A pressure instrument protector

Abstract

The present invention discloses a pressure instrument protector, which includes a protection joint, a shock-absorbing rubber tube and an equipment joint connected in sequence. The measured medium enters the pressure instrument after passing through the equipment joint, the shock-absorbing rubber tube and the protection joint in sequence. An extrusion cavity and an output channel are arranged in the protection joint. A connecting channel and a pressure guiding channel are arranged between the extrusion cavity and the output channel. A plugging device for sealing the connecting channel is arranged on the connecting channel; an isolation diaphragm is arranged in the extrusion cavity. The isolation diaphragm divides the extrusion cavity into two non-connecting cavities. One of the cavities is communicated with the shock-absorbing rubber tube and is communicated with the output channel through the connecting channel. The other cavity is communicated with the output channel through the pressure guiding channel; this solution can effectively reduce the pulse pressure of the measured medium and protect the pressure instrument; during the process of reducing the pulse pressure, the pressure instrument protector can achieve self-sealing, prevent the measured medium from leaking, and avoid polluting and damaging the device and equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure instruments, and particularly relates to a pressure instrument protector. Background Art

[0002] Pressure instruments are widely used for pressure indication of device equipment in industries such as petroleum, chemical industry, metallurgy, military, aerospace, electric power, coal mine, medicine, printing and dyeing, etc. In recent years, the national industry has developed rapidly, and their usage has increased linearly. The existing product technology can no longer fully meet the technical requirements of advanced equipment, with poor usage effects, frequent maintenance and replacement, and frequent safety accidents.

[0003] The pressure instruments of existing technology products are mainly used on equipment with pressure and vibration. The main technical deficiencies are as follows:

[0004] 1. Resistance to pulsed pressure: The existing technology products solve the problem of resistance to pulsed pressure by adding a current-limiting device (i.e., a damper) or a buffer tube. Its disadvantages are: the use of a single damper and buffer tube has limited anti-pulse effect, and the more equipment components added outside the pressure instrument, the more inconvenient the installation and disassembly of the pressure instrument. Moreover, if the device components have problems or are damaged, the repair and replacement are extremely inconvenient, and the cost is also increased.

[0005] 2. Leak prevention: For the existing technology products, due to the poor anti-pulse pressure effect, the spring tube element in the meter head is prone to fatigue damage. When the spring tube element in the meter head is fatigued and damaged, the existing pressure instrument structure cannot achieve rapid self-sealing, and only allows the liquid to flow out. If the operator cannot discover and repair the leakage situation in time, it will have a serious impact on the equipment components. Summary of the Invention

[0006] The purpose of the present invention is to solve the above problems in the existing technology, and proposes a pressure instrument protector, which changes the original anti-pulse pressure technology. By setting multiple buffer technologies with different working principles, it can effectively slow down the pulsed pressure of the measured medium and protect the pressure instrument; and during the process of slowing down the pulsed pressure, the pressure instrument protector can achieve automatic adjustment and sealing, effectively preventing the measured medium from leaking and avoiding pollution and damage to the device equipment.

[0007] The technical solution of the present invention is:

[0008] A pressure gauge protector, comprising a protection joint, a shock-absorbing rubber tube and an equipment joint connected in sequence. The protection joint is connected to the pressure gauge, and the measured medium enters the pressure gauge after passing through the equipment joint, the shock-absorbing rubber tube and the protection joint in sequence. It is characterized in that an extrusion cavity and an output channel are arranged in the protection joint. The extrusion cavity is communicated with the shock-absorbing rubber tube, and the output channel is communicated with the pressure gauge; a connecting channel and a pressure guiding channel are arranged between the extrusion cavity and the output channel. Both the connecting channel and the pressure guiding channel are used to communicate the extrusion cavity with the output channel, and a blocking device for regulating the connecting channel is arranged on the connecting channel; an isolation diaphragm is arranged in the extrusion cavity. The isolation diaphragm is made of an elastic material and is fixed in the extrusion cavity; the isolation diaphragm divides the extrusion cavity into two non-communicating cavities. One cavity is communicated with the shock-absorbing rubber tube and is communicated with the output channel through the connecting channel, and the other cavity is communicated with the output channel through the pressure guiding channel.

[0009] Preferably, a pressure relief cavity is arranged in the protection joint. The pressure relief cavity is communicated with the shock-absorbing rubber tube, and the pressure relief cavity is communicated with the extrusion cavity through a main flow channel; a flow limiting device for limiting the flow diameter of the main flow channel is arranged in the main flow channel, and the flow limiting device is installed on the protection joint.

[0010] Preferably, the flow limiting device is in a strip-shaped rod structure and is slidably and sealingly arranged with the protection joint; one end of the flow limiting device extends into the main flow channel and is adapted to the main flow channel.

[0011] Preferably, an overpressure flow channel is arranged in the protection joint. One end of the overpressure flow channel is communicated with the pressure relief cavity, and the other end is communicated with the main flow channel and is located between the flow limiting device and the pressure relief cavity; the size of the overpressure flow channel is larger than that of the main flow channel, and an overpressure protection mechanism for automatically regulating the flow rate of the main flow channel is arranged in the overpressure flow channel.

[0012] Preferably, an installation cavity for installing the overpressure protection mechanism is opened on the protection joint. One end of the installation cavity penetrates the surface of the protection joint, and the other end extends into the protection joint and is communicated with the main flow channel and corresponds to the position of the connection port of the overpressure flow channel and the main flow channel; the overpressure protection mechanism includes a piston assembly and a sealing seat. The sealing seat is fixedly sealed in the installation cavity. One end of the piston assembly is connected to the sealing seat through a spring, and the other end slides through the main flow channel and is installed in the overpressure flow channel.

[0013] Preferably, the piston assembly includes a push head and a movable plug. The push head extends into the overpressure flow channel and is in sealed sliding fit with the overpressure flow channel. The movable plug is installed in the installation cavity and is in sealed sliding fit with the installation cavity. The push head and the movable plug are connected by a connecting rod. The connecting rod penetrates through the main flow channel, and the diameter of the connecting rod is smaller than the diameter of the main flow channel.

[0014] Preferably, a buffer cavity is further provided in the protection joint. The buffer cavity is located between the output channel and the extrusion cavity, and both the connecting channel and the pressure guiding channel are communicated with the buffer cavity.

[0015] Preferably, a pressure relief pipe is provided on the outer wall of the protection joint. The pressure relief channel in the pressure relief pipe is connected to the connecting channel, and the connection position is sealed by the blocking device. The blocking device is in a rod shape and is sealed and slidably installed on the protection joint. One end of the blocking device extends into the connecting channel, and the rod body part of the blocking device blocks the connection port between the pressure relief channel and the connecting channel.

[0016] Advantages of the present invention:

[0017] 1. A pressure gauge protector provided by the present invention separates the extrusion cavity by arranging an isolation diaphragm to achieve the separation of the measured medium. The pressure is applied to the separated measured medium through the deformation of the isolation diaphragm, and then acts on the pressure gauge. It can effectively slow down the pulse pressure of the measured medium. At the same time, when the pressure gauge breaks and leaks, the isolation diaphragm can timely block the pressure guiding channel, so that the air pressure in the instrument protector is isolated from the external air pressure again, avoiding continuous leakage of the measured medium and causing pollution and damage to the device and equipment, achieving the effect of rapid automatic sealing;

[0018] 2. By arranging a flow limiting device, according to the actual measurement situation, the operator can manually control and adjust the flow rate of the measured medium to slow down the passing time of the instantaneous pressure of the measured medium and reduce the pulse pressure of the measured medium;

[0019] 3. By arranging the spiral metal tube in the shock-absorbing rubber tube, the instantaneous pressure of the measured medium is slowed down, and the pulse pressure of the measured medium is reduced;

[0020] 4. By arranging a flow limiting ring in the equipment joint, the instantaneous pressure of the measured medium is slowed down, and the pulse pressure of the measured medium is reduced;

[0021] 5. By setting up an overpressure protection mechanism, when the pressure of the measured medium is higher than the maximum value that the instrument can measure, the pressure channel of the measured medium is automatically cut off to protect the instrument from damage. When the pressure of the measured medium is lower than the maximum value that the instrument can measure, the pressure channel of the measured medium is automatically opened, and the instrument can normally indicate the pressure value of the measured medium.

[0022] 6. By setting up a pressure relief cavity and a buffer cavity, the pulse pressure of the measured medium is further reduced to achieve further protection for the pressure instrument.

[0023] 7. When the pressure gauge needs to be repaired or replaced, since there is pressure in the pressure gauge and this instrument protector, it is impossible to disassemble the instrument. By setting up a pressure relief pipe and opening the plugging device, the pressure in the pressure gauge can be released under safe conditions, so that there is no pressure in the pressure gauge (or instrument), which is convenient for the disassembly and replacement of the pressure gauge.

[0024] 8. By setting up a shock-absorbing rubber tube, the vibration of the equipment is slowed down and the vibration of the instrument is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the pressure instrument protector provided by the present invention;

[0026] Figure 2 It is a schematic diagram of the internal structure of the pressure instrument protector and the filling flow direction of the measured medium;

[0027] Figure 3 It is a schematic diagram of the internal structure of the protection joint;

[0028] Figure 4 It is a schematic diagram of the pressure measurement state of the pressure instrument protector;

[0029] Figure 5 It is a schematic diagram of the pressure relief state of the pressure instrument protector;

[0030] Figure 6 It is a schematic diagram of the plugging state of the overpressure protection mechanism;

[0031] In the figure, 1. Protection joint; 101. Connection port; 102. Output channel; 103. Pressure relief cavity; 104. Main flow channel; 105. Extrusion cavity; 106. Buffer cavity; 107. Plugging port; 108. Overpressure flow channel; 109. Connection channel; 110. Pressure guiding channel;

[0032] 11. Threaded connecting pipe 1; 12. Isolation diaphragm; 13. Installation cavity;

[0033] 2. Shock-absorbing rubber; 201. Spiral pipeline;

[0034] 3. Equipment joint; 31. Threaded connecting pipe 2; 32. Input channel;

[0035] 4. Current-limiting ring;

[0036] 51. Piston assembly; 511. Pushing head; 512. Connecting rod; 513. Movable piston; 52. Sealing seat; 53. Spring;

[0037] 6. Blocking device;

[0038] 7. Current-limiting device;

[0039] 8. Pressure relief pipe; 801. Pressure relief channel; Specific implementation manner

[0040] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the present invention.

[0041] It should be understood that the orientation or positional relationship indicated by terms such as "horizontal, vertical, one end, the other end, top surface, bottom surface, both sides, above, below" is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0042] Refer to Figures 1 to 3As shown in the figure, the present invention provides a pressure gauge protector. The pressure gauge protector includes a protection joint 1, a shock-absorbing rubber tube 2, and a device joint 3 that are fixedly connected in sequence from top to bottom. Wherein, the top surface of the protection joint 1 is provided with a threaded connecting pipe 11 for connecting with the pressure gauge. The bottom surface of the device joint 3 is provided with a threaded connecting pipe 31 for connecting with the pipeline device through which the measured medium flows. The measured medium enters from the device joint 3 and enters the pressure gauge after passing through the device joint 3, the shock-absorbing rubber tube 2, and the protection joint 1 in sequence; a input channel 32 for the measured medium to flow in is provided in the device joint 3. A current-limiting ring 4 is fixed in the input channel 32. The current-limiting ring 4 is coaxially arranged with the input channel 32, and the diameter of the through hole of the current-limiting ring 4 is smaller than the diameter of the input channel 32. Its function is to conduct preliminary buffering on the measured medium flowing into the input channel 32, reduce the impact force of the measured medium, and play a preliminary protective role for the instrument protector and the pressure gauge; it should be noted that a spiral pipeline 201 for the measured medium to flow through is provided in the shock-absorbing rubber tube 2. The spiral pipeline 201 is made of metal. The two ends of the spiral pipeline 201 are respectively communicated with the input channel 32 in the protection joint 1 and the device joint 3. By providing the shock-absorbing rubber tube 2, on the one hand, it can buffer the vibration generated by the device joint 3, avoid the vibration being transmitted to the protection joint 1 and affecting the pressure gauge, and protect the pressure gauge from being damaged; on the other hand, by providing the spiral pipeline 201 in the shock-absorbing rubber tube 2, the flow path of the measured medium is increased, and the pulse pressure of the measured medium can be further reduced, protecting the instrument device from being damaged by excessive impact force; it should be noted that the pulse pressure refers to the fluctuating pressure of the measured medium, which is common knowledge in the art.

[0043] Further, referring to Figure 2 and Figure 3As shown, in a specific embodiment of the present invention, an extrusion cavity 105 and an output channel 102 are provided inside the protection joint 1. Among them, the output channel 102 is opened on the threaded connecting pipe 11 and is communicated with the pressure gauge. The extrusion cavity 105 is communicated with the shock-absorbing rubber tube 2, and the measured medium flows from the shock-absorbing rubber tube 2 into the extrusion cavity 105. A connecting channel 109 and a pressure guiding channel 110 are provided between the extrusion cavity 105 and the output channel 102. Both the connecting channel 109 and the pressure guiding channel 110 are used to connect the output channel 102 and the extrusion cavity 105. And a blocking device 6 is provided on the connecting channel 109 for adjusting the flow direction of the measured medium in the connecting channel 109. It should be noted that in this specific embodiment, the blocking device 6 is a sealing cylinder, and the blocking device 6 is inserted and installed on the protection joint 1, and is slidably sealed with the protection joint 1. One end of the blocking device 6 extends into the connecting channel 109, and the diameter size of the blocking device 6 matches the diameter size of the connecting channel 9, so as to achieve a good blocking effect on the connecting channel 109. The other end of the blocking device 6 extends into the outer wall of the protection joint 1, which is convenient for personnel to operate and adjust it. In addition, a horizontally arranged isolation diaphragm 12 is installed in the extrusion cavity 105. The isolation diaphragm 12 is made of an elastic material, specifically, it can be one of stainless steel or alloy steel. Its thickness is adjusted according to the measured medium, and the periphery of the isolation diaphragm 12 is fixed on the inner wall of the extrusion cavity 105, and the extrusion cavity 105 is divided into two non-communicating cavities, upper and lower, by the isolation diaphragm 12. It should be noted that in the two separated cavities, the lower cavity is communicated with the shock-absorbing rubber tube 2, and the lower cavity is also communicated with the connecting channel 109. The lower cavity is communicated with the output channel 102 through the connecting channel 109, so that the measured medium can flow to the pressure gauge. The upper cavity is communicated with the pressure guiding channel 110 and is communicated with the output channel 102 through the pressure guiding channel 110, and the pressure guiding channel 110 is located directly above the isolation diaphragm 12. When starting to use the device, the pressure gauge protector and the pressure gauge will be filled with the measured medium first. When the measured medium enters the extrusion cavity 105, it will first enter the lower cavity of the extrusion cavity 105, and after filling the lower cavity, it will be conveyed to the output channel 102 through the connecting channel 109. Because the pressure guiding channel 110 is also communicated with the output channel 102, and the connection interface position is at the bottom of the output channel 102, so when the measured medium enters the output channel 102, a part of the measured medium will flow back to the upper cavity of the extrusion cavity 105 through the pressure guiding channel 110 until the extrusion cavity 105 is filled.

[0044] Referring to Figure 3As shown in the figure, in a specific embodiment of the present invention, a pressure relief cavity 103 is provided inside the protection joint 1. The pressure relief cavity 103 is disposed near the bottom of the protection joint 1 and is located below the extrusion cavity 105. A connection port 101 is opened on one side of the pressure relief cavity 103. The connection port 101 penetrates through the outer wall of the protection joint 1 and is used for installing the end of the connecting spiral pipe 201. The pressure relief cavity 103 is communicated with the extrusion cavity 105 through a vertically arranged main flow channel 104. The bottom end of the main flow channel 104 is connected to the top of the pressure relief cavity 103, and the top end of the main flow channel 104 is connected to the lower cavity of the extrusion cavity 105. The measured medium enters the pressure relief cavity 103 through the spiral pipe 201. The pulse pressure of the measured medium is further buffered through the pressure relief cavity 103 to make the measured medium tend to be stable. When the pressure relief cavity 103 is filled with the measured medium, the measured medium enters the main flow channel 104 and enters the lower cavity of the extrusion cavity 105 through the main flow channel 104, and fills the extrusion cavity 105 and the pressure gauge. It should be noted that a flow limiting device 7 is provided in the main flow channel 104, and the flow limiting device 7 is installed on the protection joint 1. By setting the flow limiting device 7, it is used to control and adjust the flow diameter and flow rate of the main flow channel 4, limit the flow of the measured medium entering the main flow channel 104 and further slow down its pulse force, and protect the pressure gauge.

[0045] Refer to Figure 3 As shown in the figure, in a specific embodiment of the present invention, the above-mentioned flow limiting device 7 is a sealed cylinder, which is inserted into the protection joint 1. A sliding seal is provided between the flow limiting device 7 and the protection joint 1. One end of the flow limiting device 7 extends into the main flow channel 104, and the diameter of the flow limiting device 7 is adapted to the diameter of the main flow channel 104. The other end of the flow limiting device 7 protrudes from the outer wall of the protection joint 1. By moving the flow limiting device 7, the coverage area of its end in the main flow channel 104 can be controlled, thereby adjusting the flow rate of the medium that can pass through the main flow channel 104 and achieving the effect of slowing down the pulse strength. Also, because of the sealed sliding between the flow limiting device 7 and the protection joint 1, it avoids the measured medium flowing out along the outer wall of the flow limiting device 7 and improves the sealing performance of the device and equipment.

[0046] Refer to Figure 3As shown, in a specific embodiment of the present invention, an overpressure flow channel 108 is provided inside the protection joint 1. The overpressure flow channel 108 has a "concave" structure placed sideways. Its lower port is connected to the pressure relief cavity 103 and is in communication with the pressure relief cavity 103. The upper port of the overpressure flow channel 108 is connected to the main flow channel 104 and is located between the flow limiting device 7 and the pressure relief cavity 103. By setting the overpressure flow channel 108, there are two flow paths for the measured medium entering the pressure relief cavity 103. One is to enter the main flow channel 104, and the other is to enter the overpressure flow channel 108. It should be noted that the diameter of the overpressure flow channel 108 is larger than that of the main flow channel 104, and an overpressure protection mechanism for automatically regulating the flow rate of the main flow channel 104 is provided in the overpressure flow channel 108. When the pulse pressure of the measured medium entering the pressure relief cavity 103 suddenly increases, the pressure in the overpressure flow channel 108 is greater than the force of the spring 53 of the overpressure protection mechanism, and thus the overpressure protection mechanism in the overpressure flow channel 108 can be pushed to adjust the diameter of the main flow channel 104 to control the flow rate of the measured medium in the main flow channel 104, thereby automatically regulating the pulse pressure in the main flow channel 104 and protecting the pressure gauge. When the pressure of the measured medium entering the pressure relief cavity 103 increases to be greater than the maximum force of the spring of the overpressure protection mechanism (the maximum force of the initial adjustment spring 53 is equal to the pressure of the maximum value measured by the instrument), the overpressure protection mechanism in the overpressure flow channel 108 is pushed, causing it to close the main flow channel 104, preventing the measured medium from flowing, and protecting the pressure gauge from overpressure damage, thus protecting the pressure gauge.

[0047] Refer to Figure 2 and Figure 3As shown in the figure, in a specific embodiment of the present invention, an installation cavity 13 for installing an overpressure protection mechanism is provided on the protection joint 1. One end of the installation cavity 13 penetrates through the outer wall of the protection joint 1, and the other end extends into the protection joint 1 and communicates with the main flow channel 104. Moreover, the position of the port where the installation cavity 13 is connected to the main flow channel 104 corresponds to the position of the upper port of the overpressure flow channel 108, so as to facilitate the installation and operation of the overpressure protection structure 5. It should be noted that the overpressure protection mechanism includes a piston assembly 51 and a sealing seat 52. Among them, the sealing seat 52 is sealed and fixed at one end of the installation cavity 13 close to the outer wall of the protection joint 1. By setting the sealing seat 52, the installation cavity 13 is sealed to prevent the measured medium from leaking. In addition, one end of the piston assembly 51 is connected to the sealing seat 52 through a spring 53, and the other end of the piston assembly passes through the main flow channel 104 and is slidably installed in the overpressure flow channel 108. When the measured medium enters the overpressure flow channel 108, a certain pressure will be generated on the piston assembly 51. At this time, there will be two states. The first state is that when the pressure generated on the piston assembly 51 is much greater than the force of the spring 53, the piston assembly 51 is pushed to move, thereby realizing the adjustment of the flow rate of the main flow channel 104. When the pulse pressure in the overpressure flow channel 108 decreases, the spring 53 pushes the piston assembly 51 to reset, so that the flow rate of the measured medium in the main flow channel 104 returns to the initial state. The second state is that when the pressure generated on the piston assembly 51 is greater than the maximum force of the spring 53 (the maximum force of the initial adjustment spring 53 is equal to the pressure of the maximum value measured by the instrument), the piston assembly 51 is pushed to move, thereby realizing the closing of the main flow channel 104 to protect the instrument from overpressure damage. When the force of the measured medium is less than the maximum force of the spring 53, the spring 53 pushes the piston assembly 51 to open the channel 104 to restore the smoothness of the channel 104, and the instrument resumes normal operation.

[0048] Referring to Figure 3 As shown in the figure, in a specific embodiment of the present invention, the above-mentioned piston assembly 51 includes a push head 511 and a movable plug 513. Among them, the push head 511 extends into the overpressure flow channel 108, and its diameter size is adapted to the diameter of the overpressure flow channel 108 and is in sealed sliding fit with the overpressure flow channel 108. The movable plug 513 is installed in the installation cavity 13 and is also in sealed sliding with the installation cavity 13 to prevent the measured medium from leaking. One end of the spring 53 is fixedly connected to the end face of the movable plug 513, so that the elastic force of the spring 53 acts on the movable plug 513. In addition, a connecting rod 512 is fixedly connected between the movable plug 513 and the push head 511. The connecting rod 512, the push head 511 and the movable plug 513 are all coaxially arranged. By setting the connecting rod 512, when the push head 511 moves, the movable plug 513 is driven to move synchronously. It should be noted that the diameter size of the connecting rod 512 is smaller than the diameter size of the main flow channel 104, so that the measured medium entering the main flow channel 104 can pass through the connecting rod 512 and then enter the extrusion cavity 105.

[0049] Refer to Figure 3 As shown, in a specific embodiment of the present invention, a buffer cavity 106 is further provided in the protection joint 1. The buffer cavity 106 is located between the output channel 102 and the extrusion cavity 105, and both the connection channel 109 and the pressure guiding channel 110 are also communicated with the buffer cavity 106. By providing the buffer cavity 106, the medium entering the connection channel 109 can enter the buffer cavity 106. On the one hand, it further slows down the pulse pressure of the measured medium. On the other hand, the measured medium entering the buffer cavity 106 can enter the upper cavity of the extrusion cavity 105 along the extrusion channel 110 to fill the extrusion cavity 105; in addition, a sealing port 107 is provided at the position where the buffer cavity 106 is communicated with the connection channel 109. The position and outer contour shape of the sealing port 107 correspond to the sealing device 6, so that the sealing device 6 can better seal the connection channel 109 and prevent the measured medium from flowing.

[0050] Refer to Figure 2 and Figure 3 As shown, in a specific embodiment of the present invention, a pressure relief pipe 8 is fixedly provided on the outer wall of the protection joint 1. One end of the pressure relief channel 801 in the pressure relief pipe 8 is communicated with the connection channel 109, and the other end is communicated to the external environment; it should be noted that the position where the pressure relief channel 801 is communicated with the connection channel 109 is covered and sealed by the rod body of the sealing device 6. When the sealing device 6 moves and extends towards the connection channel 109, there will be three states. The first state is when the sealing end of the sealing device 6 has not exceeded the interface between the pressure relief channel 801 and the connection channel 109, that is, the rod body of the sealing device 6 does not seal and cover the interface between the pressure relief channel 801 and the connection channel 109. At this time, the connection channel 109 and the pressure relief channel 801 are communicated to relieve the pressure of the measured medium. The second state is when the sealing end of the sealing device 6 exceeds the interface between the pressure relief channel 801 and the connection channel 109 but does not completely extend into the connection channel 109, that is, the rod body of the sealing device 6 seals the pressure relief channel 801 but does not seal the connection channel 109. At this time, the measured medium will not flow out from the pressure relief channel 801 and will flow in the connection channel 109. The third state is when the sealing end of the sealing device 6 is in close contact with the sealing port 107. At this time, the sealing device 6 seals the connection channel 109 and the pressure relief channel 801 to prevent the measured medium from flowing.

[0051] Refer to Figure 2 、 Figures 4 to 6 As shown, the usage method and working principle of a pressure gauge protector provided by the present invention are as follows:

[0052] S1. Before installation and use, first close the flow-limiting device 7 to keep the main flow channel 104 in a closed state; adjust the plugging device 6 to make the plugging device 6 in the second state described in the above embodiment, that is, the plugging device 6 plugs the pressure relief channel 801 but does not plug the connection channel 109, so that the connection channel 109 is in an open state;

[0053] S2. After completing step S1, connect the protection joint 1 to the pressure gauge so that the output channel 102 is in communication with the pressure gauge; then connect the equipment joint 3 to the pipeline equipment through which the measured medium is flowing. First, slowly open the connection valve on the pipeline equipment and limit the flow through the valve of the pipeline equipment itself to make the measured medium slowly enter from the equipment joint 3; after the measured medium enters the equipment joint 3, fill the equipment joint 3 and the shock-absorbing rubber tube 2 in sequence. When the measured medium fills the shock-absorbing rubber tube 2, it flows into the pressure relief cavity 103 in the protection joint 1. When the pressure relief cavity 103 is filled, it flows into the main flow channel 104 to the lower part of the flow-limiting device 7. At this time, fully open the connection valve on the pipeline equipment and slowly open the regulating flow-limiting device 7. The measured medium enters the lower cavity of the extrusion cavity 105 through the main flow channel 104. And while the lower cavity of the extrusion cavity 105 is being filled with the measured medium, a part of the measured medium enters the buffer cavity 106 through the connection channel 109 and flows into the upper cavity of the extrusion cavity 105 through the pressure guiding channel 110. When both the extrusion cavity 105 and the buffer cavity 106 are filled, the measured medium flows into the output channel 102 and finally into the pressure instrument, and the pressure instrument starts to display the pressure value of the measured medium. It should be noted that when the pressure instrument starts to display the pressure value of the measured medium, observe the indication value of the pressure instrument and adjust the flow-limiting device 7 until the indication value of the pressure instrument slowly rises to the best state, and then lock the flow-limiting device 7;

[0054] S3. After completing step S2, when the pressure value displayed by the pressure instrument is equal to the actual pressure value of the measured medium, adjust the plugging device 6 to make the plugging device 6 in the third state described in the above embodiment, that is, the plugging device 6 plugs and separates the connection channel 109 to prevent the measured medium from flowing in the connection channel 109, thereby realizing the isolation of the measured medium;

[0055] S4. After step S3 is completed, due to the blocking effect of the blocking device 6, the measured medium cannot enter the pressure gauge. At this time, the change in the pressure of the measured medium in the cavity below the extrusion cavity 105 directly acts on the isolation diaphragm 12, causing the isolation diaphragm 12 to deform. During the deformation of the isolation diaphragm 12, the original measured medium in the cavity above the extrusion cavity 105 is pushed and enters the pressure gauge, enabling the pressure gauge to measure a value. It should be noted that under normal use conditions, that is, when the pressure gauge is not damaged or leaking, if the pressure of the measured medium increases, after the isolation diaphragm 12 bulges upward, it will not contact the connection port between the pressure guiding channel 110 and the extrusion cavity 105, allowing the measured medium in the cavity above the extrusion cavity 105 to flow through the pressure guiding channel 110. In addition, when the pressure gauge is damaged and leaking, at this time, the pressure of the measured medium in the cavity below the extrusion cavity 105 pushes the isolation diaphragm 12 to deform and bulge upward, causing the isolation diaphragm 12 to contact the pressure guiding channel 110 and block the connection port between the pressure guiding channel 110 and the extrusion cavity 105, thereby achieving the sealing of the pressure guiding channel 110 and preventing the continuous leakage of the measured medium from damaging the device and equipment.

[0056] S5. After step S3 is completed, if the pulse pressure (or pressure) of the measured medium increases, on the one hand, when the pulse pressure (or pressure) of the measured medium increases, when the pressure of the measured medium flowing into the overpressure flow channel 108 is greater than the force of the spring 53, the measured medium in the overpressure flow channel 108 will push the push head 511 to move, and then the push head 511 will enter the main flow channel 104, changing the flow diameter of the main flow channel 104 and achieving automatic control of the flow rate of the measured medium in the active flow channel 104, completing the effect of reducing the pulse pressure. On the other hand, when the pulse pressure (or pressure) of the measured medium increases, when the pressure of the measured medium flowing into the overpressure flow channel 108 is greater than the maximum force of the spring 53 (the initial maximum force of the spring 53 is adjusted to be equal to the maximum pressure measured by the instrument), the measured medium in the overpressure flow channel 108 will push the push head 511 to move, and then the push head 511 will enter the main flow channel 104 to close the main flow channel 104 and protect the instrument from overpressure damage. When the force of the measured medium is less than the maximum force of the spring 53 (the initial maximum force of the spring 53 is adjusted to be equal to the maximum pressure measured by the instrument), the spring 53 pushes the piston assembly 51 to open the channel 104, restoring the channel 104 to be unobstructed and the instrument to resume normal operation.

[0057] S6. After step S3 is completed, if the measured medium 32 has a pulse pressure passing through the current limiting ring 4, the pulse pressure is reduced to complete the effect of reducing the pulse pressure.

[0058] S7. When the measurement is completed or when the pressure instrument needs to be replaced and maintained, close the connection valve on the pipeline equipment. At this time, the pressure in the pressure instrument and the instrument protector is still the pressure before closing the connection valve of the pipeline equipment. Subsequently, open the plugging device 6 so that the plugging device 6 is in the first state in the above embodiment, that is, the plugging device 6 does not block the pressure relief channel 801. At this time, the measured medium pressure in the pressure instrument and the instrument protector is discharged through the pressure relief channel 801, meeting the conditions required for replacement, maintenance, and disassembly.

[0059] The above description of the specific implementation of the present invention is for illustrative and exemplifying purposes. These descriptions are not intended to limit the present invention to the precise form disclosed. Obviously, according to the above description, many changes and variations can be made. The purpose of selecting and describing the embodiments is to explain the specific principles and practical applications of the present invention, so that those skilled in the art can implement and utilize various different embodiments, as well as various different selections and changes of the present invention. The scope of the present invention is intended to be defined by the claims and their equivalents.

Claims

1. A pressure gauge protector, comprising a protection joint (1), a shock-absorbing rubber tube (2) and a device joint (3) connected in sequence. The protection joint (1) is connected to the pressure gauge, and the measured medium enters the pressure gauge after passing through the device joint (3), the shock-absorbing rubber tube (2) and the protection joint (1) in sequence. It is characterized in that, The protection joint (1) is provided with an extrusion cavity (105) and an output channel (102) connected to a pressure gauge. A connecting channel (109) and a pressure guiding channel (110) are arranged between the extrusion cavity (105) and the output channel (102). A blocking device (6) for regulating the flow rate of the connecting channel (109) is arranged on the connecting channel (109); an isolation diaphragm (12) is arranged in the extrusion cavity (105). The isolation diaphragm (12) is made of an elastic material and is fixed in the extrusion cavity (105), dividing the extrusion cavity (105) into a lower cavity and an upper cavity. The lower cavity communicates with the shock-absorbing rubber tube (2). The measured medium enters the lower cavity of the extrusion cavity through the main flow channel. And while the lower cavity of the extrusion cavity is filled with the measured medium, a part of the measured medium enters the buffer cavity through the connecting channel and flows into the upper cavity of the extrusion cavity through the pressure guiding channel. The upper cavity is connected to the output channel through the pressure guiding channel; when the pressure value displayed by the pressure gauge is equal to the actual pressure value of the measured medium, the blocking device is used to block and separate the connecting channel, so that the measured medium cannot flow in the connecting channel, thereby realizing the isolation of the measured medium; in normal use, if the pressure of the measured medium increases, the isolation diaphragm will not contact the connection port of the pressure guiding channel and the extrusion cavity after bulging upward, so that the measured medium in the upper cavity of the extrusion cavity can flow through the pressure guiding channel; When the pressure gauge is damaged and leaks, the pressure of the measured medium in the lower cavity of the extrusion cavity pushes the isolation diaphragm to deform and bulge upward, so that the isolation diaphragm contacts the pressure guiding channel and blocks the connection port of the pressure guiding channel and the extrusion cavity.

2. The pressure gauge protector according to claim 1, wherein A pressure relief cavity (103) is arranged in the protection joint (1). The pressure relief cavity (103) communicates with the shock-absorbing rubber tube (2), and the pressure relief cavity (103) communicates with the extrusion cavity (105) through a main flow channel (104). A flow limiting device (7) for restricting the flow rate of the main flow channel (104) is arranged in the main flow channel (104).

3. The pressure gauge protector according to claim 2, characterized in that, The flow limiting device (7) is of a cylindrical rod structure and is slidably and sealingly arranged with the protection joint (1); one end of the flow limiting device (7) extends into the main flow channel (104) and is adapted to the main flow channel (104), and the other end of the flow limiting device (7) protrudes from the outer wall of the protection joint (1).

4. The pressure gauge protector according to claim 2, characterized in that, An overpressure flow channel (108) is arranged in the protection joint (1). One end of the overpressure flow channel (108) communicates with the pressure relief cavity (103), and the other end communicates with the main flow channel (104) and is located between the flow limiting device (7) and the pressure relief cavity (103); the diameter of the overpressure flow channel (108) is larger than the diameter of the main flow channel (104), and an overpressure protection mechanism for regulating the flow rate of the main flow channel (104) is arranged in the overpressure flow channel (108).

5. The pressure gauge protector according to claim 4, characterized in that, An installation cavity (13) for installing the overpressure protection mechanism is formed on the protection joint (1). One end of the installation cavity (13) penetrates the surface of the protection joint (1), and the other end extends into the protection joint (1) to communicate with the main flow channel (104), and corresponds to the position of the connection port of the overpressure flow channel (108) and the main flow channel (104); the overpressure protection mechanism includes a piston assembly (51) and a sealing seat (52). The sealing seat (52) is hermetically fixed in the installation cavity (13). One end of the piston assembly (51) is connected to the sealing seat (52) through a spring (53), and the other end slides into the overpressure flow channel (108) after passing through the main flow channel (104).

6. The pressure gauge protector according to claim 5, characterized in that, The piston assembly (51) includes a push head (511) and a movable plug (513). The push head (511) extends into the overpressure flow channel (108) and is slidably sealed with the overpressure flow channel (108); the movable plug (513) is installed in the installation cavity (13) and is slidably sealed with the installation cavity (13); the push head (511) and the movable plug (513) are connected by a connecting rod (512). The connecting rod (512) penetrates the main flow channel (104), and the diameter of the connecting rod (512) is smaller than the diameter of the main flow channel (104).

7. A pressure gauge protector according to claim 1, characterized in that, A pressure relief pipe (8) is arranged on the outer wall of the protection joint (1). The pressure relief channel (801) in the pressure relief pipe (8) is connected to the connection channel (109); the plugging device (6) is in a rod shape and is installed on the protection joint (1) and is slidably sealed with the protection joint (1); one end of the plugging device (6) extends into the connection channel (109), and the other end protrudes from the outer wall of the protection joint (1), and the rod body part of the plugging device (6) is used to plug the connection port of the pressure relief channel (801) and the connection channel (109).

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