A monitoring device capable of accurately detecting the opening pressure of a safety valve online.

Abstract

This utility model discloses a monitoring device for accurately detecting the opening pressure of a safety valve online. It includes a base fixed to a spring safety valve, a piston chamber fixed above the base, a piston coaxially arranged with the valve stem of the spring safety valve connected inside the piston chamber, a screw coaxially fixed to the piston, and the screw and the valve stem connected to each other via a strain gauge. The piston chamber and the piston form a sealed cavity, and the piston chamber has an oil inlet communicating with the sealed cavity. The oil inlet is connected to a hydraulic device via a pipe. The strain gauge and the hydraulic device are both communicatively connected to a distributed control system (DCS), which is also communicatively connected to a pressure sensor. This utility model not only allows for remote operation of the control system to measure and calculate the spring stiffness of the safety valve, but also eliminates the need to shut down the furnace during the measurement process, offering better real-time performance, allowing for operation at any time, and without excessive limitations.

Description

Technical Field

[0001] This utility model relates to the field of safety valve monitoring technology, specifically to a signal processing device that can remotely detect the opening pressure of a safety valve online. Background Technology

[0002] Safety valves, as crucial safety accessories on pressure-bearing special equipment, possess critical overpressure protection functions and are essential for ensuring the safe operation of such equipment. Pressure-bearing special equipment is equipped with specific working pressure and set pressure parameters. The working pressure meets the pressure requirements of the medium, while the set pressure serves as the lower limit for pressure relief. When the pressure inside the equipment reaches the set pressure, forced pressure relief must be implemented to prevent the potential explosion hazard caused by overpressure.

[0003] To ensure safe production, national regulations require all pressure-bearing special equipment to be equipped with safety valves as forced pressure relief tools. The working principle of a safety valve is as follows: when the internal pressure of the pressure-bearing equipment unexpectedly rises from the working pressure to the set pressure, the safety valve automatically opens, allowing the medium inside the equipment to be discharged through the safety valve, thereby achieving pressure relief. Once the system pressure drops back to or slightly below the working pressure level, the safety valve automatically closes and remains sealed.

[0004] A spring-loaded safety valve is an automatic, purely mechanical special device. The spring is the core component of the drive system, ensuring the valve's normal and stable operation. However, with increasing service life, the spring, constantly under compression, experiences a decrease in stiffness. This decrease in stiffness intensifies over time or with rising temperatures, leading to a reduction in the valve's opening pressure. Although national regulations allow for a ±3% or ±0.015MPa error range between the opening pressure threshold of a spring-loaded safety valve and the system's set pressure, even a 3% allowable error can pose significant safety hazards for ultra-supercritical equipment or other ultra-high-pressure vessels operating at pressures above 30MPa.

[0005] Therefore, there is an urgent need to develop a monitoring device that can accurately detect the opening pressure of a safety valve online in order to accurately predict the opening timing of the safety valve and grasp its pressure fluctuation data. Utility Model Content

[0006] This utility model discloses a monitoring device that can accurately detect the opening pressure of a safety valve online. It can not only remotely operate the control system to complete the measurement and calculation of the spring stiffness of the safety valve, but also the measurement process does not require stopping the furnace, and has better real-time performance, can be operated at any time, and has no excessive restrictions.

[0007] This utility model discloses a monitoring device for accurately detecting the opening pressure of a safety valve online. It includes a base fixed to a spring safety valve, a piston chamber fixed above the base, a piston coaxially arranged with the valve stem of the spring safety valve connected inside the piston chamber, a screw coaxially fixed to the piston, and the screw and the valve stem connected to each other via a strain gauge. The piston chamber and the piston form a sealed cavity, and the piston chamber has an oil inlet communicating with the sealed cavity. The oil inlet is connected to a hydraulic device via a pipe. The strain gauge and the hydraulic device are both communicatively connected to a distributed control system (DCS), and the DCS is communicatively connected to a pressure sensor.

[0008] In a preferred embodiment of this utility model, the piston is a T-shaped piston, and a through threaded hole is provided in the center of the T-shaped piston.

[0009] In a preferred embodiment of this utility model, the screw is threadedly connected to the center of the T-shaped piston.

[0010] In a preferred embodiment of this utility model, a round nut is provided on the screw.

[0011] In a preferred embodiment of this utility model, a piston chamber is fixedly connected to the top of the base by a column.

[0012] In a preferred embodiment of this utility model, the central axis of the oil inlet hole is arranged perpendicular to the central axis of the piston.

[0013] In a preferred embodiment of this invention, the pressure sensor collects the pressure inside the pressure vessel.

[0014] In a preferred embodiment of this utility model, the dust cover is fixedly connected above the piston chamber, and both the piston and the screw are located inside the dust cover.

[0015] In a preferred embodiment of this utility model, the spring safety valve is fixedly connected to the pressure vessel.

[0016] In a preferred embodiment of this utility model, after the spring safety valve is welded to the pressure vessel and before it is put into production, a monitoring device capable of accurately detecting the opening pressure of the safety valve is used to conduct an opening test on the spring safety valve to verify the opening action of the safety valve and to verify the quality of the spring safety valve.

[0017] The beneficial effects of this utility model are as follows: The monitoring device disclosed in this utility model is fixed to the spring safety valve via a base, and forms a complete detection system using components such as a piston chamber, piston, screw, and strain gauge, which can monitor the operating status of the safety valve in real time. The T-shaped piston in the device is coaxially arranged with the valve stem, and the strain gauge connected to the valve stem via the screw can accurately sense the minute displacement of the valve stem, thereby achieving accurate monitoring of the safety valve's opening process. The sealed chamber formed by the piston and piston is connected to the hydraulic equipment through an oil inlet, enabling precise control of the safety valve's operation.

[0018] This invention enables remote operation and control of the safety valve spring stiffness measurement and calculation. The entire system, together with the distributed control system and pressure sensors, forms a closed-loop monitoring network, allowing for accurate recording and analysis of the safety valve's opening pressure data. Crucially, this device allows for opening tests to be conducted after the spring safety valve is welded to the pressure vessel but before it is put into production, verifying the safety valve's opening action and confirming its quality.

[0019] The measurement process requires no furnace shutdown, offers better real-time performance, and can be operated at any time without excessive restrictions—features difficult to achieve with traditional testing methods. Designs such as a column-fixed piston chamber and dust covers protecting key components further enhance the stability and reliability of the device. The vertically arranged oil inlet design optimizes the hydraulic system's efficiency, making the entire monitoring process more accurate. The device can directly collect pressure data from the pressure vessel, comparing it with the safety valve's activation status, providing comprehensive assurance for the equipment's safe operation.

[0020] This invention can effectively detect changes in the spring stiffness of a spring safety valve, construct spring stiffness data, and predict spring maintenance and safety valve replacement. This is of great significance for extending equipment service life and preventing safety accidents in advance.

[0021] This utility model equipment does not require disassembly or reassembly of the safety valve on site, nor does it require alteration of the safety structure, thus providing better safety and avoiding the safety hazards and production interruptions that may result from disassembling the safety valve in traditional testing methods.

[0022] Furthermore, this utility model has no special connection method and can be installed on most spring safety valves, which has wide applicability and convenience, greatly expanding its application range.

[0023] This online monitoring device solves the problem that traditional methods cannot accurately detect the opening pressure of safety valves under actual working conditions, greatly improving the accuracy and convenience of safety valve performance verification. It is of great significance for preventing overpressure risks in pressure vessels and ensuring production safety. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments disclosed in this invention, the accompanying drawings of the embodiments will be briefly described below. These drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0025] Figure 1 This is a schematic diagram of the structure of the spring safety valve that incorporates this utility model.

[0026] Figure 2 This is an enlarged view of the structure of this utility model;

[0027] In the diagram: 1-Spring safety valve, 2-Safety valve opening pressure detection device, 3-Pressure vessel, 4-Pressure sensor, 5-Spring safety valve support, 6-Base, 7-Column, 8-Valve stem, 9-Strain gauge, 10-Piston chamber, 11-Piston, 12-Round nut, 13-Screw, 14-Dust cover, 15-Hydraulic equipment, 16-Distributed control system. Detailed Implementation

[0028] The technical solutions (including preferred technical solutions) of the present invention will be further described in detail below with reference to the accompanying drawings and by way of listing some optional embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] This utility model discloses a monitoring device for accurately detecting the opening pressure of a safety valve online. It includes a base 6 fixed to a spring safety valve 1, a piston chamber 10 fixed above the base 6, a piston 11 coaxially arranged with the valve stem 8 of the spring safety valve 1 connected inside the piston chamber 10, a screw 13 coaxially fixed to the piston 11, and the screw 13 and the valve stem 8 connected to each other via a strain gauge 9. A dust cover 14 is provided on the piston chamber 10. The piston chamber 10 and the piston 11 form a sealed chamber. An oil inlet is provided on the piston chamber 10, communicating with the sealed chamber. The oil inlet is connected to a hydraulic device 15 via a pipe. The strain gauge 9 and the hydraulic device 15 are both communicatively connected to a distributed control system 16, which is also communicatively connected to a pressure sensor 4.

[0030] Preferably, piston 11 is a T-shaped piston with a through threaded hole at its center. The T-shaped design increases the contact area between the piston and the hydraulic oil, improving the efficiency of force transmission.

[0031] Preferably, the T-shaped piston is threaded with a screw 13 at its center. This connection method ensures a secure connection between the piston 11 and the screw 13, guaranteeing precise force transmission.

[0032] Preferably, a round nut 12 is provided on the screw 13. The round nut 12 serves to fix and adjust the position of the screw 13, ensuring the accuracy of the detection.

[0033] Preferably, the piston chamber 10 is fixedly connected to the top of the base 6 via a column 7. The column 7 provides a stable support structure, reducing the impact of external vibrations on the measurement.

[0034] Preferably, the central axis of the oil inlet is arranged perpendicular to the central axis of the piston 11. This perpendicular arrangement optimizes the flow path of the hydraulic oil and improves the system's response speed.

[0035] Preferably, pressure sensor 4 collects the pressure inside pressure vessel 3. Real-time monitoring of pressure changes inside pressure vessel 3 provides reference data for detecting the safety valve's opening pressure.

[0036] Preferably, a dust cover 14 is fixedly connected above the piston chamber 10, and both the piston 11 and the screw 13 are located inside the dust cover 14. The dust cover 14 protects the core components from environmental pollution and extends the service life of the equipment.

[0037] Preferably, the spring safety valve 1 is fixedly connected to the pressure vessel 3. This ensures that the connection between the spring safety valve 1 and the pressure vessel 3 is secure and reliable.

[0038] In a preferred embodiment of this utility model, after the spring safety valve 1 is welded to the pressure vessel 3 and before it is put into production, a monitoring device capable of accurately detecting the safety valve's opening pressure online is used to conduct a opening test on the spring safety valve 1 to verify the safety valve's opening action and confirm the quality of the spring safety valve 1. This opening test will raise the internal pressure of the pressure vessel 3 to pressure A, which is lower than the working pressure of the pressure vessel.

[0039] When the internal pressure of pressure vessel 3 rises to A, the remote control DCS system (distributed control system) drives the hydraulic equipment 15 to input stable hydraulic oil into the sealed cavity formed by the assembly relationship between piston chamber 10 and piston 11. The hydraulic oil contacts piston chamber 10 and piston 11. Piston chamber 10 is connected to spring safety valve through column 7, base 6, and spring safety valve support 5, forming a fixed constraint. Piston 11 is connected to strain gauge 9 through round nut 12 and screw 13, forming a fixed constraint. As the hydraulic oil pressure output by hydraulic equipment 15 steadily increases, piston 11 produces a small upward displacement. Piston 11 drives screw 13 to produce a small upward displacement, which in turn causes strain gauge 9 to produce a small strain and generate an electrical signal. The axial tension on valve stem 8 can be calculated based on the strain gauge 9 reading, and the equivalent medium pressure on spring safety valve 1 can be calculated.

[0040] The equivalent medium pressure is typically the sum of the upward thrust on the valve disc of the spring safety valve 1 and the upward pull on the screw 13 generated by the hydraulic equipment 15. As the hydraulic oil pressure output by the hydraulic equipment 15 steadily increases, the equivalent medium pressure on the spring safety valve 1 also increases.

[0041] When the equivalent medium pressure on the spring safety valve 1 rises to the working pressure B of the pressure vessel, the strain data b of the strain block 9 is recorded; when the equivalent medium pressure on the spring safety valve 1 rises to the set pressure C of the pressure vessel, the spring safety valve completes the opening action. If the action is continuous, the safety valve completes the setting test, and the strain data c of the strain block 9 at the opening of the spring safety valve is recorded.

[0042] During the spring safety valve 1's opening test, the axial tension on the valve stem 8 can be recorded until the axial tension on the valve stem 8 undergoes a sudden change. The spring safety valve 1 then completes the opening action, the remote control DCS system is shut down, the hydraulic equipment 15 is depressurized, and the spring safety valve 1 can then automatically open without external force.

[0043] After the spring safety valve 1 is put into production and use, if it is necessary to calculate and verify the spring stiffness attenuation of the spring of the safety valve 1, the DCS system can be remotely controlled to drive the hydraulic equipment 15 to input stable hydraulic oil into the sealed chamber formed by the piston chamber 10 and piston 11 due to the assembly relationship, measure the strain data of the strain block 9 until the safety valve opens, and calculate the equivalent medium pressure currently received by the spring safety valve 1.

[0044] After the spring safety valve 1 completes its opening, the strain data c1 of the strain block 9 can be recorded. By comparing the strain data c with the strain data c1, the difference between the equivalent medium pressure and the set pressure experienced by the safety valve during this opening can be calculated, and the stiffness decay of the spring can be calculated.

[0045] A database of spring safety valves can be created by comparing and recording multiple data points, facilitating systematic safety valve data analysis and simplifying the maintenance and replacement of spring safety valves. Through long-term data accumulation, the performance trends of spring safety valves can be predicted, providing a scientific basis for equipment maintenance and replacement, and significantly improving the safe operation level of pressure equipment.

[0046] It will be readily understood by those skilled in the art that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, combinations, substitutions, improvements, etc., made under the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A monitoring device capable of accurately detecting the opening pressure of a safety valve online, characterized in that: The system includes a base (6) fixed to a spring safety valve (1), a piston chamber (10) fixed above the base (6), a piston (11) coaxially arranged with the valve stem (8) of the spring safety valve (1) connected inside the piston chamber (10), a screw (13) coaxially fixed to the piston (11), the screw (13) and the valve stem (8) being connected to each other through a strain gauge (9), a valve seat (11) being provided on the piston chamber (10), the piston chamber (10) and the piston (11) forming a sealed chamber, an oil inlet hole communicating with the sealed chamber being provided on the piston chamber (10), the oil inlet hole being connected to a hydraulic device (15) through a pipe, the strain gauge (9) and the hydraulic device (15) being communicatively connected to a distributed control system (16), and the distributed control system (16) being communicatively connected to a pressure sensor (4).

2. The monitoring device for accurately detecting the opening pressure of a safety valve online according to claim 1, characterized in that: The piston (11) is a T-shaped piston, and a through threaded hole is provided in the center of the T-shaped piston.

3. The monitoring device for accurately detecting the opening pressure of a safety valve online according to claim 2, characterized in that: The screw (13) is threaded to the center of the T-shaped piston.

4. The monitoring device for accurately detecting the opening pressure of a safety valve online according to claim 3, characterized in that: A round nut (12) is provided on the screw (13).

5. The monitoring device for accurately detecting the opening pressure of a safety valve online according to claim 1, characterized in that: A piston chamber (10) is fixedly connected to the top of the base (6) via a column (7).

6. The monitoring device for accurately detecting the opening pressure of a safety valve online according to claim 1, characterized in that: The central axis of the oil inlet is arranged perpendicular to the central axis of the piston (11).

7. The monitoring device for accurately detecting the opening pressure of a safety valve online according to claim 1, characterized in that: The pressure sensor (4) collects the pressure inside the pressure vessel (3).

8. The monitoring device for accurately detecting the opening pressure of a safety valve online according to claim 1, characterized in that: A dust cover (14) is fixedly attached above the piston chamber (10), and the piston (11) and the screw (13) are both located inside the dust cover (14).

9. The monitoring device for accurately detecting the opening pressure of a safety valve online according to claim 1, characterized in that: The spring safety valve (1) is fixed to the pressure vessel (3).

10. The monitoring device for accurately detecting the opening pressure of a safety valve online according to claim 1, characterized in that: After the spring safety valve (1) is welded onto the pressure vessel (3) and before it is put into production, a monitoring device that can accurately detect the opening pressure of the safety valve is used to conduct an opening test on the spring safety valve (1) to verify the opening action of the safety valve and to verify the quality of the spring safety valve (1).

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