to the first valve rod 131 and the lower common diaphragm chamber 139 on the first valve rod 131 side into which the pressure P1 equivalent to that of the gas discharge port 7 is introduced. It is divided into spaces.

  In the upper common diaphragm chamber 137, an upper common spring 141 that presses the first valve rod 131 in the direction in which the first and second valve bodies 27 and 47 open is provided. The initial set load of the upper common spring 141 and the lower common spring 125 is balanced with the force generated in the common diaphragm 133 due to the differential pressure in the common differential pressure chamber 135 according to the magnitude of the secondary pressure P1 to be set. Set as follows.

  The first valve rod 131 is movably inserted into a through hole 2e formed in the body 2 between the first gas passage 103 and the common differential pressure chamber 135, and the first valve rod 131 has a first hole. Sealing materials 142 and 143 are provided in the vicinity of the gas passage 103 and the common differential pressure chamber 135.

  According to the fifth embodiment described above, by forming the common diaphragm 133 and the common differential pressure chamber 135 by the common diaphragm 133, these can be combined into one, simplifying the entire apparatus and reducing the number of parts. As a matter of course, it is not necessary to prepare a plurality of valve stems individually, and the first valve stem 131 and the second valve stem 129 can be integrated so as to be linear with each other. In addition, it can be expected that the pressure control device as a whole will be reduced in weight and space.

  That is, since the valve stems integrated with each other are connected in the same straight line, the diaphragm and the two diaphragm chambers sandwiching the diaphragm can be simplified, and the valve stem can be reduced to one integrated, In addition to the further cost reduction effect, it can be expected to contribute to the weight reduction and space saving of the entire pressure control device.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram of the pressure control apparatus which shows 1st Embodiment of this invention. (A) is operation | movement explanatory drawing of the 1st pressure control valve in 1st Embodiment, (b) is explanatory drawing which showed the relationship between a gas flow rate and a differential pressure in consideration of spring force and fluid force. is there. (A) is operation | movement explanatory drawing of the 2nd pressure control valve in 1st Embodiment, (b) is explanatory drawing which showed the relationship between a gas flow rate and differential pressure | pressure, considering spring force and fluid force. is there. It is explanatory drawing when the operation | movement of each 1st, 2nd pressure control valve is combined. It is a whole block diagram of the pressure control apparatus which shows 2nd Embodiment of this invention. It is a whole block diagram of the pressure control apparatus which shows the 3rd Embodiment of this invention. It is a flowchart for controlling the movement of the shut-off valve in the third embodiment. It is a whole block diagram of the pressure control apparatus which shows 4th Embodiment of this invention. It is a whole block diagram of the pressure control apparatus which shows 5th Embodiment of this invention.

Explanation of symbols

A 1st pressure control valve B 2nd pressure control valve 1 Gas supply port (inlet part)
3,103 first gas passage (fluid passage)
5, 50, 105 Second gas passage (fluid passage)
7 Gas exhaust port (exit part)
9, 17, 170, 107, 115 First bent portion 11, 19, 190, 109, 117 Second bent portion 13, 21, 210, 111, 119 Third bent portion 15, 23, 230, 113, 121 4th bent part 25,127 1st valve seat (throttle part)
27 First valve element (throttle part)
33 1st diaphragm 37 1st upper diaphragm chamber 39 1st lower diaphragm chamber 47 2nd valve body (throttle part)
45,123 Second valve seat (throttle part)
53 Second diaphragm 57 Second upper diaphragm chamber 59 Second lower diaphragm chamber 65 Shut-off valve 69, 131 First valve rod (valve rod integrated with each other)
71, 129 Second valve stem (integrated valve stem)
77,133 Common diaphragm 81,137 Upper common diaphragm chamber 83,139 Lower common diaphragm chamber

Claims (5)

  In the fluid passage between the inlet and outlet, a throttle part with a valve seat and valve body is formed, and different pressures are introduced into each of the two diaphragm chambers partitioned by the diaphragm connected to the valve body And a pressure control device including a pressure control valve that moves the valve body in accordance with a displacement amount of the diaphragm and changes an effective passage cross-sectional area of the throttle portion, wherein the pressure control valve is connected to the fluid passage. And at least one of the plurality of pressure control valves has a component in which the flow direction of the fluid passing through the throttle portion has the same component as the valve closing direction of the valve body. At least one of the pressure control devices is characterized in that the flow direction of the fluid passing through the throttle portion has the same component as the valve opening direction of the valve body.   The at least two of the fluid passages provided in correspondence with the plurality of pressure control valves have the same total number of bent portions between the inlet portion and the outlet portion. Pressure control device.   3. The pressure control device according to claim 1, wherein a shutoff valve for shutting off a fluid flow is provided in at least one of a plurality of fluid passages provided corresponding to the plurality of pressure control valves.   The pressure control device according to any one of claims 1 to 3, wherein at least two of the valve bodies of the plurality of pressure control valves are connected to a common diaphragm by valve rods integrated with each other. .   The pressure control device according to claim 4, wherein the valve stems integrated with each other are connected in the same straight line.

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