JP2001005533A - Pressure adjuster for leakage detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact pressure adjuster for a leakage detecting device with high performance by reducing the difference between a blocked pressure and an adjusted pressure by using two kinds of pressure adjusters, that is, master adjuster and a slave adjuster. SOLUTION: In a low pressure reducing part 69 corresponding to a slaved pressure adjuster, at the time of a small flow rate, a low pressure diaphragm 103 is displaced according to the pressure chamber of a low pressure chamber 101, and a low pressure valve 115 is opened and closed so that the pressure of the low pressure chamber 101 can be adjusted, and gas made to flow through a first gas exit passage 65a to a leakage detecting device, and at the time of a large flow rate, a pressure loss is generated between the upstream and downstream of an orifice 120, and the pressure at the downstream side is decreased. In a low pressure reducing part 131 for the feeding equivalent to a master pressure adjuster, a low pressure diaphragm 133 for the feeding is displaced, and a by-pass valve 149 is opened, and gas inflowing to a gas entrance passage 53 flows out from a low pressure reducing chamber 137 through a by-pass nozzle part 147a to a second gas exist passage 65b based on a pressure difference between the pressure decreasing part and the low pressure reducing chamber 137, being communicated with the upstream side of the orifice 120.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure regulator for regulating the pressure of gas supplied from a gas supply side to a gas use side, and more particularly to a gas leakage detection device for detecting gas leakage in a gas supply pipe of a gas supply facility. The present invention relates to a pressure regulator for a leak detection device used for a pressure sensor.

[0002]

2. Description of the Related Art A conventional gas leak detecting device shown in FIG.
It is applied to gas supply facilities that supply gas to apartment houses and other apartments. The gas supply pipe 303 has a primary pressure regulator 3
A primary pressure regulator 317 is provided in the gas supply pipe 307 via the primary pressure regulator 305.

The gas supply pipe 307 is provided with a bypass gas passage 311 for connecting the inlet side and the outlet side of the master pressure regulator 317. Gas meter 315 having a leak detector 309 and a leak detection function for detecting a small leak of gas
Are provided.

[0004] The adjustment pressure of the child pressure regulator 309 is set higher than the adjustment pressure of the parent pressure regulator 317. Further, the microcomputer gas meter 315 can accurately accumulate the minute flow rate, and monitors by the minute leak detection function.
If there is a flow rate of 3 liters / hour or more for consecutive days, it is determined that a gas leak has occurred, and the fact is indicated by lighting a lamp.

Further, when gas consumption at night or at night is almost eliminated, the pressure of the gas supply pipe 307 increases, the parent pressure regulator 317 is closed, and gas flows to the child pressure regulator 309 and the microcomputer gas meter 315, Supply path 3
It is possible to monitor a minute gas flow rate flowing through 11.

As described above, the bypass gas flow path 311 is provided in a part of the gas supply path, and the gas flows through the bypass gas flow path 311 when the flow rate is low by the regulators having different adjustment pressures. Since the micro gas leak is detected by monitoring the flow rate by the microcomputer gas meter 315 capable of detecting the flow rate, the gas leak of the gas supply pipe can be easily and reliably detected without stopping the gas supply.

FIG. 8 is a sectional view of a conventional pressure regulator. This pressure regulator is used in a combustor from a gas supply side LP gas cylinder to a gas range etc.
It is provided in the middle of a gas supply passage for supplying LP gas.
The housing 1 includes a body 3 and a cover 5 attached to an upper opening of the body 3. An inlet defining a gas inlet passage 7 through which high-pressure gas is introduced is provided at a left end of the body 3 in the drawing. On the right side of the body 3, a gas outlet passage 11 through which gas decompressed to a predetermined pressure flows is provided.
Are formed.

[0008] Between the gas inlet passage 7 and the gas outlet passage 11, an intermediate pressure reducing portion 13 and a low pressure reducing portion 15 are provided. The medium-pressure reducing unit 13 reduces the pressure of the gas introduced at 0.07 to 1.56 MPa to a medium pressure of about 0.06 MPa, and the low-pressure reducing unit 15 further reduces the pressure to 2.0.
The pressure is reduced to a low pressure of about 55 to 3.3 kPa.

The medium pressure reducing section 13 has a medium pressure diaphragm 23 which is pressed from the atmospheric pressure chamber 17 side to the medium pressure chamber 21 side by a medium pressure spring 19. An intermediate pressure valve 29 is provided at the lower end of the intermediate pressure interlock 25 fixed to the intermediate pressure diaphragm 23 via a valve rod 27, and the intermediate pressure nozzle portion 31 is opened and closed by the vertical movement of the intermediate pressure valve 29.

The low-pressure reducing unit 15 includes a low-pressure diaphragm 39 which is pressed by the low-pressure spring 35 from the atmospheric-pressure chamber 33 to the low-pressure chamber 37. One end of a lever 43 is connected to the operating rod 41 fixed to the low-pressure diaphragm 39. The lever 43 is rotatable via a pin 45, and the other end is connected to a low-pressure valve 49 that can move in the left-right direction to open and close the low-pressure nozzle unit 47.

When the gas is used on the combustor side, the pressure in the intermediate pressure chamber 21 decreases, and when the intermediate pressure diaphragm 23 is pressed downward by the intermediate pressure spring 19 and displaced, the intermediate pressure valve 29 Moves downward and the medium pressure nozzle 31
To release. Thereby, the gas introduced from the gas inlet passage 7 flows to the medium pressure chamber 21 side. When the pressure in the medium pressure chamber 21 rises and this pressure overcomes the elastic force of the medium pressure spring 19, the medium pressure valve 29 moves upward to narrow the flow path of the medium pressure nozzle portion 31, and the gas to the medium pressure chamber 21 Control the inflow of water. Thus, the intermediate pressure valve 29 controls the opening and closing of the flow path of the intermediate pressure nozzle portion 31 to control the amount of gas flowing into the intermediate pressure chamber 21, and
Adjust pressure.

On the other hand, in the low-pressure reducing section 15, the gas is used on the combustor side, so that the pressure in the low-pressure chamber 37 is reduced.
Is pressed downward and displaced, the lever 43
Rotates counterclockwise, and the low-pressure valve 49 moves rightward to open the low-pressure nozzle portion 47. This allows
The gas introduced from the medium pressure chamber 21 flows to the gas outlet passage 11 side. When the pressure in the low-pressure chamber 37 rises and this pressure overcomes the elastic force of the low-pressure spring 35, the lever 43 rotates clockwise, and the low-pressure valve 49 moves to the left, and the flow path of the low-pressure nozzle portion 47 And the flow of gas into the low-pressure chamber 37 is controlled. As described above, the low-pressure valve 49 controls the opening and closing of the flow path of the low-pressure nozzle portion 47 to control the amount of gas flowing into the low-pressure chamber 37 and adjust the pressure of the low-pressure chamber 37.

[0013]

However, in the parent-child type differential pressure regulator including the parent pressure regulator 317 and the child pressure regulator 309 used in the conventional gas leak detecting device, when the flow rate is very small, the parent-child type differential pressure regulator must be used. The closing pressure and the adjustment pressure of the child pressure regulator 309 need to be set higher than those of the parent pressure regulator 317 so that the gas flows preferentially from the child pressure regulator 309.

In this case, as shown in FIG. 7, in accordance with the technical standards, when the flow rate is very small, the adjustment pressure is set to around 3.3 kPa by a small pressure regulator. The pressure is switched from 3.3 kPa to the parent pressure regulator, and the regulated pressure is set from 3.3 kPa to 2.55 kPa. In addition, in the conventional parent-child differential pressure regulator,
Since the parent pressure regulator and the child pressure regulator were connected in parallel, the closing pressure of the child pressure regulator was set to be about 0.3 kPa higher than the closing pressure of the parent pressure regulator.

However, since the master pressure regulator and the slave pressure regulator are combined, the design of the master pressure regulator and the slave pressure regulator must be adjusted to keep the closing pressure and the adjustment pressure within the technical standards. It was difficult. Further, since the parent pressure regulator and the child pressure regulator are provided separately, the parent-child type differential pressure regulator has been increased in size.

On the other hand, in the above-described conventional pressure regulator, in order to increase the capacity in order to secure a large amount of gas supply, it is particularly necessary to increase the passage diameter of the low-pressure nozzle portion 47. Here, a simple calculation of the adjustment pressure in the pressure regulator has a relationship of adjustment pressure [P] = spring load [F] / area of the diaphragm [S]. To make the pressure 3 kPa, it is not necessary to increase the area of the low-pressure diaphragm 39. However, when the gas flow is stopped, the low pressure nozzle portion 47
Is reliably sealed with a low-pressure valve 49, and the so-called closing pressure is controlled to a specified pressure of 3.5 kPa or less.
If the passage diameter of the low-pressure nozzle portion 47 increases, the low-pressure diaphragm 39 must necessarily be increased.

Normally, the inlet pressure in the pressure regulator changes depending on the vapor pressure of the gas. Even when the low-pressure valve 49 is open (gas is flowing), the low-pressure valve 49 is set to [(pressure on the upstream side of the low-pressure valve 49-pressure on the downstream side) × the passage area of the low-pressure nozzle portion 47]. Near pressure is applied, and the adjustment pressure changes depending on the magnitude of the inlet pressure. For this reason,
In order to reduce the difference in the force applied to the low pressure valve 49 due to the change in the inlet pressure, the low pressure diaphragm 39 must be increased. Such an increase in the size of the low-pressure diaphragm 39 is remarkable, and is an obstacle to reducing the size of the pressure regulator.

Therefore, the present invention enables a large-capacity pressure regulator without increasing the size of the diaphragm in the low-pressure decompression section, and without using two types of pressure regulators, a parent and a child. An object of the present invention is to provide a compact and high-performance pressure regulator for a leak detection device, which can reduce the difference between the closing pressure and the regulation pressure.

[0019]

According to one aspect of the present invention, there is provided a pressure adjusting device for use in a gas leak detecting device for detecting a gas leak in a gas supply pipe of a gas supply facility. A first valve body capable of opening and closing a first nozzle portion that communicates a gas inlet passage with a first gas outlet passage through which gas flowing into the gas inlet passage flows out to the leak detection device; and A first pressure reducing means having a first diaphragm for performing an opening and closing operation of the first valve body by performing displacement based on a pressure change on the first gas outlet passage side; A differential pressure generating unit provided between the inlet passage and the first nozzle unit, the pressure reducing unit decreasing the pressure in accordance with the flow of gas; When a decompression chamber communicating with the upstream side of the generating means is defined In addition, a second diaphragm that is displaced based on a pressure difference between the pressure reduction unit and the decompression chamber, a second nozzle unit that connects the decompression chamber and the gas outlet passage, and a second nozzle unit. Second pressure reducing means configured to provide a second valve element that can be opened and closed in conjunction with the operation of the second diaphragm, and that allows gas flowing into the gas inlet passage to flow out to a second gas outlet passage; It is characterized by having.

According to the pressure regulator for a leak detecting device having such a configuration, at a low flow rate, the first diaphragm is displaced in accordance with a pressure change on the first gas outlet passage side, and based on this, the first diaphragm is displaced. The valve body opens and closes the first nozzle portion to adjust the pressure on the first gas outlet passage side, and the gas is sent to the leak detection device that detects gas leakage through the first gas outlet passage. In addition, when the flow rate is small, there is almost no pressure difference between the upstream side and the downstream side of the differential pressure generating means. Therefore, the second diaphragm in the second pressure reducing means connects the second valve body to the second valve body.
Is displaced so as to close the nozzle portion of the nozzle.

When the gas flow rate increases and the flow velocity increases, a pressure loss occurs between the upstream and downstream of the differential pressure generating means, and the pressure on the downstream side decreases to form a pressure reduction section. The second diaphragm is displaced by the pressure difference between the pressure lowering section and the pressure reducing chamber communicating with the upstream side of the differential pressure generating means, and the second valve body is actuated accordingly to cause the second diaphragm to move. The nozzle part of is opened. By opening the second nozzle portion, the gas flowing into the gas inlet passage passes through the second nozzle portion through the decompression chamber and passes through the second nozzle portion.
Out into the gas outlet passage.

According to a second aspect of the present invention, in the configuration of the first aspect of the present invention, a gas introducing valve body capable of opening and closing a gas introducing nozzle provided on an upstream side of the differential pressure generating means, and the gas introducing valve are provided. A gas introduction decompression means provided with a gas introduction diaphragm for performing an opening and closing operation of the body by performing displacement based on a gas pressure change between the differential pressure generation means and the gas introduction nozzle portion is provided. There is a configuration.

According to the above construction, the gas introduction diaphragm is displaced based on a change in the gas pressure between the differential pressure generating means and the gas introduction nozzle, whereby the gas introduction valve is moved to the gas introduction nozzle. To adjust the pressure on the upstream side of the differential pressure generating means.

According to a third aspect of the present invention, in the configuration of the first or second aspect, the differential pressure generating means is constituted by an orifice.

According to the above configuration, the pressure of the introduced gas drops as it passes through the orifice.

According to a fourth aspect of the present invention, in the configuration of the first or second aspect, the differential pressure generating means is configured by increasing the length of the gas passage.

According to the above configuration, the pressure of the introduced gas drops as it passes through the portion having a long passage length.

According to a fifth aspect of the present invention, in the configuration of the first or second aspect of the invention, the differential pressure generating means is configured by reducing the diameter of the gas passage.

According to the above configuration, the pressure of the introduced gas drops as it passes through a portion having a small passage diameter.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a pressure regulator for a leak detecting device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of a pressure regulator for a leak detection device according to an embodiment of the present invention. It is provided in a gas supply passage for supplying LP gas to a combustor such as a range. The housing 51 is
An upper cover 57 and a lower cover 59 are mounted above and below a body 55 having a gas inlet passage 53, respectively.

A first gas outlet passage 65a is formed at the right end of the body 55, and the first gas outlet passage 65a is provided with a microcomputer gas meter 203 (FIG. 2) having a leak detector for detecting gas leak. Shown below). The gas outlet side of the lower cover 59 is formed in a cylindrical shape, and a union 63 is attached to an end face of the cylindrical portion to form a second gas outlet passage 65b.

The gas inlet passage 53 and the first gas outlet passage 6
5a, like the conventional one shown in FIG.
The pressure of the gas introduced at 0.07 to 1.56 MPa is
A medium-pressure depressurizing section 67 as a gas-introducing depressurizing means for depressurizing to about 0.06 MPa, and further reducing the pressure by 2.55-3.3
A low-pressure reducing section 69 is provided as first pressure reducing means for reducing the pressure to about kPa. The low pressure reducing unit 69 corresponds to a child pressure regulator of a conventional parent-child differential pressure regulator.

The medium pressure reducing section 67 is a medium pressure diaphragm 77 as a gas introduction diaphragm which is pressed from the atmospheric pressure chamber 71 side to the medium pressure reducing chamber 75 by the medium pressure spring 73.
It has. The intermediate pressure diaphragm 77 has a peripheral edge fixed between the body 55 and the upper cover 57 and is fixed to the atmospheric pressure chamber 7.
1 and a decompression chamber 75 for medium pressure are hermetically partitioned.

An intermediate pressure interlock 79 is provided at the center of the intermediate pressure diaphragm 77, and the intermediate pressure diaphragm 77 is sandwiched between a flange 79a formed on the side of the intermediate pressure reducing chamber 75 and the diaphragm receiving plate 81. By fastening the nut 83, the intermediate pressure interlock 79 is fixed to the intermediate pressure diaphragm 77.

The intermediate pressure interlock 79 is provided with a medium pressure valve 87 as a gas introduction valve at the lower end thereof via a valve rod 85. The medium pressure valve 87 opens and closes a medium pressure nozzle portion 91 as a gas introduction nozzle portion of the medium pressure valve case 89, and is pressed toward the medium pressure valve case 89 by a medium pressure valve pressing spring 93. The medium pressure valve case 89 is fixed to the body 55 by a medium pressure valve case holder 95.

The low-pressure reducing section 69 includes a low-pressure diaphragm 103 as a first diaphragm which is pressed from the atmospheric pressure chamber 97 side to the low-pressure reducing chamber 101 via the diaphragm receiving plate 100 by the low-pressure spring 99. The low-pressure decompression chamber 101 communicates with the gas outlet passage 65a. The low-pressure diaphragm 103 has its peripheral edge pinched and fixed between the body 55 and the upper cover 57, and airtightly partitions the atmospheric pressure chamber 97 and the low-pressure decompression chamber 101.

An operating rod 109 is vertically provided at the center of the low-pressure diaphragm 103, and one end of a lever 111 is slidably cross-engaged below the operating rod 109. The lever 111 is pivotally supported on the body 55 about the pin 113, and the other end is connected to a low-pressure valve 115 as a first valve body.

The body 55 is provided with a gas communication passage 117 which communicates the medium pressure decompression chamber 75 with the first gas outlet passage 65a. The gas communication passage 117 is connected to the first gas outlet passage 65a on the side of the first gas outlet passage 65a. The valve case 119 is fixed.
The low-pressure valve 115 is housed in the low-pressure valve case 119 so as to be movable in the left-right direction in the drawing, and the low-pressure nozzle 121 as a first nozzle formed in the low-pressure valve case 119.
Is opened and closed, whereby the communication between the intermediate pressure reducing chamber 75 and the first gas outlet passage 65a is cut off.

An orifice 120 is formed at the end of the low-pressure valve case 119 on the gas communication passage 117 side as a differential pressure generating means. When the gas passes through the orifice 120, a pressure loss occurs between the gas communication passage 117 and the low-pressure nozzle portion 121, and the low-pressure nozzle portion 121 serves as a pressure reducing portion.

A spring receiving seat 125 is provided at a tip of the operating rod 109 projecting into the atmospheric pressure chamber 97. A safety valve adjusting spring 127 is provided between the spring receiving seat 125 and the center of the low-pressure diaphragm 103. It is interposed. The safety valve adjusting spring 127 connects the valve body 125 a of the safety valve integrally formed with the operating rod 109 to the low-pressure diaphragm 1.
It is constantly urged in the direction in which it comes into contact with the valve body receiver 129 disposed on the lower side of the valve body 03.

Below the low pressure decompression section 69, a supply low pressure decompression section 131 as a second decompression means is provided.
The supply low-pressure reducing unit 131 corresponds to a parent pressure regulator of a conventional parent-child differential pressure regulator. Low pressure decompression section 131 for supply
Is provided with a supply low-pressure diaphragm 133 as a second diaphragm whose peripheral edge is fixed between the body 55 and the lower cover 59. Low pressure diaphragm 133 for supply
Are the spring chamber 135 on the body 55 side and the lower cover 59
The supply side pressure reducing chamber 137 is airtightly partitioned from the supply side pressure reducing chamber 137 and is pressed toward the supply low pressure reducing chamber 137 by a supply low pressure spring 139 housed in a spring chamber 135.

The spring chamber 135 has a gas communication passage 117.
And the low pressure nozzle section 121. On the other hand, the supply low-pressure decompression chamber 137 is formed by the inlet bypass passage 143.
It communicates with the medium pressure decompression chamber 75 and the gas communication passage 117 side, and also communicates with the second gas outlet passage 65b through the outlet bypass passage 145.

At the end of the outlet bypass passage 145 on the side of the second gas outlet passage 65b, a bypass nozzle 147 provided with a bypass nozzle portion 147a as a second nozzle portion is mounted. A bypass valve 149 as a second valve body capable of opening and closing the bypass nozzle portion 147a is accommodated in the outlet bypass passage 145 so as to be movable in the left-right direction.

One end of a lever 151 is rotatably connected to the bypass valve 149, and the lever 151 is rotatably supported by the lower cover 59 via a support pin 155. The other end of the lever 151 is connected to the diaphragm shaft 15.
7 is slidably cross-engaged with the lower end of 7.

The diaphragm shaft 157 passes through the center of the supply low-pressure diaphragm 133, and is integrally formed with the supply low-pressure decompression chamber 137 on the side of the flange 157a.
And a nut 1 on the spring chamber 135 side.
59 are screwed together. By clamping the supply low-pressure diaphragm 133 between the flange 157a and the nut 159 via the diaphragm receiving plate 161, the diaphragm shaft 157 is fixed to the supply low-pressure diaphragm 133.

FIG. 2 shows an example of a leak detecting device provided with the pressure regulator for the leak detecting device of FIG. As shown in FIG. 2, the leak detection device includes a first pressure regulator 50 for the leak detection device.
A gas supply pipe 201 provided with a gas stopper 202 is connected to the gas outlet passage 65a, and the gas supply pipe 201 is
It is attached to one end of a microcomputer gas meter 203 having a leak detection unit for detecting a minute leak of gas. A gas supply pipe 205 provided with a gas stopper 204 is attached to the other end of the microcomputer gas meter 203.
Reference numeral 05 is connected to one end of a gas supply pipe 206 provided with a gas stopper 207. The other end of the gas supply pipe 206 is connected to the second gas outlet passage 65 of the leak detector pressure regulator 50.
b.

The microcomputer gas meter 203 can accurately accumulate the minute flow rate of the gas flowing through the gas supply pipe 201 from the first gas outlet passage 65a of the leak detector pressure regulator 50 at a small flow rate. Gas leakage is monitored by the leak detection function, and when the flow rate is equal to or more than a predetermined flow rate, it is determined that gas leakage has occurred, and the fact is indicated by lighting a lamp. The gas that has passed through the microcomputer gas meter 203 flows downstream (direction P) through the gas supply pipe 205. When the flow rate is large, the gas flows from the second gas outlet passage 65b of the leak detector pressure regulator 50 to the downstream (direction P) through the gas supply pipe 206.

Next, the operation of the pressure regulator for a leak detecting device according to the embodiment configured as described above will be described. In the intermediate pressure reducing unit 67, when the gas is used on the combustor side, the pressure in the intermediate pressure reducing chamber 75 decreases, and when the intermediate pressure diaphragm 77 is pressed downward by the intermediate pressure spring 73 and displaced, Accordingly, the intermediate pressure valve 87 moves downward to open the intermediate pressure nozzle portion 91. As a result, the gas introduced from the gas inlet passage 53 flows to the medium pressure reducing chamber 75 side. When the pressure in the intermediate-pressure decompression chamber 75 increases and this pressure overcomes the elastic force of the intermediate-pressure spring 73, the intermediate-pressure valve 87 moves upward to narrow the flow path of the intermediate-pressure nozzle portion 91, and to the intermediate-pressure decompression chamber 75. Control the flow of gas. Thus, the intermediate pressure valve 87 controls the opening and closing of the flow path of the intermediate pressure nozzle portion 91 to control the pressure of the gas flowing into the intermediate pressure decompression chamber 75.

On the other hand, in the low-pressure decompression section 69, the gas is used on the combustor side, so that the pressure in the low-pressure decompression chamber 101 is reduced, and the low-pressure spring 103 presses the low-pressure diaphragm 103 downward to displace. Then, along with this, the lever 111 rotates counterclockwise, and the low-pressure valve 115 moves rightward to open the low-pressure nozzle portion 121. As a result, the gas in the intermediate pressure reducing chamber 75 flows through the gas communication passage 117 to the first gas outlet passage 65a.

For this reason, the gas is supplied to the microcomputer gas meter 2
The microcomputer gas meter 203 accurately integrates the minute flow rate of the gas flowing from the first gas outlet passage 65a through the gas supply pipe 201, and when the flow rate is equal to or more than a predetermined flow rate, gas leakage occurs. Is determined to be performed, and the fact is indicated by lighting of the lamp.

When the pressure in the low-pressure decompression chamber 101 rises and this pressure overcomes the elastic force of the low-pressure spring 99, the low-pressure diaphragm 103 is displaced upward, and the low-pressure valve 115 moves leftward. The flow path of the low-pressure nozzle unit 121 is narrowed, and the flow of gas into the low-pressure decompression chamber 101 is controlled. As described above, the low-pressure valve 115 controls the opening and closing of the flow path of the low-pressure nozzle unit 121 to control the pressure of the gas flowing into the low-pressure decompression chamber 101.

FIG. 3 shows an intermediate pressure valve 8 in the intermediate pressure reducing section 67.
7 is opened, the low-pressure valve 115 in the low-pressure reducing unit 69 is opened, and the gas introduced into the gas inlet passage 53 passes through the medium-pressure nozzle unit 91 and the low-pressure nozzle unit 121 to the first gas outlet passage 65a. The state which flows to is shown.

Here, when the flow rate of the gas flowing through the gas communication passage 117 from the medium pressure nozzle portion 91 to the low pressure nozzle portion 121 is small, the pressure P0 of the gas communication passage 117 on the upstream side of the orifice 120 is determined. There is almost no pressure difference between the pressure and the pressure P1 of the low-pressure nozzle portion 121 on the downstream side. The pressure P0 is supplied to the supply low-pressure decompression chamber 13 communicating with the gas communication passage 117 and the outlet bypass passage 143.
7 is equal to the pressure P2, and the pressure P1 is
Equivalent to a pressure of 35.

As described above, there is almost no pressure difference between the pressure P0 and the pressure P1, that is, the pressure (P1) of the spring chamber 135 and the pressure P2 (= P0) of the supply low-pressure decompression chamber 137 are almost equal. In the same state, the supply low-pressure diaphragm 13
3 is displaced downward. As a result, the lever 151 rotates counterclockwise, and the bypass valve 149 is moved to the bypass nozzle portion 1.
47a is closed, the outflow of gas from the supply low-pressure decompression chamber 137 to the second gas outlet passage 65b is stopped, and the state shown in FIG. 3 is established.

Next, when the flow rate of the gas flowing through the gas communication passage 117 increases and the flow velocity increases, a pressure loss occurs before and after the orifice 120 so that P0> P1, and the pressure (P1) of the spring chamber 135 increases. Low pressure decompression chamber for supply 1
It becomes lower than the pressure P2 (= P0) of 37. When the pressure P2 (= P0) of the supply low-pressure decompression chamber 137 becomes higher than the pressure (P1) of the spring chamber 135 by, for example, 0.01 MPa, the supply low-pressure spring 139 is bent as shown in FIG. 133 is displaced upward, so that the lever 151 rotates clockwise. As a result, the bypass valve 149 moves to the left in the figure to open the bypass nozzle portion 147a, and the gas on the medium pressure reducing chamber 75 side is
The second gas outlet passage 65 through the supply low pressure decompression chamber 137
Flow to b. That is, at the time of a large flow rate, the gas flows downstream (direction P) from the second gas outlet passage 65b through the gas supply pipe 206.

As described above, in the pressure regulator for the leak detecting device, the low-pressure reducing unit 69 corresponds to a conventional child pressure regulator and mainly serves to adjust the pressure.
Reference numeral 1 corresponds to a conventional master pressure regulator, and mainly serves to supply gas to the second gas outlet passage 65b. Therefore, the passage diameter of the low-pressure nozzle unit 121 in the low-pressure reducing unit 69 may be small, and the low-pressure diaphragm 103 may be small.

In the supply low pressure decompression section 131,
If the capacity as the pressure regulator for the leak detection device increases, the diameter of the bypass nozzle portion 147a also increases, and in order to open the bypass valve 149, the “bypass nozzle portion 147
a passage area of [a] × [P2−the pressure of the second gas outlet passage 65b]. This force can be obtained by [load of the supply low-pressure spring 139] × [lever ratio of the lever 151], but can also be obtained by [P2-P1] × [area of the supply low-pressure diaphragm 133].

That is, if the gas flow rate in the gas communication passage 117 increases and the pressure difference [P2-P1] increases, the bypass valve 149 can be easily opened even if the area of the supply low-pressure diaphragm 133 is small. As a result, a large amount of gas can be supplied to the second gas outlet passage 65b, and a large capacity can be achieved as the pressure regulator for the leak detection device.

When the capacity as the pressure regulator for the leak detection device is increased as described above, in the embodiment, the supply low-pressure reducing section 131 is added to the conventional one. Since the low-pressure diaphragm 133 can be made small, a significant reduction in size can be achieved as compared with a case where the low-pressure diaphragm 103 of the low-pressure decompression unit 69 is conventionally made large for increasing the capacity.

Further, in the embodiment, the intermediate pressure reducing section 67 is provided on the upstream side of the orifice 120 as the differential pressure generating means, and the pressure of the gas is kept almost constant by the medium pressure reducing section 67. Therefore, the differential pressure generated in the orifice 120 is stabilized, and the gas supply operation in the supply low-pressure reducing unit 131, that is, the opening / closing operation of the bypass valve 149 is reliably performed.

Further, when the gas flows in the low pressure reducing section 69 at a predetermined flow rate or more, a differential pressure is generated between the pressure P2 and the pressure P1, and the bypass valve 149 is provided in the supply low pressure reducing section 131.
Opens, and gas flows to the second gas outlet passage 65b. That is, in the supply low pressure decompression unit 131, the low pressure decompression unit 69
If the gas does not flow at a predetermined flow rate or more, the gas does not flow to the supply low-pressure decompression unit 131, so that the pressure regulator can be designed without considering the blocking pressure of the supply low-pressure decompression unit 131.

Further, the pressure regulator for the leak detection device has a low pressure decompression unit 69 and a supply low pressure decompression unit 131 as decompression units. The adjustment pressure and the closing pressure of the pressure regulator for the leak detection device are shown in FIG. As shown, performance equivalent to that of a pressure regulator having only one pressure reducing section can be obtained.
For this reason, the differential pressure between the closing pressure and the adjustment pressure at the capacity point is reduced, whereby it is possible to provide a high-performance leak detector pressure regulator without using a conventional parent and child pressure regulator. it can.

In this embodiment, since the orifice 120 is used as the differential pressure generating means, the control of the pressure difference is facilitated and the opening and closing of the bypass valve 149 is facilitated, as shown in FIG. It is possible to generate a differential pressure without using the orifice 120. For example, it is more effective to increase the length of the gas communication passage 117 or to reduce the diameter of the gas communication passage 117.

Further, for example, the intermediate pressure reducing section 67 is abolished,
A low pressure decompression unit 69 and a supply low pressure decompression unit 131 may be provided. In this way, a significant reduction in size can be achieved.

[0066]

As described above, according to the first aspect of the present invention, when the flow rate is small, the first diaphragm is displaced, and the first valve body opens and closes the first nozzle portion. A first pressure reducing means for sending the gas to the leak detecting device through the first gas outlet passage, and a differential pressure generating means, and a second pressure reducing means for generating a second pressure based on the differential pressure generated by the differential pressure generating means at a large flow rate. The second valve body opens the second nozzle portion in accordance with the displacement, and the second pressure reducing means for discharging the inflowing gas to the second gas outlet passage is provided.
A large amount of gas can be supplied through the nozzle section of the second decompression means without increasing the size of the diaphragm of the decompression means, and a small, lightweight, and large-capacity pressure regulator for a leak detection device can be obtained.

Further, after the first pressure reducing means is activated, a predetermined pressure difference is generated and then the second pressure reducing means is activated. Therefore, the pressure adjustment can be performed without considering the closing pressure of the second pressure reducing means. The pressure difference between the closing pressure and the regulating pressure at the capacity point can be reduced because the same performance as that of the pressure regulator having only one pressure reducing section can be obtained. This makes it possible to provide a high-performance leak detector pressure regulator without using a conventional parent and child pressure regulator.

According to the second aspect of the present invention, the introduced gas is reduced to a predetermined pressure by the gas introducing pressure reducing means provided on the upstream side of the differential pressure generating means. Is ensured stably, and the gas supply operation in the second pressure reducing means is assured.

According to the third aspect of the present invention, the pressure difference can be easily obtained by using the orifice as the pressure difference generating means.

According to the fourth aspect of the present invention, since the pressure difference generating means is constituted by increasing the length of the passage, a pressure difference can be easily obtained.

According to the fifth aspect of the present invention, since the pressure difference generating means is constituted by reducing the diameter of the passage, a pressure difference can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a pressure regulator for a leak detection device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a leak detecting device including the pressure regulator for the leak detecting device of FIG. 1;

FIG. 3 is an operation explanatory view showing a state in which the pressure regulator for the leak detection device of FIG.

FIG. 4 is an operation explanatory view showing a large flow rate state of the pressure regulator for the leak detection device of FIG. 1;

FIG. 5 is a diagram showing a performance curve of the pressure regulator for the leak detection device of FIG. 1;

FIG. 6 is a diagram showing an example of a conventional gas leak detection device.

FIG. 7 is a diagram showing a performance curve of a conventional parent-child differential pressure regulator.

FIG. 8 is a sectional view of a pressure regulator showing a conventional example.

[Explanation of symbols]

53 Gas inlet passage 65 Gas outlet passage 67 Medium pressure reducing section (gas introducing pressure reducing means) 69 Low pressure reducing section (first pressure reducing means) 77 Medium pressure diaphragm (gas introducing diaphragm) 87 Medium pressure valve (gas introducing valve element) ) 91 Medium-pressure nozzle (gas introduction nozzle) 103 Low-pressure diaphragm (first diaphragm) 115 Low-pressure valve (first valve) 120, 179 orifice (differential pressure generating means) 121 Low-pressure nozzle (first) Nozzle section 131 Low pressure decompression section for supply (second decompression means) 133 Low pressure diaphragm for supply (second diaphragm) 137 Low pressure decompression chamber for supply (decompression chamber) 147a Bypass nozzle section (second nozzle section) 149 Bypass Valve (second valve element)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E072 AA01 DB10 GA30 3J071 AA02 BB11 BB14 CC11 EE37 FF03 5H316 AA11 BB05 CC01 DD11 DD12 EE02 EE10 EE15 EE30 ES02 ES05 ES06 GG01 GG09 GG15 JJ01 KK02 KK05

Claims (5)

[Claims] 1. A pressure regulator for a leak detection device used for a gas leak detection device for detecting a gas leak from a gas supply pipe of a gas supply facility, the gas regulator including a gas inlet passage and a gas flowing into the gas inlet passage. A first valve body capable of opening and closing a first nozzle portion communicating with a first gas outlet passage flowing out to the leak detection device, and opening and closing the first valve body by the first gas outlet passage A first pressure reducing means provided with a first diaphragm which is displaced based on a change in pressure on the side, and a gas flow provided between the first gas inlet passage and the first nozzle portion; A differential pressure generating means for lowering the pressure in accordance with the pressure reducing section, and a pressure reducing chamber communicating with an upstream side of the differential pressure generating means for a pressure reducing portion on the downstream side of the differential pressure generating means. Displacement based on the pressure difference between the A second diaphragm, a second nozzle portion communicating the decompression chamber with the gas outlet passage, and a second valve body capable of opening and closing the second nozzle portion in conjunction with the operation of the second diaphragm And a second pressure reducing means for discharging the gas flowing into the gas inlet passage to the second gas outlet passage. 2. A gas introducing valve body which can open and close a gas introducing nozzle provided on an upstream side of said differential pressure generating means, and an opening and closing operation of said gas introducing valve element, wherein said gas introducing valve body is opened and closed by said differential pressure generating means. 2. A leak detecting device according to claim 1, further comprising a gas introducing pressure reducing means provided with a gas introducing diaphragm which is displaced based on a change in gas pressure between the gas introducing nozzle and the gas introducing nozzle. For pressure regulator. 3. The pressure regulator for a leak detecting device according to claim 1, wherein said differential pressure generating means is constituted by an orifice. 4. The pressure regulator for a leak detecting device according to claim 1, wherein said differential pressure generating means is configured to extend a gas passage length. 5. The apparatus according to claim 1, wherein said differential pressure generating means is configured to reduce a gas passage diameter.
Or a pressure regulator for a leak detection device according to claim 2.