A clamping and sealing device for off-line calibration of safety valves

Abstract

The application discloses a clamping and sealing device for off-line calibration of a safety valve, and relates to the technical field of safety valve calibration.The device comprises a base plate, a frame body and a calibration mechanism, which are all arranged on the base plate.The calibration mechanism comprises a mechanical clamping mechanism and a sealing mechanism.The frame body is provided with a flexible pad, and the flexible pad is provided with a first through hole.The mechanical clamping mechanism is used for clamping the safety valve.After the safety valve is clamped by the mechanical clamping mechanism, the sealing mechanism seals the outer periphery of the air inlet of the safety valve by the flexible pad, and the first through hole is in communication with the air inlet of the safety valve.By installing the sealing mechanism and the mechanical clamping mechanism on the base plate, the mechanical clamping mechanism can be adapted to safety valves of different sizes within a certain size range.The mechanical clamping mechanism adopts mechanical clamping, which is convenient for adjusting the clamping force and is not prone to safety accidents.The sealing mechanism can completely seal the edge of the air inlet of the safety valve by the flexible pad, and ensures that the safety valve can work normally during the calibration process.

Description

Technical Field

[0001] This invention relates to the field of safety valve calibration technology, and more specifically, to a clamping and sealing device for offline calibration of safety valves. Background Technology

[0002] Safety valves, as key pressure relief protection devices for pressure-bearing special equipment, are widely used in modern industry. In order to ensure the safe operation of pressure vessels, protect people's lives and property, and promote the development of the national economy, according to the "Safety Valve Safety Technical Supervision Regulations", safety valve accessories should be subject to a periodic inspection system. Safety valves must be calibrated at least once a year, that is, the sealing performance of the safety valve under its working pressure and its pressure relief performance under overpressure should be inspected.

[0003] Currently, safety valve calibration technologies mainly fall into two categories: offline calibration and online calibration. For offline calibration, the procedure involves first clamping the safety valve using a fixture, and then testing its sealing performance. Currently used offline calibration devices typically employ nitrogen or compressed air as the pressure source to clamp and secure the safety valve. However, this clamping method has the following drawbacks: due to the rapid diffusion of the gas, the impact force is large, which can easily lead to injury; furthermore, this clamping method has poor sealing performance, affecting the subsequent calibration results of the safety valve's sealing performance. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a clamping and sealing device for offline calibration of safety valves.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A clamping and sealing device for offline calibration of a safety valve includes a base plate, a frame and a calibration mechanism both mounted on the base plate. The calibration mechanism includes a mechanical clamping mechanism and a sealing mechanism. A flexible pad is provided on the frame, and a first through hole is formed on the flexible pad. The mechanical clamping mechanism is used to clamp the safety valve. After the safety valve is clamped by the mechanical clamping mechanism, the sealing mechanism causes the flexible pad to seal the outer periphery of the air inlet of the safety valve, and connects the first through hole with the air inlet of the safety valve.

[0007] Furthermore, in this invention, the aforementioned mechanical clamping mechanism includes a base that is pulverically connected to the aforementioned sealing mechanism and a drive mechanism disposed on the aforementioned base. The drive mechanism is pulverically connected to two sliders, and the drive mechanism is used to drive the two sliders to move closer to each other or further away from each other. A clamping block is disposed on any of the aforementioned sliders. After the safety valve is clamped by the two aforementioned clamping blocks, the aforementioned sealing mechanism causes the aforementioned safety valve to move toward the aforementioned flexible pad until the aforementioned flexible pad seals the outer periphery of the air inlet of the aforementioned safety valve.

[0008] Furthermore, in this invention, the driving mechanism is a lead screw and nut mechanism, and the lead screw of the driving mechanism is provided with two threaded portions at intervals, and the two threaded portions have opposite directions of rotation, and the two sliders are respectively threadedly connected to the two threaded portions.

[0009] Furthermore, in this invention, the sealing mechanism includes a screw jack mounted on the base plate and a guide rod rotatably mounted on the base plate. The actuator end of the screw jack and one end of the guide rod are both connected to the base. The lifting direction of the screw jack and the central axis of the guide rod are both parallel to the central axis of the first through hole.

[0010] Furthermore, in this invention, the flexible pad is located between the two clamping blocks, and the two clamping blocks are symmetrically arranged about the central axis of the first through hole.

[0011] Furthermore, in this invention, any of the aforementioned sliders is slidably connected to the aforementioned base, and the sliding direction of any of the aforementioned sliders is parallel to the central axis of the lead screw of the aforementioned driving mechanism.

[0012] Furthermore, in this invention, a flexible clamping piece is provided on the side of any of the clamping blocks that is close to the other clamping block.

[0013] Furthermore, in this invention, the frame is provided with a second through hole for installing the flexible pad; when the flexible pad is installed in the second through hole, the first through hole communicates with the second through hole.

[0014] The beneficial effects of this invention are:

[0015] This invention provides a clamping and sealing device for offline calibration of safety valves. By installing a mechanical clamping mechanism and a sealing mechanism on the base plate, the mechanical clamping mechanism can be adapted to safety valves of different sizes within a certain size range. The mechanical clamping mechanism uses mechanical clamping, which makes it easy to adjust the clamping force and reduces the risk of safety accidents. The sealing mechanism allows the flexible pad to completely seal the outer periphery of the air inlet of the safety valve, ensuring the sealing performance of the safety valve during the calibration process. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention;

[0017] Figure 2 for Figure 1 Exploded view.

[0018] In the diagram: 101-base plate; 201-frame; 301-mechanical clamping mechanism; 3011-base; 3012-drive mechanism; 3013-slider; 3014-clamping block; 401-sealing mechanism; 4011-screw jack; 4012-guide rod; 501-flexible pad; 601-safety valve; 701-flexible clamping plate. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1 and Figure 2 The present invention provides a technical solution:

[0021] A clamping and sealing device for offline calibration of a safety valve includes a base plate 101, a frame 201 fixedly mounted on the base plate 101, and a calibration mechanism. The calibration mechanism includes a mechanical clamping mechanism 301 and a sealing mechanism 401. A flexible pad 501 is mounted on the frame 201. In this embodiment, the flexible pad 501 has a cylindrical structure and a first through hole (not marked in the figure) is provided on the flexible pad 501. The central axis of the first through hole is parallel to the vertical direction. The mechanical clamping mechanism 301 is used to clamp the safety valve 601. After the safety valve 601 is clamped by the mechanical clamping mechanism 301, the sealing mechanism 401 seals the outer periphery of the air inlet of the safety valve 601 with the flexible pad 501 and connects the first through hole with the air inlet of the safety valve 601.

[0022] Preferably, in this embodiment, the mechanical clamping mechanism 301 includes a base 3011 that is pulsatorically connected to the sealing mechanism 401 and a drive mechanism 3012 mounted on the base 3011. In this embodiment, the drive mechanism 3012 is a screw-nut mechanism. The screw of the drive mechanism 3012 has two threaded portions spaced apart, and the two threaded portions have opposite directions of rotation. Each threaded portion is threadedly connected to a slider 3013, and any slider 3013 is slidably connected to the base 3011. The sliding direction of any slider 3013 is parallel to the central axis of the screw of the drive mechanism 3012. In this way, when the screw of the drive mechanism 3012 rotates, the two sliders 3013 can move closer to each other or further away from each other.

[0023] In this embodiment, the forward and reverse rotation of the lead screw of the drive mechanism 3012 can be controlled by a worm gear mechanism, which has the characteristics of good compactness, large transmission ratio and self-locking capability. When the safety valve 601 is clamped, the rotation of the lead screw is prevented from causing relative displacement of the two sliders 3013.

[0024] In this embodiment, each slider 3013 is equipped with a clamping block 3014. Each clamping block 3014 has a cuboid structure, and a flexible clamping piece 701 is installed on the side of each clamping block 3014 closest to the other clamping block 3014. The flexible clamping piece 701 can be fixed to the clamping block 3014 with screws. In this embodiment, the frame 201 has a U-shaped structure, with its two ends fixedly connected to the base plate 101. After installation, it is located between the two sliders 3013, that is, the flexible pad 501 is located between the two clamping blocks 3014. The installation position of the flexible pad 501 should ensure that the two clamping blocks 3014 are symmetrically arranged about the central axis of the flexible pad 501, so that the distance from the two sliders 3013 to the flexible pad 501 is the same.

[0025] To facilitate the installation of the flexible pad 501, a second through hole (not marked in the figure) is also provided on the frame 201 in this embodiment for installing the flexible pad 501.

[0026] Preferably, in this embodiment, the sealing mechanism 401 includes a screw jack 4011 mounted on the base plate 101 and two guide rods 4012 rotatably mounted on the base plate 101. The actuator end of the screw jack 4011 and one end of the two guide rods 4012 are both connected to the base 3011 for transmission. The lifting direction of the screw jack 4011 and the central axis of the two guide rods 4012 are both parallel to the vertical direction. Both guide rods 4012 are rotatably connected to the base plate 101 through linear bearings. The screw jack 4011 is prior art, so its working principle will not be described in detail here.

[0027] from Figure 1 or Figure 2 From the perspective of the mechanical clamping mechanism 301, after the safety valve 601 is clamped by the mechanical clamping mechanism 301, the air inlet of the safety valve 601 (located at the bottom of the safety valve 601) has not yet come into contact with the flexible pad 501. Then the screw jack 4011 is started, and the base 3011 moves downward under the control of the screw jack 4011, so the entire mechanical clamping mechanism 301 moves downward synchronously. After the air inlet of safety valve 601 comes into contact with the flexible pad 501, it continues to move downwards a certain distance, so that the flexible pad 501 completely seals the edge of the air inlet of safety valve 601, ensuring that safety valve 601 can work normally during the calibration process (ensuring that the gas entering safety valve 601 through the second through hole, the first through hole and the air inlet of safety valve 601 in sequence will not escape outwards from the contact point between the air inlet of safety valve 601 and the flexible pad 501). Then, the gas enters the air inlet of safety valve 601 through the second through hole and the first through hole on the flexible pad 501 in sequence for offline calibration.

[0028] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A clamping and sealing device for offline calibration of a safety valve, characterized in that: The system includes a base plate (101), a frame (201) mounted on the base plate (101), and a calibration mechanism. The calibration mechanism includes a mechanical clamping mechanism (301) and a sealing mechanism (401). A flexible pad (501) is provided on the frame (201), and a first through hole is provided on the flexible pad (501). The mechanical clamping mechanism (301) is used to clamp the safety valve (601). After the safety valve (601) is clamped by the mechanical clamping mechanism (301), the sealing mechanism (401) causes the flexible pad (501) to seal the outer periphery of the air inlet of the safety valve (601) and connects the first through hole with the air inlet of the safety valve (601). The mechanical clamping mechanism (301) includes a base (3011) that is convectively connected to the sealing mechanism (401) and a drive mechanism (3012) disposed on the base (3011). The drive mechanism (3012) is convectively connected to two sliders (3013). The drive mechanism (3012) is used to drive the two sliders (3013) to move closer to each other or further away from each other. A clamping block (3014) is disposed on any of the sliders (3013). After the safety valve (601) is clamped by the two clamping blocks (3014), the sealing mechanism (401) causes the safety valve (601) to move toward the flexible pad (501) until the flexible pad (501) seals the outer periphery of the air inlet of the safety valve (601). The sealing mechanism (401) includes a screw jack (4011) mounted on the base plate (101) and a guide rod (4012) rotatably mounted on the base plate (101). The execution end of the screw jack (4011) and one end of the guide rod (4012) are both connected to the base (3011) for transmission. The lifting direction of the screw jack (4011) and the central axis of the guide rod (4012) are both parallel to the central axis of the first through hole.

2. The clamping and sealing device for offline calibration of a safety valve according to claim 1, characterized in that: The driving mechanism (3012) is a lead screw and nut mechanism. The lead screw of the driving mechanism (3012) is provided with two threaded parts at intervals, and the two threaded parts have opposite directions of rotation. The two sliders (3013) are respectively threadedly connected to the two threaded parts.

3. The clamping and sealing device for offline calibration of a safety valve according to claim 1, characterized in that: The flexible pad (501) is located between the two clamping blocks (3014), and the two clamping blocks (3014) are symmetrically arranged about the central axis of the first through hole.

4. The clamping and sealing device for offline calibration of a safety valve according to claim 2, characterized in that: Any of the sliders (3013) is slidably connected to the base (3011), and the sliding direction of any slider (3013) is parallel to the central axis of the lead screw of the drive mechanism (3012).

5. The clamping and sealing device for offline calibration of a safety valve according to claim 1, characterized in that: A flexible clamping piece (701) is provided on the side of any of the clamping blocks (3014) near the other clamping block (3014).

6. The clamping and sealing device for offline calibration of a safety valve according to claim 3, characterized in that: The frame (201) has a second through hole for installing the flexible pad (501); when the flexible pad (501) is installed in the second through hole, the first through hole is connected to the second through hole.

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