Quick connecting device for operating rod and driving rod in high-pressure state

Abstract

The invention relates to the technical field of oil and gas equipment connecting devices, and discloses a quick connecting device for an operating rod and a driving rod in a high-pressure state, which comprises an upper valve rod, a lower valve rod is arranged at the bottom of the upper valve rod, and two couplings symmetrically sleeve the outer side of the connecting end part of the upper valve rod and the lower valve rod; the two couplings are arranged at the connecting end of the upper valve rod and the lower valve rod in a surrounding and clamping mode, a thrust washer is further arranged between the connecting end of the upper valve rod and the connecting end of the lower valve rod, the outer side of the upper valve rod is sleeved with a nut gland, the outer side of the lower valve rod is sleeved with a packing gland, the bottom of the lower valve rod is sleeved with a connecting packing, and the upper valve rod and the lower valve rod are connected through the connecting packing. The upper valve rod and the lower valve rod are arranged, and the coupling and the thrust washer are arranged at the joint of the upper valve rod and the lower valve rod, so that the practical problems in equipment structure, transmission, sealing and maintenance in a high-pressure environment are solved essentially through the functions of connection, compensation and adaptation, and stable and safe operation of high-pressure equipment is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of oil and gas equipment connection device technology, specifically a quick connection device for operating rod and drive rod under high pressure. Background Technology

[0002] With the depletion of conventional oil and gas resources, the development of high-sulfur oil and gas fields has become an important supplement to energy supply. However, these oil and gas media contain large amounts of hydrogen sulfide (H2S), which is highly corrosive (causing sulfide stress corrosion cracking and hydrogen embrittlement in metals) and is also a highly toxic gas. Leaks can lead to serious safety accidents. Furthermore, high-sulfur oil and gas wells are often accompanied by high pressure (wellhead pressure may reach tens or even hundreds of megapascals), further exacerbating the stress on equipment and the risk of leakage. Therefore, wellhead equipment specifically designed to withstand the dual harsh conditions of "high pressure + high sulfur" must be used.

[0003] As an important component of wellhead equipment, the control line needle valve is a key "precision control element". Its core function is to ensure the operational reliability of the wellhead control line (the line that transmits hydraulic, pneumatic power or signals) through high-precision adjustment, stable control and safe isolation, thereby indirectly controlling the safe operation of the core wellhead equipment (such as blowout preventers, throttle valves, gate valves, etc.).

[0004] Couplings are key components in control line needle valves. Their core function is to connect two valve stems and transmit motion and torque, while also providing protection or compensation during transmission. Due to manufacturing and installation errors, vibrations during equipment operation, or thermal deformation, the upper and lower valve stems often cannot maintain perfect concentricity (radial, axial, or angular deviations may exist). Couplings can absorb or compensate for these deviations through their structure, preventing additional stress on the shaft system due to forced rigid connection and reducing equipment wear.

[0005] While existing control line needle valves are widely used in wellhead equipment, they suffer from numerous unavoidable "pain points" due to limitations in materials, structural design, and manufacturing processes. These issues arise under complex wellhead conditions such as high pressure, high sulfur content, and frequent operation. Frequent pressure fluctuations in the wellhead control line (e.g., instantaneous pressure shocks during pump start-up and shutdown, and actuator movements) cause the valve stem packing of traditional needle valves (such as ordinary graphite or rubber O-rings) to loosen due to repeated pressure shocks, leading to external leakage between the valve stem and body. This risk is even higher under high-pressure conditions, potentially causing a fire due to the ejection of flammable media. Consequently, traditional valves suffer from cumbersome upper and lower valve stem installation, high maintenance costs, and require high coaxiality during installation to ensure valve sealing and normal operation. High-pressure needle valves, in particular, have thin valve stems with high torque that is difficult to control, making coaxiality difficult to guarantee during installation and potentially requiring multiple adjustments, which is time-consuming and labor-intensive. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a quick connection device for the operating rod and drive rod under high pressure. This solves the problem that while existing control line needle valves are widely used in wellhead equipment, they suffer from numerous unavoidable drawbacks under complex wellhead conditions such as high pressure, high sulfur content, and frequent operation due to limitations in materials, structural design, and manufacturing processes. Frequent pressure fluctuations in the wellhead control line (such as instantaneous pressure shocks during pump start-up and shutdown, and actuator movements) cause the valve stem packing of traditional needle valves (such as ordinary graphite or rubber O-rings) to easily loosen due to repeated pressure shocks, leading to external leakage between the valve stem and valve body. This risk is even higher under high pressure conditions, and could even cause a fire due to the ejection of flammable media. Consequently, the installation of the upper and lower valve stems of traditional valves is cumbersome, maintenance costs are high, and a high degree of coaxiality must be ensured during installation; otherwise, the valve's sealing performance and normal operation will be affected. This is especially true for high-pressure needle valves, where the thin valve stem has a large torque that is difficult to control, making it difficult to ensure coaxiality during installation and potentially requiring multiple adjustments, which is time-consuming and labor-intensive.

[0007] The present invention provides the following technical solution: a device for quick connection of an operating rod and a driving rod under high pressure, comprising an upper valve rod, wherein a lower valve rod is provided at the bottom of the upper valve rod;

[0008] Two couplings are symmetrically fitted on the outer sides of the connecting ends of the upper valve stem and the lower valve stem. The two couplings are fitted together and locked onto the connecting ends of the upper valve stem and the lower valve stem. A thrust washer is also provided between the connecting ends of the upper valve stem and the lower valve stem. A nut cover is fitted on the outer side of the upper valve stem. A packing cover is fitted on the outer side of the lower valve stem. A connecting packing is fitted on the bottom of the lower valve stem.

[0009] Preferred technical solution 1: An installation groove is provided on the side of the top end of the upper valve stem.

[0010] Preferred technical solution 2: The middle part of the nut cap is hollow.

[0011] Preferred technical solution 3: The middle part of the packing gland is hollow.

[0012] Preferred technical solution four: The middle part of the connecting packing is hollow.

[0013] This design allows the lower valve stem to be better inserted into the connecting packing.

[0014] Preferred technical solution five: The packing gland and the connecting packing are connected by bolts.

[0015] This solution enables a more stable connection between the packing gland and the connecting packing.

[0016] Compared with the prior art, the present invention provides a quick connection device for operating rod and drive rod under high pressure, which has the following beneficial effects: The present invention is provided with an upper valve rod and a lower valve rod, and a coupling and a thrust washer are provided at the connection between the upper valve rod and the lower valve rod. The upper valve rod and the lower valve rod are connected by the coupling, and the thrust washer is used for lubrication between the upper valve rod and the lower valve rod, which can effectively reduce torque. The application of connecting the upper valve rod and the lower valve rod at the high-pressure terminal flange through the coupling is essentially to solve the practical problems in equipment structure, transmission, sealing and maintenance under high pressure environment through its connection, compensation and adaptation functions, so as to ensure the stable and safe operation of high-pressure equipment. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the internal structure of the present invention;

[0018] Figure 2 For the present invention Figure 1 Enlarged view of the structure of the coupling;

[0019] Figure 3 For the present invention Figure 1 Schematic diagram of the structure of the coupling;

[0020] Figure 4 For the present invention Figure 1 A schematic diagram of the upper valve stem.

[0021] In the diagram: 1. Upper valve stem; 2. Lower valve stem; 3. Coupling; 4. Thrust washer; 5. Nut cover; 6. Packing cover; 7. Connecting packing. Detailed Implementation

[0022] Please see Figure 1-4 ,

[0023] Example 1: A device for quick connection of an operating rod and a drive rod under high pressure includes an upper valve rod 1 and a lower valve rod 2 at the bottom of the upper valve rod 1.

[0024] Two couplings 3 are symmetrically fitted on the outer sides of the connecting ends of the upper valve stem 1 and the lower valve stem 2. The two couplings 3 are fitted together and locked in place at the connecting ends of the upper valve stem 1 and the lower valve stem 2. A thrust washer 4 is also provided between the connecting ends of the upper valve stem 1 and the lower valve stem 2. A nut cover 5 is fitted on the outer side of the upper valve stem 1. A packing cover 6 is fitted on the outer side of the lower valve stem 2. A connecting packing 7 is fitted on the bottom of the lower valve stem 2.

[0025] An installation groove is provided on the side of the top of the upper valve stem 1.

[0026] The center of the nut cap 5 is hollow.

[0027] Example 2: The difference between this example and Example 1 is that the middle part of the packing cap 6 is hollow.

[0028] Example 3: The difference between this example and Example 1 is that the middle part of the connecting packing 7 is hollow.

[0029] This allows the lower valve stem 2 to be better inserted into the connecting packing 7.

[0030] Example 4: The difference between this example and Example 1 is that the packing gland 6 and the connecting packing 7 are connected by bolts.

[0031] This makes the connection between the packing gland 6 and the connecting packing 7 more stable.

[0032] In this embodiment, although existing control pipeline needle valves are widely used in wellhead equipment, they are limited by materials, structural design, and processing technology. Under complex wellhead conditions such as high pressure, high sulfur, and frequent operation, there are many unavoidable "pain points". Due to frequent pressure fluctuations in the wellhead control pipeline, such as the instantaneous pressure shocks during pump start-up and shutdown and actuator operation, the valve stem packing of traditional needle valves, such as ordinary graphite and rubber O-rings, is prone to "gap loosening" due to repeated pressure shocks, resulting in "external leakage" between the valve stem and valve body. Especially under high pressure conditions, the risk of external leakage is even higher, and it may even cause a fire due to the spray of leaked medium if the medium is flammable. This makes the installation of the upper and lower valve stems of traditional valves troublesome and maintenance costs high. High coaxiality must be ensured during installation, otherwise it will affect the valve's sealing performance and normal opening and closing. Especially for high-pressure needle valves, the small valve stem has a large torque that is difficult to control, and it is difficult to ensure coaxiality during installation. Multiple adjustments may be required, which is time-consuming and labor-intensive.

[0033] In summary, during implementation, the upper valve stem 1, the thrust washer 4, and the lower valve stem 2 are connected together via coupling 3. The upper valve stem 1 and the lower valve stem 2 are respectively inserted into the nut cover 5, the packing cover 6, and the connecting packing 7. Other components are then installed to assemble the device. By using the combination of the upper valve stem 1 and the lower valve stem 2 inside the valve and connecting them via coupling 3, and using the thrust washer 4 for lubrication between the upper valve stem 1 and the lower valve stem 2, torque can be effectively reduced.

[0034] The upper valve stem 1 and the lower valve stem 2 may have a certain spatial gap or coaxiality deviation due to equipment reasons. The flexible or rigid connection characteristics of the coupling 3 can adapt to the layout requirements of this structure and achieve effective connection between the upper valve stem 1 and the lower valve stem 2.

[0035] Since the valve stem plays a crucial role in high-pressure equipment in controlling the flow of media, such as the opening and closing of valves or transmitting operating force, it is necessary to ensure the stability and accuracy of power / motion transmission. The coupling 3 can eliminate the slight coaxiality error when the upper valve stem 1 and the lower valve stem 2 are installed through its own structure, avoid transmission jamming and uneven force due to misalignment, and thus prevent valve stem deformation or damage, ensuring the normal operation response of the equipment.

[0036] Meanwhile, in high-pressure scenarios, the requirements for the sealing and safety of the equipment are extremely high. The terminal flange is a key area for sealing. The design of coupling 3 can be adapted to the sealing structure of the flange to avoid sealing failure such as gap leakage caused by improper valve stem connection. At the same time, its stable connection can reduce the shaking of the valve stem under the impact of high-pressure media, reduce the safety hazards caused by loose connection, and improve the overall pressure resistance reliability of the equipment.

[0037] Furthermore, the installation and maintenance of high-pressure equipment are quite difficult. The use of coupling 3 simplifies the docking process of the upper valve stem 1 and the lower valve stem 2, eliminating the need to strictly guarantee the absolute coaxiality of the upper valve stem 1 and the lower valve stem 2, thus reducing the installation accuracy requirements. During equipment maintenance, the upper valve stem 1 and the lower valve stem 2 can be quickly separated by disassembling coupling 3, facilitating the individual replacement or maintenance of components such as valve stems and seals, reducing the complexity of overall disassembly and improving maintenance efficiency.

[0038] The body material used in this solution needs to withstand high sulfur content conditions, so a corrosion-resistant alloy conforming to NACE 0175 standards is selected. The three parts of the coupling are made of aluminum bronze or other copper grades with equivalent performance. Because aluminum bronze combines corrosion resistance, high strength and self-lubrication, it is particularly suitable for critical friction components such as glands, gaskets and handwheels of high-pressure needle valves. It is resistant to both seawater and H2S, improving its corrosion resistance, and is 10% lighter than stainless steel. In extreme conditions such as marine, wellhead and hydrogen energy, it can transmit large torque and achieve zero backlash and maintenance-free operation, making it an ideal choice for high-pressure compact transmission.

Claims

1. A quick connect device for operating lever and drive rod under high pressure, characterized in that: The upper valve rod (1) is provided with a lower valve rod (2) at the bottom thereof; Two shaft couplings (3) are symmetrically arranged outside the joint end of the upper valve rod (1) and the lower valve rod (2), and the two shaft couplings (3) are clamped around the joint end of the upper valve rod (1) and the lower valve rod (2), and a thrust washer (4) is further arranged between the joint ends of the upper valve rod (1) and the lower valve rod (2), the outer side of the upper valve rod (1) is sleeved with a nut gland (5), the outer side of the lower valve rod (2) is sleeved with a packing gland (6), and the bottom of the lower valve rod (2) is sleeved with a connecting packing (7).

2. A quick connecting device for operating lever and driving rod under high pressure according to claim 1, characterized in that: A mounting groove is formed in the side of the top end of the upper valve rod (1).

3. A quick connect device for operating lever and drive rod under high pressure according to claim 2, characterized in that: The middle part of the nut gland (5) is hollow.

4. The quick connect device for operating lever and driving rod under high pressure according to claim 3, characterized in that: The middle part of the packing gland (6) is hollow.

5. A quick connect device for operating lever and drive rod under high pressure according to claim 4, characterized in that: The middle part of the connecting packing (7) is hollow.

6. A quick connect device for operating lever and drive rod under high pressure conditions as claimed in claim 5 wherein: The packing gland (6) and the connecting packing (7) are connected through bolts.

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