Safe automatic control method during pressure test of valve

Abstract

The invention relates to the technical field of valves, in particular to a safe automatic control method during valve pressure testing. According to the technical scheme, the method comprises the following steps that S1, an electric contact pressure gauge is installed on a valve pressure test inlet mother pipe, the pressure of the electric contact pressure gauge is set, the high-position pressure is the strength test pressure of the valve, and the low-position pressure is the leakproofness test pressure; s2, setting a first power-off time-delay relay and a second power-off time-delay relay, searching strength test time and tightness test time of the valve according to pipeline specifications, and respectively setting time of the two time relays; and S3, connecting the booster pump for valve pressure test and the electric contact pressure gauge into a control box according to a preset drawing. According to the invention, the error of manual pressure observation can be reduced, the accuracy of test pressure control is improved, meanwhile, when the pressure reaches the preset value, the subsequent operation can be automatically triggered, the test stage does not need to be manually switched, and the automation degree of the test process is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of valves, in particular to a safety automatic control method during valve pressure test. BACKGROUND

[0002] In the field of building pipeline construction, as the key control component of fluid conveying system, the pressure strength and sealing performance of the valve directly determine the safety of the pipeline system operation. Before construction, the valve must be tested for strength and tightness. The strength test pressure needs to reach 1.5 times the nominal pressure of the valve, and the tightness test pressure needs to reach 1.1 times the nominal pressure. Both tests need to be maintained for a specified period of time at the corresponding pressure to verify that the valve has no rupture or leakage. The existing valve pressure test is manually controlled by the test pressure pump to inject test medium into the valve. When the pressure gauge on the test pressure pump shows that the test pressure is reached, the power of the test pressure pump is manually turned off and the time is manually counted. Not only does the test pressure personnel need to be on duty throughout the process, but also multiple valves cannot be tested simultaneously, resulting in high labor costs and low detection efficiency. Manual judgment of pressure value and manual switching of test stage are prone to errors, and manual timing is not accurate enough, which directly affects the accuracy of test results. There is also a safety hazard of manual emergency disposal lag when the valve body cracks or leaks under high pressure. Therefore, the present application proposes a safety automatic control method during valve pressure test. SUMMARY

[0003] The purpose of the present application is to solve the problem of manual control of the test pressure pump to inject test medium into the valve. When the pressure gauge on the test pressure pump shows that the test pressure is reached, the power of the test pressure pump is manually turned off and the time is manually counted. Not only does the test pressure personnel need to be on duty throughout the process, but also multiple valves cannot be tested simultaneously, resulting in high labor costs and low detection efficiency. Manual judgment of pressure value and manual switching of test stage are prone to errors, and manual timing is not accurate enough, which directly affects the accuracy of test results. There is also a safety hazard of manual emergency disposal lag when the valve body cracks or leaks under high pressure. Therefore, the present application proposes a safety automatic control method during valve pressure test.

[0004] The technical solution of the present application is a safety automatic control method during valve pressure test, comprising the following steps: S1, installing an electric contact pressure gauge on the valve pressure test inlet pipe, setting the pressure of the electric contact pressure gauge, the high pressure being the strength test pressure of the valve, and the low pressure being the tightness test pressure; S2, setting a first power-off delay relay and a second power-off delay relay, according to the pipeline specification, finding the strength test time and tightness test time of the valve, and setting the time of the two time relays respectively; S3, connecting the pressure pump and the electric contact pressure gauge of the valve pressure test to the control box according to the pre-designed drawing; S4, determine the strength test pressure of the valve is P1, the strength test time is T1, the tightness test pressure is P2, the tightness test time is T2, wherein P1>P2, T1>T2; S5, close the circuit breaker, power indicator light, press the start button, AC contactor coil and the first power-off delay relay and the second power-off delay relay, the first normally open contact closed to form a self-holding circuit, the second normally open contact is closed, the strength test timing lamp and the tightness test timing lamp are bright, the booster pump starts, the valve pressure mother pipe on the electric contact pressure tube pressure rises; when the valve pressure increases to P1, the common line of the electric contact pressure gauge is connected with the first terminal, the first intermediate relay coil is powered on, the normally closed contact is opened, the first power-off delay relay and the AC contactor coil are all powered off, the booster pump stops working, and the first power-off delay relay starts timing; after the time reaches T1, the normally closed contact is opened, the strength test timing lamp is extinguished, and the strength test is completed. S6, open the valve pressure mother pipe pressure relief valve, slowly operate to make the pressure to P2, then close the pressure relief valve, ensure that the electric contact pressure gauge reads P2, at this time the common line is connected with the second terminal, the second intermediate relay coil is powered on, the normally closed contact is opened, the first intermediate relay coil is powered off and starts timing; after the time reaches T2, the closed contact is opened, the normally open contact state is restored, the tightness test timing lamp is extinguished, and the tightness test is completed. S7, open the valve pressure mother pipe pressure relief valve, the pressure is released to 0, remove the valve that has been tested, and install the next valve to be tested on the valve pressure platform. S8, press the start button, repeat the above steps S5 to S7.

[0005] Optionally, in step S1, the high pressure value of the electric contact pressure gauge is the same as the strength test pressure value of the valve, and the low pressure value is the same as the tightness test pressure value of the valve.

[0006] Optionally, in step S2, the power-off delay time of the normally closed contact is set as the strength test time T1 of the valve, and the power-off delay time of the first intermediate relay coil is set as the tightness test time T2 of the valve.

[0007] Optionally, in step S5, after pressing the start button, the self-holding circuit formed by the first normally open contact closed maintains the power-on state of the AC contactor coil and the first power-off delay relay and the second power-off delay relay.

[0008] Optionally, in step S5, when the valve pressure reaches P1, the common line of the electric contact pressure gauge is connected with the first terminal, triggering the first intermediate relay coil to be powered on, and then making the normally closed contact open, realizing the power-off of the first power-off delay relay and the AC contactor coil.

[0009] Optionally, in step S5, the first power-off delay relay starts timing after power-off, and when the timing reaches T1, the normally closed contact is disconnected, the closed contact is disconnected, and the intensity test timing lamp is extinguished to indicate that the intensity test is completed.

[0010] Optionally, in step S6, after the pressure is released to P2 and the pressure release valve is closed, the electric contact pressure gauge common line is connected to the second terminal, the second intermediate relay coil is powered on, the normally closed contact is disconnected, and the first intermediate relay coil is powered off and starts timing.

[0011] Optionally, in step S6, when the timing of the first intermediate relay coil reaches T2, the closed contact is disconnected, the tightness test timing lamp is extinguished, and the tightness test is ended.

[0012] Optionally, step S9 is further included, if the valve test pressure is unqualified, internal leakage or valve body cracking occurs, the pressure release valve is immediately opened, and the circuit breaker is closed.

[0013] Optionally, in step S3, the preset drawing is an electrical schematic diagram capable of realizing correct electrical connection of the booster pump, the electric contact pressure gauge and the control box.

[0014] Compared with the prior art, the present application has the following beneficial technical effects: The present application realizes automatic monitoring and control of the valve strength test pressure P1 and the tightness test pressure P2 by setting the electric contact pressure gauge, replaces manual pressure value judgment, reduces the error of manual observation of pressure, improves the accuracy of test pressure control, and automatically triggers subsequent operations when the pressure reaches the preset value, without manual switching of test stages, improving the automation degree of the test process. Further, the present application configures the first power-off delay relay and the second power-off delay relay to automatically time the valve strength test time T1 and the tightness test time T2 respectively, replaces manual timing, significantly improves the timing accuracy, and does not require test personnel to be on duty throughout the process, so that the staff can simultaneously carry out detection of multiple valves, reduces the labor cost, and when the valve body is abnormal in the high pressure state, the automatic control logic can cooperate with the emergency operation mechanism to reduce the safety hidden danger caused by the lag of manual emergency disposal. BRIEF DESCRIPTION OF DRAWINGS

[0015] Fig. 1 A block diagram of a safety automatic control method for valve pressure testing is given; Fig. 2 A structure schematic diagram of a safety automatic control method for valve pressure testing is given; Fig. 3 A booster pump connection structure schematic diagram is given.

[0016] REFERENCE NUMERALS: 1. Normally closed contact; 2. First power-off delay relay; 3. Start button; 4. First normally open contact; 5. AC contactor coil; 6. Common line; 7. Electrical contact pressure gauge; 8. First terminal; 9. Second terminal; 10. Second power-off delay relay; 11. Normally closed contact; 12. Second normally open contact; 13. Closed contact; 14. First intermediate relay coil; 15. Second intermediate relay coil; 16. Strength test timing lamp; 17. Tightness test timing lamp; 18. Power indicator lamp; 19. Booster pump; 20. Circuit breaker. DETAILED DESCRIPTION

[0017] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments.

[0018] The components of the embodiments of the present application generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the present application.

[0019] Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present application.

[0020] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are merely for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0021] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0022] EMBODIMENT

[0023] As Figs. 1 to 3As shown, the automatic safety control method for valve pressure testing proposed in this invention includes the following steps: S1: An electric contact pressure gauge 7 is installed on the valve test inlet header. This electric contact pressure gauge 7 has a common line 6 and corresponding high and low pressure first terminals 8 and second terminals 9, which can switch the circuit on and off by pressure changes. The high pressure is set as the valve strength test pressure, and the low pressure is set as the tightness test pressure, thereby realizing pressure monitoring and control at different test stages. S2: A first power-off delay relay 2 and a second power-off delay relay 10 are set. Both include coils, normally closed contacts, and other structures. Their characteristic is that they start timing after power failure and change the contact state after the set time is reached. According to relevant pipeline specifications, the required strength test time and tightness test time for the valve are accurately located and determined. These two time parameters are set into the corresponding time relays to ensure that the test process is strictly carried out according to the standard duration. S3: According to the preset electrical schematic diagram, the booster pump 19 for valve pressure testing is used as the power source for the system pressure, and the electric contact pressure gauge 7 is connected to the control box. The control box integrates various control components, which form a complete control loop through reasonable circuit connections, providing the hardware foundation for the automated control of the entire pressure testing process; S4: Specify the various test parameters for the valve, including the strength test pressure P1 and the strength test time T1, the tightness test pressure P2 and the tightness test time T2, and satisfy the relationship that P1>P2 and T1>T2. This is determined by the nature and requirements of the two tests. S5: Close the circuit breaker 20, which serves as the main power switch for the main circuit. At this time, the power indicator light 18 illuminates, indicating that the system power supply is normal. Press the start button 3, which serves as the trigger element for the control process. The actuator controlling the on / off of the booster pump power supply circuit, the AC contactor coil 5, and the first power-off delay relay 2 and the second power-off delay relay 10 are energized. The first normally open contact 4 closes to form a self-holding circuit. This self-locking structure allows the above components to be continuously energized. At the same time, the second normally open contact 12 closes, and the strength test timing light 16 and the tightness test timing light 17, which indicate the corresponding test stage operation status, both illuminate. The booster pump 19 starts, and the pressure in the pressure pipe at the power contact of the valve pressure header begins to rise. When the valve pressure increases to P1, the common line 6 of the electric contact pressure gauge 7 is connected to the first terminal 8. Responding to the high-pressure signal, the intermediate control element, the first intermediate relay coil 14, is energized, and the normally closed contact 1 opens. This causes both the first power-off delay relay 2 and the AC contactor coil 5 to lose power, the booster pump 19 stops working, and the first power-off delay relay 2 begins timing. After time T1 is reached, the normally closed contact 1 opens, the closed contact opens, and the strength test timing light 16 goes out, marking the completion of the strength test. S6: open the hand-operated component for releasing system pressure, open the pressure relief valve of the valve pressure test main pipe, slowly operate to release pressure to P2, then close the pressure relief valve, and ensure that the electric contact pressure gauge 7 reads P2 stably. At this time, the common line 6 is connected to the second terminal 9, the second intermediate relay coil 15 is powered in response to the low-voltage signal of the intermediate control element, the normally closed contact 11 is disconnected, and the first intermediate relay coil 14 loses power and starts timing. After the time reaches T2, the closed contact 13 is disconnected, the normally open contact state is restored, and the tightness test timing lamp 17 is turned off, indicating that the tightness test is completed; S7: open the pressure relief valve of the valve pressure test main pipe again, release the system pressure to 0, then remove the valve that has completed pressure test, and install the next valve to be tested on the valve pressure test platform for the next pressure test; S8: press the start button 3, and repeat the above steps S5 to S7 to perform pressure test on the next valve, so that continuous valve pressure test is realized.

[0024] Secondly, in steps S1 to S3, the high pressure value of the electric contact pressure gauge 7 accurately corresponds to the strength test pressure value of the valve, and the low pressure value completely corresponds to the tightness test pressure value of the valve, so as to ensure the accuracy of pressure monitoring. The power-off delay time of the normally closed contact 1 is accurately set as the strength test time T1 of the valve, and the power-off delay time of the first intermediate relay coil 14 is set as the tightness test time T2 of the valve, so as to ensure that the test time meets the specification requirements. The preset drawing is an electrical schematic diagram that can realize correct electrical connection of the booster pump 19, the electric contact pressure gauge 7 and the control box, and provides accurate guidance for circuit connection.

[0025] Further, in step S5, after the start button 3 is pressed, the self-holding circuit formed by the closure of the first normally open contact 4 can stably maintain the power-on state of the alternating current contactor coil 5, the first power-off delay relay 2 and the second power-off delay relay 10, so as to ensure continuous operation of the system. When the valve pressure reaches P1, the common line 6 of the electric contact pressure gauge 7 is connected to the first terminal 8, the first intermediate relay coil 14 is powered, and then the normally closed contact 1 is disconnected, so as to realize power-off of the first power-off delay relay 2 and the alternating current contactor coil 5. After the first power-off delay relay 2 loses power, timing starts, and when the timing reaches T1, the normally closed contact 1 is disconnected, the closed contact is disconnected, and the strength test timing lamp 16 is turned off, so as to clearly indicate that the strength test is completed.

[0026] In addition, after the pressure is released to P2 and the pressure release valve is closed in step S6, the electric contact pressure gauge 7 is connected to the second terminal 9 through the common line 6, the second intermediate relay coil 15 is energized, the normally closed contact 11 is opened, and the first intermediate relay coil 14 is de-energized and starts timing. When the first intermediate relay coil 14 timing reaches T2, the closed contact 13 is opened, the tightness test timing lamp 17 is turned off, and a clear visual signal indicates that the tightness test is completed.

[0027] Furthermore, the method further includes an emergency treatment step S9: if the valve test pressure is found to be unqualified, internal leakage or valve body cracking occurs, or other abnormal conditions occur during the pressure test, the operator should immediately open the pressure release valve, quickly release the system pressure, and close the circuit breaker 20 to cut off the power supply, so as to ensure the safety of the test and avoid the expansion of the accident.

[0028] The above specific embodiments are only several optional embodiments of the present application, and based on the technical solutions of the present application and the related inspirations of the above embodiments, those skilled in the art can make various alternative improvements and combinations on the above specific embodiments.

Claims

1. A method for automatically controlling the safety of a valve during pressure testing, characterized in that, The method comprises the following steps: S1, installing an electric contact pressure gauge (7) on the valve pressure inlet pipe, setting the electric contact pressure gauge (7) pressure, the high pressure is the strength test pressure of the valve, and the low pressure is the tightness test pressure; S2, setting a first power-off delay relay (2) and a second power-off delay relay (10), searching the strength test time and the tightness test time of the valve according to the pipeline specification, and setting the time of the two time relays; S3, connecting the pressure pump (19) and the electric contact pressure gauge (7) of the valve pressure test to the control box according to the preset drawing; S4, determining that the strength test pressure of the valve is P1, the strength test time is T1, the tightness test pressure is P2, and the tightness test time is T2, wherein P1>P2 and T1>T2; S5, closing the circuit breaker (20), the power indicator light (18) is on, the start button (3) is pressed, the AC contactor coil (5), the first power-off delay relay (2) and the second power-off delay relay (10) are powered on, the first normally open contact (4) is closed to form a self-holding circuit, the second normally open contact (12) is closed, the strength test timing light (16) and the tightness test timing light (17) are on, the pressure pump (19) is started, and the electric contact pressure pipe pressure on the valve pressure inlet pipe rises; when the valve pressure increases to P1, the common line (6) of the electric contact pressure gauge (7) is connected with the first terminal (8), the first intermediate relay coil (14) is powered on, the normally closed contact (1) is disconnected, the first power-off delay relay (2) and the AC contactor coil (5) are powered off, the pressure pump (19) stops working, and the first power-off delay relay (2) starts timing; after the time reaches T1, the normally closed contact (1) is disconnected, the closed contact is disconnected, the strength test timing light (16) is turned off, and the strength test is completed; S6, opening the valve pressure test inlet pipe pressure relief valve, slowly operating to make the pressure leak to P2, then closing the pressure relief valve, ensuring that the electric contact pressure gauge (7) reads P2, at this time, the common line (6) is connected with the second terminal (9), the second intermediate relay coil (15) is powered on, the normally closed contact (11) is disconnected, the first intermediate relay coil (14) is powered off and starts timing; after the time reaches T2, the closed contact (13) is disconnected, the normally open contact state is restored, the tightness test timing light (17) is turned off, and the tightness test is completed; S7, opening the valve pressure test inlet pipe pressure relief valve, leaking the pressure to 0, removing the tested valve, and installing the next valve to be tested on the valve pressure test platform; S8, pressing the start button (3), and repeating the above steps S5 to S7.

2. The method for automatically controlling the safety of a valve during pressure testing according to claim 1, characterized in that: In step S1, the high pressure value of the electric contact pressure gauge (7) is the same as the strength test pressure value of the valve, and the low pressure value is the same as the tightness test pressure value of the valve.

3. The method for automatically controlling the safety of a valve during pressure testing according to claim 1, characterized in that: In step S2, the power-off delay time of the normally closed contact (1) is set as the strength test time T1 of the valve, and the power-off delay time of the first intermediate relay coil (14) is set as the tightness test time T2 of the valve.

4. The method for automatically controlling the safety of a valve during pressure testing according to claim 1, characterized in that: In step S5, after pressing the start button (3), the self-holding circuit formed by closing the first normally open contact (4) maintains the power-on state of the AC contactor coil (5), the first power-off delay relay (2) and the second power-off delay relay (10).

5. The method for automatically controlling the safety of a valve during pressure testing according to claim 1, characterized in that: In step S5, when the valve pressure reaches P1, the electrical contact pressure gauge (7) common line (6) is connected to the first terminal (8), triggering the first intermediate relay coil (14) to power on, and then making the normally closed contact (1) open, realizing the power-off of the first power-off delay relay (2) and the AC contactor coil (5).

6. The method for automatically controlling the safety of a valve during pressure testing according to claim 1, characterized in that: In step S5, after the first power-off delay relay (2) loses power, the timing starts, and when the timing reaches T1, the normally closed contact (1) opens the closed contact, making the strength test timing lamp (16) go out to indicate that the strength test is completed.

7. The method for automatically controlling the safety of a valve during pressure testing according to claim 1, characterized in that: In step S6, after the pressure is released to P2 and the pressure relief valve is closed, the electrical contact pressure gauge (7) common line (6) is connected to the second terminal (9), making the second intermediate relay coil (15) power on, and the normally closed contact (11) opens, causing the first intermediate relay coil (14) to lose power and start timing.

8. The method for automatically controlling the safety of a valve during pressure testing according to claim 1, characterized in that: In step S6, when the first intermediate relay coil (14) timing reaches T2, the closed contact (13) is opened, making the tightness test timing lamp (17) go out to indicate that the tightness test is completed.

9. The method for automatically controlling the safety of a valve during pressure testing according to claim 1, characterized in that: Step S9 is also included, if the valve test pressure is unqualified during the test, there is internal leakage or valve body cracking, immediately open the pressure relief valve and close the circuit breaker (20).

10. The method for automatically controlling the safety of a valve during pressure testing according to claim 1, characterized in that: In step S3, the pre-set drawing is an electrical schematic diagram that can realize the correct electrical connection of the booster pump (19) and the electrical contact pressure gauge (7) with the control box.

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