Grease injection valve for gas production wellhead and use method

Abstract

The grease injection valve comprises a valve body, a containing groove is formed in one end of the inner wall of the valve body, a valve channel is formed in the other end of the inner wall of the valve body, a communicating groove is formed in the valve body and the end, close to the valve channel, of the outer side of the containing groove, and the valve channel communicates with the interiors of the containing groove and the communicating groove; a blocking ball is movably arranged in the end, close to the valve channel, of the containing groove, a filling unit is arranged in the other end of the containing groove, the blocking ball is connected with the filling unit through a supporting unit, a guiding unit is arranged in the supporting unit and connected with the blocking ball, and a valve cap is fixedly connected to the outer portion of the end, close to the valve channel, of the valve body. The blocking ball rotates on the inner wall of the containing groove, adhesion of sealing grease can be reduced through rotation, the sealing faces can be converted in the rotation process, corrosion and abrasion of only one sealing face in the sealing process are avoided, and therefore the purpose that the sealing effect is good is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of grease injection valves, and in particular relates to a grease injection valve for a gas production wellhead and a use method thereof. Background Art

[0002] Natural gas is a flammable gas stored deep underground. It is a clean, convenient and efficient fuel. It is also an important chemical raw material with high economic value. Natural gas is usually extracted through gas wellheads. The extracted natural gas cannot be used directly and needs to be processed before it can be used as fuel, chemical raw materials or other purposes. According to the different uses of natural gas, the extracted natural gas is transported to different places through different paths for corresponding treatment. The flat gate valves and ball valves used in the extraction and transportation process of oil and gas fields are all equipped with grease injection valves. In the daily maintenance of the valve, it is necessary to add sealing grease to the grease injection valve to protect the sealing mechanism inside the valve and prevent leakage. At present, most of the grease injection valves produced domestically are single-seal grease injection valves. This single-seal method is prone to the phenomenon of "running and leaking" grease, which cannot play the role of grease in lubricating the entire valve, and has a great negative impact on the use of the entire valve. Summary of the invention

[0003] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a grease injection valve for a gas wellhead and a method of use, so as to solve the technical problems in the prior art that the single-sealed grease injection valve is prone to "leakage" of grease, affecting the filling of sealing grease, and the leakage of the grease injection valve also leaves a safety hazard.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention discloses a grease injection valve for a gas production wellhead, comprising: a valve body, a receiving groove is provided at one end of the inner wall of the valve body, a valve channel is provided at the other end, a connecting groove is provided inside the valve body and outside the receiving groove near one end of the valve channel, the valve channel is connected with the insides of the receiving groove and the connecting groove, a blocking ball is movably provided inside the receiving groove near one end of the valve channel, a filling unit is provided inside the other end of the receiving groove, the blocking ball is connected to the filling unit via a supporting unit, and a guide unit is provided inside the supporting unit and connected to the blocking ball, and a valve cap is fixedly connected to the outside of the valve body near one end of the valve channel.

[0006] Preferably, the support unit includes a support ring, which is connected to the plugging ball, and the support ring is fixedly connected to a support tube through a connecting rod, the support tube is connected to one end of a damping spring through a fixing ring, the other end of the damping spring is connected to the filling unit, and a support frame is provided inside the damping spring, one end of which is connected to the filling unit, and the other end is connected to the guide unit.

[0007] Preferably, the guide unit comprises a guide column, one end of which is fixedly connected to the blocking ball, and the other end surface of which is movably connected to a guide tube, which is fixed on the support unit.

[0008] Preferably, a fixed block is fixedly installed at one end of the guide tube away from the support tube, the fixed block is fixedly connected to the support frame of the support unit, the surface of the support frame is fixedly connected with a guide ring, and the guide ring is sleeved on the surface of the guide tube, the surface of the guide ring is fixedly connected with a first limiting plate, the surface of the guide tube is fixedly connected with a second limiting plate, and the first limiting plate and the second limiting plate fit each other.

[0009] Preferably, the guide column is a spiral structure, and the inner wall of the guide tube matches the surface of the guide column.

[0010] Preferably, the filling unit includes a fixing pin, which is movably arranged at one end of the accommodating groove away from the valve channel, a filling hole is opened inside the fixing pin, and the filling hole passes through the fixing pin and is connected to the inside of the accommodating groove, and the outside of the fixing pin is connected to a supporting unit.

[0011] Preferably, a fixing column is rotatably connected to the center of the valve cap at a position corresponding to the valve body, a plug is fixedly connected to the fixing column, a rubber pad is arranged outside the plug, and a sealing ring is fixedly connected to the surface of the rubber pad.

[0012] Preferably, the cross section of the plug is trapezoidal.

[0013] Preferably, an air outlet hole is opened inside the valve cap, and the air outlet hole passes through and connects two ends of the valve cap.

[0014] The present invention also discloses a method for using a grease injection valve for a gas production wellhead, comprising the following steps:

[0015] Inject sealing grease into the valve channel;

[0016] The sealing grease pushes the plugging ball to move, and the guide unit drives the plugging ball to rotate, so that the sealing grease enters the filling unit through the receiving groove to complete the filling;

[0017] The support unit pushes the plugging ball to move in the opposite direction without rotating, and returns to the original position for sealing.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The grease injection valve for a gas wellhead disclosed in the present invention uses a guide unit to allow the sealing grease to push the plugging ball, and the plugging ball rotates on the inner wall of the accommodating groove. This rotation can not only reduce the adhesion of the sealing grease, but also convert the sealing surface during the rotation process, thereby avoiding corrosion and wear on only one sealing surface during the sealing process, thereby achieving the purpose of better sealing effect.

[0020] Furthermore, in the support unit, when the sealing grease no longer pushes the blocking ball, the damping spring cooperates with the fixing ring, the support tube, the connecting rod and the support ring to drive the blocking ball to move toward one end of the valve channel, and at the same time the guide column moves toward one end of the valve channel, and at this time the guide tube rotates counterclockwise, so that the blocking ball does not rotate when it moves to one end of the valve channel for sealing, so that when the blocking ball rotates, the adhesion of the sealing grease can be reduced, and the sealing surface can be converted during the rotation process, thereby avoiding corrosion and wear on only one sealing surface during the sealing process, thereby affecting the sealing effect.

[0021] Furthermore, the inner wall of the guide tube in the guide unit cooperates with the surface of the guide column, so that when the sealing grease pushes the blocking ball, the blocking ball rotates on the inner wall of the accommodating groove.

[0022] Furthermore, a fixing column is rotatably connected to the position of the valve body at the center of the valve bonnet, and a plug is fixedly connected to the fixing column. When the valve bonnet is threadedly connected to the surface of the valve body, the valve bonnet drives the plug to block the valve channel, and when the valve bonnet rotates, the plug will not rotate under the action of the fixing column, so that the plug is pressed against the inner wall of the valve channel, and the rubber pad is tightly fitted to the inner wall of the valve channel through the rubber pad and the sealing ring, and the sealing ring is tightly fitted to one end of the valve body corresponding to the valve bonnet position, thereby achieving a better sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a front cross-sectional view of the overall structure of a grease injection valve for a gas wellhead of the present invention;

[0024] Figure 2 This is a front cross-sectional view of a valve body structure of a grease injection valve for a gas wellhead of the present invention;

[0025] Figure 3 It is a partial front cross-sectional view of a guide pipe structure of a grease injection valve for a gas wellhead of the present invention;

[0026] Figure 4 It is a partial side cross-sectional view of a guide pipe structure of a grease injection valve for a gas wellhead of the present invention;

[0027] Figure 5 The present invention is a flow chart of a method for using a grease injection valve for a gas wellhead.

[0028] Among them: 1-valve body; 2-accommodating groove; 3-fixing pin; 4-filling hole; 5-valve channel; 6-connecting groove; 7-ball blocking; 8-support ring; 9-connecting rod; 10-support tube; 11-fixing ring; 12-damping spring; 13-support frame; 14-fixing block; 15-guide tube; 16-guide column; 17-valve cap; 18-air outlet; 19-fixing column; 20-plug; 21-rubber pad; 22-sealing ring; 23-guide ring; 24-first limit plate; 25-second limit plate. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0031] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0032] In actual use, the prior art has the problem that the transported medium is generally corrosive and will corrode the sealing structure inside the grease injection valve, causing leakage. The added sealing grease will be squeezed out of the grease injection valve by the gas, affecting the filling of the sealing grease. At the same time, the leakage of the grease injection valve also leaves a safety hazard. The present invention provides a grease injection valve for a gas wellhead to solve the above problem.

[0033] See also Figure 1 A grease injection valve for a gas wellhead disclosed in the present invention comprises: a valve body 1, a receiving groove 2 is provided at one end of the inner wall of the valve body 1, and a valve channel 5 is provided at the other end, a connecting groove 6 is provided inside the valve body 1 and outside the receiving groove 2 near the end of the valve channel 5, the valve channel 5 is connected with the insides of the receiving groove 2 and the connecting groove 6, a blocking ball 7 is movably provided inside the receiving groove 2 near the end of the valve channel 5, a filling unit is provided inside the other end of the receiving groove 2, the blocking ball 7 is connected to the filling unit through a supporting unit, and a guide unit is provided inside the supporting unit and connected to the blocking ball 7, and a valve cap 17 is fixedly connected to the outside of the valve body 1 near the end of the valve channel 5.

[0034] When the sealing grease pushes the plugging ball through the guide unit, the plugging ball rotates on the inner wall of the receiving groove. This rotation can not only reduce the adhesion of the sealing grease, but also convert the sealing surface during the rotation process, thereby avoiding corrosion and wear of only one sealing surface during the sealing process, thereby achieving the purpose of better sealing effect.

[0035] Working principle:

[0036] Sealing grease is injected into the position of the valve channel 5; the sealing grease pushes the plugging ball 7 to move, and the guide unit drives the plugging ball 7 to rotate, so that the sealing grease enters the filling unit through the receiving groove 2 to complete the filling; when the sealing grease no longer pushes the plugging ball, the supporting unit pushes the plugging ball 7 to move in the opposite direction without rotating, and returns to the original position for sealing.

[0037] In some embodiments, the support unit includes a support ring 8, which is connected to the blocking ball 7, and the support ring 8 is fixedly connected to a support tube 10 through a connecting rod 9. The support tube 10 is connected to one end of a damping spring 12 through a fixing ring 11, and the other end of the damping spring 12 is connected to the filling unit, and a support frame 13 is provided inside the damping spring 12, one end of which is connected to the filling unit, and the other end is connected to the guide unit.

[0038] Working principle:

[0039] Sealing grease is injected into the position of the valve channel 5; the sealing grease pushes the plugging ball 7 to move, and the guide unit drives the plugging ball 7 to rotate, so that the sealing grease enters the filling unit through the receiving groove 2 to complete the filling; when the sealing grease no longer pushes the plugging ball, the damping spring 12 cooperates with the fixing ring 11, the support tube 10, the connecting rod 9 and the support ring 8 to drive the plugging ball 7 to move toward one end of the valve channel 5, and at the same time the guide column 16 moves toward one end of the valve channel 5, and at this time the guide tube 15 rotates counterclockwise, so that the plugging ball 7 does not rotate when it moves to one end of the valve channel 5 for sealing.

[0040] In some embodiments, the guide unit includes a guide column 16, one end of which is fixedly connected to the blocking ball 7, and the other end of the guide column 16 is movably connected to a guide tube 15 on its surface, and the guide tube 15 is fixed on the support unit.

[0041] In some embodiments, a fixing block 14 is fixedly installed at one end of the guide tube 15 away from the support tube 10, and the fixing block 14 is fixedly connected to the support frame 13 of the support unit. A guide ring 23 is fixedly connected to the surface of the support frame 13, and the guide ring 23 is sleeved on the surface of the guide tube 15. A first limiting plate 24 is fixedly connected to the surface of the guide ring 23, and a second limiting plate 25 is fixedly connected to the surface of the guide tube 15. The first limiting plate 24 and the second limiting plate 25 are fitted together.

[0042] In some embodiments, the guide post 16 is a spiral structure, and the inner wall of the guide tube 15 matches the surface of the guide post 16 .

[0043] How it works

[0044] Inject sealing grease at the position of the valve channel 5; the sealing grease pushes the plugging ball 7 to move until the sealing grease enters the interior of the receiving groove 2 corresponding to the position of the valve channel 5, and enters the interior of the receiving groove 2 corresponding to the position of the fixing pin 3 through the connecting groove 6. At this time, under the action of pressure, the sealing grease can enter the interior of the filling hole 4 through the receiving groove 2 and complete the grease injection operation. When the sealing grease pushes the plugging ball 7 to move, the plugging ball 7 drives the guide column 16 to move toward the inner wall of the guide tube 15. The guide column 16 is a spiral structure, and the inner wall of the guide tube 15 cooperates with the surface of the guide column 16, so that the guide column 16 While moving toward the inner wall of the guide tube 15 and rotating, the guide ring 23, the first limit plate 24 and the second limit plate 25 cooperate with each other, so that the guide tube 15 can only rotate counterclockwise. When the guide column 16 moves toward the inner wall of the guide tube 15, the guide tube 15 cannot rotate clockwise, so that the guide column 16 drives the blocking ball 7 to rotate, so that when the sealing grease pushes the blocking ball 7, the blocking ball 7 rotates on the inner wall of the receiving groove 2, so that the sealing grease enters the filling unit through the receiving groove 2 to complete the filling; when the sealing grease no longer pushes the blocking ball, the supporting unit pushes the blocking ball 7 to move in the opposite direction without rotating, and returns to the original position for sealing.

[0045] In some embodiments, the filling unit includes a fixing pin 3, which is movably arranged at one end of the accommodating groove 2 away from the valve channel 5, and a filling hole 4 is opened inside the fixing pin 3, and the filling hole 4 passes through the fixing pin 3 and is connected to the inside of the accommodating groove 2, and the fixing pin 3 is externally connected to a support unit.

[0046] In some embodiments, a fixing column 19 is rotatably connected to the valve body 1 at the center of the valve cap 17 , a plug 20 is fixed to the fixing column 19 , a rubber pad 21 is arranged outside the plug 20 , and a sealing ring 22 is fixed to the surface of the rubber pad 21 .

[0047] In some embodiments, the cross section of the plug 20 is trapezoidal.

[0048] In some embodiments, an air outlet 18 is formed inside the valve cap 17 , and the air outlet 18 passes through and connects two ends of the valve cap 17 .

[0049] See also Figure 5 The present invention also discloses a method for using a grease injection valve for a gas wellhead, comprising the following steps:

[0050] S1: Inject sealing grease into the valve channel 5;

[0051] S2: The sealing grease pushes the plugging ball 7 to move, and the guide unit drives the plugging ball 7 to rotate, so that the sealing grease enters the filling unit through the receiving groove 2, and the filling is completed;

[0052] S3: The support unit pushes the blocking ball 7 to move in the reverse direction without rotating, and returns to the original position for sealing.

[0053] See also Figure 1 , Figure 2 The present invention provides a technical solution: it includes a valve body 1, an inner wall of the valve body 1 is provided with a receiving groove 2, one end of the valve body 1 is provided with a valve channel 5, an interior of the valve body 1 corresponding to the position of the receiving groove 2 is provided with a connecting groove 6, the interior of the valve channel 5 is respectively connected with the interiors of the receiving groove 2 and the connecting groove 6, a blocking ball 7 is movably connected to the inner wall of the receiving groove 2, an end of the blocking ball 7 away from the valve channel 5 is rotatably connected to a support ring 8, a connecting rod 9 is fixedly installed at the end of the support ring 8 away from the blocking ball 7, a supporting tube 10 is fixedly installed at the end of the connecting rod 9 away from the supporting ring 8, a fixing ring 11 is fixedly installed on the surface of the support tube 10, a damping spring 12 is fixedly installed on the end of the fixing ring 11 away from the valve channel 5, a guide column 16 is fixedly installed at the end of the blocking ball 7 away from the valve channel 5, and a guide tube 15 is movably connected to the surface of the guide column 16.

[0054] As a preferred solution, a fixing pin 3 is movably connected to one end of the accommodating groove 2 away from the valve channel 5, and a filling hole 4 is opened inside the fixing pin 3. The filling hole 4 passes through and is connected to both ends of the fixing pin 3, and the interior of the filling hole 4 is connected to the interior of the accommodating groove 2.

[0055] As a preferred solution, one end of the damping spring 12 away from the support tube 10 is fixedly mounted on one end of the fixing pin 3 corresponding to the support tube 10 .

[0056] As a preferred solution, see Figure 4 , a fixing block 14 is fixedly installed at one end of the guide tube 15 away from the support tube 10, and a support frame 13 is fixedly installed at one end of the fixing block 14 away from the guide tube 15, and the support frame 13 is fixedly installed at one end of the fixing pin 3 corresponding to the support tube 10, a guide ring 23 is fixedly connected to the surface of the support frame 13, and the guide ring 23 is sleeved on the surface of the guide tube 15, a first limiting piece 24 is fixedly connected to the surface of the guide ring 23, and a second limiting piece 25 is fixedly connected to the surface of the guide tube 15 corresponding to the position of the first limiting piece 24, the first limiting piece 24 and the second limiting piece 25 are fitted with each other, and the first limiting piece 24 and the second limiting piece 25 are both rubber components, and the guide column 16 is a spiral structure, see Figure 3 , and the inner wall of the guide tube 15 matches the surface of the guide column 16.

[0057] As a preferred solution, a valve cap 17 is threadedly connected to the surface of one end of the valve body 1 away from the fixing pin 3, and an air outlet 18 is provided inside the valve cap 17, and the air outlet 18 penetrates and communicates with both ends of the valve cap 17. The end of the valve cap 17 corresponding to the position of the valve body 1 is rotatably connected to a fixing column 19 through a bearing, and a plug 20 is fixedly installed on the end of the fixing column 19 away from the position of the valve cap 17, and the cross section of the plug 20 is a trapezoidal structure.

[0058] Further preferably, a rubber pad 21 is fixedly installed on the surface of the plug 20, and a sealing ring 22 is fixedly installed on the surface of the rubber pad 21. The end of the valve channel 5 away from the position of the plug ball 7 is a flared structure, and the inner wall of the valve channel 5 is movably connected to the surface of the rubber pad 21. When the valve bonnet 17 is threadedly connected to the surface of the valve body 1, the valve bonnet 17 drives the plug 20 to block the valve channel 5, and when the valve bonnet 17 rotates, the plug 20 will not rotate under the action of the fixing column 19, so that the plug 20 is pressed against the inner wall of the valve channel 5, and the rubber pad 21 cooperates with the sealing ring 22, so that the rubber pad 21 is tightly fitted to the inner wall of the valve channel 5, and the sealing ring 22 is tightly fitted to the end of the valve body 1 corresponding to the position of the valve bonnet 17, thereby achieving a better sealing effect.

[0059] Working principle: When in use, the invention injects sealing grease into the position of the valve channel 5, and the sealing grease pushes the blocking ball 7 to move on the inner wall of the receiving groove 2 toward the end away from the valve channel 5, until the sealing grease enters the interior of the receiving groove 2 corresponding to the position of the valve channel 5, and enters the interior of the receiving groove 2 corresponding to the position of the fixing pin 3 through the connecting groove 6. At this time, under the action of pressure, the sealing grease can enter the interior of the filling hole 4 through the receiving groove 2 and complete the grease injection operation. When the sealing grease pushes the blocking ball 7 to move, the blocking ball 7 drives the guide column 16 to move toward the inner wall of the guide tube 15. The guide column 16 is a spiral structure, and the inner wall of the guide tube 15 cooperates with the surface of the guide column 16, so that the guide column 16 rotates while moving toward the inner wall of the guide tube 15, and cooperates between the guide ring 23, the first limit plate 24 and the second limit plate 25. This will make the guide tube 15 only able to rotate counterclockwise, and when the guide column 16 moves toward the inner wall of the guide tube 15, the guide tube 15 cannot rotate clockwise, so that the guide column 16 drives the blocking ball 7 to rotate, so that when the sealing grease pushes the blocking ball 7, the blocking ball 7 rotates on the inner wall of the accommodating groove 2, and when the sealing grease no longer pushes the blocking ball 7, the damping spring 12 cooperates with the fixing ring 11, the support tube 10, the connecting rod 9 and the support ring 8 to drive the blocking ball 7 to move toward one end of the valve channel 5, and at the same time the guide column 16 moves toward one end of the valve channel 5, and at this time the guide tube 15 rotates counterclockwise, so that the blocking ball 7 does not rotate when it moves to one end of the valve channel 5 for sealing, so that when the blocking ball 7 rotates, the adhesion of the sealing grease can be reduced, and the sealing surface can be converted during the rotation process, thereby avoiding corrosion and wear of only one sealing surface during the sealing process, thereby affecting the sealing effect.

[0060] The present invention has the following advantages:

[0061] 1. The present invention cooperates the inner wall of the guide tube with the surface of the guide column, so that when the sealing grease pushes the blocking ball, the blocking ball rotates on the inner wall of the receiving groove. This rotation can reduce the adhesion of the sealing grease and convert the sealing surface during the rotation process, thereby avoiding corrosion and wear of only one sealing surface during the sealing process, thereby achieving the purpose of better sealing effect;

[0062] 2. The present invention also enables the valve bonnet to drive the plug to block the valve channel when the valve bonnet is threadedly connected to the surface of the valve body, and when the valve bonnet rotates, the plug will not rotate under the action of the fixing column, so that the plug is pressed against the inner wall of the valve channel, and the rubber pad is matched with the sealing ring, so that the rubber pad is tightly fitted to the inner wall of the valve channel, and the sealing ring is tightly fitted to one end of the valve body corresponding to the valve bonnet position, so that the sealing effect is better.

[0063] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A grease injection valve for a gas wellhead, characterized in that: include: A valve body (1) is provided with a receiving groove (2) at one end of the inner wall of the valve body (1), and a valve channel (5) at the other end; a connecting groove (6) is provided inside the valve body (1) and outside the receiving groove (2) near one end of the valve channel (5); the valve channel (5) is connected with the inside of both the receiving groove (2) and the connecting groove (6); a blocking ball (7) is movably arranged inside the receiving groove (2) near one end of the valve channel (5); a filling unit is arranged inside the other end of the receiving groove (2); the blocking ball (7) is connected to the filling unit via a supporting unit, and a guiding unit is arranged inside the supporting unit and connected to the blocking ball (7); a valve cap (17) is fixedly connected to the outside of the valve body (1) near one end of the valve channel (5).

2. A grease injection valve for a gas wellhead according to claim 1, characterized in that: The support unit comprises a support ring (8), the support ring (8) is connected to the plugging ball (7), and the support ring (8) is fixedly connected to a support tube (10) via a connecting rod (9), the support tube (10) is connected to one end of a damping spring (12) via a fixing ring (11), the other end of the damping spring (12) is connected to the filling unit, and a support frame (13) is arranged inside the damping spring (12), one end of which is connected to the filling unit, and the other end of which is connected to the guide unit.

3. A grease injection valve for a gas wellhead according to claim 1, characterized in that: The guide unit comprises a guide column (16), one end of which is fixedly connected to the blocking ball (7), and the other end of which is movably connected to a guide tube (15), which is fixed on the support unit.

4. A grease injection valve for a gas wellhead according to claim 3, characterized in that: A fixing block (14) is fixedly mounted on one end of the guide tube (15) away from the support tube (10); the fixing block (14) is fixedly connected to a support frame (13) of the support unit; a guide ring (23) is fixedly connected to the surface of the support frame (13); the guide ring (23) is sleeved on the surface of the guide tube (15); a first limiting piece (24) is fixedly connected to the surface of the guide ring (23); a second limiting piece (25) is fixedly connected to the surface of the guide tube (15); the first limiting piece (24) and the second limiting piece (25) are fitted to each other.

5. A grease injection valve for a gas wellhead according to claim 3, characterized in that: The guide column (16) is a spiral structure, and the inner wall of the guide tube (15) matches the surface of the guide column (16).

6. A grease injection valve for a gas wellhead according to claim 1, characterized in that: The filling unit comprises a fixing pin (3), the fixing pin (3) being movably arranged at one end of the containing groove (2) away from the valve channel (5), a filling hole (4) being provided inside the fixing pin (3), and the filling hole (4) passing through the fixing pin (3) and being connected to the inside of the containing groove (2), and a supporting unit being connected to the outside of the fixing pin (3).

7. A grease injection valve for a gas wellhead according to claim 1, characterized in that: A fixing column (19) is rotatably connected to the center of the valve cap (17) at a position corresponding to the valve body (1), a plug (20) is fixedly connected to the fixing column (19), a rubber pad (21) is arranged outside the plug (20), and a sealing ring (22) is fixedly connected to the surface of the rubber pad (21).

8. A grease injection valve for a gas wellhead according to claim 7, characterized in that: The cross section of the plug (20) is trapezoidal.

9. A grease injection valve for a gas wellhead according to claim 1, characterized in that: An air outlet hole (18) is provided inside the valve cap (17), and the air outlet hole (18) penetrates and communicates with both ends of the valve cap (17).

10. The method for using a grease injection valve for a gas wellhead according to any one of claims 1 to 9, characterized in that: The following steps are involved: Inject sealing grease into the valve channel (5); The sealing grease pushes the plugging ball (7) to move, and the guide unit drives the plugging ball (7) to rotate, so that the sealing grease enters the filling unit through the receiving groove (2), and the filling is completed; The support unit pushes the blocking ball (7) to move in the reverse direction without rotating, and returns to the original position for sealing.

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