JPH06235680A - Method and equipment for testing check valve - Google Patents

Abstract

PURPOSE:To prevent the data of a previous bit wire from being written in a memory cell to be in a selected state or to prevent next data from being written in the memory cell in a non-selected state. CONSTITUTION:Logic operation of circuits for controlling the selection signal of the column and row of memory cells 51-54 and pulses for pulling up and balancing bit wires l1, L2; L3, L4 is performed to prevent column and row selection signals from being selected during pulse generation period or only the column and row selection signals to be selected turn into operation state after pulse generation ends.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved check valve test apparatus and a check valve test method, and is mainly used for testing a high-performance check valve capable of making a check valve pressure extremely low. It is something.

[0002]

2. Description of the Related Art A check valve includes a cracking test, a reverse closing pressure test (low pressure seat leak test), a seat leak test (valve seat leak test), a pressure resistance / air tightness test and the like. Then, in the cracking test, when a forward pressure is applied from the primary side in a state where the secondary side is open to the atmosphere, the minimum pressure at which a predetermined amount of fluid starts to flow to the secondary side is inspected. Further, in the reverse closing pressure test, the minimum pressure at which the reverse flow of the fluid can be shut off is tested when a positive pressure in the reverse direction is applied from the secondary side with the primary side open to the atmosphere. Furthermore, in the seat leak test,
The amount of sheet leak is examined when a predetermined reverse pressure is applied from the secondary side with the primary side open to the atmosphere.

For example, in the above-mentioned conventional check valve pressure check, as shown in FIG. 7, the primary side S ₁ of the check valve A is opened to the atmosphere, and the pressure P applied from the secondary side S ₂ is 0 kgf.
The pressure is gradually increased from / cm ² G, and it is confirmed by the so-called water displacement method that the leakage of the fluid from the sheet to the primary side has stopped. If the pressure ΔP when the leak is stopped is 0.1 kgf / cm ² G or less, it is determined that the check valve reverse closing pressure is a pass value.

On the other hand, in recent years, the performance of check valves has been greatly improved,
For example, in the diaphragm type check valve A having the structure as shown in FIG. 8, the check valve pressure ΔP is 0.01 kgf / cm ² a.
It is possible to reduce the pressure to as low as bs. Therefore, in the inspection of a high-performance check valve such as the diaphragm check valve A, it is necessary to detect the leak from the seat with high accuracy, and inevitably a highly sensitive leak detection method is required. Will be done. However, the leak detection methods such as the water displacement method and the soap film method used in the conventional check valve reverse closing pressure test and seat leak test have a minimum leak detection sensitivity of 10 ⁻⁵ Acc / s (1 bubble). 0.1 cc, 3
Since the detected value is about 600 seconds), which is relatively bad, when it is applied to a reverse closing pressure test of a high-performance check valve or the like, the reverse closing pressure ΔP includes a large error.

On the other hand, as a measure for detecting a fluid leak with high sensitivity, a helium leak detector (hereinafter referred to as HeL) is used.
(D) may be used. The HeLD has a minimum leak detection sensitivity of about 5 × 10 ⁻¹¹ Acc / s, which is extremely good, and enables highly accurate leak detection and, in turn, highly accurate reverse closing pressure ΔP measurement.

[0006] Therefore, in the leak detection by the HeLD, usually, the primary side S ₁ is in a high vacuum (about 10 ^-4 torr).
In addition, the secondary side S ₂ is maintained at a state close to the atmospheric pressure. Therefore, in the seat leak test (valve seat leak test), the leak amount can be easily and easily detected with high accuracy by connecting the HeLD to the primary side of the check valve to be inspected. On the other hand, in the reverse closing pressure test, as described above, the differential pressure ΔP between the primary and secondary is 0.01.
Since the leak must be detected in the vicinity of kgf / cm ² abs, there is a problem that the conventional leak detection method using HeLD cannot be applied as it is.

[0007]

SUMMARY OF THE INVENTION The present invention provides a high-performance check valve in the case of using the above-mentioned problems in the conventional check valve inspection, that is, the leak inspection by the water displacement method or the soap film method. In that case, it is not possible to detect the check valve pressure with high accuracy, and it is possible to perform leak detection with high accuracy using HeLD. Since it is extremely low, it is intended to solve the problem that the conventional leak detection method using HeLD cannot be directly applied to the check closing pressure check of high-performance check valves. We provide a check valve test device and check valve test method that enable various checks such as check valve pressure check and seat leak test to be performed easily and with high accuracy even for stop valves. It is a thing.

[0008]

The device invention of the present invention is
Control valve V on the primary side of check valve 1₈A helicopter connected via
Um leak detector 2; two of the check valve 1 to be inspected
Control valve V on the next side₂Helium flow rate adjustment connected via
And a control valve V to the helium flow controller 5 ₁Through
And a helium gas supply port 9 for supplying helium gas;
Control valve V₂Control valve V on the outlet side of_FourConnected via
A vacuum pump 3 and a primary pressure of the check valve 1 to be inspected
A pressure gauge 7 for measuring and a pressure gauge 8 for measuring the secondary pressure.
This is a basic configuration of the invention.

In the method of the present invention, the secondary side of the check valve 1 to be inspected is communicated with the atmosphere, and the primary side of the check valve 1 is kept at a high vacuum by the vacuum pump of the helium leak detector 2. After blocking the communication of the check valve 1 to the atmosphere on the secondary side, helium gas is supplied to the secondary side of the check valve 1 to be inspected through the helium flow rate controller 5, and the check valve 1 The helium leak detector in the case where the secondary side is sequentially evacuated by the vacuum pump 3 and the difference ΔP between the secondary side pressure P ₂ and the primary side pressure P ₁ of the check valve 1 to be inspected is set to a desired set value. The basic configuration of the invention is to confirm the reverse closing pressure of the check valve to be inspected from the detected value of 2.

[0010]

The primary side of the check valve 1 to be inspected is evacuated by the vacuum pump of the pre-clamped helium leak detector 2 and is maintained at a high vacuum level of pressure P ₁ . On the other hand, sufficient helium gas is continuously supplied to the secondary side of the check valve 1 to be inspected through the helium flow rate controller 5, and the secondary side of the check valve 1 to be inspected is continuously supplied by the vacuum pump 3. Exhausted. As a result, the secondary pressure P _{2 of the} check valve 1 to be inspected
Is adjusted to a desired low pressure P ₂ that is determined by the helium gas supplied at a constant flow rate through the flow rate controller 5 and the helium gas flow rate discharged by the vacuum pump 3, and the secondary side pressure P ₂ and the primary side pressure P ₂ are adjusted. The difference ΔP from the pressure P ₁ is applied to the valve body of the check valve 1 to be inspected. The check of the reverse closing pressure of the check valve 1 to be inspected is carried out by the magnitude of the leak detection value of the helium leak detector 2 when the differential pressure ΔP is a predetermined value.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall system diagram of a check valve test apparatus according to the present invention, in which 1 is a check valve to be inspected, 2 is a helium leak detector, 3 is a vacuum pump, 4 is an airtight test box, 5 is a helium flow controller, 6 is a nitrogen flow controller, 7
Is a primary pressure gauge, 8 is a secondary pressure gauge, 9 and 10 are helium gas supply ports, 11 is a nitrogen gas N ₂ supply port, 12 is an exhaust port, 13 is a control device, and V _{1 to} V ₁₂ are control valves. Is.

The check valve 1 to be inspected is a high-performance check valve such as a diaphragm type check valve, and is removably housed in a metal airtight test box 4. A known DLMS-33LS turbo specification (manufactured by Nippon Vacuum Technology Co., Ltd.) is used for the helium leak detector 2, and the minimum detected leak amount is 4 × 10 ^-12 bubbles / m ³ / sec.
(3 × 10 ⁻¹¹ torr, 1 / sec). Furthermore,
An oil rotary pump or a dry pump is used as the vacuum pump 3, and the ultimate pressure is set to 10 ^-2 torr and the exhaust speed is set to 150 l / min.

The airtight test box 4 is a pressure-proof and airtight container made of metal, and the check valve 1 is housed inside by opening the upper lid.
After connecting this to the primary side and secondary side pipes via metal seal type joints, respectively, the upper lid is closed to seal the check valve 1. It is desirable that the check valve 1 and the conduit are connected automatically by using an automatic connecting mechanism such as an air cylinder, and the amount of internally released gas is reduced to facilitate vacuuming. Therefore, it is desirable that the joint mechanism has a metal type structure.

The helium flow rate controller 5 and the nitrogen flow rate controller 6 are so-called mass flow controllers. By inputting an operation signal (0 to 5 V), the flow rate of helium gas or nitrogen gas (maximum flow rate 5 l / min) is changed. Adjusted. The primary and secondary pressure gauges 7 and 8 are so-called Barametron type vacuum gauges (0.01 kgf / cm ² abs).
˜15 kgf / cm ² abs), and a vacuum gauge having a resolution of about 0.01 kgf / cm ² is used in this embodiment.

The control valves V _{1 to} V ₁₂ are pneumatically operated stop valves, the maximum working pressure of which is 20 kgf / cm.
It is set to ² G. Further, 1.33 kgf / cm ² abs (0.3 kgf /
cm ² G) and helium gas and 12.03 kgf / cm ²
Abs (11 kgf / cm ² G) helium gas is switchably supplied, and 1 is supplied to the helium gas supply port 10.
Helium gas of 2.03 kgf / cm ² abs is supplied. Further, 2.03 is supplied to the nitrogen gas supply port 11.
Nitrogen gas of kgf / cm ² abs (1 kgf / cm ² G) is supplied.

The control device 13 is mainly composed of a microcomputer, and automatically controls the operations of the helium leak detector 2, the vacuum pump 3, the flow rate adjusters 5, 6 and the control valves V ₁ -V _12. Thus, each test of the check valve 1 to be inspected described later is automatically performed in a predetermined order, and the standard set values of the helium leak detector 2 and the pressure gauges 7 and 8 are compared with the measured values. , The pass / fail of each test result is determined, and this is recorded and displayed.

Next, various test methods using the check valve test apparatus according to the present invention will be described. The check valve 1 to be inspected has a nominal diameter of 6.35φ and a maximum operating pressure of 11.
03 kgf / cm ² abs, pressure resistance 16.03 kgf / c
m ² abs are used, the reverse closing pressure is 0.01 kgf / cm ² abs or less, the cracking pressure is 0.07 kgf / cm ² abs or less, and the seat leak amount is 1 × 10 ^-9 Acc / s or less. Are set respectively. (1) Cracking pressure test As shown in FIG. 2, the control valves V ₃ , V ₅ , V ₉ and V ₁₀ are opened and the other control valves are closed by a signal from the control device 13 (not shown). Next, 3 l from the flow rate regulator 6
/ Min N ₂ gas in the forward direction to the check valve 1 to be inspected,
Measure the reading of the secondary pressure gauge 8. At this time, if the reading of the secondary pressure gauge 8 is less than the reference value of 0.07 kgf / cm ² abs, the check valve 1 passes the cracking pressure test, and the reading of the pressure gauge 8 is 0.07 kgf / cm ² a
If it is bs or more, it is rejected. It should be noted that these pass / fail judgments are automatically made in the control device 13.

(2) Reverse Closing Pressure Test FIG. 3 is an explanatory diagram of the check finger pressure test of the check valve. In the test, the control valves V ₂ , V ₄ , V ₆ , V ₇ , V ₁₀ , V ₁₁ ,
With V ₁₂ closed and control valves V ₃ , V ₅ and V ₈ opened, the helium leak detector 2 is operated with the secondary side of the check valve 1 open to the atmosphere, and the primary valve of the check valve 1 is operated. Evacuate side to high vacuum.

Next, V₃Close V₂And V_FourSwitch to open
He (1.33k) through the helium flow controller 5
gf / cm²abs) at a high flow rate and a vacuum pump
Start the valve 3 and gradually increase the secondary side of the check valve 1 from atmospheric pressure.
Exhaust. The pumping speed of the vacuum pump 3 is the helium flow.
A speed that matches the He flow rate supplied from the quantity regulator 5.
It is adjusted every time. And the secondary pressure gauge 8 is 0.01k.
gf / cm²Helium Lee when decompressed to abs
The setting value of the detector 2 (that is, is it the secondary side of the check valve 1?
Of the helium leak to the primary side)
The setting value of Detector 2 rises above the background value.
If there is not, or the measured value of leakage amount within 5 seconds is 1 × 1
0 ^-9If it does not exceed Acc / s, the check valve 1 is reversed.
It has passed the compression pressure test. Also, on the contrary, check
In the process of adjusting the secondary pressure of valve 1, helium leak
The measured value of Tector 2 is 1 x 10^-8When exceeding Acc / s
The check valve fails the reverse pressure closing pressure test,
Control valve V₈Close. In this case, the control valve V ₈
The so-called helium leak detector H is closed.
e This is to prevent contamination.

(3) Low Pressure Seat Leak Test and High Pressure Seat Leak Test FIG. 4 is a diagram for explaining the low pressure seat leak test and the high pressure seat leak test of the check valve 1, which are control valves V ₁ , V ₂ and V _5.
And V ₈ are opened, and V ₃ , V ₄ , V ₆ , V ₇ ,
The V _10, V ₁₁ and V ₁₂ in the closed, 1. from the supply port 9 33
Helium of kgf / cm ² abs is supplied to the inlet side of the control valve V ₁ . At this time, if the measured value of the helium leak detector 2 in which the primary side is pre-clamped to a high vacuum state does not exceed the background value, or if the leakage amount within 5 seconds is 1 × 1.
If it is 0 ^-9 Acc / s or less, the check valve is considered to have passed the low pressure seatley crust, and conversely, if the leak measurement value within the 5 seconds exceeds 1 × 10 ^-9 Acc / s. Fails the low pressure seat leak test.

Next, the He supply line to the control valve V ₁ is switched to 12.3 kgf / m from the helium gas supply port 9.
While supplying helium of cm ² abs (11 kg / cm ² G), the secondary side of the check valve 1 is gradually pressurized through the helium flow controller 5. During the boosting, the set value of the helium leak detector 2 is 1 × 10 ⁻⁸ Acc /
If it exceeds s, the check valve fails the high pressure seat leak test. The reading of the secondary side pressure gauge 8 is 1
If the leak amount within 5 seconds after the pressure becomes 2.03 kg / cm ² abs is 1 × 10 ⁻⁹ Acc / s or less, the check valve 1 is considered to have passed the high pressure seat leak test.

(4) Air-tightness test When the high-pressure seat leak test is completed, the control valve V ₂ is first closed and the control valve V ₃ is opened as shown in FIG. Purge. Next, control valves V ₂ , V
₃ is closed and the control valve V ₁₂ is opened, the interior of the airtight test box 4 is evacuated by the vacuum pump of the helium leak detector 2, and it is confirmed that the helium leak detector 2 is ready for operation. After that, the control valve V ₁₁ is opened, and the supply port 10 is operated at 12.03 kgf / c.
Helium of m ² abs (11 kg / cm ² G) is applied to the primary side of the check valve 1. At this time, when the measured value of the helium leak detector 2 exceeds 1 × 10 ⁻⁸ Acc / s, the control valve 12 is closed and the check valve 1 fails the airtightness test. Moreover, the measured value of the helium leak detector 2 within 10 seconds is 1 × 10 ⁻⁹ Acc / s.
In the following cases, the check valve 1 has passed the airtightness test.

(5) Purge operation of the check valve test device After the tests (1) to (4) are completed, finally the He gas in the system is purged. First, as shown in FIG.
The control valves V ₅ and V ₃ are opened to open the secondary side of the check valve 1 to the atmosphere, then the control valve V ₃ is closed, the control valve V ₁₀ is opened, and the nitrogen gas ( 2.03 kgf / cm ²
Abs) is charged into the system. Next, the control valves V ₃ , V ₁₀ are closed, the control valves V ₄ , V ₆ , V ₇ are opened, and the vacuum pump 3
To exhaust the system for about 10 seconds.

After repeating the N ₂ filling operation and the vacuum evacuation operation as described above a plurality of times, the control valve V ₃ is opened, the airtight test box 4 is further opened, and the check valve 1 to be inspected is replaced with another one. Exchange.

In the present invention, all the tests (1) to (5) and the purging operation are automatically performed by the command from the controller 13, and similarly, each test of the check valve 1 is performed. The control device 13 also automatically determines whether the result is acceptable or not.

[0026]

According to the present invention, the helium leak detector 2 is connected to the primary side of the check valve 1 to be inspected, and the primary side of the check valve 1 is evacuated to a high vacuum degree P ₁ by the helium leak detector 2. In addition, while supplying a predetermined flow rate of helium gas to the secondary side of the check valve 1 through the helium flow rate controller 5, the primary side of the check valve 1 is connected to the vacuum pump 3
It is configured to evacuate. As a result, by adjusting the vacuum drawing amount by the vacuum pump 3,
The secondary pressure P ₂ of the check valve 1 to be inspected can be easily adjusted to a desired value, whereby the differential pressure ΔP between the primary and secondary sides of the check valve 1 to be inspected ΔP (ΔP = P ₂ -P ₁₎ can be easily and accurately adjustable, even very low performance check valve in the reverse closing pressure, such as a diaphragm-type check valve, or detecting reverse closure pressure, etc. with high precision You can check.

Further, in the present invention, the control device 13
By performing switching operation of each control valve, etc., the cracking pressure test, reverse closing pressure test, low / high pressure seat leak test, airtightness test and purge operation required for the check valve 1 are performed in order and with high efficiency. It becomes possible to carry out with accuracy. As described above, the present invention has excellent practical utility.

[Brief description of drawings]

FIG. 1 is a system diagram of a check valve test apparatus according to the present invention.

FIG. 2 is a diagram for explaining a cracking pressure test of a check valve.

FIG. 3 is a diagram for explaining a reverse closing pressure test of a check valve.

FIG. 4 is a diagram for explaining a low pressure and high pressure seat leak test of a check valve.

FIG. 5 is an explanatory diagram of an airtightness test of a check valve.

FIG. 6 is an explanatory diagram of a nitrogen filling operation and a vacuum evacuation operation in the purging operation of the check valve test apparatus.

FIG. 7 is an explanatory diagram of a conventional reverse closing pressure test.

FIG. 8 shows an example of a diaphragm check valve.

[Explanation of symbols]

1 is a check valve to be inspected, 2 is a helium leak detector,
3 is a vacuum pump, 4 is an airtight test box, 5 is a helium flow controller, 6 is a nitrogen flow controller, 7 is a primary pressure gauge, 8 is a secondary pressure gauge, 9 and 10 are helium gas supply ports, 11 Is a nitrogen gas supply port, 12 is an exhaust port, 13 is a control device, V ₁ ...
V ₁₂ is a control valve.

Claims (4)

[Claims] 1. A helium leak detector (2), which is connected to the primary side of the check valve (1) to be inspected through a control valve (V ₈ ); and a secondary side of the check valve (1) to be inspected. Helium flow controller (5) connected to the control side through a control valve (V ₂ )
When, the helium flow regulator (5) to the control valve (V ₁₎ helium gas supply port for supplying helium gas through (9) and; control valve on the outlet side of said control valve (V ₂₎ to (V ₄₎ A vacuum pump (3) connected via an intermediary; a pressure gauge (7) for measuring the primary pressure of the check valve (1) and a pressure gauge (8) for measuring the secondary pressure. A check valve test device characterized by the above. 2. An airtight test box (4) in which the check valve (1) to be inspected is detachably housed; a control valve for the primary side of the check valve (1) to be inspected in the airtight test box (4). (V ₈ )
And a helium leak detector (2) connected to the inside of the airtight test box (4) through a control valve (V ₁₂ ), respectively;
The secondary side control valve of the inspection check valve (1) (V ₅₎ and the control valve (V ₂₎ Helium flow controller which is connected by interposed a (5); the helium flow regulator (5 ) To control valve (V
₁₎ through the low-pressure helium gas or high-pressure helium gas switching interchangeably to supply helium gas supply port (9) and, the control valve (V ₂₎ and the control valve (V ₅₎ and the control valve to the connection conduit (V ₄ ), And a control valve (V ₇ ) in the connecting conduit between the control valve (V ₈ ) and the check valve (1) to be inspected, and further the airtight test box (4). Control valve (V ₆ ) inside
A vacuum pump (3) connected to each other via a pressure gauge; and a pressure gauge (7) for measuring the primary pressure of the check valve (1) and a pressure gauge (8) for measuring the secondary pressure. A helium gas supply port (10) for supplying high pressure helium through a control valve (V ₁₁ ) to the primary side of the check valve (1) to be inspected; and a control valve to the primary side of the check valve (1) to be inspected A nitrogen flow rate regulator (6) connected via (V ₁₀ ); and a nitrogen gas supply port (11) for supplying nitrogen gas to the nitrogen flow rate regulator (6) through a control valve (V ₉ ); An exhaust port (12) connected to the secondary side of the check valve (1) to be inspected through a control valve (V ₃ );
The control valves (V _{1 to} V ₁₂ ) and the flow rate regulators (5),
Controls the operation of (6) and both pressure gauges (7), (8)
And a control device (14) for judging and displaying whether the test result is acceptable or not based on the measurement value of the helium leak detector (2). 3. The airtight test box (4) is provided with an automatic connection mechanism for automatically connecting the primary side and the secondary side of the check valve (1) to be inspected to each pipeline. The test device for a check valve according to. 4. The check valve (1) to be tested is connected to the secondary side thereof to the atmosphere, and the primary side thereof is maintained at a high vacuum by a vacuum pump of a helium leak detector (2).
While interrupting communication with the atmosphere on the secondary side of the check valve (1) to be inspected, while supplying helium gas to the secondary side of the check valve (1) to be inspected through the helium flow controller (5). The secondary side of the check valve (1) to be inspected is sequentially evacuated by the vacuum pump (3), and the difference ΔP between the secondary pressure P ₂ and the primary pressure P ₁ of the check valve (1) to be inspected. From the detected value of the helium leak detector (2) when is set to the desired setting value,
A test method for a check valve, characterized by inspecting the check valve closing pressure of the check valve.