CN115307845A - Check leakage rate test system and test method for check valve - Google Patents

Abstract

The invention relates to the technical field of valves, in particular to a test system and a test method for a check valve backstop leakage rate. The invention provides a check valve leakage rate system, which can meet the requirements of backstop sealing when it is tested to work in a shallow water area of 0-500mm and a deep water area of several hundred meters. The leakage rate of deep water and shallow water stop check valve is measured under the same system, and PLC control is adopted. This system integrates the high-precision measurement of low pressure difference and the measurement method of pressure sensor to measure pressure difference, and realizes a high degree of automation of life test. The problem that there is no pressure sensor suitable for the range in the shallow water area test system is solved, and the automatic data collection is realized. The leakage rate measured by this system is close to the actual working conditions and has high precision.

Description

A test system and test method for check leakage rate of stop check valve

technical field

The invention relates to the technical field of valves, in particular to a test system and a test method for the backstop leakage rate of a stop check valve.

Background technique

Stop-check valve (stop-check valve) is a multi-purpose valve with both stop valve and check valve functions. Its structure is similar to that of globe valve, but the stem and disc are not fixedly connected. When the valve stem is lowered to press the disc tightly on the valve seat, it acts as a stop valve; when the valve stem rises, it acts as a check valve. On pipelines that need to install stop valves (or gate valves) and check valves at the same time (such as the outlet end of water pumps), or in places where the installation position is limited (such as ships), the use of stop and check valves can save installation costs and space. .

The stop check valve tested by this system is used in the shallow water area of 0-500mm and the deep water area of hundreds of meters. The performance of the stop check valve requires that the check leakage rate under two different pressure conditions must meet the requirements. At present, a test system is needed to realize the check performance and service life of the stop check valve in the shallow water area and the deep water area respectively. Therefore, there is an urgent need for a method and system that can simultaneously detect the check leakage rate of the stop check valve in the deep water area and the shallow water area.

Contents of the invention

In order to solve the above-mentioned problems and deficiencies in the prior art, the present invention proposes a test system and detection method for the backstop leakage rate of stop check valves in the shallow water area of 0-500mm and the deep water area of hundreds of meters.

Due to the pressure sensor with a measurement range below 500mm, it is still unable to meet the accuracy level of the pressure difference of 1mm. Therefore, the shallow water backstop test in this paper adopts the water column method. However, for deep water tests at a depth of several hundred meters, the conditions of using the water column method are harsh, and the economic benefits are unreasonable. The pressure sensor at a depth of several hundred meters can meet the accuracy requirements. Therefore, this test method uses the water column method for shallow water tests below half a meter. The 100-meter deep water test adopts the method of adding air pressure to the water column. An automatic control system is designed to automatically control the parameters set by the test through valves and test devices to achieve the purpose of the test.

In order to realize the foregoing invention object, the technical scheme of the present invention is specifically as follows:

A check leakage rate test system for a cut-off check valve, comprising a positive medium electric valve 1, a water storage tank 17 and a nitrogen cylinder 24, and the positive medium electric valve 1 is sequentially connected with a flow meter 2 and an exhaust valve through a pipeline Group 3, temperature sensor 4, pressure sensor 5, drainage valve 6, and collection valve 7 are connected. The collection valve 7 is connected to one end of the electric stop check valve 9, and the other end of the electric stop check valve 9 is provided with two shunts. One branch is connected to the discharge solenoid valve 12, and the other branch is connected to the shallow water tank 10 through the test water inlet solenoid valve 11. The submersible tank 10 is provided with a liquid level sensor 14; the water storage tank 17 is provided with two flow paths , one flows to the shallow water tank 10 through the water supply solenoid valve 15, and the other flows to the shallow water tank 10 through the water supply valve 16; , the surge tank 21 is connected with the shallow water tank 10 through the test air intake solenoid valve 18 .

Further, a pressure sensor 19 and a regulating valve 20 are arranged above the pressure stabilizing tank 21 .

Further, a measuring cylinder 8 is arranged below the collection valve 7 for measuring the liquid flowing out through the collection valve 7 .

Further, the system is equipped with PLC control and counted by PLC.

Further, the height difference between the flange on the tested stop check valve 9 and the liquid level of the shallow water tank is 0~500mm.

The invention provides a method for testing the backstop leakage rate of a stop check valve with a depth of 0-500mm, which includes the following steps:

A. Preparation: The test cut-off check valve 9 is electrically opened, and the positive fluid medium is prepared. Open the drain valve 16 to fill the shallow water tank. The water level of each water tank is at the normal water level, and the gauge pressure of the nitrogen cylinder is 8MPa;

B. Open the stop check valve 9 in the positive fluid medium: the valve 12 is opened, and the valve behind the stop check valve 9 is normal pressure. After 10 seconds, the valve 1 is opened, and the positive fluid medium will push the stop check valve open, and the flow meter 2 will display Flow rate, record flow rate after 5 seconds, record pressure 5 and temperature 4, after valve 1 is opened for 8 seconds, the opening action of the stop check valve is completed, valve 1 is closed, and the time delay is 2 seconds. Close, valve 6 is opened for 5 seconds, the stop check valve 9 releases pressure and drains water in front of the valve, providing conditions for the backstop test, the opening action is completed, and the counter statistics are not displayed;

C. Interval 10S, reverse setting water level check test: valve 13 is opened, the shallow water tank is connected to air, valve 11 is opened, normal temperature water is injected into the stop check valve 9 and reversed, wait until the liquid level sent by the liquid level gauge 14 reaches the set value value signal, if the liquid level is lower than the set value, the valve 15 will be opened in a jog, and the water in the water storage tank 17 will supplement the liquid level in the shallow water tank 10. After waiting for 5 seconds, the pressure is stable, and the stop check valve 9 is completed. When the stop closing action is completed, the counter counts 1 on/off

100 switching cycles are 1 group. After each group is completed, it will pause and make a sound, and do a leak rate test of holding pressure for 10 minutes;

D. Leakage rate test with pressure maintained for 10 minutes: open the valve 7, and there will be no water dripping within 3 minutes, and remove the water in front of the stop check valve 9. Keep the valve 7 open, place the measuring cylinder 8 at the drain, open the valve 13, connect the air to the shallow water tank, open the valve 11, and turn the normal temperature water into the stop check valve 9 until the liquid level sent by the liquid level gauge 14 reaches the set value value signal, if the liquid level is lower than the set value, the valve 15 will be opened in a jog, and the water in the water storage tank 17 will supplement the liquid level of the shallow water tank 10, wait for 5 seconds, the pressure will be stable, and the stop check valve 9 will complete the reverse stop action, and the timing will be 10 After 10 minutes, read the volume of water in the measuring cylinder and record it, and calculate the leakage rate according to the formula (the formula is: leakage rate = volume of water in the measuring cylinder read in 10 minutes × (60 minutes/10 minutes), leakage The unit of rate is m³/h, close valve 11;

E. After testing the leak rate test, click Continue to continue counting, and repeat operations B, C, and D at intervals of 10 seconds until the number of backstops required by the test is reached.

The invention provides a method for testing the backstop leakage rate of a deep water stop check valve, which includes the following steps:

A. Preparation: The test cut-off check valve 9 is electrically opened, and the positive fluid medium is prepared. Open the drain valve 16 to fill the shallow water tank. The water level of each water tank is at the normal water level, and the gauge pressure of the nitrogen cylinder is 8MPa;

B. Open the stop check valve 9 in the positive fluid medium: the valve 12 is opened, and the valve behind the stop check valve 9 is normal pressure. After 10 seconds, the valve 1 is opened, and the positive fluid medium will push the stop check valve open, and the flow meter 2 will display Flow rate, record flow rate after 5 seconds, record pressure 5 and temperature 4, after valve 1 is opened for 8 seconds, the opening action of the stop check valve is completed, valve 1 is closed, and the time delay is 2 seconds. Close, valve 6 is opened for 5 seconds, the stop check valve 9 releases pressure and drains water in front of the valve, providing conditions for the backstop test, the opening action is completed, and the counter statistics are not displayed;

C. Interval 10S, reverse set water level + nitrogen pressurization, backstop check valve 9 tests:

The valve 11 is opened, and the normal temperature water is injected into the cut-off check valve 9 in the opposite direction. When the liquid level gauge 14 sends a signal that the liquid level reaches the set value, if the liquid level is lower than the set value, the valve 15 is opened in a jog, and the water in the water storage tank 17 Supplement the liquid level for the shallow water tank 10, close the valve 13, and close the shallow water tank;

The valve 23 remains open, the air source is ready, and the pressure sensor 19 displays the set value in MPa. If the pressure is lower than the set value, the valve 22 is opened in a jog, and the nitrogen cylinder 24 is used to charge the pressure tank 21; Set the value, alarm, manually open the valve 20 to exhaust and reduce pressure, and re-establish the set value pressure;

The valve 18 is opened, the reverse water column + nitrogen pressurization, the check valve 9, 2S later, the pressure is stable, record the reading of the pressure sensor 19, that is, the check pressure value, the valve closing action is completed, and the valve 18 is opened 3S later, After the recording is completed, the valve 18 is closed, counted on/off once, and 100 switching cycles are 1 group. After each group is completed, it pauses and emits a prompt sound, and performs a leak rate test of holding pressure for 10 minutes;

D. Reverse water column + nitrogen pressurization, backstop check valve 9, leak rate measurement:

Valve 7 is opened, until there is no water dripping within 3 minutes, get rid of the water before the stop check valve 9 valve. Keep the valve 7 open, place the measuring cylinder 8 at the drain; open the valve 11, inject normal temperature water into the stop check valve 9 and reverse it, and wait for the liquid level gauge 14 to send a signal that the liquid level reaches the set value (if the liquid level is lower than the set value value, the valve 15 is jogged to open, and the water in the water storage tank 17 is the supplementary liquid level of the shallow water tank 10). The valve 13 is closed, and the shallow water tank is closed; the valve 23 remains open, and the air source is ready. The pressure sensor 19 displays the set value in MPa. If the pressure is lower than the set value, the valve 22 is opened in a jog, and the nitrogen cylinder 24 is used to charge the pressure tank 21; if the pressure exceeds the set value, an alarm is issued, and the valve 20 is manually opened. Air depressurization, re-establish the set point pressure; valve 18 is opened, reverse water column + nitrogen pressurization, backstop check valve 9, after timing for 10 minutes, read the volume of water in the measuring cylinder, and record. Calculate the leakage rate according to the formula, and the formula is: leakage rate = volume of water in the measuring cylinder read in 10 minutes × (60 minutes/10 minutes), the unit of the leakage rate is m³/h, and the valve 11 is closed;

E. After testing the leak rate test, click Continue to continue counting, and repeat operations B, C, and D at intervals of 10 seconds until the number of backstops required by the test is reached.

Beneficial effect of the present invention: the present invention provides a kind of backstop leakage rate system of cut-off check valve, when testing its shallow water area of 0-500mm and hundreds of meters of deep water area work, meet backstop sealing requirement, and measure the shallow water area and The leakage rate after the life test in the deep water area, under the same system, the backstop leakage rate measurement of the deep water and shallow water cut-off check valves is realized, and PLC control is adopted.

This system integrates the high-precision measurement of the low pressure difference and the measurement method of the pressure sensor to measure the pressure difference, and realizes the high automation of the life test. It solves the problem that there is no pressure sensor suitable for the range in the shallow water area test system, and realizes automatic data collection. The leakage rate measured by this system is close to the requirements of actual working conditions and has high precision.

Description of drawings

Accompanying drawing 1 is the test system diagram of the check leakage rate of the stop check valve of the present application.

Among them, positive medium electric valve 1, flow meter 2, exhaust valve group 3, temperature sensor 4, pressure sensor 5, drain valve 6, collection valve 7, measuring cylinder 8, tested stop check valve 9, shallow water tank 10, Test water inlet solenoid valve 11, discharge solenoid valve 12, ventilation solenoid valve 13, liquid level sensor 14, replenishment solenoid valve 15, water supply valve 16, water storage tank 17, test intake solenoid valve 18, pressure sensor 19, regulating valve 20, Regulator tank 21, air supply solenoid valve 22, air supply hand valve 23, nitrogen cylinder 24.

Detailed ways

Example 1.

A check leakage rate test system for a cut-off check valve, comprising a positive medium electric valve 1, a water storage tank 17 and a nitrogen cylinder 24, and the positive medium electric valve 1 is sequentially connected with a flow meter 2 and an exhaust valve through a pipeline Group 3, temperature sensor 4, pressure sensor 5, drainage valve 6, and collection valve 7 are connected. The collection valve 7 is connected to one end of the electric stop check valve 9, and the other end of the electric stop check valve 9 is provided with two shunts. One branch is connected to the discharge solenoid valve 12, and the other branch is connected to the shallow water tank 10 through the test water inlet solenoid valve 11. The submersible tank 10 is provided with a liquid level sensor 14; the water storage tank 17 is provided with two flow paths , one flows to the shallow water tank 10 through the water supply solenoid valve 15, and the other flows to the shallow water tank 10 through the water supply valve 16; , the surge tank 21 is connected with the shallow water tank 10 through the test air intake solenoid valve 18 .

A pressure sensor 19 and a regulating valve 20 are arranged above the surge tank 21 .

A graduated cylinder 8 is arranged below the collection valve 7 for measuring the liquid flowing out through the collection valve 7 .

Embodiment 2.: Method for measuring leakage rate of backstop test in shallow water area.

A. Preparation: The tested cut-off check valve 9 is electrically opened, and the preparation of the positive fluid medium is completed. Open the drain valve 16 to fill the shallow water tank. The water level in the shallow water tank reaches the set value, and the water level in the water storage tank is within the set range. The gauge pressure of the bottle is 8MPa;

B. Open the stop check valve 9 in the positive fluid medium: the valve 12 is opened, and the valve behind the stop check valve 9 is normal pressure. After 10 seconds, the valve 1 is opened, and the positive fluid medium will push the stop check valve open, and the flow meter 2 will display Flow rate, record flow rate after 5 seconds, record pressure 5 and temperature 4, after valve 1 is opened for 8 seconds, the opening action of the stop check valve is completed, valve 1 is closed, and the time delay is 2 seconds. Close, the valve 6 is opened for 5 seconds, the front of the stop check valve 9 is pressure-relieved and drained, providing conditions for the backstop test, the opening action is completed, and the counter statistics are not displayed; the positive medium is fresh water, sea water, etc.;

C. Interval 10S, reverse setting water level check test: valve 13 is opened, the shallow water tank is connected to air, valve 11 is opened, normal temperature water is injected into the stop check valve 9 and reversed, wait until the liquid level sent by the liquid level gauge 14 reaches the set value value signal, if the liquid level is lower than the set value, the valve 15 will be opened in a jog, and the water in the water storage tank 17 will supplement the liquid level in the shallow water tank 10. After waiting for 5 seconds, the pressure is stable, and the stop check valve 9 is completed. When the stop closing action is completed, the counter counts 1 on/off

100 switching cycles are 1 group. After each group is completed, it will pause and make a sound, and do a leak rate test of holding pressure for 10 minutes;

D. Leakage rate test with pressure maintained for 10 minutes: open the valve 7, and there will be no water dripping within 3 minutes, and remove the water in front of the stop check valve 9. Keep the valve 7 open, place the measuring cylinder 8 at the drain, open the valve 13, connect the air to the shallow water tank, open the valve 11, and turn the normal temperature water into the stop check valve 9 until the liquid level sent by the liquid level gauge 14 reaches the set value value signal, if the liquid level is lower than the set value, the valve 15 will be opened in a jog, and the water in the water storage tank 17 will supplement the liquid level of the shallow water tank 10, wait for 5 seconds, the pressure will be stable, and the stop check valve 9 will complete the reverse stop action, and the timing will be 10 After 10 minutes, read the volume of water in the measuring cylinder and record it, and calculate the leakage rate according to the formula. The formula is: leakage rate = volume of water in the measuring cylinder read in 10 minutes × (60 minutes/10 minutes), leakage rate The unit is m³/h, close the valve 11;

E. After testing the leak rate test, click Continue to continue counting, and repeat operations B, C, and D at intervals of 10 seconds until the number of backstops required by the test is reached.

Embodiment 3. A method for testing the backstop leakage rate of a stop check valve in a deep water area.

A. Preparation: The tested cut-off check valve 9 is electrically opened, and the preparation of the positive fluid medium is completed. Open the drain valve 16 to fill the shallow water tank. The water level in the shallow water tank reaches the set value, and the water level in the water storage tank is within the set range. The gauge pressure of the bottle is 8MPa;

B. Open the stop check valve 9 in the positive fluid medium: the valve 12 is opened, and the valve behind the stop check valve 9 is normal pressure. After 10 seconds, the valve 1 is opened, and the positive fluid medium will push the stop check valve open, and the flow meter 2 will display Flow rate, record flow rate after 5 seconds, record pressure 5 and temperature 4, after valve 1 is opened for 8 seconds, the opening action of the stop check valve is completed, valve 1 is closed, and the time delay is 2 seconds. Close, the valve 6 is opened for 5 seconds, the front of the stop check valve 9 is pressure-relieved and drained, providing conditions for the backstop test, the opening action is completed, and the counter statistics are not displayed; the positive medium is fresh water, sea water, etc.;

C. Interval 10S, reverse set water level + nitrogen pressurization, backstop check valve 9 tests:

The valve 11 is opened, and the normal temperature water is injected into the cut-off check valve 9 in the opposite direction. When the liquid level gauge 14 sends a signal that the liquid level reaches the set value, if the liquid level is lower than the set value, the valve 15 is opened in a jog, and the water in the water storage tank 17 Supplement the liquid level for the shallow water tank 10, close the valve 13, and close the shallow water tank;

The valve 23 remains open, the air source is ready, and the pressure sensor 19 displays the set value in MPa. If the pressure is lower than the set value, the valve 22 is opened in a jog, and the nitrogen cylinder 24 is used to charge the pressure tank 21; Set the value, alarm, manually open the valve 20 to exhaust and reduce pressure, and re-establish the set value pressure;

The valve 18 is opened, the reverse water column + nitrogen pressurization, the check valve 9, 2S later, the pressure is stable, record the reading of the pressure sensor 19, that is, the check pressure value, the valve closing action is completed, and the valve 18 is opened 3S later, After the recording is completed, the valve 18 is closed, counted on/off once, and 100 switching cycles are 1 group. After each group is completed, it pauses and emits a prompt sound, and performs a leak rate test of holding pressure for 10 minutes;

D. Reverse water column + nitrogen pressurization, backstop check valve 9, leak rate measurement:

Valve 7 is opened, until there is no water dripping within 3 minutes, get rid of the water before the stop check valve 9 valve. Keep the valve 7 open, place the measuring cylinder 8 at the drain; open the valve 11, inject normal temperature water into the stop check valve 9 and reverse it, and wait for the liquid level gauge 14 to send a signal that the liquid level reaches the set value (if the liquid level is lower than the set value value, the valve 15 is jogged to open, and the water in the water storage tank 17 is the supplementary liquid level of the shallow water tank 10). The valve 13 is closed, and the shallow water tank is closed; the valve 23 remains open, and the air source is ready. The pressure sensor 19 displays the set value in MPa. If the pressure is lower than the set value, the valve 22 is opened in a jog, and the nitrogen cylinder 24 is used to charge the pressure tank 21; if the pressure exceeds the set value, an alarm is issued, and the valve 20 is manually opened. Air depressurization, re-establish the set point pressure; valve 18 is opened, reverse water column + nitrogen pressurization, backstop check valve 9, after timing for 10 minutes, read the volume of water in the measuring cylinder, and record. Calculate the leakage rate according to the formula, and the formula is: leakage rate = volume of water in the measuring cylinder read in 10 minutes × (60 minutes/10 minutes), the unit of the leakage rate is m³/h, and the valve 11 is closed;

E. After testing the leak rate test, click Continue to continue counting, and repeat operations B, C, and D at intervals of 10 seconds until the number of backstops required by the test is reached.

Claims (7)

1. A test system for check leakage rate of cut-off check valve, comprising positive medium electric valve 1, water storage tank 17 and nitrogen cylinder 24, characterized in that, said positive medium electric valve 1 is sequentially connected with the flow rate through the pipeline Meter 2, exhaust valve group 3, temperature sensor 4, pressure sensor 5, drain valve 6, collection valve 7 are connected, the collection valve 7 is connected with one end of the electric stop check valve 9, and the other end of the electric stop check valve 9 There are two shunts, one shunt is connected to the discharge solenoid valve 12, the other shunt is connected to the shallow water tank 10 through the test water inlet solenoid valve 11, and the diving tank 10 is provided with a liquid level sensor 14; the water storage tank 17 There are two flow paths, one flows to the shallow water tank 10 through the water supply solenoid valve 15, and the other flows to the shallow water tank 10 through the water supply valve 16; the nitrogen cylinder 24 passes through the gas supply solenoid valve 22 and the gas supply hand valve 23 in turn It is connected with the surge tank 21, and the surge tank 21 is connected with the shallow water tank 10 through the test intake electromagnetic valve 18. 2 . The test system for check leakage rate of stop check valve according to claim 1 , wherein a pressure sensor 19 and a regulating valve 20 are arranged above the surge tank 21 . 3 . The test system for check leakage rate of stop check valve according to claim 1 , wherein a measuring cylinder 8 is arranged below the collection valve 7 for measuring the liquid flowing out through the collection valve 7 . 4. A test system for check leakage rate of stop check valve according to claim 1, characterized in that the system is controlled by PLC and counted by PLC. 5. A kind of stop check valve backstop leakage rate test system according to claim 1, characterized in that the height difference between the flange on the tested stop check valve 9 and the liquid level of the shallow water tank is 0 ~ 500mm . 6. A method for testing the check leakage rate of a cut-off check valve with a depth of 0-500 mm, comprising the following steps: A. Preparation: The tested cut-off check valve 9 is electrically opened, and the preparation of the positive fluid medium is completed. Open the drain valve 16 to fill the shallow water tank. The water level in the shallow water tank reaches the set value, and the water level in the water storage tank is within the set range. The gauge pressure of the bottle is 8MPa; B. Open the stop check valve 9 in the positive fluid medium: the valve 12 is opened, and the valve behind the stop check valve 9 is normal pressure. After 10 seconds, the valve 1 is opened, and the positive fluid medium will push the stop check valve open, and the flow meter 2 will display Flow rate, record flow rate after 5 seconds, record pressure 5 and temperature 4, after valve 1 is opened for 8 seconds, the opening action of the stop check valve is completed, valve 1 is closed, and the time delay is 2 seconds. Close, valve 6 is opened for 5 seconds, the stop check valve 9 releases pressure and drains water in front of the valve, providing conditions for the backstop test, the opening action is completed, and the counter statistics are not displayed; C. Interval 10S, reverse setting water level check test: valve 13 is opened, the shallow water tank is connected to air, valve 11 is opened, normal temperature water is injected into the stop check valve 9 and reversed, wait until the liquid level sent by the liquid level gauge 14 reaches the set value value signal, if the liquid level is lower than the set value, the valve 15 will be opened in a jog, and the water in the water storage tank 17 will supplement the liquid level in the shallow water tank 10. After waiting for 5 seconds, the pressure is stable, and the stop check valve 9 is completed. When the closing action is completed, the counter counts 1 on/off, and 100 switching cycles are 1 group. After each group is completed, it pauses and emits a prompt sound, and performs a leak rate test for holding pressure for 10 minutes; D. Leak rate test for 10 minutes of pressure holding: open valve 7, until there is no water dripping within 3 minutes, remove the water in front of the stop check valve 9; keep valve 7 open, place measuring cylinder 8 at the drain, valve 13 Open, the shallow water tank is connected to the air, the valve 11 is opened, the normal temperature water is injected into the stop check valve 9 and reversed, and the liquid level gauge 14 sends a signal that the liquid level reaches the set value. If the liquid level is lower than the set value, the valve 15 moves inching Open, the water in the water storage tank 17 is the supplementary liquid level of the shallow water tank 10, wait for 5 seconds, the pressure is stable, the stop check valve 9 backstop action is completed, after timing for 10 minutes, read the volume of the water in the measuring cylinder, and record it, according to the formula To calculate the leakage rate, the formula is: leakage rate = volume of water in the measuring cylinder read in 10 minutes × (60 minutes/10 minutes), close the valve 11; E. After testing the leak rate test, click Continue to continue counting, and repeat operations B, C, and D at intervals of 10 seconds until the number of backstops required by the test is reached. 7. A method for testing the backstop leakage rate of a deep-water stop check valve, characterized in that it comprises the following steps: A. Preparation: The tested cut-off check valve 9 is electrically opened, and the preparation of the positive fluid medium is completed. Open the drain valve 16 to fill the shallow water tank. The water level in the shallow water tank reaches the set value, and the water level in the water storage tank is within the set range. The gauge pressure of the bottle is 8MPa; B. Open the stop check valve 9 in the positive fluid medium: the valve 12 is opened, and the valve behind the stop check valve 9 is normal pressure. After 10 seconds, the valve 1 is opened, and the positive fluid medium will push the stop check valve open, and the flow meter 2 will display Flow rate, record flow rate after 5 seconds, record pressure 5 and temperature 4, after valve 1 is opened for 8 seconds, the opening action of the stop check valve is completed, valve 1 is closed, and the time delay is 2 seconds. Close, valve 6 is opened for 5 seconds, the stop check valve 9 releases pressure and drains water in front of the valve, providing conditions for the backstop test, the opening action is completed, and the counter statistics are not displayed; C. Interval 10S, reverse set water level + nitrogen pressurization, backstop check valve 9 tests: The valve 11 is opened, and the normal temperature water is injected into the cut-off check valve 9 in the opposite direction. When the liquid level gauge 14 sends a signal that the liquid level reaches the set value, if the liquid level is lower than the set value, the valve 15 is opened in a jog, and the water in the water storage tank 17 Supplement the liquid level for the shallow water tank 10, close the valve 13, close the shallow water tank; keep the valve 23 open, the air source is ready, the pressure sensor 19 displays the set value and the unit of indication is MPa, if the pressure is lower than the set value, the valve 22 moves inching Open the nitrogen cylinder 24 to pressurize the surge tank 21; if the pressure exceeds the set value, an alarm will be issued, and the valve 20 will be manually opened to exhaust and depressurize, and the set value pressure will be re-established; The valve 18 is opened, the reverse water column + nitrogen pressurization, the check valve 9, 2S later, the pressure is stable, record the reading of the pressure sensor 19, that is, the check pressure value, the valve closing action is completed, and the valve 18 is opened 3S later, After the recording is completed, the valve 18 is closed, counted on/off once, and 100 switching cycles are 1 group. After each group is completed, it pauses and emits a prompt sound, and performs a leak rate test of holding pressure for 10 minutes; D. Reverse water column + nitrogen pressurization, check the stop check valve 9, measure the leakage rate: open the valve 7, and there will be no water dripping within 3 minutes, remove the water in front of the stop check valve 9, keep the valve 7 open, Place the measuring cylinder 8 at the drain port; open the valve 11, inject normal temperature water into the stop check valve 9 and reverse it, and wait for the liquid level gauge 14 to send a signal that the liquid level reaches the set value (if the liquid level is lower than the set value, the valve 15 will move slightly) open, the water in the water storage tank 17 is the supplementary liquid level of the shallow water tank 10), the valve 13 is closed, and the shallow water tank is closed; the valve 23 remains open, the air source is ready, and the pressure sensor 19 displays the set value indicating unit MPa, if the pressure Lower than the set value, the valve 22 is opened in a jog, and the nitrogen cylinder 24 is used to charge the pressure tank 21; if the pressure exceeds the set value, an alarm is issued, and the valve 20 is manually opened to exhaust and reduce pressure, and the set value pressure is re-established; the valve 18 is opened , reverse water column+nitrogen pressurization, backstop check valve 9, after timing for 10 minutes, read the volume of water in the measuring cylinder, and record, calculate the leakage rate according to the formula, the formula is: leakage rate=10 minutes Read the volume of water in the graduated cylinder × (60 minutes/10 minutes), close the valve 11; E. After testing the leak rate test, click Continue to continue counting, and repeat operations B, C, and D at intervals of 10 seconds until the number of backstops required by the test is reached.

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