A double-valve spring-loaded safety valve

Abstract

This invention discloses a dual-valve-disc spring-loaded safety valve, comprising a valve body, a valve seat, a valve cover, and a valve stem. The valve body has an inlet chamber on its lower side and an outlet chamber on its right side. The valve seat is disposed within the inlet chamber, and the valve cover is located on the upper end of the valve body. The valve stem is movable up and down and passes through the valve cover, and is equipped with a compression spring. The lower end of the valve stem extends into the valve body. The valve body contains an inner guide sleeve and an outer guide sleeve arranged coaxially. The lower end of the outer guide sleeve contains an inner valve disc and an outer valve disc arranged coaxially. The inner and outer valve discs are movable up and down and are equipped with corresponding position adjustment mechanisms. The lower ends of the inner and outer valve discs are sealed to the upper end of the valve seat. The lower end of the valve stem is connected to a push rod, which is movable up and down within the inner guide sleeve. The upper ends of the inner and outer valve discs are pressed against the push rod. This invention uses dual valve discs for switching to change the medium's tolerance, thus meeting pipeline strength testing requirements.

Description

Technical Field

[0001] This invention relates to an improved safety valve, and more particularly to an improved double-disc spring-loaded safety valve. Background Technology

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

[0003] Before new pipelines are put into use or after old pipelines are repaired, a strength test is required to ensure their suitability. The pressure for pipeline strength testing is generally a liquid test, i.e., a hydrostatic test, and the test pressure is usually much higher than the set pressure of the safety valve. In current technology, during pipeline strength testing, the safety valve needs to be disassembled, a cap installed on the flange of the equipment pipeline connected to the safety valve, and then the safety valve reinstalled after the hydraulic strength test is completed. This process is cumbersome and inconvenient.

[0004] However, since safety valve fittings cannot undergo strength testing, leaks are prone to occur at the gasket seal between the safety valve fitting and the equipment pipeline flange. Summary of the Invention

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

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This double-valve spring-loaded safety valve includes a valve body, a valve seat, a valve cover, and a valve stem. The valve body has an inlet chamber on its lower side and an outlet chamber on its right side. The valve seat is disposed within the inlet chamber. The valve cover is disposed on the upper end of the valve body. The valve stem can move up and down through the valve cover and is equipped with a compression spring. The lower end of the valve stem extends into the valve body. The valve body is characterized by having an inner guide sleeve and an outer guide sleeve arranged coaxially. The lower end of the outer guide sleeve has an inner valve disc and an outer valve disc arranged coaxially. The inner and outer valve discs can be adjusted up and down. Correspondingly, the inner and outer valve discs are equipped with position adjustment mechanisms. The lower ends of the inner and outer valve discs are sealed to the upper end of the valve seat. The lower end of the valve stem is connected to a push rod, which can move up and down within the inner guide sleeve. The upper ends of the inner and outer valve discs are pressed against the push rod.

[0007] The position adjustment mechanism includes a switching rod, an outer inclined block, an inner inclined block, and an inner drive block. The lower ends of the inner and outer inclined blocks have opposing inclined surfaces, which are located at the upper ends of the inner and outer valve discs, respectively. The upper ends of the inner and outer valve discs are respectively equipped with drive inclined surfaces. The upper ends of the inner and outer inclined blocks are pressed against the lower end of the push rod. The outer inclined block is driven by the switching rod. The corresponding switching rod is threaded and passes through the valve body. The outer end of the switching rod is equipped with a locking nut, and the inner end of the switching rod is equipped with a switching sleeve. The switching sleeve can be moved into the inner and outer guide sleeves. The inner end of the switching sleeve is equipped with a ball bearing, which abuts against the outer surface of the outer inclined block. The inner inclined block is driven by the inner drive block. The inner drive block can be moved up and down in a sealed manner within the inner valve disc. The inner valve disc is equipped with a lower limit step. A tension spring is provided between the upper end of the inner drive block and the push rod. The adjacent sides of the inner drive block and the inner inclined block are set with inclined surfaces for transmission.

[0008] The top rod is connected to the inner valve disc and the outer valve disc by an inner pull rod and an outer pull rod, respectively. The inner pull rod and the outer pull rod are respectively able to move up and down and are passed through the top rod. The upper end of the inner pull rod is equipped with an inner pre-tension spring, and the upper end of the outer pull rod is equipped with an outer pre-tension spring.

[0009] The position adjustment mechanism is evenly arranged in several groups along the circumference.

[0010] The inner and outer tie rods are evenly arranged in several groups along the circumference.

[0011] The compression spring is sleeved on the valve stem, and the 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. The upper end of the upper spring seat is provided with an adjusting screw sleeve, which is sleeved on the valve stem and threadedly connected to and passes through the valve cover.

[0012] The inner guide sleeve has an anti-rotation groove on its inner circle, and the push rod has an anti-rotation block on its outer circle. The anti-rotation block cooperates with the anti-rotation groove.

[0013] The beneficial effect of this invention is that the improved double-valve spring-loaded safety valve, by setting an inner valve disc and an outer valve disc and adjusting the positions of the inner and outer valve discs, can achieve sealing cooperation between the inner and outer valve discs and the valve seat, forming sealing surfaces of different sizes on the valve seat. When the inner valve disc contacts the sealing surface of the valve seat, the sealing surface becomes smaller. Under the condition that the safety valve's force remains consistent, it can withstand a higher inlet-side medium pressure, ensuring that the safety valve will not open when the pipeline is undergoing strength testing. Attached Figure Description

[0014] The specific embodiments of the present invention will be 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 Enlarged view of part A.

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

[0019] The accompanying drawings illustrate the structure of the present invention, and further details will be described below in conjunction with the drawings. In this embodiment, see the attached drawings. Figure 1-4 This double-disc spring-loaded safety valve includes a valve body 1, a valve seat 2, a valve cover 3, and a valve stem 4. The valve body 1 has an inlet 5 on its lower side and an outlet 6 on its right side. The valve seat 2 is located inside the inlet 5. The valve cover 3 covers the upper end of the valve body 1. The valve stem 4 is movable up and down and passes through the valve cover 3. The valve stem 4 is equipped with a compression spring 7, which provides a downward force to compress the valve disc. The lower end of the valve stem 4 extends into the valve body 1. The valve body 1 contains an inner guide sleeve 8 and an outer guide sleeve 9 arranged coaxially. The lower end of the outer guide sleeve 9 is lower than the lower end of the inner guide sleeve 8. The valve seat 2 has an inner valve disc 10 and an outer valve disc 11 arranged coaxially inside and outside. The inner valve disc 10 and the outer valve disc 11 are in contact with each other and a sealing ring is provided between them. The sealing ring is embedded in the inner circle of the outer valve disc 11. The inner valve disc 10 and the outer valve disc 11 can be adjusted up and down. The inner valve disc 10 and the outer valve disc 11 are equipped with position adjustment mechanisms. The lower ends of the inner valve disc 10 and the outer valve disc 11 are sealed to the upper end of the valve seat 2. The lower end of the valve stem 4 is connected to a push rod 12. The push rod 12 can be moved up and down and is set in the inner guide sleeve 8. The upper ends of the inner valve disc 10 and the outer valve disc 11 are pressed together with the push rod 12.

[0020] As a further improved embodiment, the position adjustment mechanism includes a switching rod 13, an outer inclined block 14, an inner inclined block 15, and an inner drive block 16. The lower ends of the inner inclined block 15 and the outer inclined block 14 have opposing inclined surfaces, and are respectively located at the upper ends of the inner valve disc 10 and the outer valve disc 11. The upper ends of the corresponding inner valve disc 10 and the outer valve disc 11 are respectively provided with drive inclined surfaces. The upper ends of the inner inclined block 15 and the outer inclined block 14 are pressed against the lower end of the push rod 12. The outer inclined block 14 is driven by the switching rod 13. The corresponding switching rod 13 is threaded and passes through the valve body 1. The outer end of the switching rod 13 is provided with a locking nut 1. 7. A switching sleeve 18 is provided at the inner end of the switching rod 13. The switching sleeve 18 can be moved into the inner and outer guide sleeves 9. A ball bearing 19 is provided at the inner end of the switching sleeve 18. The ball bearing 19 abuts against the outer side surface of the outer inclined block 14. The inner inclined block 15 is in transmission cooperation with the inner drive block 16. The inner drive block 16 can be moved up and down in a sealed manner within the inner valve disc 10. A lower limit step 20 is provided in the inner valve disc 10 to limit the inner drive block 16 from moving down and disengaging from the inner valve disc 10. A tension spring 21 is provided between the upper end of the inner drive block 16 and the top rod 12. The adjacent sides of the inner drive block 16 and the inner inclined block 15 are inclined surfaces for transmission cooperation.

[0021] As a further improved specific implementation, the top rod 12 is connected to the inner valve disc 10 and the outer valve disc 11 by an inner pull rod 22 and an outer pull rod 23, respectively. The inner pull rod 22 and the outer pull rod 23 are respectively movable up and down and pass through the top rod 12. The upper end of the inner pull rod 22 is equipped with an inner preload spring 24, which is sleeved on the upper end of the inner pull rod 22 and limited between the top step of the inner pull rod 22 and the upper end face of the inner valve disc 10, applying an upward elastic tension to the inner valve disc 10. The upper end of the outer pull rod 23 is equipped with an outer preload spring 25, which is sleeved on the upper end of the outer pull rod 23 and limited between the top step of the outer pull rod 23 and the upper end face of the outer valve disc 11, applying an upward elastic tension to the outer valve disc 11.

[0022] As a further improved 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 disc 10 and the outer valve disc 11 are subjected to more uniform force during position adjustment.

[0023] As a further improved implementation, the inner tie rod 22 and the outer tie rod 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 disc 10 and the outer valve disc 11 is more uniform.

[0024] As a further improved embodiment, the compression spring 7 is sleeved on the valve stem 4. The valve stem 4 has a lower spring seat 26 and an upper spring seat 27. The lower spring seat 26 is located at the lower end of the valve stem 4, and a step is provided at the lower end of the valve stem 4 to restrict the lower spring seat 26 from moving downwards. 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 threadedly connected to and passes through the valve cover 3. During operation, rotating the adjusting screw sleeve 28 causes the upper spring seat 27 to move downwards, compressing the compression spring 7. The compression force of the compression spring 7 is transmitted to the push rod 12 through the valve stem 4. The push rod 12 causes 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 the set pressure requires the removal of the safety valve and adjustment of the set pressure value at a designated special equipment testing center, or adjustment online using professional equipment. It requires professional personnel and equipment to disassemble the valve cap and readjust the rotation amount.

[0025] In the above, the compression spring 7 acts on the valve stem 4, and the valve stem 4 acts on the valve disc. A sealing pressure is generated between the valve disc and the valve seat 2. When the pressure in the inlet chamber 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, the inner guide sleeve 8 is provided with an anti-rotation groove 29 on its inner circle, and the top rod 12 is provided with an anti-rotation block 30 on its outer circle. The anti-rotation block 30 cooperates with the anti-rotation groove 29 to limit the rotation of the top rod 12.

[0027] The working principle of this invention is as follows: Under the action of the compression spring 7, the valve stem 4 generates a downward pressing force on the push rod 12, which in turn generates a downward pressing force on the inner valve disc 10 and the outer valve disc 11. Loosening the locking bolt causes the switching rod 13 to rotate inward, driving the switching sleeve 18 and the ball bearing 19 to move inward. The ball bearing 19 pushes against the outer inclined block 14 and moves inward. The outer inclined block 14 drives the outer valve disc 11 downward through its inclined surface, forming a seal between the outer valve disc 11 and the valve seat 2. Meanwhile, the inner inclined block 15 is pushed inward by the outer inclined 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. The sealing surface of the inner valve disc 10 separates from the sealing surface of the valve seat 2, meaning the outer valve disc 11 participates in the sealing, thus providing a seal for the safety valve. The switching lever 13 rotates outward, causing the tension spring 21 to move the inner drive block 16 upward. The inner drive block 16 then drives the inner inclined block 15 outward via the inclined surface. The inner inclined block 15, in turn, drives the inner valve disc 10 downward via the inclined surface. The inner valve disc 10 forms a seal with the valve seat 2, and the outer inclined block 14 is driven outward by the inner inclined block 15. Correspondingly, the outer valve disc 11 moves upward under the action of the outer pull rod 23 and the outer preload spring 25. The sealing surface of the outer valve disc 11 separates from the sealing surface of the valve seat 2, meaning that the inner valve disc 10 participates in the sealing. The sealing surface becomes smaller, and the set pressure increases. This is equivalent to a smaller surface area for the medium to bear the force. With the force of the compression spring 7 remaining consistent, the inlet-side medium pressure that can be withstood is higher, which is necessary for pipeline strength testing. The adjustment of the set pressure does not require the safety valve to be removed and taken to a designated special equipment testing center, nor does it require professional personnel or specialized equipment for adjustment. It is achieved simply by switching the sealing between the inner and outer valve discs using the switching valve, which is very convenient and quick.

[0028] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within 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, wherein the valve body has an inlet chamber on its lower side and an outlet chamber on its right side; the valve seat is disposed within the inlet chamber; the valve cover is disposed on the upper end of the valve body; the valve stem is movable up and down and passes through the valve cover; and the valve stem is equipped with a compression spring, with its lower end extending into the valve body, characterized in that: The valve body is provided with an inner guide sleeve and an outer guide sleeve arranged coaxially inside and outside. The lower end of the outer guide sleeve is provided with an inner valve disc and an outer valve disc arranged coaxially inside and outside. The inner valve disc and the outer valve disc can be adjusted up and down respectively. The corresponding inner valve disc and the outer valve disc are equipped with a position adjustment mechanism. The lower end of the inner valve disc and the outer valve disc 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 set in the inner guide sleeve. The upper end of the inner valve disc and the outer valve disc are pressed with the push rod. The position adjustment mechanism includes a switching rod, an outer inclined block, an inner inclined block, and an inner drive block. The lower ends of the inner and outer inclined blocks have opposing inclined surfaces, which are located at the upper ends of the inner and outer valve discs, respectively. The upper ends of the inner and outer valve discs are respectively equipped with drive inclined surfaces. The upper ends of the inner and outer inclined blocks are pressed against the lower end of the push rod. The outer inclined block is driven by the switching rod. The corresponding switching rod is threaded and passes through the valve body. The outer end of the switching rod is equipped with a locking nut, and the inner end of the switching rod is equipped with a switching sleeve. The switching sleeve can be moved into the inner and outer guide sleeves. The inner end of the switching sleeve is equipped with a ball bearing, which abuts against the outer surface of the outer inclined block. The inner inclined block is driven by the inner drive block. The inner drive block can be moved up and down in a sealed manner within the inner valve disc. The inner valve disc is equipped with a lower limit step. A tension spring is provided between the upper end of the inner drive block and the push rod. The adjacent sides of the inner drive block and the inner inclined block are set with inclined surfaces for transmission. The top rod is connected to the inner valve disc and the outer valve disc by an inner pull rod and an outer pull rod, respectively. The inner pull rod and the outer pull rod are respectively able to move up and down and are passed through the top rod. The upper end of the inner pull rod is equipped with an inner pre-tension spring, and the upper end of the outer pull rod is equipped with an outer pre-tension spring.

2. The double-valve spring-loaded safety valve as described in claim 1, characterized in that: The position adjustment mechanism is evenly arranged in several groups along the circumference.

3. The double-valve spring-loaded safety valve as described in claim 1, characterized in that: The inner and outer tie rods are evenly arranged in several groups along the circumference.

4. The double-valve spring-loaded safety valve as described in claim 1, characterized in that: The compression spring is sleeved on the valve stem, and the 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. The upper end of the upper spring seat is provided with an adjusting screw sleeve, which is sleeved on the valve stem and threadedly connected to and passes through the valve cover.

5. The double-valve spring-loaded safety valve as described in claim 1, characterized in that: The inner guide sleeve has an anti-rotation groove on its inner circle, and the push rod has an anti-rotation block on its outer circle. The anti-rotation block cooperates with the anti-rotation groove.

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