Safety valve on-line verification device

Abstract

The utility model relates to an on-line verification device for a safety valve, and belongs to a safety valve inspection and detection mechanism. The air source is in air circuit connection with the balance air supply pipeline and the setting air supply pipeline through the pressure reducing valve, the balance air supply pipeline is connected with a balance cabin air port of the lifting device through an air circuit, and the setting air supply pipeline is connected with a setting cabin air port of the lifting device through an air circuit and further connected with the top of an air cylinder piston lifting rod of the lifting device through the guide valve. The bottom of the lifting device is installed on the support. The safety valve online verification device has the advantages of novel structure, light weight, flexibility and convenience, the function of online verification is enhanced, the verification mode is simpler and more convenient, the safety valve online verification device is suitable for online verification of various safety valves with valve rods, safety valves with tiny sizes and low-pressure or micro-pressure safety valves, and the test data is sensitive, accurate and visual.

Description

Technical Field

[0001] This utility model relates to safety valve inspection and testing institutions, and more particularly to an online safety valve calibration device. Background Technology

[0002] A safety valve is an automatic valve that opens automatically when the pressure of the medium inside the protected equipment exceeds a preset safety pressure value, releasing a certain amount of fluid. It then automatically closes again when the pressure drops to or slightly below the safety pressure value, thus protecting the equipment. Due to the importance of safety valves, they are typically calibrated at least once a year.

[0003] Existing safety valve calibration methods include line calibration and online calibration, among which:

[0004] Offline calibration: On a safety valve calibration bench, clamp the safety valve to be tested and introduce compressed air into the inlet of the safety valve. The pressure rises to the open position of the safety valve, and the pressure measured at this point is the set pressure. Then, when the pressure drops to the specified level, use a pressure gauge or other legally mandated methods to check for any media leakage during a sealing pressure test.

[0005] Online calibration: In a pressure system, an external lifting force is applied to the online safety valve via an oil pump or manual pressurization. Under the combined action of this external lifting force and the initial pressure of the medium, the valve resists the spring preload applied to the valve disc. When these forces cancel each other out, i.e., when the sealing stress between the valve disc and the valve seat is zero, the valve disc disengages from the valve seat. The external lifting force value at this moment is detected, and the specified pressure value at the instant the safety valve opens is calculated using the neutral effective area of ​​the safety valve's sealing surface.

[0006] The current disadvantage of offline calibration is that production must be stopped, the safety valve removed, and sent to the inspection department for calibration. After the calibration is passed, it can be reinstalled and put back into production. The calibration cycle is long and affects the production schedule.

[0007] Disadvantages of online calibration: Existing online safety valve calibrators are designed for calibrating large-diameter safety valves in power plants and cannot adapt to calibrating small-diameter miniature safety valves. Existing online safety valve calibrators are suitable for high-pressure safety valves but cannot accurately test low-pressure safety valves below one MPa, resulting in an overly narrow testing range. Online calibration is cumbersome and complex; when the safety valve requires pressure adjustment, the testing equipment must be disassembled, the pressure adjusted, and then reassembled for calibration. Summary of the Invention

[0008] This invention provides an online safety valve calibration device to solve the problems of narrow detection range, inability to adapt to the calibration of small-diameter miniature safety valves, and cumbersome and complicated online calibration operations in current online safety valve calibration methods.

[0009] The technical solution adopted by this utility model is as follows: it includes an air source, a balancing air supply pipeline, a setting air supply pipeline, a lifting device, and a support. The air source is connected to the balancing air supply pipeline and the setting air supply pipeline through a pressure reducing valve. The balancing air supply pipeline is connected to the balancing chamber air port of the lifting device through an air passage. The setting air supply pipeline is connected to the setting chamber air port of the lifting device through an air passage and is also connected to the top of the cylinder piston lifting rod of the lifting device through a pilot valve. The bottom of the lifting device is mounted on the support.

[0010] The gas source includes a gas cylinder and a pressure reducing valve, and the gas outlet of the gas cylinder and the pressure reducing valve are connected through a gas circuit.

[0011] The balanced air supply pipeline includes a balanced valve, a balanced pressure relief valve, and a balanced digital display pressure transmitter. One end of the balanced valve is connected to the pressure reducing valve through an air circuit, and the other end is connected to the balanced chamber of the lifting device through an air circuit. The balanced pressure relief valve and the balanced digital display pressure transmitter are connected in series in the air circuit between the balanced valve and the balanced chamber.

[0012] The setting air supply line includes a setting valve, a setting pressure relief valve, a setting digital pressure transmitter, and a pilot valve. One end of the setting valve is connected to the pressure reducing valve through an air circuit, and the other end is connected to the setting chamber of the lifting device through an air circuit. The setting pressure relief valve and the setting digital pressure transmitter are connected in series in the air circuit between the setting valve and the setting chamber. The pilot valve is connected in parallel in the air circuit between the setting digital pressure transmitter and the setting chamber.

[0013] The lifting device includes a housing, a cylinder piston lifting rod, a cylinder piston sealing ring, a balance chamber, a settling chamber, a balance chamber air port, and a settling chamber air port. The cylinder piston lifting rod and the cylinder piston sealing ring are fixedly connected, and the cylinder piston sealing ring is slidably connected to the inside of the housing, dividing the inside of the housing into a balance chamber and a settling chamber. The side wall of the balance chamber has a balance chamber air port, and the side wall of the settling chamber has a settling chamber air port.

[0014] The upper part of the lifting device housing has a sealing ring 1 at the sliding connection between the upper part and the cylinder piston lifting rod, and the lower part has a sealing ring 2 at the sliding connection between the lower part and the cylinder piston lifting rod.

[0015] The cylinder piston sealing ring has a sealing ring three on its outer circumference.

[0016] The advantages of this utility model are its novel structure, lightweight and flexible design, and ability to maintain synchronous micro-opening of the pilot valve and safety valve sealing surfaces. This effectively controls the valve disc opening height, reduces the spring's reaction force on the valve disc, and prevents the sealing surface from deforming due to high-pressure impact. It also effectively prevents slag inclusion on the sealing surface, thus avoiding leakage. The dual-chamber design of the lifting device adopts a pilot principle, enhancing the online verification function and simplifying the verification process. It is suitable for online verification of various safety valves with valve stems, as well as for online verification of small-sized safety valves and low-pressure or micro-pressure safety valves. The test data is sensitive, accurate, and intuitive.

[0017] This invention provides a more convenient online inspection method for safety valves, expands the scope of online verification capabilities, solves the problem of production shutdowns required for offline verification, enables online verification to better serve enterprise production, and ensures the safe operation of special equipment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the gas source structure of this utility model;

[0020] Figure 3 This is a schematic diagram of the balanced gas supply pipeline of this utility model;

[0021] Figure 4 This is a schematic diagram of the structure of the gas supply pipeline of this utility model;

[0022] Figure 5 This is a structural schematic diagram of the lifting device of this utility model. Detailed Implementation

[0023] See Figure 1 , 2 5, including air source 1, balancing air supply line 2, setting air supply line 3, lifting device 4 and support 5, wherein air source 1 is connected to the balancing air supply line 2 and setting air supply line 3 through pressure reducing valve 102 respectively. Balancing air supply line 2 is connected to the balancing chamber air port 406 of lifting device 4 through an air passage. Setting air supply line 3 is connected to the setting chamber air port 407 of lifting device 4 through an air passage and is also connected to the top of cylinder piston lifting rod 402 of lifting device 4 through pilot valve 304. The bottom of lifting device 4 is mounted on support 5.

[0024] See Figure 2 The gas source 1 includes a gas storage cylinder 101 and a pressure reducing valve 102, and the gas outlet of the gas storage cylinder 101 and the pressure reducing valve 102 are connected through a gas circuit.

[0025] See Figure 3 The balanced air supply line 2 includes a balanced valve 201, a balanced pressure relief valve 202, and a balanced digital display pressure transmitter 203. One end of the balanced valve 201 is connected to the pressure reducing valve 102 through an air passage, and the other end is connected to the balanced chamber 404 of the lifting device 4 through an air passage. The balanced pressure relief valve 202 and the balanced digital display pressure transmitter 203 are connected in series in the air passage between the balanced valve 201 and the balanced chamber 404.

[0026] See Figure 4The setting air supply line 3 includes a setting valve 301, a setting pressure relief valve 302, a setting digital display pressure transmitter 303, and a pilot valve 304. One end of the setting valve 301 is connected to the pressure reducing valve 102 via an air passage, and the other end is connected to the setting chamber 405 of the lifting device 4 via an air passage. The setting pressure relief valve 302 and the setting digital display pressure transmitter 303 are connected in series in the air passage between the setting valve 301 and the setting chamber 405. The pilot valve 304 is connected in parallel in the air passage between the setting digital display pressure transmitter 303 and the setting chamber 405 via an air passage.

[0027] See Figure 5 The lifting device 4 includes a housing 401, a cylinder piston lifting rod 402, a cylinder piston sealing ring 403, a balance chamber 404, a settling chamber 405, a balance chamber air port 406, and a settling chamber air port 407. The cylinder piston lifting rod 402 and the cylinder piston sealing ring 403 are fixedly connected. The cylinder piston sealing ring 403 is slidably connected to the inside of the housing 401, dividing its interior into a balance chamber 404 and a settling chamber 405. The side wall of the balance chamber 404 has a balance chamber air port 406, and the side wall of the settling chamber has a settling chamber air port 407.

[0028] See Figure 5 The upper part of the lifting device housing 401 has a sealing ring 40101 at the sliding connection between the upper part and the cylinder piston lifting rod 402, and the lower part has a sealing ring 40102 at the sliding connection between the lower part and the cylinder piston lifting rod 402.

[0029] See Figure 5 The outer circumference of the cylinder piston sealing ring 403 has a sealing ring 40301.

[0030] Working principle:

[0031] Place the bracket 5 on the safety valve 6 to be tested. Connect the bottom end of the cylinder piston lifting rod 402 of the lifting device 4 to the top end of the valve stem of the safety valve 6 to be tested. Determine the pressure of the balance chamber. Inject the gas from the gas storage cylinder 101 into the setting chamber 405 through the setting gas supply line 3. This makes the pressure in the setting chamber overcome the spring preload of the safety valve 6 to be tested. At the same time, the cylinder piston lifting rod 402 lifts the valve stem of the safety valve 6 and opens the pilot valve 304 to release pressure. Keep the valve disc of the safety valve 6 and the pilot valve slightly open synchronously. The setting pressure value measured at this time is the setting pressure.

Claims

1. An online calibration device for safety valves, characterized in that: It includes an air source, a balancing air supply line, a setting air supply line, a lifting device, and a support frame. The air source is connected to the balancing air supply line and the setting air supply line via a pressure reducing valve. The balancing air supply line is connected to the balancing chamber air port of the lifting device via an air line. The setting air supply line is connected to the setting chamber air port of the lifting device via an air line and is also connected to the top of the cylinder piston lifting rod of the lifting device via a pilot valve. The bottom of the lifting device is mounted on the support frame.

2. The safety valve online calibration device according to claim 1, characterized in that: The gas source includes a gas cylinder and a pressure reducing valve, and the gas outlet of the gas cylinder and the pressure reducing valve are connected through a gas circuit.

3. The safety valve online calibration device according to claim 1, characterized in that: The balanced air supply pipeline includes a balanced valve, a balanced pressure relief valve, and a balanced digital display pressure transmitter. One end of the balanced valve is connected to the pressure reducing valve through an air circuit, and the other end is connected to the balanced chamber of the lifting device through an air circuit. The balanced pressure relief valve and the balanced digital display pressure transmitter are connected in series in the air circuit between the balanced valve and the balanced chamber.

4. The safety valve online calibration device according to claim 1, characterized in that: The setting air supply line includes a setting valve, a setting pressure relief valve, a setting digital pressure transmitter, and a pilot valve. One end of the setting valve is connected to the pressure reducing valve through an air circuit, and the other end is connected to the setting chamber of the lifting device through an air circuit. The setting pressure relief valve and the setting digital pressure transmitter are connected in series in the air circuit between the setting valve and the setting chamber. The pilot valve is connected in parallel in the air circuit between the setting digital pressure transmitter and the setting chamber.

5. The safety valve online calibration device according to claim 1, characterized in that: The lifting device includes a housing, a cylinder piston lifting rod, a cylinder piston sealing ring, a balance chamber, a settling chamber, a balance chamber air port, and a settling chamber air port. The cylinder piston lifting rod is fixedly connected to the cylinder piston sealing ring, and the cylinder piston sealing ring is slidably connected to the inside of the housing, dividing the inside of the housing into a balance chamber and a settling chamber. The side wall of the balance chamber has a balance chamber air port, and the side wall of the settling chamber has a settling chamber air port.

6. The safety valve online calibration device according to claim 5, characterized in that: The upper part of the lifting device housing has a sealing ring 1 at the sliding connection between the upper part and the cylinder piston lifting rod, and the lower part has a sealing ring 2 at the sliding connection between the lower part and the cylinder piston lifting rod.

7. The safety valve online calibration device according to claim 5, characterized in that: The cylinder piston sealing ring has a sealing ring three on its outer circumference.

Images