An air-charged trim type low pressure safety valve

Abstract

The utility model relates to a kind of low pressure safety valves of air inflation fine adjustment, including valve body, valve seat, valve flap, valve cover, guide sleeve and pressure setting device guide column on the back of valve flap and guide sleeve inner hole dynamic cooperation;Its characterized is that:the pressure setting device is composed of rubber air bag being arranged in the inner cavity of valve cover and inflation device and air pressure regulating device on the upper end of valve cover;The rubber air bag is installed in the inner cavity wall of valve cover, and its lower part is in contact with the top of the upper end surface of guide column;The inflation device is composed of inflation connector and check valve.By inflating device, the air pressure is filled in the air cavity of rubber air bag, the pressure in air cavity is adjusted and controlled by air pressure regulating device, set pre-set pressure value, and the pre-set pressure value has good adjustment sensitivity and high precision, and can be applicable to low pressure, ultra-low pressure working condition.

Description

Technical Field

[0001] This utility model relates to a safety valve, and more particularly to a low-pressure safety valve. Background Technology

[0002] Traditional spring-loaded safety valves, when used in low-pressure conditions, exert a downward force on the valve disc due to the weight of the valve stem, spring, and spring seat, which is greater than the upward force exerted by the inlet medium on the valve disc. Therefore, existing spring-loaded safety valves are not suitable for low-pressure and ultra-low-pressure conditions. Consequently, in low-pressure and ultra-low-pressure conditions, gravity-type safety valves are generally used, utilizing the weight of a counterweight to set the set pressure value. However, the counterweight in gravity-type safety valves has a fixed weight, making it impossible to adjust the preset set pressure value. Utility Model Content

[0003] This utility model addresses the problems existing in the prior art by providing an air-filled fine-tuning low-pressure safety valve that can be used in low-pressure conditions and has good sensitivity and high accuracy in adjusting the preset set pressure value.

[0004] The technical solution for realizing this utility model is as follows: A pneumatically adjustable low-pressure safety valve includes a valve body, a valve seat, a valve disc, a valve cover, a guide sleeve, and a pressure setting device. The lower end face of the valve disc and the valve seat cooperate to form a sealing pair, and the guide post on the back of the valve disc is dynamically fitted with the inner hole of the guide sleeve. The pressure setting device consists of a rubber air bladder disposed in the inner cavity of the valve cover, an inflation device at the upper end of the valve cover, and a pressure regulating device. The rubber air bladder is installed on the inner wall of the valve cover, and its lower part contacts the upper end face of the guide post. The inflation device consists of an inflation connector and a check valve. The inflation connector has an air hole, and the check valve is disposed between the lower end of the air hole of the inflation connector and the air cavity of the rubber air bladder.

[0005] The preferred embodiment is that the check valve consists of a check valve body, a check valve seat, a check ball, and a spring. The upper part of the check valve body is provided with an external thread, and the lower part is provided with a radial shoulder. The upper end of the rubber air bladder is provided with a top block. The upper end face of the top block is mounted on the valve cover through a pull rod and a pre-tightening spring. The upper part of the check valve body passes through the rubber air bladder and is threadedly connected to the center hole of the top block. The spring and the check ball are installed in the inner cavity of the check valve body. The check ball is installed on the upper end of the spring and cooperates with the sealing surface of the lower end of the check valve seat to form a sealing pair. The lower end of the inner hole of the check valve seat is connected to the inner cavity of the check valve body, and the upper end is connected to the lower end of the air hole of the air inlet connector.

[0006] The preferred embodiment is that the air pressure regulating device consists of an adjusting screw sleeve installed between the valve cover and the inflation connector. The outer circle of the adjusting screw sleeve is threadedly connected to the inner hole of the valve cover, and the inner hole is threadedly connected to the outer circle surface of the inflation connector. The lower end of the adjusting screw sleeve presses against the upper end surface of the top block.

[0007] A preferred embodiment is to provide an adjusting pin between the air hole of the inflation connector and the inner hole of the check valve seat. The lower end of the adjusting pin passes through the inner hole of the check valve seat and contacts the check ball. The upper end is provided with a radial shoulder, which is pressed into the radial step of the air hole of the inflation connector by a fixing ring. A vent hole is provided between the upper and lower end faces of the radial shoulder.

[0008] Compared with the prior art, the beneficial effect of this utility model is that the pressure setting device consists of a rubber air bladder set in the inner cavity of the valve cover, an inflation device and a pressure regulating device at the upper end of the valve cover. The inflation device fills the air cavity of the rubber air bladder with air pressure, and the pressure regulating device adjusts and controls the pressure in the air cavity to set a preset setting pressure value. The preset setting pressure value adjustment has good sensitivity and high accuracy, and can be applied to low pressure and ultra-low pressure working conditions. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the structure of this utility model.

[0010] Figure 2 This is a utility model Figure 1 Enlarged view of the local structure at point A in the middle.

[0011] In the diagram: 1 Valve body, 2 Valve seat, 3 Adjusting ring, 4 Valve disc, 5 Guide sleeve, 6 Valve cover, 7 Inner cavity, 8 Adjusting pin, 9 Adjusting screw sleeve, 10 Air hole, 11 Valve cap, 12 Inflation connector, 13 Pull rod, 14 Pre-tightening spring, 15 Top block, 16 Rubber air bag, 17 Air chamber, 18 Outlet cavity, 19 Inlet cavity, 20 Spring, 21 Check ball, 22 Vent hole, 23 Fixing ring, 24 Check valve seat, 25 Check valve body, 26 Center hole. Detailed Implementation

[0012] like Figure 1The illustrated inflatable micro-adjustable low-pressure safety valve includes a valve body 1, a valve seat 2, a valve disc 4, a valve cover 6, a guide sleeve 5, and a pressure setting device. The valve body 1 has an inlet cavity 19 and an outlet cavity 18. The inlet cavity 19 communicates with the inner cavity of the pressure pipeline. The lower end face of the valve disc 4 and the valve seat 2 cooperate to form a sealing pair. The guide post on the back of the valve disc 4 is dynamically engaged with the inner hole of the guide sleeve 5. An adjusting ring 3 is provided on the outer side of the sealing surface of the valve seat 2 to adjust the opening height of the valve disc 4. Its characteristic is that the pressure setting device is provided on the valve cover... The device consists of a rubber airbag 16 within the inner cavity of the valve cover 6, an inflation device, and a pressure regulating device at the upper end of the valve cover 6. A valve cap 11 is provided at the upper end of the valve cover 6 to prevent dust from entering the inflation device and pressure regulating device components. The rubber airbag 16 is tightly fitted against the inner wall of the valve cover 6, with its lower center in close contact with the upper end face of the guide post. The inflation device consists of an inflation connector 12 and a check valve. The inflation connector 12 has an air hole 10, and the check valve is located between the lower end of the air hole 10 and the air cavity 17 of the rubber airbag 16. External air pressure is injected into the air cavity 17 of the rubber airbag 16 through the inflation connector 12 and the check valve. When the air pressure in the air cavity 17 reaches the preset set pressure value, the external air source pressure is disconnected, the check valve automatically closes to prevent air pressure leakage in the air cavity 17, and the pressure regulating device finely adjusts the air pressure in the air cavity 17 to keep it consistent with the preset set pressure value. When the pressure in the inlet cavity 19 of valve body 1 exceeds the set pressure value, the medium pressure overcomes the air pressure in the air chamber 17 of rubber airbag 16, pushing valve disc 4 to open and release the medium pressure to the outlet cavity 18, thus avoiding the influence of valve stem and spring gravity on the set pressure under low pressure conditions in existing technologies.

[0013] The check valve consists of a check valve body 25, a check valve seat 24, a check ball 21, and a spring 20. The check valve body 25 has an external thread on its upper part and a radial shoulder on its lower part. A top block 15 is provided on the upper end face of the rubber air bladder 16. The upper end face of the top block 15 is positioned on the valve cover 6 by a pull rod 13 and a preload spring 14. Several pull rods 13 are evenly arranged in the circumferential direction on the upper plane of the top block 15. The outer surface of the pull rod is clearance-fitted with the shaft hole of the valve cover 6, so that the pull rod 13 drives the top block 15 to move axially within the shaft hole of the valve cover 6. The upper part of the check valve body 25 passes through... The rubber airbag 16 is threadedly connected to the center hole of the top block 15. Its lower radial shoulder presses the rubber airbag 16 and the top block 15 together for a sealed connection. The spring 20 and check ball 21 are installed inside the inner cavity 7 of the check valve body 25. The check ball 21 is installed on the upper end of the spring 20 and mates with the lower sealing surface of the check valve seat 24 to form a sealing pair. The lower end of the inner hole of the check valve seat 24 communicates with the inner cavity 7 of the check valve body 25, and the upper end communicates with the lower end of the air hole 10 of the inflation connector 12. The inner cavity 7 of the check valve body 25 is connected to the air chamber 17 through the center hole 26. Figure 2 As shown, the inflation pressure pushes the check ball 21 to compress the spring 20 to open the check valve. After inflation ends, the spring 20 pushes the check ball 21 to seal with the check valve seat 24.

[0014] The air pressure regulating device consists of an adjusting screw sleeve 9 installed between the valve cover 6 and the inflation connector 12. The outer circle of the adjusting screw sleeve 9 is threadedly connected to the inner hole of the valve cover 6, and the inner hole is threadedly connected to the outer circle of the inflation connector 12. The lower end of the adjusting screw sleeve 9 presses against the upper end face of the top block 15. By rotating the adjusting screw sleeve 9, its vertical position on the valve cover 6 is adjusted, which pushes the top block 15 to move up and down, changing the volume of the air chamber 17 of the rubber air bag 16, thereby regulating the air pressure in the air chamber 17 and accurately setting the set pressure value.

[0015] An adjusting pin 8 is provided between the air hole 10 of the inflation connector 12 and the inner hole of the check valve seat 24. The lower end of the adjusting pin 8 penetrates the inner hole of the check valve seat 24 and contacts the check ball 21. The radial shoulder at its upper end is press-fitted into the radial step of the air hole 10 of the inflation connector 12 by a fixing ring 23. A vent hole 22 is provided between the upper and lower end faces of the radial shoulder, and the vent hole 22 connects the air hole 10 and the inner hole of the check valve seat 24. There is an annular gap between the outer circumference of the adjusting pin 8 and the inner hole of the check valve seat 24. Figure 2 As shown, when adjusting the pre-set pressure, fix the adjusting screw sleeve 9, rotate the air inlet connector 12 to move the adjusting pin 8 downward, push open the check ball 21, and release the air pressure in the air chamber 17. When the air pressure reaches the pre-set pressure value, rotate the air inlet connector 12 in the opposite direction to close the check valve, so as to achieve fine adjustment of the air pressure in the air chamber 17 and accurately set the pressure value.

Claims

1. A pneumatically adjustable low-pressure safety valve, comprising a valve body (1), a valve seat (2), a valve disc (4), a valve cover (6), a guide sleeve (5), and a pressure setting device, wherein the lower end face of the valve disc (4) and the valve seat (2) cooperate to form a sealing pair, and the guide post on the back of the valve disc (4) is dynamically engaged with the inner hole of the guide sleeve (5); characterized in that: The pressure setting device consists of a rubber air bladder (16) installed in the inner cavity of the valve cover (6), an inflation device and a pressure regulating device on the upper end of the valve cover (6); the rubber air bladder (16) is close to the inner wall of the valve cover (6), and its lower center is in close contact with the upper end face of the guide column; the inflation device consists of an inflation connector (12) and a check valve, the inflation connector (12) is provided with an air hole (10), and the check valve is located between the lower end of the air hole (10) and the air cavity (17) of the rubber air bladder (16).

2. The air-filled fine-tuning low-pressure safety valve according to claim 1, characterized in that: The check valve consists of a check valve body (25), a check valve seat (24), a check ball (21), and a spring (20). The upper part of the check valve body (25) is provided with an external thread, and the lower part is provided with a radial shoulder. A top block (15) is provided on the upper end face of the rubber air bladder (16). The upper end face of the top block (15) is positioned and installed on the valve cover (6) by a pull rod (13) and a preload spring (14). Several pull rods (13) are evenly arranged in the circumferential direction on the upper plane of the top block (15), and their outer circular surface is between the shaft hole of the valve cover (6). With clearance fit, the upper part of the check valve body (25) passes through the rubber air bladder (16) and is threadedly connected to the center hole of the top block (15). The spring (20) and the check ball (21) are installed in the inner cavity (7) of the check valve body (25). The check ball (21) is installed on the upper end of the spring (20) and cooperates with the sealing surface of the lower end of the check valve seat (24) to form a sealing pair. The lower end of the inner hole of the check valve seat (24) is connected to the inner cavity (7) of the check valve body (25), and the upper end is connected to the lower end of the air hole (10) of the air inlet (12).

3. The air-filled fine-tuning low-pressure safety valve according to claim 2, characterized in that: The air pressure regulating device consists of an adjusting screw sleeve (9) installed between the valve cover (6) and the air inlet (12). The outer circle of the adjusting screw sleeve (9) is threadedly connected to the inner hole of the valve cover (6), and the inner hole is threadedly connected to the outer circle of the air inlet (12). The lower end of the adjusting screw sleeve (9) presses against the upper surface of the top block (15).

4. The air-filled fine-tuning low-pressure safety valve according to claim 2 or 3, characterized in that: An adjusting pin (8) is provided between the air hole (10) of the air connector (12) and the inner hole of the check valve seat (24). The lower end of the adjusting pin (8) passes through the inner hole of the check valve seat (24) and touches the check ball (21). The radial shoulder at its upper end is pressed into the radial step of the air hole (10) of the air connector (12) by a fixing ring (23). A vent hole (22) is provided between the upper and lower end faces of the radial shoulder. There is an annular gap between the outer circumference of the adjusting pin (8) and the inner hole of the check valve seat (24).

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