Double-valve-clack spring type safety valve

Abstract

The double-valve-clack spring type safety valve comprises a valve body, a valve seat, a valve deck and a valve rod, an inlet cavity is formed in the lower side of the valve body, an outlet cavity is formed in the right side of the valve body, the valve seat is arranged in the inlet cavity, the valve deck covers the upper end of the valve body, the valve rod can move up and down to be arranged on the valve deck in a penetrating mode, the valve rod is provided with a compression spring in a matched mode, and the lower end of the valve rod extends into the valve body. The check valve is characterized in that an inner guide sleeve and an outer guide sleeve which are coaxially arranged inside and outside are arranged in the valve body, an inner valve clack and an outer valve clack which are coaxially arranged inside and outside are arranged in the lower end of the outer guide sleeve, the inner valve clack and the outer valve clack can respectively move up and down to be adjusted, and the inner valve clack and the outer valve clack are correspondingly provided with a position adjusting mechanism in a matched mode. The lower end of the valve rod is connected with an ejector rod, the ejector rod is arranged in the inner guide sleeve in an up-down moving mode, and the upper ends of the inner valve clack and the outer valve clack are matched with the ejector rod in a pressing mode. According to the invention, the double valve clacks are used in a switching manner to change the medium tolerance so as to meet the pipeline strength test.

Description

Technical Field

[0001] The present invention relates to an improved invention of a safety valve, in particular to an improved invention of a double-valve flap spring type safety valve. Background Art

[0002] A safety valve is an opening and closing component that is normally closed under external force. When the medium pressure in the equipment or pipeline rises above the specified value, it prevents the medium pressure in the pipeline or equipment from exceeding the specified value by discharging the medium outside the system.

[0003] Before a new pipeline is put into use or after an old pipeline is repaired, a strength test is required to ensure that the pipeline is suitable for use. The pressure of the pipeline strength test is generally liquid-type, that is, a water pressure test, and the test pressure is generally much higher than the set pressure of the safety valve. In the existing technology, when conducting a pipeline strength test, the safety valve needs to be disassembled and a blind cap installed on the equipment pipe flange connected to the safety valve joint. After the pipeline hydraulic strength test is completed, the safety valve is reinstalled. This process is relatively cumbersome and difficult to operate.

[0004] However, there is no way to perform strength tests on the safety valve joints, so the gasket seal between the safety valve joints and the equipment pipe flanges is prone to leakage. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a double-valve spring-type safety valve.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: the double-valve flap spring safety valve comprises a valve body, a valve seat, a valve cover and a valve stem, the lower side of the valve body is provided with an inlet cavity, the right side of the valve body is provided with an outlet cavity, the valve seat is arranged in the inlet cavity, the valve cover is arranged on the upper end of the valve body, the valve stem can be moved up and down and is penetrated by the valve cover, and the valve stem is equipped with a compression spring, and the lower end of the valve stem extends into the valve body, which is characterized in that: an inner guide sleeve and an outer guide sleeve are coaxially arranged inside and outside the valve body, and an inner valve flap and an outer valve flap coaxially arranged inside and outside are arranged in the lower end of the outer guide sleeve, the inner valve flap and the outer valve flap can be adjusted up and down respectively, and the corresponding inner valve flap and the outer valve flap are equipped with a position adjustment mechanism, the lower ends of the inner valve flap and the outer valve flap are sealed with the upper end of the valve seat, the lower end of the valve stem is connected to a push rod, the push rod can be moved up and down and is arranged in the inner guide sleeve, and the upper ends of the inner valve flap and the outer valve flap are pressed and fitted with the push rod.

[0007] The cam is secured to the valve body by a spring, and the cam is secured to the valve body with a spring, which allows the cam to move freely in the valve body and slide into the valve body, thereby ensuring that the cam is in a state of emergency and that the valve body is in a state of emergency.

[0008] The push rod is connected to the inner valve disc and the outer valve disc respectively by an inner pull rod and an outer pull rod. The inner pull rod and the outer pull rod can be moved up and down and are respectively passed through the push rod. The upper end of the inner pull rod is equipped with an inner preload spring, and the upper end of the outer pull rod is equipped with an outer preload spring.

[0009] The position adjustment mechanisms are evenly arranged in a plurality of groups along the circumferential direction.

[0010] The inner pull rods and the outer pull rods are evenly arranged in a plurality of groups along the circumferential direction.

[0011] The compression spring is sleeved on the valve stem, and the corresponding valve stem is provided with a lower spring seat and an upper spring seat. The lower spring seat is limited to the lower end of the valve stem, and the upper spring seat can move up and down. An adjusting screw sleeve is provided on the upper end of the upper spring seat, and the adjusting screw sleeve is sleeved on the valve stem. The adjusting screw sleeve is threaded and passed through the valve cover.

[0012] An anti-rotation groove is provided on the inner circle of the inner guide sleeve, and an anti-rotation block is provided on the outer circle of the push rod, and the anti-rotation block matches the anti-rotation groove.

[0013] The beneficial effect of the present invention is that the improved double-valve flap spring-type safety valve, by arranging the inner valve flap and the outer valve flap and adjusting the position of the inner valve flap and the outer valve flap, can realize the inner valve flap and the outer valve flap to seal with the valve seat respectively, and form sealing surfaces of different sizes on the valve seat. When the inner valve flap contacts the sealing surface of the valve seat, the sealing surface becomes smaller. When the force of the safety valve remains consistent, the inlet side medium pressure that can be tolerated is higher, ensuring that the safety valve will not open when the pipeline is subjected to strength testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0015] Figure 1 This is a diagram showing the contact state between the outer valve disc sealing surface and the valve seat sealing surface of the present invention.

[0016] Figure 2 This is a diagram showing the contact state between the inner valve disc sealing surface and the valve seat sealing surface of the present invention.

[0017] Figure 3 For the present invention Figure 1 Magnified view of part A.

[0018] Figure 4 For the present invention Figure 2 Enlarged view of part B. DETAILED DESCRIPTION

[0019] The accompanying drawings show the structure of the present invention, and the following further describes its relevant details in conjunction with the accompanying drawings. Figure 1-4 The double-valve spring safety valve includes a valve body 1, a valve seat 2, a valve cover 3 and a valve stem 4. The lower side of the valve body 1 is provided with an inlet cavity 5, and the right side of the valve body 1 is provided with an outlet cavity 6. The valve seat 2 is arranged in the inlet cavity 5, and the valve cover 3 is covered on the upper end of the valve body 1. The valve stem 4 can be moved up and down and is penetrated on the valve cover 3, and the valve stem 4 is equipped with a compression spring 7, so that the valve stem 4 has the force to press the valve disc downward. The lower end of the valve stem 4 extends into the valve body 1. The valve body 1 is provided with an inner guide sleeve 8 and an outer guide sleeve 9 arranged coaxially inside and outside. The lower end of the outer guide sleeve 9 is lower than the lower end of the inner guide sleeve 8, and the lower end of the outer guide sleeve 9 is lower than the lower end of the inner guide sleeve 8. An inner valve flap 10 and an outer valve flap 11 are coaxially arranged inside and outside the end. The inner valve flap 10 and the outer valve flap 11 fit together, and a sealing ring is provided between the two. The sealing ring is embedded in the inner circle of the outer valve flap 11. The inner valve flap 10 and the outer valve flap 11 can be moved up and down and adjusted respectively. The corresponding inner valve flap 10 and the outer valve flap 11 are equipped with a position adjustment mechanism. The lower ends of the inner valve flap 10 and the outer valve flap 11 are sealed with the upper end of the valve seat 2. The lower end of the valve stem 4 is connected to a push rod 12, which can be moved up and down and arranged in the inner guide sleeve 8. The upper ends of the inner valve flap 10 and the outer valve flap 11 are pressed against the push rod 12.

[0020] As a further improved specific embodiment, the position adjustment mechanism includes a switching rod 13, an outer oblique block 14, an inner oblique block 15 and an inner driving block 16. The lower ends of the inner oblique block 15 and the outer oblique block 14 have inclined surfaces arranged opposite to each other and are respectively located at the upper ends of the inner valve disc 10 and the outer valve disc 11. The corresponding upper ends of the inner valve disc 10 and the outer valve disc 11 are respectively provided with driving inclined surfaces. The upper ends of the inner oblique block 15 and the outer oblique block 14 are pressed against the lower end of the push rod 12; the outer oblique block 14 is in transmission cooperation with the switching rod 13, the corresponding switching rod 13 is threadedly connected and penetrated on the valve body 1, and the outer end of the switching rod 13 is provided with a locking nut 1 7. The inner end of the switching rod 13 is equipped with a switching sleeve 18, which can be moved into the inner and outer guide sleeves 9. The inner end of the switching sleeve 18 is provided with a ball 19, which abuts against the outer surface of the outer oblique block 14. The inner oblique block 15 is matched with the inner drive block 16 for transmission. The inner drive block 16 can be sealed and moved up and down in the inner valve disc 10, and a lower limit step 20 is provided in the inner valve disc 10 to limit the inner drive block 16 from moving downward from the inner valve disc 10. A tension spring 21 is provided between the upper end of the inner drive block 16 and the push rod 12, and the adjacent sides of the corresponding inner drive block 16 and the inner oblique block 15 are arranged as inclined surfaces for transmission cooperation.

[0021] As a further improved specific implementation method, the push rod 12 is respectively connected to the inner valve flap 10 and the outer valve flap 11 with an inner pull rod 22 and an outer pull rod 23. The inner pull rod 22 and the outer pull rod 23 can be moved up and down and are respectively passed through the push rod 12, and the upper end of the inner pull rod 22 is provided with an inner pre-tightening spring 24, which is sleeved on the upper end of the inner pull rod 22 and is limited between the top step of the inner pull rod 22 and the upper end face of the inner valve flap 10, applying an upward elastic pulling force to the inner valve flap 10; the upper end of the outer pull rod 23 is provided with an outer pre-tightening spring 25, which is sleeved on the upper end of the outer pull rod 23 and is limited between the top step of the outer pull rod 23 and the upper end face of the outer valve flap 11, applying an upward elastic pulling force to the outer valve flap 11.

[0022] As a further improved specific implementation, the position adjustment mechanism is evenly arranged in several groups along the circumferential direction, preferably three or four groups, so that the inner valve flap 10 and the outer valve flap 11 are subjected to more uniform force during position adjustment.

[0023] As a further improved specific implementation, the inner pull rods 22 and the outer pull rods 23 are evenly arranged in several groups along the circumferential direction, preferably three or four groups, so that the upward pulling force on the inner valve flap 10 and the outer valve flap 11 is more uniform.

[0024] As a further improved specific embodiment, the compression spring 7 is sleeved on the valve stem 4, and the corresponding valve stem 4 is provided with a lower spring seat 26 and an upper spring seat 27. The lower spring seat 26 is limited to the lower end of the valve stem 4, and the corresponding lower end of the valve stem 4 is provided with a step for limiting the downward movement of the lower spring seat 26. The upper spring seat 27 can move up and down, and an adjusting screw sleeve 28 is provided at the upper end of the upper spring seat 27. The adjusting screw sleeve 28 is sleeved on the valve stem 4, and the adjusting screw sleeve 28 is threadedly connected and passed through the valve cover 3. During operation, by rotating the adjusting screw sleeve 28, the upper spring seat 27 is driven to move downward, causing the compression spring 7 to be compressed. The compression force of the compression spring 7 is transmitted to the push rod 12 through the valve stem 4, and the push rod 12 drives the valve disc to press against the valve seat 2. Therefore, the rotation amount of the adjusting screw sleeve 28 can control the set pressure of the safety valve. The above adjustment of set pressure requires the removal of the safety valve and going to a designated special equipment testing center to adjust the set pressure value, or using professional equipment to adjust it online. Professional personnel and professional equipment are required to disassemble the valve cap and readjust the rotation amount.

[0025] As shown above, the compression spring 7 acts on the valve stem 4, and the valve stem 4 acts on the valve disc. A sealing specific pressure is generated between the valve disc and the valve seat 2. When the pressure in the inlet cavity 5 rises, the force of the medium pushing the valve disc upward is balanced with the force of the valve disc downward. The instantaneous force that pushes the valve disc open is called the set pressure of the safety valve.

[0026] As a further improved specific implementation method, an anti-rotation groove 29 is provided on the inner circle of the inner guide sleeve 8, and an anti-rotation block 30 is provided on the outer circle of the push rod 12. The anti-rotation block 30 cooperates with the anti-rotation groove 29 to limit the rotation of the push rod 12.

[0027] The working principle of the present invention is that the valve stem 4 generates a downward pressing force on the push rod 12 under the action of the compression spring 7, and then the push rod 12 generates a downward pressing force on the inner valve disc 10 and the outer valve disc 11; loosen the locking bolt, the switching rod 13 rotates inward, driving the switching sleeve 18 and the ball 19 to move inward, and the ball 19 moves inward against the outer bevel block 14, and the outer bevel block 14 drives the outer valve disc 11 downward through the bevel, and the outer valve disc 11 forms a seal with the valve seat 2, and the inner bevel block 15 is pushed inward by the outer bevel block 14, and the corresponding inner valve disc 10 moves upward under the action of the inner pull rod 22 and the inner preload spring 24, and the sealing surface of the inner valve disc 10 is separated from the sealing surface of the valve seat 2, that is, the outer valve disc 11 participates in the sealing, providing a safety valve. Participate in normal operation; when the switch rod 13 rotates outward, the tension spring 21 drives the inner drive block 16 to move upward, and the inner drive block 16 drives the inner bevel block 15 outward through the inclined surface, and the inner bevel block 15 drives the inner valve disc 10 downward through the inclined surface, and the inner valve disc 10 forms a seal with the valve seat 2, and the outer bevel block 14 is driven outward by the inner bevel block 15. The corresponding outer valve disc 11 moves upward under the action of the outer pull rod 23 and the outer preload spring 25, and the sealing surface of the outer valve disc 11 is separated from the sealing surface of the valve seat 2, that is, the inner valve disc 10 participates in the seal, the sealing surface becomes smaller, and the set pressure increases, which is equivalent to the medium force surface becoming smaller. When the force of the compression spring 7 remains consistent, the inlet side medium pressure that can be tolerated is higher, which is suitable for pipeline strength testing. The above set pressure adjustment does not require the safety valve to be disassembled and taken to a designated special equipment testing center, nor does it require professional personnel and professional equipment to make adjustments. It is only achieved by switching the seal between the inner and outer valve discs through the switching valve, which is very convenient and fast.

[0028] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A double-valve spring-loaded safety valve, comprising a valve body, a valve seat, a valve cover, and a valve stem. The valve body is provided with an inlet cavity on the lower side and an outlet cavity on the right side. The valve seat is disposed in the inlet cavity. The valve cover is disposed on the upper end of the valve body. The valve stem is movable up and down and is provided on the valve cover. The valve stem is equipped with a compression spring, and the lower end of the valve stem extends into the valve body. The valve stem is characterized in that: The valve body is provided with an inner guide sleeve and an outer guide sleeve which are coaxially arranged inside and outside. The lower end of the outer guide sleeve is provided with an inner valve flap and an outer valve flap which are coaxially arranged inside and outside. The inner valve flap and the outer valve flap can be moved up and down and adjusted respectively. The corresponding inner valve flap and the outer valve flap are equipped with a position adjustment mechanism. The lower ends of the inner valve flap and the outer valve flap are sealed with the upper end of the valve seat. The lower end of the valve stem is connected with a push rod, which can be moved up and down and arranged in the inner guide sleeve. The upper ends of the inner valve flap and the outer valve flap are pressed and fitted with the push rod.

2. The double-flap spring-loaded safety valve according to claim 1, characterized in that: The cam is secured to the valve body by a spring, and the cam is secured to the valve body with a spring, which allows the cam to move freely in the valve body and slide into the valve body, thereby ensuring that the cam is in a state of emergency and that the valve body is in a state of emergency.

3. The double-flap spring-loaded safety valve according to claim 1 or 2, characterized in that: The push rod is connected to the inner valve disc and the outer valve disc respectively by an inner pull rod and an outer pull rod. The inner pull rod and the outer pull rod can be moved up and down and are respectively passed through the push rod. The upper end of the inner pull rod is equipped with an inner preload spring, and the upper end of the outer pull rod is equipped with an outer preload spring.

4. The double-flap spring-loaded safety valve according to claim 2, characterized in that: The position adjustment mechanisms are evenly arranged in a plurality of groups along the circumferential direction.

5. The double-flap spring-loaded safety valve according to claim 3, characterized in that: The inner pull rods and the outer pull rods are evenly arranged in a plurality of groups along the circumferential direction.

6. The double-flap spring-loaded safety valve according to claim 1, characterized in that: The compression spring is sleeved on the valve stem, and the corresponding valve stem is provided with a lower spring seat and an upper spring seat. The lower spring seat is limited to the lower end of the valve stem, and the upper spring seat can move up and down. An adjusting screw sleeve is provided on the upper end of the upper spring seat, and the adjusting screw sleeve is sleeved on the valve stem. The adjusting screw sleeve is threaded and passed through the valve cover.

7. The double-flap spring-loaded safety valve according to claim 1, characterized in that: An anti-rotation groove is provided on the inner circle of the inner guide sleeve, and an anti-rotation block is provided on the outer circle of the push rod, and the anti-rotation block matches the anti-rotation groove.

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