CN204628658U - One-way valve - Google Patents

Abstract

The utility model provides a one-way valve, which comprises: a valve body; a first-stage one-way valve arranged in the valve body; a second-stage one-way valve arranged in the valve body and connected in series with the first-stage one-way valve. Further, the outlet of the first-stage one-way valve is the inlet of the second-stage one-way valve, and the outlet of the first-stage one-way valve is located in the valve body. In the utility model, two-stage check valves are arranged in one check valve. Even if one of the check valves fails, the other check valve will also play a role, and no large leakage will occur. Compared with the single-stage check valve In case of failure of the valve, the one-way valve of the present invention can reduce the problem of large leakage.

Description

check valve

technical field

The utility model relates to a one-way valve.

Background technique

Gas wells need to inject some liquid chemicals into the downhole casing or gas pipeline during the gas production process, and the pressure range in the pipeline is 1Mpa-25Mpa; Prevent fluid backflow.

Due to the pulsating characteristics of the plunger pump, the power source for the injection of the agent, the one-way valve is in a pulsating state of continuous opening and closing during the injection of the agent, which easily leads to failure of the sealing surface and greatly reduces the life of the one-way valve.

At present, the one-way valves used in gas well injection are straight-through one-way valves. The sealing type adopts end face seal or cone face seal, and the sealing surface has soft seal and hard seal, etc., which are not suitable for this working condition.

The end face seal type check valve adopts the end face (rubber pad) soft seal, which is easy to manufacture and has a wide range of applications; but it is not very suitable for working conditions such as gas well injection (high pressure, frequent pulsation, impurities).

One is that when the filling is stopped, impurities are easy to get stuck on the sealing surface, resulting in poor sealing;

The second is that the frequent pulsating opening and closing of the one-way valve will easily lead to fatigue deformation of the gasket, and the gasket will turn up under complex flow conditions such as high pressure, so that the failure of the one-way valve will cause large leakage.

However, if a straight-through cone seal and a spherical seal check valve are used, the sealing surfaces of these two check valves are all hard seals. Compared with the soft seal on the end face (rubber pad), the service life is longer, but these two hard seal methods , or the conical surface seal is a small length of annular conical surface, or the spherical hard seal is an annular line seal, the sealing effect is not as good as the end face (rubber pad) soft seal, and there is generally poor sealing (there is a certain amount of leakage) .

To sum up, there are at least the following problems in the prior art: the existing one-way valve has the problem of large leakage due to failure of the sealing surface.

Utility model content

The utility model provides a one-way valve to solve the problem of large leakage caused by the failure of the sealing surface in the existing one-way valve.

For this reason, the utility model proposes a kind of one-way valve, and described one-way valve comprises:

valve body;

a first-stage one-way valve arranged in the valve body;

A second-stage one-way valve is arranged in the valve body and connected in series with the first-stage one-way valve.

Further, the outlet of the first-stage one-way valve is the inlet of the second-stage one-way valve, and the outlet of the first-stage one-way valve is located in the valve body.

Further, the first-stage one-way valve includes: an intermediate valve seat arranged in the valve body, a first valve core arranged in the valve body and at the inlet of the first-stage one-way valve, and an abutment The first spring is pressed between the middle valve seat and the first valve core.

Further, the second-stage one-way valve includes: a second valve core arranged on the middle valve seat, and a second spring pressed between the middle valve seat and the second valve core;

The second valve core and the first valve core are respectively located at both ends of the middle valve seat;

The first valve core and the second valve core share the middle valve seat.

Further, the first valve core is spherical, the second valve core is cylindrical, and the second valve core includes: an annular side wall, an end wall arranged at one end of the annular side wall, and an opening provided at the other end of the annular side wall, the annular side wall is provided with a through hole passing through the side wall, and the end wall seals the inlet of the second-stage check valve through surface contact .

Further, the one-way valve further includes: a filter screen arranged at the outlet of the second-stage one-way valve.

Further, the intermediate valve seat is provided with an annular groove, and an O-ring is installed in the annular groove, and the depth of the annular groove is greater than the wire diameter of the O-ring, and the O-ring and the annular groove are interference assembly.

Further, the first-stage one-way valve further includes: a primary guide cylinder guiding the first valve core, the primary guide cylinder is located outside the middle valve seat and inside the valve body , the first spring and the first valve core are located inside the first-stage guide cylinder, and the two ends of the first-stage guide cylinder are provided with overflow grooves extending to the outer surface of the first-stage guide cylinder.

Further, the second-stage one-way valve further includes: a secondary guide cylinder guiding the second valve core, the secondary guide cylinder is located outside the intermediate valve seat and inside the valve body , the second spring and the second valve core are located inside the secondary guide cylinder, and the outer surface of the secondary guide cylinder is provided with a plurality of elongated holes for diversion.

Further, the first-stage one-way valve also includes: an inlet valve seat arranged in the valve body, the inlet valve seat is located at the inlet end of the valve body and between the valve body and the Between the first valve core, the valve seat at the inlet port is detachably connected to the valve body.

In the utility model, two-stage check valves are arranged in one check valve. Even if one of the check valves fails, the other check valve will also play a role, and no large leakage will occur. Compared with the single-stage check valve In case of failure of the valve, the one-way valve of the present invention can reduce the problem of large leakage.

Furthermore, compared with the series connection of two separate one-way valves, the utility model can reduce the installation times of the two separate one-way valves respectively connected to the working pipeline, and the utility model only needs one installation to replace two separate one-way valves. The double installation of the check valve saves installation time, reduces the intermediate connecting pipes and seals required to connect two separate check valves when installing two separate check valves, and reduces the chance of leakage , reducing the maintenance difficulty and cost of use of personnel.

Furthermore, in the one-way valve of the present invention, the outlet of the first-stage one-way valve is the inlet of the second-stage one-way valve. Compared with the series connection of two independent one-way valves, the utility model avoids liquid from In the process of two separate one-way valves flowing to the working pipeline, it is caused by the change of the flow channel cross-section due to the passage from the outlet of one one-way valve to the inlet of the other one-way valve through the connecting pipe in the middle. The pulse phenomenon or vibration, or the pulse phenomenon or vibration caused by too long flow channel, especially for the one-way valve conveying high-pressure liquid, the utility model can reduce the pulse phenomenon, and can reduce the occurrence of pulsation when used with the plunger pump The pulse (pulsation) phenomenon or vibration is beneficial to increase the service life of the check valve and the stability of other equipment, and increase the safety of the entire working pipeline.

Furthermore, the valve core of the first-stage one-way valve and the second-stage one-way valve share the middle valve seat, that is, the one-way valve of the present invention is a one-way valve, but only one valve seat is needed, which reduces the volume. , length, weight and cost.

Furthermore, the one-way valve of the present invention also includes: a filter screen, which is arranged at the outlet of the second-stage one-way valve, so that impurities can be filtered to prevent impurities from polluting the sealing surface, thereby increasing the safety of the seal.

Description of drawings

Fig. 1 is a schematic diagram of the external three-dimensional structure of the check valve of the first embodiment of the present invention;

Fig. 2 is a structural schematic diagram of the external front view direction of the one-way valve of the first embodiment of the utility model;

Fig. 3 is the B-B sectional view of Fig. 2;

Fig. 4 is a schematic diagram of the first-stage guide cylinder and the second-stage guide cylinder of the one-way valve of the first embodiment of the present invention;

Fig. 5 is a cross-sectional view of the check valve of the second embodiment of the present invention.

Fig. 6 is a three-dimensional exploded schematic diagram of the first angle of the one-way valve of the second embodiment of the present invention, wherein the valve body and the valve cover are removed.

Fig. 7 is a perspective exploded structure schematic diagram of the second angle of the check valve of the second embodiment of the present invention, wherein the valve body and the valve cover are removed.

Explanation of reference numbers:

1 valve body 2 first spool 3 first spring 4 primary guide cylinder 5 sealing gasket 6 intermediate valve seat 7-O ring 8 secondary guide cylinder 9 second valve core 10 second spring 11 gasket 12 strainer 13 Gasket 14 Sealing gasket 15 Bonnet 20 Inlet port valve seat 25 Sealing gasket 40 Overcurrent groove 41 Annular groove 60 Outlet of first-stage check valve 80 Strip hole 91 End wall 92 Through hole 100 First-stage single Directional valve 200 second stage one-way valve

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the present utility model, the utility model is now described with reference to the accompanying drawings.

As shown in Fig. 1, Fig. 2 and Fig. 3, the utility model proposes a one-way valve, and the one-way valve includes:

The valve body 1, the valve body 1 may have an interface connected to the working pipeline, so as to be connected to the working pipeline (the working pipeline is, for example, an oil pipe or a water pipe);

The first-stage one-way valve 100 is arranged in the valve body 1;

The second-stage one-way valve 200 is arranged in the valve body 1 and is connected in series with the first-stage one-way valve 100. The second-stage one-way valve 200 is arranged downstream of the first-stage one-way valve 100, and the fluid ( Such as liquid) enters from the inlet P1 of the one-way valve, and the process of flowing out from the outlet P2 of the one-way valve is then: fluid enters the first stage from the inlet P1 of the one-way valve that is to enter the inlet of the first-stage one-way valve 100 The one-way valve 100 then flows out from the outlet of the first-stage one-way valve 100, then enters the inlet of the second-stage one-way valve 200, and then flows out from the outlet of the second-stage one-way valve 200, which is the outlet P2 of the one-way valve .

The first-stage one-way valve 100 and the second-stage one-way valve 200 are all arranged in the valve body 1, and the outlet 60 of the first-stage one-way valve is the inlet of the second-stage one-way valve. The series connection of two separate one-way valves, the utility model avoids the process of liquid flowing from two separate one-way valves to the working pipeline, due to the process of entering from the outlet of one one-way valve to the inlet of the other one-way valve, The pulse phenomenon or vibration caused by the change of the flow channel section through the intermediate connecting pipe, or the pulse phenomenon or vibration caused by the too long flow channel, especially for the one-way valve for conveying high-pressure liquid, the utility model can Reducing the pulse phenomenon can reduce the pulse (pulsation) phenomenon or vibration that occurs when the plunger pump is used, which is beneficial to increase the service life of the check valve and the stability of other equipment, and increase the safety of the entire working pipeline.

As shown in Figure 3, the outlet 60 of the first-stage check valve includes, for example, a tapered tapered section to better control the flow at the outlet of the first-stage check valve 100 and reduce the occurrence of pulse (pulsation) phenomenon or vibration .

Further, as shown in FIG. 3 , the first-stage one-way valve 100 includes: an intermediate valve seat 6 arranged in the valve body, arranged in the valve body 1 and located at the inlet of the first-stage one-way valve The first valve core 2 at the place, and the first spring 3 pressed between the middle valve seat 6 and the first valve core 2 . The first spring 3 is, for example, a compression spring, and the one-way switching or reset function of the first-stage one-way valve 100 can be realized by the first spring 3 .

Further, as shown in FIG. 3 , the second-stage one-way valve 200 includes: a second valve core 9 arranged on the middle valve seat, and a second valve core pressed against the middle valve seat 6 and the second valve core. 9 between the second spring 10; the second spring 10 is, for example, a compression spring, which plays a reset role, and the second valve core 9 and the first valve core 2 are respectively located at the two ends of the middle valve seat 6; The first valve core and the second valve core share the intermediate valve seat 6, and the intermediate valve seat 6 respectively supports the valve core of the first-stage check valve and the valve core of the second-stage check valve. In this way, On the one hand, the outlet of the first-stage one-way valve can be made to be the inlet of the second-stage one-way valve, reducing pulses; on the other hand, it also reduces the use of valve seats, facilitates production and installation, and reduces volume and length , weight and cost.

Further, as shown in FIG. 3 , the first valve core 2 is spherical, for example, the first valve core is an oxide ceramic ball (higher than steel), and the spherical surface is hard-sealed, which is not easy to wear and has a long service life. The second spool is cylindrical or cylindrical with one end closed. In this way, the second-stage check valve is an end-face spool, and the end face is a soft seal. Like this, the one-way valve of the present utility model is the series connection of the one-way valve of a spherical spool and the one-way valve of a cylindrical spool, the first-stage one-way valve 100 is a spherical hard seal, and the second-stage one-way valve It is the soft seal of the end face, and the two cooperate with each other, which can not only make up for the shortcoming of the hard seal that is prone to a little leakage, but also make up for the short service life of the soft seal and the shortcoming of large area leakage after long-term use. Compared with the series connection of two spools of the same type, the combination of these two spools can achieve a better sealing effect.

As shown in Fig. 3 and Fig. 6 and Fig. 7, the second spool 9 includes: an annular side wall, a valve disposed at one end of the annular side wall (at the outlet 60 of the first-stage check valve) End wall 91, and the opening that is arranged on the other end of described annular side wall, described annular side wall is provided with the through hole 92 that runs through side wall, and described end wall 91 is contacted by surface (with O type ring 7 cooperate to form a seal) to seal the inlet of the second-stage check valve (at the outlet 60 of the first-stage check valve). When sealing, the O-ring 7 is compressed in a close to airtight space between the annular groove of the valve seat 6 and the annular plane of the second valve core 9, and the deformation of the O-ring 7 is limited by the airtight space, so it is not easy to be damaged and is not susceptible to fatigue deformation. Sensitive, good sealing effect. The sealing surface of the end face spool (the second spool 9) is an annular plane, and the width of the annular plane is clearance fit with the width of the annular groove of the valve seat. The seal of the second-stage check valve is a standard O-ring, which is easy to purchase and easy to replace, and the material can be selected according to the pressure (fluorine rubber for high pressure, nitrile rubber for low pressure)

Further, as shown in FIG. 3 , the one-way valve further includes: a filter screen 12 disposed at the outlet P2 of the second-stage one-way valve 200 . In this way, the sealing surface is effectively prevented from being polluted by the outlet impurities, which increases the safety of the sealing. For the working condition of no impurity backflow (turbulent flow) at the outlet, the gasket 11, the stainless steel wire filter 12 and the gasket 13 for the regulation function can be omitted; the secondary guide sleeve 8 and the valve cover 15 outlet hole It only needs to be smaller than the outer diameter of the second spring 10 .

Further, as shown in Fig. 3, an annular groove is provided on the intermediate valve seat 6, and an O-ring 7 is installed in the annular groove, the depth of the annular groove is greater than the wire diameter of the O-ring, and the O-ring The type ring and the annular groove are interference fit, so that the O-ring 7 is not easy to be washed out by the turbulent flow of the medium or turned out of the annular groove, the sealing effect is better, and the service life of the second-stage one-way valve 200 is increased. The deformation of the O-ring 7 is limited by the confined space, and it is not easily damaged and is not sensitive to fatigue deformation. If the O-ring 7 is damaged, after the failure of the second-stage check valve, the first-stage check valve is hard-sealed, and only a little leakage will occur; large area leakage can be avoided, just replace the O-ring.

Further, as shown in FIG. 3 and FIG. 4 , the first-stage check valve 100 further includes: a primary guide cylinder 4 guiding the first valve core, and the primary guide cylinder 4 is located in the middle The valve seat 6 is located inside the valve body 1, the first spring 3 and the first valve core 2 are located inside the primary guide cylinder 4, and the two ends of the primary guide cylinder are provided with extensions. To the overflow groove 40 on the outer surface of the primary guide cylinder. The spherical spool (the first spool 1) is in clearance fit with the first-stage guide cylinder 4, and can move freely in the axial direction; the two sides of the first-stage guide cylinder 4 are provided with flow grooves 40, and the cylindrical surface of the first-stage guide cylinder is provided with annular grooves 41 , the overflow groove 40 and the annular groove 41 may communicate, for example.

Further, as shown in Fig. 3 and Fig. 4, the second-stage one-way valve also includes: a second-stage guide cylinder 8 guiding the second valve core, and the second-stage guide cylinder 8 is located at the middle valve Outside the seat 6 and inside the valve body 1, the second spring 10 and the second valve core 9 are located inside the secondary guide cylinder 8, and the outer surface of the secondary guide cylinder 8 is provided with multiple The elongated hole 80 of bar flow guiding effect. The end face spool (the second spool 9) is in clearance fit with the secondary guide cylinder 8, and can move freely along the axial direction.

Further, Fig. 5, Fig. 6 and Fig. 7 are the structure of the one-way valve of the second embodiment of the present invention, as shown in Fig. 5, the main structure of the one-way valve of this embodiment and the one-way valve shown in Fig. 3 The difference is that the first stage check valve 100 also includes: an inlet valve seat 20 arranged in the valve body, the inlet valve seat 20 is located at the inlet port P1 of the valve body, and is located at the Between the valve body 1 and the first valve core 2, the inlet valve seat 20 is detachably connected to the valve body 1 as a wearing part for easy replacement. A sealing gasket 25 is provided between the inlet valve seat 20 and the valve body 1 for sealing.

As shown in Figure 1 and Figure 3, the utility model is also provided with a valve cover 15 sleeved with the valve body 1, so as to install and disassemble and protect the valve cores at all levels. The valve cover 15 can be connected with a working pipeline, for example, and the outlet P2 of the second-stage one-way valve 200 or the outlet P2 of the entire one-way valve can be located at the end of the valve cover 15 .

In the one-way valve of the present utility model, between the two-stage one-way valve, between the one-way valve body and the outside world, there are sealing pads 5 and gaskets 14 made of polytetrafluoroethylene, and these polytetrafluoroethylene pads are placed between Close to the airtight space compression seal, the compression amount is small, it will not be squeezed inward to affect the medium flow and installation, and the sealing effect is good.

The one-way valve of the utility model can be used in the process of gas production of the gas well, under the working condition of injecting some liquid medicine in the downhole casing or the gas transmission pipeline, because of the filter screen, it can avoid: because the gas well fluid generally contains There are a lot of impurities (mainly sand, dust, debris, etc.), and before the check valve is closed, the impurities are easy to contaminate the sealing surface with the backflow (or turbulent flow), resulting in the phenomenon that the check valve is not tightly sealed.

The first-level guide cylinder or the second-level guide cylinder of the utility model is easy to process to open and discharge the flow groove, and has a large flow area, and the small gap between the valve core in the first or second guide cylinder and the guide cylinder cooperates. Compared with ordinary one-way Valve, when the spool moves, it is not easy to deviate.

When this embodiment is implemented and used, in Fig. 3, the P1 port is the liquid inlet (the inlet of the one-way valve of the present utility model), which can be connected with the outlet of the high-pressure pump through a high-pressure pipeline; a filter can be connected in series before the liquid inlet of the high-pressure pump To ensure that the medium entering the check valve from P1 port is clean and free of impurities.

Among Fig. 3, P2 port (outlet P2 of the one-way valve of the present utility model) is liquid outlet, connects the pipeline or container that needs to inject liquid by joint or high-pressure pipeline.

When working, the medium enters through the P1 port, the medium first pushes the first valve core 2, and the first valve core 2 moves along the primary guide cylinder 4, so that the first spring 3 is compressed;

Then the medium flows to the port of the middle valve seat 6 (the outlet 60 of the first-stage check valve) through the opening groove 40 of the first-stage guide cylinder 4 and the annular groove 41 on the outer circular surface. Through this port, the medium pushes away the second valve core. 9;

The second valve core 9 moves along the secondary guide cylinder 8 to compress the second spring 10;

Then the medium passes through the waist-shaped grooves (elongated holes 80) evenly distributed on the circumference of the secondary guide cylinder 8, partly passes through the four circular through-holes 92 around the second valve core 9, and finally reaches the overflow gasket 11. Pass through the through hole 92 of the overflow gasket 11 and 8 small holes evenly distributed around it, then flow through the stainless steel wire filter 12, and finally discharge from the P2 port.

Due to the pulsating characteristics of the plunger pump, the actual liquid inlet and outlet of the check valve are intermittent, that is, the check valve keeps opening and closing cycles, and the flow direction of the medium at the P2 port is in a disordered state from time to time; when the check valve stops working , The stainless steel wire filter 12 will well block the medium around the P2 port from penetrating to the other side, so as to ensure that the sealing surface is not polluted by impurities.

Taking the agent injection in the Sulige gas field in Inner Mongolia as an example, because the gas wells in the gas field generally have a wide range, a large number, and are scattered, some wells are far away from the maintenance department (tens, hundreds of kilometers), and some wells have high pressure and impurities. The above objective reasons make ordinary check valves not durable. And the maintenance cost of going to the well is high (in addition to labor, the cost of a single trip to the well can reach 300 to 400 yuan). The utility model just makes up for the problem that the above common one-way valve is not durable.

The above descriptions are only illustrative specific implementations of the present utility model, and are not intended to limit the scope of the present utility model. Because the components of this utility model can be combined with each other under the condition of no conflict, any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principles of this utility model shall belong to this utility model. The scope of utility model protection.

Claims (10)

1. A check valve, characterized in that, said check valve comprises: valve body; a first-stage one-way valve arranged in the valve body; A second-stage one-way valve is arranged in the valve body and connected in series with the first-stage one-way valve. 2. The check valve according to claim 1, wherein the outlet of the first stage check valve is the inlet of the second stage check valve, and the outlet of the first stage check valve is located in the valve body. 3. The one-way valve according to claim 2, wherein the first-stage one-way valve comprises: an intermediate valve seat arranged in the valve body, arranged in the valve body and positioned at the first The first valve core at the inlet of the stage check valve, and the first spring pressed between the middle valve seat and the first valve core. 4. The one-way valve according to claim 3, wherein the second-stage one-way valve comprises: a second valve core arranged on the middle valve seat, and a second valve core pressed against the middle valve seat and the second spring between the second spool; The second valve core and the first valve core are respectively located at both ends of the middle valve seat; The first valve core and the second valve core share the middle valve seat. 5. The one-way valve according to claim 4, wherein the first valve core is spherical, the second valve core is cylindrical, and the second valve core comprises: an annular side wall, An end wall disposed at one end of the annular side wall and an opening disposed at the other end of the annular side wall, the annular side wall is provided with a through hole passing through the side wall, the end wall The inlet of the second stage check valve is sealed by surface contact. 6. The one-way valve according to claim 2, characterized in that, the one-way valve further comprises: a filter screen arranged at the outlet of the second-stage one-way valve. 7. The one-way valve according to claim 3, wherein an annular groove is provided on the intermediate valve seat, an O-ring is installed in the annular groove, and the depth of the annular groove is greater than the line of the O-ring. diameter, and the O-ring and the annular groove are interference fit. 8. The one-way valve according to claim 3, characterized in that, the first-stage one-way valve further comprises: a one-stage guide cylinder guiding the first valve core, the one-stage guide cylinder is located at the outside the middle valve seat and inside the valve body, the first spring and the first valve core are inside the first-stage guide cylinder, and the two ends of the first-stage guide cylinder are opened with The overflow groove on the outer surface of the primary guide cylinder. 9. The one-way valve according to claim 5, wherein the second-stage one-way valve further comprises: a two-stage guide cylinder for guiding the second valve core, the two-stage guide cylinder is located at the Outside the middle valve seat and inside the valve body, the second spring and the second valve core are located inside the secondary guide cylinder, and the outer surface of the secondary guide cylinder is provided with a plurality of guides Functional elongated hole. 10. The one-way valve according to claim 1, wherein the first-stage one-way valve further comprises: an inlet valve seat arranged in the valve body, and the inlet valve seat is located on the The inlet end of the valve body is located between the valve body and the first valve core, and the valve seat at the inlet end is detachably connected to the valve body.