CN114517850A

CN114517850A - Check valve

Info

Publication number: CN114517850A
Application number: CN202011304904.5A
Authority: CN
Inventors: 马志强; 杨培伦; 郭丽莉; 汤天磊; 杨小勇; 王佩; 孙晓光; 陈晓海
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2020-11-19
Filing date: 2020-11-19
Publication date: 2022-05-20

Abstract

The application discloses check valve belongs to the oil field development field, and the check valve includes: the valve comprises a valve body, a valve clack, a valve rod, an ejector rod and an ejector rod guide structure; the valve body comprises a liquid inlet chamber, a valve seat and a liquid outlet chamber, the valve seat is provided with a through hole, the liquid inlet chamber is communicated with the liquid outlet chamber through the through hole on the valve seat, and the first end of the valve rod is connected with one surface of the valve clack; the ejector rod guide structure is installed in the liquid outlet cavity and comprises a guide hole, the second end of the valve rod is located in the guide hole and can move in the guide hole along the axial direction of the guide hole, the valve clack is driven to abut against the valve seat, the first end of the ejector rod is located in the guide hole and is arranged opposite to the second end of the valve rod, and the ejector rod is used for pushing the valve rod in the axial direction of the guide hole. The problem of the check valve among the prior art need stop pipeline crude oil transportation when the valve clack can't support on the disk seat, to pipeline pressure release and change check valve, the maintenance degree of difficulty is big is solved. The effect of reducing the operation degree of difficulty of maintaining the check valve is achieved.

Description

Check valve

Technical Field

The application relates to the field of oilfield development, in particular to a check valve.

Background

In the crude oil exploitation process, the crude oil exploited in the well is output to the metering station through the pipeline, the pipeline is connected with a check valve, and the check valve can prevent the crude oil conveyed in the pipeline from flowing back to the shaft.

The check valve in the related art comprises a liquid inlet, a liquid outlet, a valve seat, a valve clack, a spring and a valve cover, wherein the orthographic projection of the valve cover coincides with the valve clack, one end of the spring is connected with the valve clack, the other end of the spring is connected with the valve cover, a channel is arranged between the liquid inlet and the liquid outlet, the valve seat is two bosses extending out of the inner wall of the channel, the channel is blocked when the valve clack abuts against the two bosses, when crude oil enters the channel from the liquid inlet, the valve clack is lifted by pressure, the spring contracts, the channel can be used for flowing out of the liquid, when the crude oil flows back from the liquid outlet, the valve clack abuts against the valve seat under the action of the pressure, and the channel is blocked, so that the crude oil is prevented from flowing back to a shaft.

However, the check valve in the above related art often has a situation that the valve flap cannot abut against the valve seat when in use, and at this time, the operation difficulty is large when crude oil transportation in the pipeline is stopped, the pipeline is depressurized, and the check valve is replaced.

Disclosure of Invention

The embodiment of the application provides a check valve. The technical scheme is as follows:

in a first aspect, there is provided a check valve comprising: the valve comprises a valve body, a valve clack, a valve rod, an ejector rod and an ejector rod guide structure;

the valve body comprises a liquid inlet cavity, a valve seat and a liquid outlet cavity, the valve seat is provided with a through hole, the liquid inlet cavity is communicated with the liquid outlet cavity through the through hole in the valve seat, and the first end of the valve rod is connected with one surface of the valve clack;

the ejector rod guide structure is arranged in the liquid outlet cavity and comprises a guide hole, the second end of the valve rod is located in the guide hole and can move in the guide hole along the axial direction of the guide hole and drive the valve clack to abut against the valve seat, the first end of the ejector rod is located in the guide hole and is opposite to the second end of the valve rod, and the ejector rod is used for pushing the valve rod in the axial direction of the guide hole.

Optionally, the ejector rod guide structure includes a valve cover, the valve cover has the guide hole, a sealing ring and a sleeve are sequentially arranged in the guide hole along a direction close to the valve seat, the first end of the ejector rod penetrates through the sealing ring and is located in the sleeve, and the second end of the valve rod is located in the sleeve.

Optionally, the ejector rod guide structure further comprises a guide flange, a threaded hole is formed in the guide flange, the guide flange is mounted on the valve cover, and the threaded hole is opposite to the guide hole in the valve cover;

the outer part of the ejector rod is provided with an external thread, and the ejector rod is assembled in the threaded hole of the guide flange through the external thread.

Optionally, the guide flange includes a column structure and a protective cap, the column structure has a groove, the threaded hole is located at the bottom of the groove, and the protective cap is located at an opening of the groove and is in threaded connection with the column structure;

the second end of the ejector rod is positioned in the groove.

Optionally, the sleeve is a copper sleeve.

Optionally, the material of the sealing ring comprises polytetrafluoroethylene.

Optionally, the check valve further comprises a protective barrel covering the valve cover.

Optionally, the protective barrel is clamped with the valve cover.

Optionally, the check valve further comprises a pull wrench, the pull wrench comprises a pull rod and a handle connected with one end of the pull rod, and the other end of the pull rod is provided with an external thread;

and a nut is arranged outside the protective barrel, and the internal thread of the nut is matched with the external thread on the pull rod.

Optionally, the material of the valve body comprises steel.

The technical scheme provided by the embodiment of the application can have the following beneficial effects:

the utility model provides a when valve clack in the check valve is out of control and can't support on the disk seat, can push the second end of valve rod through the ejector pin at the axial direction of guiding hole, makes the valve rod can move along the axial direction of guiding hole in the guiding hole to drive the valve clack and support on the disk seat. The problem of the check valve among the prior art need stop pipeline crude oil transportation when the valve clack can't support on the disk seat, to pipeline pressure release and change check valve, the maintenance degree of difficulty is big is solved. The effect of reducing the operation degree of difficulty of maintaining the check valve is achieved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

FIG. 1 is a schematic structural diagram of a check valve provided in an embodiment of the present application;

FIG. 2 is a schematic structural diagram of another check valve provided in the embodiments of the present application;

fig. 3 is a schematic structural diagram of another check valve provided in the embodiments of the present application.

With the above figures, there are shown specific embodiments of the present application, which will be described in more detail below. These drawings and written description are not intended to limit the scope of the inventive concepts in any manner, but rather to illustrate the inventive concepts to those skilled in the art by reference to specific embodiments.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The check valve is a valve capable of preventing fluid from flowing backwards, when fluid flows into the check valve from an inlet end, pressure jacks up a valve clack on a valve seat, and the fluid flows out from an outlet end through a through hole on the valve seat, namely when the pressure at the inlet end is greater than the sum of the weight of the valve clack and the flow resistance of the valve clack, the valve is opened. Otherwise, the valve is closed when the fluid flows backwards. During the crude oil extraction process, crude oil extracted from each single well is conveyed to a gathering pipeline through a single well pipeline and conveyed to a crude oil metering station for storage through the gathering pipeline.

Be provided with the check valve on single well pipeline or the gathering line between pit shaft and the measurement station among the correlation technique, the check valve is in the use, when the spring damages, the condition that the valve clack can't lean on the dead weight to support on the disk seat easily appears, the check valve that needs to be renewed this moment, operating personnel pauses the oil well operation earlier, close the feed liquor valve and carry out the pressure release operation to the pipeline, later change the check valve, whole operation process is consuming time longer, the degree of difficulty is great, and oil well oil production efficiency has been reduced.

The embodiment of the application provides a check valve, which can solve the problems existing in the related art.

Fig. 1 is a schematic structural diagram of a check valve provided in an embodiment of the present application. The check valve may include:

valve body 11, valve clack 12, valve rod 13, ejector rod 14 and ejector rod guide structure 15.

The valve body 11 includes a liquid inlet chamber 111, a valve seat 112 and a liquid outlet chamber 113, the valve seat 112 has a through hole 1121, the liquid inlet chamber 111 and the liquid outlet chamber 113 are communicated through the through hole 1121 of the valve seat 112, and the first end 131 of the valve rod 13 is connected with one surface of the valve flap 12.

The push rod guide structure 15 is installed in the liquid outlet chamber 113 and includes a guide hole 151, the second end 132 of the valve rod 13 is located in the guide hole 151 and can move in the guide hole 151 along the axial direction of the guide hole 151 and drive the valve flap 12 to abut against the valve seat 112, the first end 141 of the push rod 14 is located in the guide hole 151 and is opposite to the second end 132 of the valve rod 13, and the push rod 14 is used for pushing the valve rod 13 in the axial direction of the guide hole 151.

To sum up, this application embodiment provides a check valve including valve body, valve clack, valve rod, ejector pin and ejector pin guide structure, and when the valve clack in the check valve was out of control can't be supported on the disk seat, can drive the second end of valve rod through the ejector pin at the axial direction of guiding hole, make the valve rod can remove along the axial direction of guiding hole in the guiding hole to drive the valve clack and support on the disk seat. The problem of the check valve among the correlation technique will stop pipeline crude oil transportation when the valve clack can't support on the disk seat, to pipeline pressure release and change the check valve, the maintenance operation degree of difficulty is big is solved. The effect of reducing the operation degree of difficulty of maintaining the check valve is achieved.

Please refer to fig. 2, which illustrates a schematic structural diagram of another check valve provided in the embodiment of the present application.

Optionally, the stem guide 15 includes a valve cover 152, the valve cover 152 has a guide hole 151, a sealing ring 16 and a sleeve 17 are sequentially disposed in the guide hole along a direction close to the valve seat 112, a first end of the stem 14 passes through the sealing ring 16 and is located in the sleeve 17, and a second end of the valve rod 13 is located in the sleeve 17. The feed liquor cavity 111 and play liquid cavity 113 of check valve are used for flowing through liquid, and ejector pin guide structure 15 is installed in play liquid cavity 113, therefore, ejector pin guide structure 15 can also include the valve gap 152 that can shutoff check valve top, wherein valve gap 152 and valve clack orthographic projection coincide, the valve gap has guiding hole 151, the first end of ejector pin 14 and the second end of valve rod 13 all are located the guiding hole 151 of valve gap 152, guiding hole 151 can be when ejector pin 14 and valve rod 13 move along the axial direction of guiding hole 151, play the limiting displacement to ejector pin 14 and valve rod 13, valve rod 13 bending damage when avoiding ejector pin 14 to push valve rod 13.

One end that the guiding hole inner wall is close to the disk seat is provided with sleeve pipe 17, and sleeve pipe 17 can play limiting displacement to the first end of ejector pin 14 and the second end of valve rod 13, can protect guiding hole 151 simultaneously, destroys the guiding hole when avoiding valve rod 13 to damage.

The sealing ring 16 is arranged at one end of the inner wall of the guide hole 151, which is far away from the valve seat 112, and because the guide hole 151 is located in the liquid outlet chamber 113, when crude oil flows from the liquid inlet chamber 111 to the liquid outlet chamber 113, part of the crude oil enters the guide hole 151 under the pushing of pressure, and the sealing ring 16 can avoid the valve cover 152, thereby avoiding the crude oil from leaking from the guide hole 151 and the valve cover 152. A certain gap can be left between the sealing ring 16 and the sleeve 17, and a certain deformation space is left for the sealing ring 16 or the sleeve 17 extruded by thermal expansion and cold contraction or pressure.

Optionally, the ejector rod guide structure 15 further includes a guide flange 153, a threaded hole is formed in the guide flange 153, the guide flange 153 is mounted on the valve cover 152, and the threaded hole is opposite to the guide hole 151 on the valve cover 153; the jack 14 has an external thread on the outside, and the jack 14 is fitted into the threaded hole of the guide flange 153 by the external thread. The guide flange 153 may be connected to the valve cap 152 by a nut, the first end 141 of the push rod 14 is located in the guide hole 151, the second end passes through the guide hole of the valve cap 152 and is located in the threaded hole of the guide flange 153, and since the push rod 14 can push the valve rod 13 when moving along the axial direction of the guide hole 151, so that the valve flap 12 abuts against the valve seat 112, it is important to make the push rod 14 move along the axial direction of the guide hole 151.

Optionally, the guiding flange 153 comprises a post structure 1531, the post structure 1531 has a groove, the threaded hole is located at the bottom of the groove, and the second end of the top rod 14 is located in the groove. The pillar structure 1531 can protect the push rod 14, and the external thread of the second end of the push rod 14 is matched with the internal thread of the threaded hole at the bottom of the groove, so that the push rod 14 can move in the axial direction along the guide hole 151.

Because the second end of the ejector rod 14 is located in the groove, the difficulty of rotating the second end of the ejector rod 14 by the bare hand of an operator is large, therefore, the check valve can also be provided with the wrench 30, the wrench 30 is matched with the second end of the ejector rod 14, the operator drives the ejector rod 14 to rotate by screwing the wrench 30, the ejector rod 14 converts the circular motion into the axial stress, the circular motion gradually approaches the valve rod 13 in the screw thread rotation and finally butts against the valve rod 13, at the moment, the wrench 30 is continuously rotated, the ejector rod 14 applies the force in the axial direction to the valve rod 13, the valve rod 13 is extruded to move downwards, and the valve clack 12 connected with the valve rod 13 is driven to move downwards until the valve clack 12 butts against the valve seat 112, the wrench 30 is reversely rotated, the ejector rod 14 is retracted through the screw thread rotation, and the second end of the ejector rod 14 is located in the groove again. The check valve restores the usable state, and the whole operation process can be completed by only using one operator, and the operation is convenient. The wrench 30 used in the embodiment of the present application is an allen wrench, and may be other wrenches, which is not limited herein in the embodiment of the present application.

In addition, the inner wall of the groove of the upright column structure may not include threads, and a material with certain elasticity and friction resistance is attached to the inner wall, and the second end of the ejector rod 14 is a smooth second end, so that when the operation is performed, the axial thrust can be directly applied to the ejector rod to push the ejector rod to move towards the valve rod, when the valve flap abuts against the valve seat, the opposite force is applied to the ejector rod, the ejector rod is withdrawn again until the second end of the ejector rod is located in the groove, the operation can be completed by using a pliers, or other tools can be used, and the embodiment of the present application is not limited herein.

Fig. 3 is a schematic structural diagram of another check valve provided in an embodiment of the present application.

Optionally, the guiding flange 153 further comprises a protective cap 1532, the protective cap 1532 covers the opening of the groove and is screwed to the pillar structure 153. Because the operation to the ejector pin is not daily high frequency operation, consequently can set up one on the recess of guide flange 153 and can cover opening part protective cap 1532 at the recess, when the check valve can normally be used, with protective cap 1532 and stand structure 153 threaded connection, threaded connection's sealing performance is better, can play the sealing effect when the protection ejector pin does not receive the damage, this protective cap 1532 and sealing washer 16 are sealed layer by layer, and the combined action has avoided crude oil to leak, causes environmental pollution. The protective cap 1532 may also be connected to the pillar structure 153 by a snap-fit connection or other connection, which is not limited herein.

In the related art, a check valve is usually arranged on a gathering and transportation pipeline, one end of the gathering and transportation pipeline is connected with each single-well pipeline, crude oil conveyed from the single-well pipelines is gathered and then conveyed to a metering station by the gathering and transportation pipeline in a unified mode, and the crude oil is collected and processed. And in this application, for the maintenance efficiency who improves the check valve, can all install a check valve on each well single pipeline, well single pipeline one end is connected with the well single shaft, the other end and defeated pipeline connection of collection, when the valve clack of check valve is malfunctioning can't support on the disk seat, can stop the well pressure release with this well single, operating personnel uses the ejector pin to support the valve clack back on the disk seat, short and all the other oil wells and defeated pipeline can normally work during whole operation process, the efficiency of recovering oil has been improved.

In order to install the check valve on each single pipeline conveniently, the liquid inlet and the liquid outlet of the check valve can be connected with the single-well pipeline in the embodiment of the application, and the check valve is buried in soil, so that the check valve in the application also has better corrosion resistance and sealing performance, and the corrosion of substances in the soil to all parts in the check valve, and the waste and the pollution to the environment and the soil caused by crude oil leakage are prevented.

Optionally, the material of the sealing ring 16 comprises polytetrafluoroethylene. The polytetrafluoroethylene has good sealing performance, and also has the performances of corrosion resistance, wear resistance, high toughness and strength and the like. The sealing ring 16 is arranged in the guide hole, the ejector rod can generate friction with the sealing ring in the process of pushing the valve rod downwards by using the ejector rod, and the polytetrafluoroethylene has the performances of wear resistance, toughness, high strength and the like, so that the sealing performance of the sealing ring 16 is prevented from losing efficacy due to the fact that the sealing ring 16 is damaged in friction, and meanwhile, the polytetrafluoroethylene has low friction coefficient and can play a role in lubricating in the axial movement of the ejector rod. In addition, polytetrafluoroethylene also has corrosion resistance, and when the check valve is buried in soil, the sealing performance failure and crude oil leakage caused by corrosion to the sealing ring can be avoided. In the embodiment of the present application, polytetrafluoroethylene is used as a sealing material to seal the guide hole, and other sealing materials may also be used as a sealing ring.

Optionally, the sleeve 17 is a copper sleeve. The copper sleeve has better anti-corrosion performance, the soil contains a plurality of chemical compounds which can react with metal to corrode the metal, and the copper has better anti-corrosion performance, so that the sleeve is made of pure copper materials in the embodiment of the application. In addition, the pure copper material described in the embodiment of the present application refers to a material having a high copper content, and is not limited to a material having one hundred percent of copper. Other materials with better corrosion resistance can be used for the sleeve 17, and the embodiment of the present application is not limited herein.

Optionally, the material of the valve body comprises steel. The valve body of the check valve can be made of stainless steel materials which can resist weak corrosive media such as air, steam, water and the like so as to prevent substances in soil from corroding the valve body. In addition, compared with other corrosion-resistant materials, stainless steel has the characteristics of low cost and convenience in manufacturing, and the check valve is arranged on each single well pipeline in the embodiment of the application, so that the total cost can be reduced due to the check valve made of the stainless steel.

Optionally, the check valve further comprises a protective barrel 20, and the protective barrel 20 covers the valve cover 152. The protective barrel 20 can provide a closed space for the mandril guiding structure, that is, the protective barrel 20 can seal and protect the mandril guiding structure. The protective barrel 20 can prevent the check valve from being corroded by external substances and prevent crude oil from leaking to the outside from the check valve, the protective barrel 20 can be used as a third layer of sealing structure of the check valve, the first layer of sealing structure is a sealing ring in a guide hole, the sealing ring can prevent crude oil from leaking from the guide hole, the second layer of sealing structure is a protective cap of a guide flange, when the sealing ring carelessly fails, the protective cap and the upright post structure form a second layer of sealing, and crude oil leaking out of the guide hole can be prevented from further leaking. When the protective cap is inadvertently lost due to not being screwed down, the protective barrel 20 can serve as a third layer of sealing structure to seal the crude oil leaking from the protective cap in the protective barrel 20. That is, the protective barrel 20 simultaneously achieves the effects of preventing the corrosion of the check valve and enhancing the sealing performance of the check valve.

Optionally, the protective barrel 20 is snap-fitted with the valve cap 152. Protective barrel 20 can be clamped with valve cap 152 or can be connected by a screw cap, wherein protective barrel 20 is clamped with valve cap 152 to facilitate the detachment of protective barrel 20 by an operator.

Optionally, the check valve further includes a pull wrench 21, the pull wrench 21 includes a pull rod 211 and a handle 212 connected to one end of the pull rod 211, and the other end of the pull rod 211 has an external thread; the exterior of the protective barrel 20 has a nut 22, the internal thread of which matches the external thread on the tie rod. Protection bucket 20 is square protection bucket 20 or circular protection bucket 20 usually, when the check valve buries underground, if operating personnel directly carries out the dismouting to protection bucket 20, the operation degree of difficulty is great, consequently can set up on protection bucket 20 and carry a pull wrench 21, the operating personnel of being convenient for passes through the handle 212 application of force, the handle 212 receives the power of carrying that operating personnel applyed and carries and transmit to protection bucket 20 through pull rod 211, because protection bucket 20 and valve gap 152 joint, operating personnel can be through the quick laborsaving will protect bucket 20 of handle 212 and lift off. In addition, the other end of the pull rod 211 is connected with the protective barrel 20 through a nut and a thread, so that the pull rod 211 is convenient to detach, and the other end of the pull rod 211 can also be connected with the protective barrel 20 through other connection modes such as welding.

To sum up, this application embodiment provides a check valve including valve body, valve clack, valve rod, ejector pin and ejector pin guide structure, and when the valve clack in the check valve was out of control can't be supported on the disk seat, can drive the second end of valve rod through the ejector pin at the axial direction of guiding hole, make the valve rod can remove along the axial direction of guiding hole in the guiding hole to drive the valve clack and support on the disk seat. The problem of the check valve among the prior art need stop pipeline crude oil transportation when the valve clack can't support on the disk seat, to pipeline pressure release and change check valve, the maintenance operation degree of difficulty is big is solved. The effect of reducing the operation degree of difficulty of maintaining the check valve is achieved.

In the related art check valve in which the flap fails to abut the valve seat, the step of disposing of the failed check valve may include:

1) and stopping the well and releasing the pressure of each single well connected to one gathering and transportation pipeline.

Because each gathering pipeline is connected with a plurality of single-well pipelines, the workload of stopping and decompressing each single well is large, 4-5 workers are generally required to perform simultaneously, and the required time is 1-2 hours. And when the pressure relief time is long, the risk of well blockage is increased, and the efficiency is influenced.

2) The check valve is replaced with a new one.

When the valve clack can't support on the disk seat among the prior art, can't maintain this trouble check valve, change new check valve after the pressure release. Because the reason that influences the valve clack and support on the disk seat is more, consequently the fault rate of check valve is higher, and the check valve of frequent renewal is wasted time and energy. And frequent shut-in of the well affects the efficiency of crude oil production.

When the check valve in any of the above embodiments is used, the following steps may be performed to deal with a failed check valve when the valve flap fails to abut against the valve seat, and these steps may include:

1) and stopping the well and relieving the pressure of the oil well on the single well pipeline connected with the check valve.

All set up a check valve on each single well pipeline in this application, after confirming the trouble check valve, only stop the work of this oil well, all the other oil wells can carry out normal production, very big reduction to the exploitation efficiency's of oil well influence, and stop the well pressure release operation to an oil well, an operating personnel can accomplish, need not many staff simultaneous operation, has both alleviateed staff intensity of labour, has improved work efficiency again.

2) The protective barrel is detached through the handle.

When the lifting wrench is connected with the protection barrel through the nut, an operator can firstly connect the lifting wrench with the protection barrel, and the protection barrel is clamped with the valve cover in the embodiment of the application, so that the operator can apply lifting force through the handle and can directly detach the protection barrel; when the lifting wrench is welded with the protective barrel, an operator directly applies force to the handle to lift the protective barrel; when the protective barrel is in threaded connection with the valve cover, an operator removes the protective barrel by rotating the handle.

3) And disassembling the protective cap and installing a wrench.

When the check valve is normally used, in order to achieve a better sealing effect, the upright column structure of the guide flange is in threaded connection with the protective cap to complete sealing, when the ejector rod needs to be used, the protective cap is detached, and a spanner matched with the ejector rod is clamped at the second end of the ejector rod located in the groove. When the second end of the carrier rod is not threadedly connected to the recess, other tools may be used to perform the operation.

4) And continuously applying force to the ejector rod until the ejector rod pushes the valve rod, and the valve rod drives the valve clack to abut against the valve seat.

The spanner is used for continuously rotating the ejector rod, the ejector rod moves downwards in the axial direction of the guide hole, after a first end of the ejector rod, which is located in the guide hole, is contacted with a second end of the valve rod, which is located in the guide hole, the ejector rod continuously applies force to the ejector rod, the ejector rod pushes the valve rod to be close to the valve seat in the axial direction, and the valve rod drives the valve clack to move in the axial direction until the valve clack is abutted to the valve seat.

5) And lifting the mandril.

After the valve clack is abutted to the valve seat, the ejector rod is rotated in the opposite direction, so that the ejector rod rises, a certain distance is generated between the first end of the ejector rod and the second end of the valve rod, the valve clack can rise under the action of pressure, and the check valve can be reused.

Until the step is finished, the use function of the failed check valve can be recovered, a new check valve does not need to be replaced, the service life of the check valve is greatly prolonged, and an operator can complete the operation steps within 5 minutes, so that time and labor are saved.

6) And disassembling the wrench and installing the protective cap.

If the wrench is left in the groove to be connected with the push rod, although the operation process can be simplified, the sealing effect of the check valve is greatly reduced, and if the check valve is applied to the ground and liquid which does not cause environmental pollution flows through the pipeline, the operation can be finished after the step 4. And the check valve in this application embodiment buries in soil, need fully to guarantee the leakproofness of check valve, prevents that crude oil from leaking to soil from the check valve in, not only causes crude oil extravagant, reduces crude oil output, has polluted the environment simultaneously. Therefore, in this application, after having maintained the trouble check valve, dismantle spanner or other instrument, install the protective cap on the stand is structural, can seal the guiding flange, prevent to continue to leak from the interior outflow crude oil of guiding hole.

7) And a protective barrel is installed, and a lifting wrench is disassembled.

The check valve buried in the soil has the advantages that the anti-leakage function of the check valve is improved, and meanwhile, the anti-corrosion effect of the check valve is also enhanced, so that the protection barrel is reconnected with the valve cover, and the multiple protection of the check valve is completed.

The operation steps can be completed by only one operator, the operation is convenient and fast, the labor force is greatly saved, and the effects of avoiding the corrosion of the check valve and improving the sealing performance of the check valve are achieved.

In addition, the check valve in this application embodiment still is applicable to the oil well that crude oil impurity is many, the crude oil of high condensation carries the operating mode, thereby this kind of crude oil easily leaves impurity in the check valve and leads to check valve inner wall impurity to block the valve clack and can't support on the disk seat, and check valve fault rate is high, uses the check valve in this application embodiment, can push back the valve clack that blocks on the disk seat, need not the check valve that frequently renews, has reduced cost of maintenance.

In the present invention, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "plurality" means two or more unless expressly limited otherwise.

The above description is intended only to illustrate the alternative embodiments of the present application, and should not be construed as limiting the present application, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A check valve, comprising: the valve comprises a valve body, a valve clack, a valve rod, an ejector rod and an ejector rod guide structure;

2. The check valve of claim 1, wherein the stem guide comprises a valve cap having the guide hole, a sealing ring and a sleeve are sequentially disposed in the guide hole in a direction close to the valve seat, a first end of the stem passes through the sealing ring and is disposed in the sleeve, and a second end of the stem is disposed in the sleeve.

3. The check valve of claim 2, wherein the ram guide further comprises a guide flange having a threaded bore therein, the guide flange being mounted to the valve cover opposite the guide bore in the valve cover;

4. The check valve of claim 3, wherein the guide flange comprises a post structure having a recess therein, and a protective cap at the bottom of the recess, the protective cap being at the opening of the recess and threadedly coupled to the post structure;

the second end of the ejector rod is positioned in the groove.

5. The check valve of claim 2, wherein the sleeve is a copper sleeve.

6. The check valve of claim 2, wherein the material of the sealing ring comprises polytetrafluoroethylene.

7. The check valve of any of claims 1-6, further comprising a protective barrel that covers the valve cap.

8. The check valve of claim 7, wherein the protective barrel is snap-fit to the valve cover.

9. The check valve of claim 7, further comprising a pull wrench, the pull wrench comprising a pull rod and a handle connected to one end of the pull rod, the other end of the pull rod having external threads;

10. The check valve of any of claims 1-6, wherein the material of the valve body comprises steel.