CN113790151A

CN113790151A - Fluid end and plunger pump

Info

Publication number: CN113790151A
Application number: CN202111283476.7A
Authority: CN
Inventors: 李晓斌; 王宝杰; 王继鑫; 李朋; 姜琛; 崔海萍; 张树林; 葛安鹏
Original assignee: Yantai Jereh Petroleum Equipment and Technologies Co Ltd
Current assignee: Yantai Jereh Petroleum Equipment and Technologies Co Ltd
Priority date: 2021-11-01
Filing date: 2021-11-01
Publication date: 2021-12-14
Anticipated expiration: 2041-11-01
Also published as: CN113790151B; WO2023070852A1

Abstract

A fluid end and plunger pump is provided. The liquid end includes: a valve box including an inner cavity, the inner cavity including an alternating cavity and a low pressure cavity; a first valve assembly located in the inner cavity, configured to open to communicate the low pressure cavity and the alternating cavity or configured to close to separate the low-pressure chamber and the alternating chamber; a pressure-bearing structural member, at least a part of which is located in the low-pressure chamber, and a first sealing structure located between the pressure-bearing structural member and the valve box; the valve box and the pressure-bearing structure At least one of the pieces has a relief passage configured to communicate fluid in the event of a failure of a portion of the first sealing structure. The hydraulic end has a leakage channel, and the leakage point is artificially created. Once the seal fails, it will be found quickly and intuitively, which is convenient for timely replacement of accessories, and avoids large puncture leakage in the inner cavity, which may cause safety accidents.

Description

Fluid end and plunger pump

Technical Field

Embodiments of the present disclosure relate to a hydraulic tip and plunger pump.

Background

At present, fracturing construction in the oil and gas field exploitation process is a main yield increasing mode, and a plunger pump is main equipment for pumping fracturing medium in yield increasing operation. In other words, throughout the entire flow of oil and gas production, whatever process is required to deliver the medium to the well at a particular pressure, needs to be accomplished by the plunger pump.

Disclosure of Invention

The embodiment of the disclosure provides a hydraulic end and a plunger pump, wherein the hydraulic end is provided with a drainage channel, leakage points are artificially manufactured, once sealing failure is found out quickly and intuitively, accessories are convenient to replace in time, and the phenomenon that a large puncture is caused in an inner cavity to cause a safety accident is avoided.

Embodiments of the present disclosure provide a hydraulic tip, comprising: a valve box comprising an inner cavity, the inner cavity comprising an alternating cavity and a low pressure cavity; a first valve assembly located in the inner chamber configured to open to communicate the low pressure chamber and the alternating chamber or configured to close to isolate the low pressure chamber and the alternating chamber; a pressure-bearing structure, at least a portion of which is located in the low-pressure cavity, and a first seal structure located between the pressure-bearing structure and the valve box; at least one of the valve box and the pressure-containing structure has a vent passage configured to communicate fluid upon failure of a portion of the first seal structure.

According to the hydraulic end provided by the embodiment of the disclosure, the first sealing structure comprises a first sealing and a second sealing, the drain passage comprises a first drain port and a second drain port, the first drain port is closer to the first sealing structure than the second drain port, and the first drain port is located between the first sealing and the second sealing.

According to the hydraulic end provided by the embodiment of the disclosure, the leakage flow channel is arranged in the valve box, and the leakage flow channel is obliquely arranged relative to the first axis of the inner cavity.

According to the hydraulic end provided by the embodiment of the disclosure, the acute angle formed by the drainage channel and the first axis of the inner cavity is greater than or equal to 30 degrees and less than or equal to 60 degrees.

According to the hydraulic end provided by the embodiment of the disclosure, the pressure-bearing structure comprises a first pressure-bearing assembly and a second pressure-bearing assembly, and the first valve assembly, the first pressure-bearing assembly and the second pressure-bearing assembly are sequentially arranged along the extension direction of the first axis of the inner cavity.

According to the hydraulic end provided by the embodiment of the disclosure, the first pressure bearing assembly comprises an alternating pressure cover and an alternating pressure cap, the alternating pressure cover is closer to the first valve assembly than the alternating pressure cap, and the alternating pressure cap is in threaded connection with the valve box.

According to the hydraulic end provided by the embodiment of the disclosure, the pressure-bearing structural part comprises a gland and a pressure cap, the pressure cap is connected with the valve box through threads, and the leakage flow channel is located in the gland.

According to a fluid end provided by an embodiment of the present disclosure, the gland includes: a body, the body being cylindrical, the body including a first end, a second end, and a side connecting the first end and the second end; a primary flow passage extending along an axis of the body; a plurality of secondary runners, each secondary runner communicating with the primary runner; a first opening at the first end and in communication with the primary flow passage; and a plurality of second openings located on the side surface of the body, wherein the secondary flow passage is communicated with at least one of the plurality of second openings.

According to a fluid end provided by an embodiment of the present disclosure, the gland has a low pressure fluid passage that communicates with the upper fluid port of the valve housing.

According to the hydraulic end that this disclosed embodiment provided, the inner chamber of valve box is the type of falling T structure, alternating chamber with the low-pressure chamber is followed the extending direction setting of the first axis of inner chamber.

According to a hydraulic end provided by an embodiment of the present disclosure, the valve housing further includes a high pressure chamber; the alternating cavity and the high-pressure cavity are arranged along the extension direction of a second axis of the inner cavity, and the first axis is intersected with the second axis.

According to the hydraulic end provided by the embodiment of the disclosure, the valve box is provided with the liquid feeding hole, and the liquid feeding hole and the high-pressure cavity are arranged in a staggered mode in the extending direction of the first axis.

According to the hydraulic end that this disclosed embodiment provided, hydraulic end still includes plunger, packing package subassembly, packing and presses cap, packing cover and packing cover to press the cap, wherein, the inner chamber still includes the plunger chamber, the plunger chamber is configured to place the plunger, the packing cover is located packing package subassembly with between the valve box, packing cover presses the cap to be configured to the packing cover is exerted pressure, packing is pressed the cap and is configured to the packing package subassembly is exerted pressure.

According to the hydraulic end provided by the embodiment of the disclosure, the hardness of the packing sleeve is greater than that of the valve box, and the packing sleeve pressing cap is connected with the valve box in a welded mode.

According to the hydraulic end provided by the embodiment of the disclosure, the packing sleeve pressing cap is connected with the valve box in a welding mode.

Embodiments of the present disclosure also provide a plunger pump including any of the above-described fluid ends.

Drawings

To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly introduced below, and it is apparent that the drawings in the following description relate only to some embodiments of the present disclosure and are not limiting to the present disclosure.

Fig. 1A is a sectional view of a plunger pump.

FIG. 1B is a schematic view of the fluid end of the plunger pump shown in FIG. 1A.

FIG. 1C is a schematic view of a valve box in the fluid end shown in FIG. 1B.

Fig. 2 is a cross-sectional view of a gland provided in an embodiment of the present disclosure.

Fig. 3 is a perspective view of a gland provided by an embodiment of the present disclosure.

Fig. 4 is a cross-sectional view of a fluid end provided by an embodiment of the present disclosure.

FIG. 5 is a front and side view of a spring bracket in a hydraulic end provided by an embodiment of the present disclosure.

Fig. 6 is a perspective view of another gland provided by embodiments of the present disclosure.

Fig. 7 is a cross-sectional view of a fluid end provided by an embodiment of the present disclosure.

FIG. 8 is a cross-sectional view of a valve housing in a hydraulic end provided by an embodiment of the present disclosure.

Fig. 9 is a cross-sectional view of a fluid end provided by an embodiment of the present disclosure.

Fig. 10 is a cross-sectional view of a fluid end provided by an embodiment of the present disclosure.

Fig. 11 is a cross-sectional view of a fluid end provided by an embodiment of the present disclosure.

Fig. 12A is a partial schematic view at the bleed passage in the valve housing of fig. 10.

FIG. 12B is a partial schematic view of the packing set and the packing set extrusion in the valve box of FIG. 10.

Fig. 13 is a schematic illustration of the regions of the internal cavity in a hydraulic-end valve housing provided by an embodiment of the present disclosure.

Fig. 14 is a schematic view of a fluid end valve box provided by an embodiment of the present disclosure.

Fig. 15 is a perspective view of a fluid end provided by an embodiment of the present disclosure.

Fig. 16 is a schematic view of another fluid end valve box provided by embodiments of the present disclosure.

FIG. 17 is a schematic illustration of a intersection of the internal chambers of a valve box in a hydraulic end provided by an embodiment of the present disclosure.

FIG. 18 is a schematic view of a intersection of the internal chambers of the valve box in another hydraulic end provided by an embodiment of the present disclosure.

FIG. 19 is a schematic illustration of a second valve assembly in a hydraulic end provided by an embodiment of the present disclosure.

Fig. 20 is a schematic diagram of a valve housing on the discharge side of a hydraulic end provided by an embodiment of the present disclosure.

Fig. 21 is a schematic view of a sealing structure on a discharge side of a fluid end according to an embodiment of the present disclosure.

Fig. 22 is a schematic diagram of a valve housing on the suction side of a hydraulic end provided by an embodiment of the present disclosure.

Fig. 23 is a schematic view of a sealing structure on the suction side of a fluid end according to an embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more apparent, the technical solutions of the embodiments of the present disclosure will be described clearly and completely with reference to the drawings of the embodiments of the present disclosure. It is to be understood that the described embodiments are only a few embodiments of the present disclosure, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the disclosure without any inventive step, are within the scope of protection of the disclosure.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. Likewise, the word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

The plunger pump is used as one of key devices for fracturing construction, and mainly has the main function of converting fracturing fluid with certain viscosity under normal pressure into high-pressure and high-flow fracturing fluid to be injected into a stratum, and the performance of the fracturing fluid directly influences the technical level of fracturing construction operation of an oil-gas field. At present, the structure of fracturing pumps at home and abroad generally adopts a reciprocating horizontal multi-cylinder plunger pump, such as a three-cylinder plunger pump and a five-cylinder plunger pump, and the fracturing pump is generally composed of a hydraulic end and a power end. The hydraulic end is used for converting mechanical energy into pressure energy of the working fluid. The power end is used for transmitting the kinetic energy of the prime mover to the hydraulic end through the speed reducing transmission system and the crank-link mechanism.

Fig. 1A is a sectional view of a plunger pump. FIG. 1B is a schematic view of the fluid end of the plunger pump shown in FIG. 1A. FIG. 1C is a schematic view of a valve box in the fluid end shown in FIG. 1B. As shown in fig. 1A, the plunger pump 003 includes a power end 002 and a fluid end 001. As shown in fig. 1A and 1B, the fluid end 001 mainly includes a valve housing 01, a plunger 02, a valve assembly 03, a valve assembly 04, a sealing member, a gland 05, and a gland 06. Fig. 1A also shows a yoke 07, a tie rod 08, a crosshead 09, a connecting rod 010, a case 011, and a crankshaft 012. As shown in fig. 1B, the fluid tip 001 further includes a valve seat 021, a spring 022, a suction gland 023, a suction gland 024, a spring 025, a weep hole 026, a packing assembly 027 for sealing, and a packing gland 028. Fig. 1C shows a cruciform arrangement of the valve housing 01.

As shown in fig. 1A and 1B, the plunger pump operates as follows: the crankshaft 012 of the power end 002 rotates under the driving of the prime mover, so as to drive the connecting rod 010 and the crosshead 09 to horizontally reciprocate, and the crosshead 09 drives the plunger 02 to horizontally reciprocate in the valve box 01 through the pull rod 08. When the plunger 02 moves in a return stroke, the internal volume of the valve box 01 is gradually increased to form partial vacuum, the valve component 03 is opened at the moment, the valve component 04 is closed, the medium enters the inner cavity of the valve box 01, when the plunger 02 returns to the limit position, the inner cavity of the valve box 01 is filled with the medium, and the liquid suction action is finished. When the plunger 02 moves in a process, the volume in the valve box 01 is gradually reduced, the medium is squeezed, the pressure is increased, the valve assembly 04 is opened, the valve assembly 03 is closed, the medium enters the liquid discharge hole 026 under the action of the pressure, when the plunger 02 moves to the limit position, the medium accommodating space in the valve box 01 is minimum, and the liquid discharge action is finished. Because the plunger 02 is continuously reciprocated, the processes of liquid suction and liquid discharge are alternately carried out, and the high-pressure medium is continuously output.

Referring to fig. 1A to 1C, a valve box of a general hydraulic end is a cross-shaped intersecting structure, as shown in fig. 1C, an inner cavity of the valve box 02 is divided into a low-pressure cavity 01A, an alternating cavity 01b and a high-pressure cavity 01C according to pressure, however, an intersecting line is just located in the alternating cavity 01b, and mechanical analysis shows that stress concentration at the intersecting line is obvious, and in addition, due to the action of an alternating load, fatigue cracks are easily generated at the intersecting line, so that the valve box 01 cracks and leaks water, the valve box is frequently replaced on site, replacement cost is high, and time and labor are consumed.

Along with the fracturing construction difficulty is higher and higher (the working pressure is higher), the single machine large discharge capacity also becomes the market emergency demand, and if the stress concentration effect at the intersection part cannot be effectively improved all the time, the service life of the valve box cannot be prolonged.

The embodiment of the disclosure provides a valve box with a T-shaped inner cavity, so as to prolong the service life of the valve box, and provides a gland to simplify the structure of a hydraulic end and improve the performance of the hydraulic end. Embodiments of the present disclosure provide a hydraulic end and plunger pump that also contains the gland and a valve box with a T-shaped cavity.

The gland, fluid end and plunger pump provided by embodiments of the present disclosure are described below.

Fig. 2 is a cross-sectional view of a gland provided in an embodiment of the present disclosure. Fig. 3 is a perspective view of a gland provided by an embodiment of the present disclosure. Fig. 4 is a cross-sectional view of a fluid end provided by an embodiment of the present disclosure. FIG. 5 is a front and side view of a spring bracket in a hydraulic end provided by an embodiment of the present disclosure. Fig. 5(a) is a front view of the spring holder. Fig. 5(b) is a side view of the spring holder. Fig. 6 is a perspective view of another gland provided by embodiments of the present disclosure. Fig. 7 is a cross-sectional view of a fluid end provided by an embodiment of the present disclosure. FIG. 8 is a cross-sectional view of a valve housing in a hydraulic end provided by an embodiment of the present disclosure. Fig. 9 is a cross-sectional view of a fluid end provided by an embodiment of the present disclosure.

As shown in fig. 2, 3, 6, and 7, embodiments of the present disclosure provide a gland 10, the gland 10 including: the main body 100, the main flow passage 1021, a plurality of sub-flow passages 1022, a first opening P1, and a plurality of second openings P2. As shown in fig. 2, 3, 6 and 7, the body 100 is cylindrical, and the body 100 includes a first end E1, a second end E2, and a side S0 connecting the first end E1 and the second end E2; the primary flow passage 1021 extends along an axis of the body 100; each secondary flow passage 1022 communicates with the primary flow passage 1021; the first opening P1 is located at the first end E1 and communicates with the main flow passage 1021; the plurality of second openings P2 are located on the side surface S0 of the body 100, and the secondary flow passage 1022 communicates with at least one of the plurality of second openings P2.

The gland 10 provided by the embodiment of the disclosure facilitates fluid circulation, simplifies the structure of a hydraulic end, and the plunger pump containing the gland can realize large discharge output.

Fig. 2 to 4, 7 and 9 show the gland 10a, and fig. 6 shows the gland 10 b.

For example, as shown in fig. 2 and 7, the primary flow passage 1021 is located on an axis a0 of the body 100, and the primary flow passage 1021 does not extend through the body 100 on the axis of the body 100. As shown in fig. 2 and 7, the left end of the main flow passage 1021 communicates with the first opening P1, and the right end communicates with the sub flow passage 1022. For example, the primary flow passage 1021 extends in the direction of extension of the axis a0 of the body 100.

For example, as shown in fig. 2 and 7, in order to facilitate the flow of fluid, the aperture of the primary channel 1021 is larger than the aperture of the secondary channel 1022.

For example, as shown in fig. 3 and 6, in order to achieve a large discharge amount stable output, the plurality of second openings P2 are evenly distributed in the circumferential direction of the body 100. With the second opening P2 on side S0, the aperture of the secondary flow passage 1022 and the size of the second opening P2 can be set larger to facilitate fluid passage through the gland. The embodiment of the present disclosure is explained taking as an example that the gland 10 includes four second openings P2 evenly distributed in the circumferential direction of the body 100.

For example, as shown in fig. 2 and 7, in order to improve the performance of the gland and extend the lifespan of the gland, the sub-flow passage 1022 is disposed obliquely with respect to the main flow passage 1021.

In some embodiments, the plurality of secondary runners 1022 are inclined in the same direction and to the same degree with respect to the primary runner 1021. As shown in fig. 2 and 7, the plurality of secondary runners 1022 are all inclined to the right and have the same angle with the primary runner 1021.

For example, as shown in fig. 2 and 7, the acute angle θ 1 between the center line L2 of the secondary flow channel 1022 and the center line L1 of the primary flow channel 1021 ranges from 20 to 80 degrees. The gland shown in fig. 2 and 7 is described by taking an example in which the center line L1 of the main flow channel 1021 coincides with the axis a0 of the main body 100.

For example, as shown in fig. 2 and 7, the distance from the secondary flow passage 1022 to the axis a0 of the body 100 gradually increases in a direction from the first end E1 to the second end E2. That is, as shown in fig. 2, the sub-flow passage 1022 is inclined toward the right. Of course, in other embodiments, the secondary flow passage 1022 may be inclined toward the left, in which case the distance from the secondary flow passage 1022 to the axis a0 of the body 100 gradually decreases from the first end E1 to the second end E2.

For example, as shown in fig. 3, 6 and 7, the gland 10 further includes a drain passage 1000, and a first drain port 1001 and a second drain port 1002 located at both ends of the drain passage 1000, the first drain port 1001 being located at the side surface S0 of the body 100, and the second drain port 1002 being located at the end surface S2 of the second end E2 of the body 100.

For example, as shown in fig. 2-4, the gland 10a further includes a first sealing position PS1 and a second sealing position PS2, the first sealing position PS1 configured to provide a first seal 1011S, the second sealing position PS2 configured to provide a second seal 1012S, and both the first sealing position PS1 and the second sealing position PS2 located on the side S0.

For example, as shown in fig. 2-4, the first vent 1001 is located between the first sealing position PS1 and the second sealing position PS 2.

For example, as shown in fig. 6, the gland 10b further includes a first seal groove 1011 and a second seal groove 1012, the first seal groove 1011 is configured to receive a first seal ring 1011S, the second seal groove 1012 is configured to receive a second seal ring 1012S, and both the first seal groove 1011 and the second seal groove 1012 are located at the side surface S0. The first seal groove 1011 and the first seal 1011s form a first seal SL1, and the second seal groove 1012 and the second seal 1012s form a second seal SL 2.

For example, as shown in fig. 6, a first vent 1001 is located between a first seal groove 1011 and a second seal groove 1012.

For example, the first seal groove 1011 and the second seal groove 1012 form the seal groove 101. The first seal 1011s and the second seal 1012s constitute a first seal structure 101 s.

For example, the bleed passage 1000 is configured to circulate fluid upon failure of a portion of the first sealing structure 101 s.

For example, as shown in fig. 3, 6 and 7, the drain passage 1000 does not communicate with the primary passage 1021 and does not communicate with the secondary passage 1022.

For example, as shown in fig. 3, 6, and 7, the first drain 1001 is located on the side of the side surface S0 close to the end surface S1 of the first end E1.

For example, as shown in fig. 4, 7-9, the fluid end further includes a valve box 70. The valve box 70 includes an interior cavity 07. For example, as shown in fig. 8 and 9, the inner cavity 07 of the valve housing 70 includes a low pressure chamber 07a, an alternating chamber 07b, and a high pressure chamber 07 c.

For example, in embodiments of the present disclosure, the pressure of the fluid within high pressure chamber 07c is greater than the pressure of the fluid within low pressure chamber 07a, and the pressure of the fluid within alternating chamber 07b may be alternately varied.

As shown in fig. 7 and 9, the hydraulic end includes a press cap 20, and the press cap 20 is threadedly coupled to the valve housing 70.

As shown in fig. 7, one end of the drain passage 1000 is bored from the end surface S2 of the gland (second drain port 1002), and the other end is bored in the outer diameter of the gland (first drain port 1001). The first leakage port 1001 is arranged between two seals (a first seal SL1 and a second seal SL2), when the first seal SL1 fails, liquid leaks, the annular cavity between the valve box 70 and the gland 10 is filled with the liquid, the liquid flows to the gap between the gland 10 and the gland 20 along the leakage channel 1000, and when a certain amount of liquid is accumulated, the liquid flows out along the outer diameter (thread) or inner hole of the gland 20, at the moment, the liquid leakage is observed, which indicates that the first seal SL1 fails, so that an operator can judge the use condition of the first seal SL1 according to whether the liquid leakage exists at the position, and cannot timely react when the first seal SL1 fails, so that high-pressure liquid penetrates into the low-pressure liquid after the second seal SL2 fails, and the equipment is pressed and damaged.

For example, as shown in fig. 2 and 7, the gland 10 further includes a valve seat groove 1013, the valve seat groove 1013 is located at the first end E1 and communicates with the main flow passage 1021, and the valve seat groove 1013 has a relief groove 1013a at a side facing away from the first end E1 for reducing stress concentration.

For example, in order to facilitate the disassembly and assembly of the gland during maintenance, the gland 10 further includes a drawing hole 1003, the drawing hole 1003 is located at the second end E2 of the body 100, and the drawing hole 1003 is not communicated with the second drainage port 1002 and is not communicated with the drainage channel 1000. For example, the drawing hole 1003 is located on the axis of the body 100.

For example, as shown in fig. 2 to 4, 6 to 7, and 9, the gland 10 may be provided with flow passages (main flow passage 1021, sub flow passage 1022) and a drain passage 1000 inside, a drawing hole 1003 and a valve seat groove 1013 on an end surface, and a seal groove may be provided on an outer diameter of the gland 10. The low-pressure liquid flows through the inside of the flow passage and is formed by intersecting a main flow passage 1021 and auxiliary flow passages 1022, the axis of the main flow passage 1021 (the center line L1 of the main flow passage 1021) is overlapped with the axis of the gland 10, and the auxiliary flow passages 1022 are uniformly distributed in the circumferential direction of the gland; the bottom of the valve seat slot 1013 is a plane, the side is a conical surface, the root has a relief slot 1013a for reducing stress concentration, and the corresponding valve seat is also provided with a conical surface to match and fix.

For example, in some embodiments, as shown in fig. 2 and 3, the left side of the gland at the fluid end is not provided with a sealing groove, the sealing groove is arranged on the valve box, and the outer diameter of the gland 10 is in interference fit with the sealing element, so that the high-pressure fluid and the low-pressure fluid are prevented from being mixed. As shown in fig. 8 and 9, after the gland 10 is worn by the seal members (the first seal ring 1011s and the second seal ring 1012s), the gland can be replaced, and maintenance cost can be reduced. Note that, as shown in fig. 6, the seal groove 101 may be provided on the left side of the gland, and is not limited to the seal groove provided in the valve housing 70. Fig. 8 shows seal groove 1018 and seal groove 1019 in valve housing 70. As shown in fig. 7 and 8, a first seal 1011s is provided in the seal groove 1018, and a second seal 1012s is provided in the seal groove 1019.

Embodiments of the present disclosure provide a gland 10 that includes at least one of the following benefits.

(1) The end plug, the flow channel and the base are integrated, and multiple functions are integrated, so that the overall structure of the hydraulic end is more compact and simple, and the hydraulic end can be fixed and limited by using a common pressure cap in the hydraulic end.

(2) The gland uses as the base of disk seat, when the disk seat wearing and tearing need be changed, can be with its and gland whole change, need not use other instruments to pull out it again, avoids reducing maintenance efficiency, and maintenance time is very short when fracturing construction after all, adopts whole change can improve on-the-spot maintenance efficiency greatly.

(3) The built-in earial drainage passageway of gland, whether can be fast, direct judgement is sealed to become invalid, prevents to lead to the cluster pressure in time because of discovering, causes equipment damage, influences the fracturing construction.

(4) The hollow structure (runner) of gland makes the low pressure liquid circulation smooth and easy, and fracturing fluid all is sand inclusion fracturing fluid generally, and the risk that sand was blocked up can be reduced to a plurality of vice runners and the cooperation of large aperture sprue use.

Embodiments of the present disclosure also provide a hydraulic end including any of the above-described glands 10.

The valve box inner cavity of the hydraulic end provided by the embodiment of the disclosure is of a T-shaped structure, and the intersecting position is designed into a horn mouth form, so that the problem of stress concentration at the intersecting line of the inner cavity is solved. The valve box 70 may be referred to as a T-type valve box.

For example, as shown in fig. 8 and 9, the gland 10 is located in the low pressure chamber 07a, the inner chamber 07 of the valve box 70 has an inverted T-shaped structure, the alternating chamber 07b and the low pressure chamber 07a are disposed along an extending direction of a first axis a1 of the inner chamber 07, the alternating chamber 07b and the high pressure chamber 07c are disposed along an extending direction of a second axis a2 of the inner chamber 07, and the first axis a1 intersects the second axis a 2. The embodiment of the disclosure is illustrated with the first axis a1 perpendicular to the second axis a 2.

Fig. 8 shows a first axis a1 and a second axis a2 of the lumen 07. As shown in fig. 8, the inner chamber 07 includes a horizontal chamber 0701 and a vertical chamber 0702.

For example, as shown in fig. 8 and 9, the inner cavity of the valve housing 70 has a T-shaped structure, the inner cavity 07 is divided into a low pressure cavity 07a, an alternating cavity 07b and a high pressure cavity 07c according to the installation positions of the first valve assembly and the second valve assembly, and the intersection of the inner cavities 07 is designed in a form of a "bell mouth" and is smoothly transited, so that the stress concentration effect can be effectively improved.

The structure of the valve box of the hydraulic end provided by the embodiment of the disclosure has the following characteristics compared with the valve box of the common hydraulic end.

1) The stress concentration effect of the inner cavity is obviously improved.

The lumen of the cross-shaped intersecting structure is shown in fig. 1C, and the intersecting position includes a position Pa, a position Pb, a position Pc, and a position Pd. Stress concentration points are arranged at the position Pc and the position Pd, stress concentration is very obvious from mechanical analysis, fatigue cracks are easy to be generated, and the valve box is cracked.

The valve box in the hydraulic end provided by the embodiment of the disclosure has the advantages that the right angle does not exist at the intersecting part of the inner cavity, the transition of the intersecting part of the inner cavity is smooth, the optimal design is carried out at the position where stress concentration is most easily generated, the intersecting part is in a bell mouth shape, no stress concentration point exists, and the stress concentration effect is obviously improved by analyzing the stress concentration effect in mechanics.

2) Simple structure, the leakproofness is strong.

The valve box in usual fluid end is split type structure, and packing chamber, suction chamber (low pressure chamber) and discharge chamber (high pressure chamber) need with the bolt tight to the main part of valve box on, this structure is comparatively miscellaneous, and needs multiple sealing member to seal, has increased many places in the intangible and has leaked. The sealing surface has high processing precision, more man-hours required for the sealing surface are more, the processing efficiency is lower, and finally the sealing can not be completely ensured.

The valve box in the hydraulic end provided by the embodiment of the disclosure is of an integral structure, is tight in sealing and high-pressure resistant, uses fewer sealing elements and does not use bolts, and is simple and compact in structure and low in risk of leakage of the valve box.

3) The maintenance is convenient.

The axis of the plunger in usual fluid end is not the collineation with the axis of valve case, and the plunger can not draw out from the suction side, when the plunger damaged or need change packing package subassembly, need pull down whole fluid end, because the fluid end is heavier, can use the crane to assist during, greatly reduced maintenance efficiency, during the actual fracturing construction, the first side can not remain the long time and change the accessory. In some conventional hydraulic ports, the axis of the plunger is collinear with the axis of the horizontal chamber of the valve housing, but there are several inconveniences associated with maintaining the valve. For example, when the plunger or the packing package assembly is maintained, the diameter of the plunger is large, the plunger cannot be pulled out of the inner cavity of the valve box, the maintenance is performed after the whole hydraulic end is disassembled, and even if the diameter of the plunger is small, the plunger can be pulled out of the inner cavity of the valve box, the suction side needs to be disassembled, so that the maintenance can be performed.

The hydraulic end provided by the embodiment of the disclosure does not have the problem of inconvenient maintenance, the axis of the plunger coincides with the first axis (horizontal axis) of the valve box, the suction side of the hydraulic end is provided with the pressing cap, the axis of the pressing cap coincides with the axis of the plunger, and the hydraulic end can be operated according to the routine operation of a well site during maintenance.

For example, the most efficient conventional operations for well site servicing of a plunger or packing set assembly are: the method comprises the following steps of disassembling a pressure cap at a suction side, opening a horizontal cavity of a valve box, disassembling a hoop, disconnecting a hydraulic end from a power end, pulling out a plunger from the suction side along the axis of the horizontal cavity of the valve box by using a pulling tool, carrying out normal maintenance, recovering accessories by reverse operation according to the action after maintenance, and not disassembling the hydraulic end from a plunger pump in the whole maintenance process.

For example, as shown in fig. 4 and 7 to 9, the valve housing 70 has an upper fluid hole 700, and the upper fluid hole 700 and the high-pressure chamber 07c are arranged to be offset in the extending direction of the first axis a 1.

For example, as shown in fig. 4 and 9, the fluid end further includes a first valve assembly V1, the first valve assembly V1 being configured to open to communicate the low pressure chamber 07a and the alternating chamber 07b or to close to isolate the low pressure chamber 07a from the alternating chamber 07 b.

For example, as shown in fig. 4 and 9, the first valve assembly V1 includes a valve body 1a, a seal 1b (functioning as a seal), a valve seat 1c, a spring 1d, and a spring holder 1 e.

For example, as shown in fig. 4 and 9, the seal 1b is fitted into the valve body 1a, and when the first valve assembly V1 is opened, the valve body 1a fitted with the seal 1b is moved leftward, and the low pressure chamber 07a and the alternate chamber 07b communicate with each other.

As shown in fig. 5, the spring support 1e is a hollow structure, and includes a main body e1 and a hollow structure e0, and is limited with the valve box 70 by an inclined surface S01. Spring bracket 1e with hollow out construction e0 is favorable to the liquid circulation smooth and easy to carry on spacingly through inclined plane S01, prevent that spring bracket 1e from rocking in the horizontal intracavity of valve box 70, the horizontal chamber of corresponding valve box also is equipped with the inclined plane cooperation of inclined plane and spring bracket 1e, and spring bracket 1e passes through the inclined plane contact with valve box 70.

For example, as shown in fig. 9, the fluid end further includes a second valve assembly V2, the second valve assembly V2 being configured to open to communicate between the alternating chamber 07b and the high pressure chamber 07c or to close to isolate the alternating chamber 07b from the high pressure chamber 07 c.

For example, as shown in fig. 9, the second valve assembly V2 includes a valve body 2a, a seal 2b (functioning as a seal), a valve seat 2c, a spring 2d, and a seat 2 f.

For example, as shown in fig. 9, the seal 2b is fitted into the valve body 2a, and when the second valve assembly V2 is opened, the valve body 2a fitted with the seal 2b is moved upward, and the high-pressure chamber 07c and the alternating chamber 07b communicate with each other.

As shown in fig. 9, the second valve assembly V2 is adjacent the outlet orifice 7005 and is open to allow high pressure fluid flow during plunger travel; the first valve component V1 is close to the liquid feeding hole 700, and is opened during the return stroke of the plunger to circulate low-pressure liquid; the base 2f of the second valve unit V2 is directly fitted into the valve housing 70, and has a hardness greater than that of the valve housing 70, so that the valve housing 70 is prevented from being damaged during opening and closing (during slapping), and the service life of the valve housing 70 is prolonged.

For example, as shown in fig. 8, the valve housing 70 is formed in a flare shape at a intersection 7006 of the inner cavity 07 by machining, for example, but not limited thereto, the flare shape may be machined by boring.

For example, as shown in fig. 8 and 9, the intersection of inner cavity 07 comprises a first sub-cavity 071 and a second sub-cavity 072, the first sub-cavity 071 and the second sub-cavity 072 are arranged along the extension direction of second axis a2, the second sub-cavity 072 is closer to the portion of inner cavity 07 extending along first axis a1 (horizontal cavity) than the first sub-cavity 071, and in order to alleviate stress concentration, the maximum dimension h2 of the second sub-cavity 072 in the extension direction of second axis a2 is greater than the maximum dimension h1 of the first sub-cavity 071 in the extension direction of second axis a 2. The second valve assembly V2 is not disposed within the first sub-chamber 071 and the second sub-chamber 072. Second valve assembly V2 is located outside of first sub-chamber 071 and second sub-chamber 072. First sub-chamber 071 and second sub-chamber 072 may be cavities for fluid communication only. For example, as shown in fig. 8 and 9, second valve assembly V2 and second sub-chamber 072 are located on opposite sides of first sub-chamber 071.

For example, as shown in fig. 8 and 9, to mitigate stress concentrations, the dimension D1 of the second subcavity 072 in the direction of extension of the first axis a1 gradually increases from a location distal to the first axis a1 to a location proximal to the first axis a 1.

For example, the portion of valve box 70 used to form second subchamber 072 is angled 30-80 degrees from first axis A1. For further example, the portion of valve box 70 used to form second subchamber 072 is angled 30-60 degrees from first axis a 1.

For example, as shown in fig. 9, the first sub-cavity 071 is a cylindrical cavity, but is not limited thereto. For example, as shown in fig. 2, the second sub-cavity 072 is a truncated cone shaped cavity, but is not limited thereto.

For example, as shown in fig. 9, valve box 70 is provided with a protective jacket 73 at a position corresponding to first sub-chamber 071 and second sub-chamber 072. A protective sleeve 73 is arranged at the bell mouth position of the inner cavity 07 of the valve box 70 to protect the inner cavity 07, and the service life of the valve box 70 is prolonged.

For example, as shown in fig. 9, the gland 10 is a rotary body structure, and is horizontally placed inside the valve box 70, the left side is in contact with the first valve assembly V1, the right side is in contact with the press cap 20, and the press cap 20 is screwed into the valve box 70.

For example, as shown in fig. 9, the fluid end includes a plunger 81. The plunger 81 is a rotary body, one end of the plunger 81 reciprocates in contact with the liquid in the valve housing 70, and the other end is connected to the power end of the plunger pump via a yoke 86. For example, as shown in fig. 9, the fluid end also includes a plunger side 70 c.

For example, as shown in fig. 8, the internal cavity 09 further includes a plunger cavity 07d, the plunger cavity 07d configured to house the plunger 81. The plunger chamber 07d, the alternating chamber 07b, and the low pressure chamber 07d are arranged in this order along the extending direction of the first axis a1 of the inner chamber 07.

For example, in the embodiment of the present disclosure, the extending direction of the first axis a1 may be the arrangement direction of the alternating chamber 07b and the low pressure chamber 07a, or the extending direction of the first axis a1 may be the arrangement direction of the plunger chamber 07d, the alternating chamber 07b, and the low pressure chamber 07 a. For example, in the embodiment of the present disclosure, the extending direction of the second axis a2 may be the arrangement direction of the high pressure chamber 07c and the alternating chamber 07 b.

For example, as shown in fig. 9, the fluid end further includes a packing set assembly 82, the packing set assembly 82 including a packing set 821, a spacer ring 822, and a compression ring 823.

For example, as shown in fig. 9, the packing set 821 includes three packing rings, but the number of packing rings is not limited to that shown in the figure and may be determined as needed. For example, the material of the packing ring includes, but is not limited to, rubber.

For example, as shown in fig. 9, a lubricating oil passage 7007 is provided on the plunger side of the valve housing for lubricating a packing set 821 (rubber) to make the reciprocating motion of the plunger 81 smoother; the plunger 81 is surrounded by a packing 821, and the packing 821 plays a sealing role to prevent liquid from leaking when the plunger 81 reciprocates.

For example, as shown in fig. 9, the inner wall of the packing set 821 is in interference fit with the plunger 81 to perform a sealing function; the plunger 81 reciprocates to rub against the inner wall of the packing 821 with forced lubrication to reduce friction.

For example, the plunger 81 has a drawing hole (bolt hole) at the front end thereof, and a drawing tool is provided, and when maintenance is performed, the clip 86 is removed, disconnected from the power end, and the plunger 81 is drawn out from the suction side 70a along the first axis a1 of the valve housing 70 by the drawing tool.

For example, as shown in fig. 9, the hydraulic end also includes a packing cap 83, the packing cap 83 configured to press against the packing assembly 82.

For example, as shown in fig. 9, the packing set 821 is fixed by a packing cap 83, and the packing cap 83 is screwed to the valve housing 70. The packing gland 83 functions as: when the plunger 81 reciprocates, the packing 821 is prevented from moving axially, and the packing 821 is expanded by screwing and pressing, which is advantageous for sealing. Packing package 821's both ends are equipped with spacer ring 822 and clamping ring 823 respectively, and spacer ring 822 keeps apart packing package 821 and valve box 70, and clamping ring 823 keeps apart packing package 821 and packing pressure cap 83, and protection packing package 821 prolongs packing package 821's life. For example, the spacer ring 822 and the pressure ring 823 may be metal pieces.

For example, as shown in fig. 9, the fluid end further includes a packing sleeve 84 and a packing sleeve pressure cap 85, the plunger cavity 07d is configured to receive the plunger 81, the packing sleeve 84 is positioned between the packing assembly 82 and the valve housing 70, and the packing sleeve pressure cap 85 is configured to press the packing sleeve 84.

For example, as shown in FIG. 9, the packing set 84 is axially retained by a shoulder and packing set gland 85.

For example, as shown in FIG. 9, at least one of the packing set 84 and the packing set gland 85 is welded to the valve housing 70.

For example, as shown in FIG. 9, the packing set 84 has a hardness greater than the valve housing 70. Because the packing set 84 has a hardness higher than that of the valve housing 70, the packing set 84 is not damaged when the valve housing 70 is damaged, and therefore the packing set 84 and the valve housing 85 can be fixed by welding.

For example, as shown in FIG. 9, the outer diameter of the packing set 821 contacts the packing sleeve 84, and the inner diameter of the packing set 821 contacts the plunger 81; the front end of the packing sleeve 84 is provided with a sealing piece 7008, so that high-pressure liquid is prevented from entering a gap to cause liquid leakage and damage to a valve box; the packing set 84 is a wear-resistant member and is in interference fit with the valve housing 70, and the hardness of the packing set 84 is higher than that of the valve housing. The packing sleeve 84 is arranged to prevent the packing package 821 from being damaged due to friction, and the service life of the valve box is prolonged.

For example, as shown in fig. 9, both the inner diameter and the outer diameter of the packing set pressing cap 85 are provided with threads, the outer thread of the packing set pressing cap 85 is engaged with the valve box 70, and the inner thread of the packing set pressing cap 85 is engaged with the packing set pressing cap 83, so that the packing set pressing cap 85 can be fixed to the valve box 70 by welding in order to prevent the packing set pressing cap 85 from becoming loose when the plunger 81 reciprocates.

Fig. 9 also shows the discharge side 70b of the fluid end. The suction side 70a of the valve box 70 is provided with a liquid supply hole 700, and the discharge side 70b is provided with a discharge hole 7005. For example, the upper liquid hole 700 is connected with an upper water manifold, and low-pressure liquid flows inside; the discharge port 7005 is connected to the discharge flange, and a high-pressure liquid flows through the inside.

Fig. 9 also shows the body 77 of the valve box 70. The valve housing 70 includes a body 77 and an internal cavity 07.

For example, as shown in fig. 8 and 9, the valve housing 70 is provided with a suction-side screw 7001, a discharge-side screw 7002, and a plunger-side screw 7003. The pressure cap 20 is connected to the valve housing 70 by suction side threads 7001. The pressure cap 50 is connected to the valve housing 70 via the discharge side screw 7002. The packing set pressure cap 85 is connected to the valve housing 70 by the plunger-side threads 7003.

For example, as shown in FIG. 9, the first valve assembly V1 and the second valve assembly V2 are both one-way valves. For example, as shown in FIG. 9, the first valve assembly V1 and the second valve assembly V2 may be interchanged. For example, the second valve assembly V2 is positioned vertically, the first valve assembly V1 is positioned horizontally, and the axial directions of the first valve assembly V1 and the second valve assembly V2 are perpendicular to each other.

As shown in fig. 4 and 9, with the first valve assembly V1, the valve seat 1c is disposed in the valve seat groove 1013 of the gland 10, and the left side of the gland 10 serves as a base of the valve seat 1c for fixing the valve seat 1 c. For example, the gland 10 is used in cooperation with the valve body 1a, the seal 1b, the spring 1d, and the spring holder 1e to form a check valve. For example, the axis of the first valve assembly V1 coincides with the axis of the gland 10. When the plunger returns, the valve body 1a is opened, and low-pressure liquid enters the valve box 70; during plunger travel, the valve body 1a closes, preventing low pressure fluid from entering the valve housing 70.

For example, referring to fig. 9, the fluid entering the fluid end is described as a fracturing fluid, and the working principle of the fluid end is as follows.

During liquid suction, the plunger 81 returns (translates leftwards), the first valve assembly V1 is opened, the second valve assembly V2 is closed, and fracturing fluid flows into the alternating cavity 07b from the suction manifold through the upper fluid hole 700, the auxiliary fluid passage 1022 and the main fluid passage 1021 until the alternating cavity 07b is filled with the fracturing fluid, wherein the fluid in the inner cavity 07 is low-pressure fluid.

During discharge, the plunger 81 progresses (translates to the right), the first valve assembly V1 closes, the second valve assembly V2 opens, and the fracturing fluid flows from the alternating chamber 07b into the high pressure chamber 07c and is discharged through the discharge orifice 7005, wherein the fluid in the internal chamber 07 is high pressure fluid.

The embodiment of the present disclosure provides the fluid end having at least one of the following effects.

1) The stress concentration effect of the inner cavity is obviously improved.

The valve box at the hydraulic end provided by the embodiment of the disclosure has the advantages that the right angle does not exist at the intersecting part of the inner cavity, the intersecting part of the inner cavity is in smooth transition, the shape design is carried out at the position where stress concentration is most easily generated, the intersecting part is in a bell mouth shape, no stress concentration point exists, and the stress concentration effect is obviously improved by analyzing the stress concentration effect in mechanics.

2) Simple structure, the leakproofness is strong.

The valve box of the hydraulic end provided by the embodiment of the disclosure is of an integral structure, is tight in sealing and high-pressure resistant, uses fewer sealing elements and does not use bolts, and is simple and compact in structure, and the risk of leakage of the valve box is lower.

3) The maintenance is convenient.

According to the hydraulic end provided by the embodiment of the disclosure, the axis of the plunger coincides with the first axis (horizontal axis) of the valve box, the suction side is provided with the pressing cap (the axis of the pressing cap coincides with the axis of the plunger, and the pressing cap is detachable), and the maintenance can be performed according to the conventional operation of a well site.

Embodiments of the present disclosure also provide a plunger pump including any of the above-described fluid ends. Because the gland 10 is located on the suction side 70a of the fluid end, the gland 10 may also be referred to as a suction gland.

For example, the gland 10, fluid end containing the gland 10, and plunger pump may be used in an oil and gas field fracturing/cementing apparatus.

Embodiments of the present disclosure provide a fluid end having two sets of pressure bearing assemblies on the suction side and a plunger pump including the fluid end to facilitate maintenance and extend the service life of a valve box.

The hydraulic tip and plunger pump provided by embodiments of the present disclosure are described below.

Fig. 10 is a cross-sectional view of a fluid end provided by an embodiment of the present disclosure. Fig. 11 is a cross-sectional view of a fluid end provided by an embodiment of the present disclosure. Fig. 12A is a partial schematic view at the bleed passage in the valve housing of fig. 11. FIG. 12B is a partial schematic view of the packing set and the packing set extrusion in the valve box of FIG. 11. Fig. 13 is a schematic illustration of the regions of the internal cavity in a hydraulic-end valve housing provided by an embodiment of the present disclosure. Fig. 14 is a schematic view of a fluid end valve box provided by an embodiment of the present disclosure. Fig. 15 is a perspective view of a fluid end provided by an embodiment of the present disclosure. Fig. 16 is a schematic view of another fluid end valve box provided by embodiments of the present disclosure. FIG. 17 is a schematic illustration of a intersection of the internal chambers of a valve box in a hydraulic end provided by an embodiment of the present disclosure. Fig. 17(a) is a cross-sectional view of the XY plane of the inner chamber of the valve housing. Fig. 17(b) is a schematic view of the YZ plane of the inner cavity of the valve box. FIG. 18 is a schematic view of a intersection of the internal chambers of the valve box in another hydraulic end provided by an embodiment of the present disclosure. Fig. 18(a) is a cross-sectional view of the XY plane of the inner chamber of the valve housing. Fig. 18(b) is a schematic view of the YZ plane of the inner cavity of the valve box. Fig. 15 shows the X direction, the Y direction, and the Z direction. For example, the X direction is an extending direction of a first axis a1 mentioned later, and the Y direction is an extending direction of a second axis a2 mentioned later.

For example, the valve box shown in FIG. 8 is the valve box in the fluid end shown in FIG. 9. For example, the valve box shown in FIG. 13 is the valve box in the fluid end shown in FIG. 10. For example, the valve box shown in FIG. 14 is the valve box in the fluid end shown in FIG. 11.

The fluid ends shown in fig. 10 and 11 each include a T-shaped valve housing. The inner cavity of the T-shaped valve box is T-shaped. The fluid end shown in fig. 10 includes one set of pressure containing assemblies, while the fluid end shown in fig. 11 includes two sets of pressure containing assemblies.

As shown in fig. 11, embodiments of the present disclosure provide a fluid end comprising: a valve box 70, a first valve assembly V1, a first pressure containing assembly M1, and a second pressure containing assembly M2.

As shown in fig. 10, 11, 13, and 14, the valve housing 70 includes an inner chamber 07, and the inner chamber 07 includes an alternating chamber 07b and a low pressure chamber 07 a.

As shown in fig. 10, 11, and 13, the first valve assembly V1 is configured to open to communicate the low pressure chamber 07a and the alternating chamber 07b or to close to isolate the low pressure chamber 07a and the alternating chamber 07 b.

As shown in fig. 11, the first pressure bearing assembly M1 is in contact with the first valve assembly V1.

As shown in fig. 11, the second bearing assembly M2 is disposed in series with the first bearing assembly M1 along the extension direction of the first axis a1 of the inner cavity 07.

As shown in fig. 11, the first valve assembly V1, the first pressure-containing assembly M1 and the second pressure-containing assembly M2 are arranged in this order along the extension direction of the first axis a1 of the inner cavity 07.

Fig. 11 and 15 show the suction side 70a, the discharge side 70b and the plunger side 70c of the fluid end.

According to the hydraulic end provided by the embodiment of the disclosure, two sets of pressure bearing assemblies are arranged on the suction side 70a, namely, a first pressure bearing assembly M1 and a second pressure bearing assembly M2 are arranged, the first valve assembly V1 is connected with the valve box 70 through the first pressure bearing assembly M1 instead of being directly seated on the valve box 70, the first valve assembly V1 is not in direct contact with the valve box, the maintenance is convenient, and the service life of the valve box is prolonged.

For example, as shown in FIG. 11, a first pressure bearing assembly M1 is removably connected to the valve housing 70 and a second pressure bearing assembly M2 is removably connected to the valve housing 70 to facilitate removal of the plunger 81 from the suction side 70 a.

For example, as shown in fig. 11, the first pressure bearing assembly M1 includes a gland 13 and a gland 23, the gland 13 being closer to the first valve assembly V1 than the gland 23, the gland 23 being threadably connected to the valve housing 70.

For example, alternating gland 13 is subject to alternating loads and alternating gland 23 is subject to alternating loads. The gland 13 may also be referred to as an intermediate gland or directly as a gland and the gland 23 may also be referred to as an intermediate gland or directly as a gland.

For example, as shown in fig. 11, the maximum length of gland 13 in first axis a1 is less than the maximum length of gland 23 in first axis a 1.

In the hydraulic end provided by the embodiment of the present disclosure, the first valve component V1 is not directly "seated" on the valve box 70, but is indirectly connected with the valve box 70 through the alternating pressure cover 13, the alternating pressure cover 13 is forced to move, and therefore, the alternating pressure cap 23 is required to be used for fixing and limiting, for example, the alternating pressure cap 23 is in contact with the alternating pressure cover 13, and the alternating pressure cap 23 is fastened with the valve box 70 by screw threads, but not limited thereto. When alternating gland 13 is subjected to alternating load, load can be transmitted to the screw thread of alternating pressure cap 23, and because the contact area between alternating gland 13 and alternating pressure cap 23 is small, and the screw thread of alternating pressure cap 23 is long, through finite element analysis, the stress at the screw thread of alternating pressure cap 23 is smaller than the stress at the screw thread of the pressure cap at a common hydraulic end, and the hydraulic end provided by the embodiment of the disclosure can prolong the service life of valve box 70.

For example, as shown in fig. 11 and 12A, a first seal structure SE is provided between the alternating gland 13 and the valve housing 70, and the valve housing 70 has a bleed passage 7000, and the bleed passage 7000 is configured to circulate fluid when a portion of the first seal structure SE fails.

For example, as shown in fig. 11 and 12A, the bleed flow path 7000 extends through the body 100 of the valve housing 70. Bleed flow path 7000 leads from the outside of valve housing body 77 into interior cavity 07.

For example, as shown in fig. 11 and 12A, to facilitate manufacturing and to provide a valve box with greater strength, vent path 7000 is angled relative to first axis a1 of bore 07 such that an acute angle θ a of vent path 7000 with respect to first axis a1 of bore 07 is greater than or equal to 30 degrees and less than or equal to 60 degrees.

For example, as shown in FIG. 11, the end of the vent path 7000 remote from the internal cavity 07 is closer to the suction side 70a than the end of the vent path 7000 near the internal cavity 07. That is, as shown in fig. 11, the end of bleed flow passage 7000 remote from internal cavity 07 is further to the right than the end of bleed flow passage 7000 near internal cavity 07.

For example, as shown in fig. 11 and 12A, the first seal structure SE includes a first seal SE1 and a second seal SE2, and the end of the bleed flow passage 7000 near the gland 13 is located between the first seal SE1 and the second seal SE 2. For example, the first seal SE1 includes a seal ring, and the second seal SE2 includes a seal ring.

As shown in fig. 10 and 11, the seal groove of the first seal structure SE is provided in the alternating pressure cover 13. In other embodiments, the seal groove of the first seal structure SE may also be provided in the valve housing 70.

For example, as shown in fig. 10 and 11, the first valve assembly V1 includes a valve body 1a, a seal 1b, and a valve seat 1c, with the alternating gland 13 as a base of the valve seat 1 c.

For example, as shown in fig. 10 and 11, the first valve assembly V1 further includes a spring 1d and a spring holder 1 e.

For example, as shown in fig. 11, the spring support 1e includes a hollow structure e0, and is limited by the inclined surface S01 with the valve box 70. Spring bracket 1e with hollow out construction e0 is favorable to the liquid circulation smooth and easy to carry on spacingly through inclined plane S01, prevent that spring bracket 1e from rocking in the horizontal intracavity of valve box 70, the horizontal chamber of corresponding valve box also is equipped with the inclined plane cooperation of inclined plane and spring bracket 1e, and spring bracket 1e passes through the inclined plane contact with valve box 70.

For example, as shown in fig. 11, the seal 1b is fitted into the valve body 1a, and when the first valve assembly V1 is opened, the valve body 1a fitted with the seal 1b is moved leftward, and the low pressure chamber 07a and the alternating chamber 07b communicate with each other.

The first valve assembly V1 of the fluid end shown in fig. 10 includes a base 1 f. While the crossover gland 13 in the fluid end shown in figure 10 includes a base for use as the first valve assembly V1. Also, the valve housing of the fluid end shown in fig. 11 is provided with a bleed passage 7000, whereas the valve housing of the fluid end shown in fig. 10 is not provided with a bleed passage.

For example, as shown in fig. 10, 11, 13, 14, and 16, the valve housing 70 has a liquid feed hole 700. Fig. 10, 11, 13, 14 show the liquid wells on one side. Fig. 16 shows a double-sided weep hole 700: upper fluid port 700a and upper fluid port 700 b. The valving 70 may be single sided or double sided. For example, the liquid on one side can meet the operation of small discharge capacity and low sand ratio, and the sand blocking phenomenon is avoided; the liquid feeding on the two sides can meet the operation of large discharge capacity and high sand ratio, the liquid feeding stability can be ensured by the liquid feeding holes on the two sides, and the sand blocking risk is reduced.

For example, as shown in fig. 11, the alternating gland 13 has a low pressure fluid passage 130, and the low pressure fluid passage 130 communicates with an upper fluid port 700 of the valve housing 70. The low pressure fluid passage 130 may also be referred to as a first passage 130.

For example, as shown in fig. 11, the alternating pressure cap 23 has a low pressure fluid passage 230, and the low pressure fluid passage 230 communicates with an upper fluid hole 700 of the valve housing 70. The low pressure fluid passage 230 may also be referred to as a second passage 230.

For example, as shown in fig. 11, the second pressure bearing assembly M2 includes a suction gland 33 and a suction pressure cap 43, the suction gland 33 is closer to the first pressure bearing assembly M1 than the suction pressure cap 43, and the suction pressure cap 43 is screw-coupled with the valve housing 70.

For example, as shown in fig. 11, a first pressure bearing assembly M1 and a second pressure bearing assembly M2 are disposed on opposite sides of the upper fluid opening 700. For example, as shown in fig. 11, a first pressure bearing assembly M1 and a second pressure bearing assembly M2 are provided on both sides of the upper fluid port 700 in the extending direction of the first axis a 1. As shown in fig. 11, the first pressure bearing assembly M1 is on the left side of the upper fluid port 700, and the second pressure bearing assembly M2 is on the right side of the upper fluid port 700.

For example, as shown in fig. 11, alternating gland 13 and suction gland 33 are disposed on opposite sides of alternating gland 23. For example, as shown in fig. 11, the alternating pressure cap 23 and the suction gland 33 are disposed on opposite sides of the upper fluid hole 700. As shown in fig. 11, the alternate-pressure cap 23 is provided on the left side of the upper fluid hole 700, and the suction cap 33 is provided separately on the right side of the upper fluid hole 700.

The first valve assembly V1 of the fluid end shown in fig. 4 includes a base 1 f. And the use of the crossover gland 13 in the fluid end shown in fig. 11 as the first valve assembly V1 includes a seat to make the fluid end more compact. The base 1f shown in fig. 4 has a low-pressure liquid passage 330, and the low-pressure liquid passage 330 communicates with the upper liquid hole 700 of the valve housing 70.

For example, as shown in fig. 10, 11, 13 and 14, the inner cavity 07 has an inverted T-shaped configuration, and the alternating cavity 07b and the high pressure cavity 07c are disposed along the extending direction of the second axis a2 of the inner cavity 07, and the first axis a1 intersects the second axis a 2. Thus, the fluid end includes an interior cavity 07 having an inverted T-shaped configuration, and the valve housing 70 may be referred to as a T-shaped valve housing. The embodiment of the disclosure is illustrated with the first axis a1 perpendicular to the second axis a 2.

For example, as shown in fig. 11, the fluid end further includes a second valve assembly V2, the inner cavity 07 further includes a high pressure chamber 07c, and the second valve assembly V2 is configured to open to communicate between the alternating chamber 07b and the high pressure chamber 07c or to close to separate the alternating chamber 07b and the high pressure chamber 07 c.

For example, as shown in fig. 11, the second valve assembly V2 includes a valve body 2a, a seal 2b (functioning as a seal), a valve seat 2c, a spring 2d, and a seat 2 f.

For example, as shown in fig. 11, the seal 2b is fitted into the valve body 2a, and when the second valve assembly V2 is opened, the valve body 2a fitted with the seal 2b is moved upward, and the high-pressure chamber 07c and the alternating chamber 07b communicate with each other.

As shown in fig. 11, the second valve assembly V2 is adjacent the outlet orifice 7005 and is open to allow high pressure fluid flow during plunger travel; the first valve component V1 is close to the liquid feeding hole 700, and is opened during the return stroke of the plunger to circulate low-pressure liquid; the base 2f of the second valve unit V2 is directly fitted into the valve housing 70, and has a hardness greater than that of the valve housing 70, so that the valve housing 70 is prevented from being damaged during opening and closing (during slapping), and the service life of the valve housing 70 is prolonged.

For example, as shown in fig. 11, the fluid end further includes a third pressure bearing assembly M3, the third pressure bearing assembly M3 is located in the inner cavity, and the third pressure bearing assembly M3 and the second valve assembly V2 are sequentially arranged in the extending direction of the second axis a 2. The area of the internal chamber 07 between the second valve assembly V2 and the third pressure containing assembly M3 is the high pressure chamber 07 c.

As shown in fig. 11, the third bearing assembly M3 includes a gland 40 and a gland 50. The gland 40 may be referred to as a discharge gland 40 and the gland 50 may be referred to as a discharge gland 50.

For example, as shown in fig. 11, the upper fluid hole 700 and the high pressure chamber 07c are arranged to be offset in the extending direction of the first axis a 1.

For example, as shown in fig. 11 and 14, the intersection of inner cavity 07 comprises a first sub-cavity 071 and a second sub-cavity 072, the first sub-cavity 071 and the second sub-cavity 072 are arranged along the extension direction of second axis a2, the second sub-cavity 072 is closer to the portion of inner cavity 07 extending along first axis a1 (horizontal cavity) than the first sub-cavity 071, and in order to alleviate stress concentration, the maximum dimension h2 of the second sub-cavity 072 in the extension direction of second axis a2 is greater than the maximum dimension h1 of the first sub-cavity 071 in the extension direction of second axis a 2. The second valve assembly V2 is not disposed within the first sub-chamber 071 and the second sub-chamber 072. Second valve assembly V2 is located outside of first sub-chamber 071 and second sub-chamber 072. First sub-chamber 071 and second sub-chamber 072 may be cavities for fluid communication only.

For example, as shown in fig. 11 and 14, to mitigate stress concentrations, the dimension D1 of the second subcavity 072 in the direction of extension of the first axis a1 gradually increases from a location distal to the first axis a1 to a location proximal to the first axis a 1. That is, the dimension D1 of the second subchamber 072 in the direction of extension of the first axis a1 gradually increases from top to bottom.

For example, as shown in fig. 11 and 14, the portion of valve box 70 used to form second subchamber 072 is angled 30-80 degrees from first axis a 1. For further example, the portion of valve box 70 used to form second subchamber 072 is angled 30-60 degrees from first axis a 1.

For example, as shown in fig. 11, the first sub-cavity 071 is a cylindrical cavity, but is not limited thereto. For example, as shown in fig. 11, the second sub-cavity 072 is a truncated cone shaped cavity, but is not limited thereto.

For example, as shown in fig. 11, valve box 70 is provided with a protective jacket 73 at a position corresponding to first sub-chamber 071 and second sub-chamber 072. A protective sleeve 73 is arranged at the bell mouth position of the inner cavity 07 of the valve box 70 to protect the inner cavity 07, and the service life of the valve box 70 is prolonged.

For example, as shown in fig. 11, the valve housing 70 is formed into a flare shape at the intersection 7006 of the inner cavity 07 by machining, for example, but not limited thereto, the flare shape may be machined by boring.

For example, as shown in fig. 4 and 11, a boot 73 is provided at the "flare" of the interior chamber of the valve housing 70 in order to prevent wear to the interior chamber. After the inner cavity is abraded, the surface roughness of the inner cavity is increased, and in addition, fatigue cracks are easily generated on the surface of the inner cavity through high-pressure operation, so that the joint (matched) protection mode of the bell mouth and the protective sleeve 73 at the intersecting position can reduce the cracking risk and prolong the service life of the valve box. For example, the protective sleeve 73 may be mounted to the inside of the valve housing by cold-fitting, but is not limited to cold-fitting, and the protective sleeve 73 may be mounted by machining or hot-working.

Fig. 17 and 18 show the bell mouth 76, the horizontal chamber 0701, and the body 77 of the valve housing 70.

The valve box inner cavity of the hydraulic end provided by the embodiment of the disclosure is of a T-shaped structure, and the intersecting position is designed into a horn mouth form, so that the problem of stress concentration at the intersecting line of the inner cavity is solved.

For example, as shown in fig. 11 and 14, the alternating pressure cover 13 is located in the low pressure chamber 07a, the alternating pressure cap 23 is located in the low pressure chamber 07a, the inner chamber 07 of the valve box 70 has an inverted T-shaped structure, the alternating chamber 07b and the low pressure chamber 07a are arranged along the extending direction of the first axis a1 of the inner chamber 07, the alternating chamber 07b and the high pressure chamber 07c are arranged along the extending direction of the second axis a2 of the inner chamber 07, and the first axis a1 intersects the second axis a 2. Fig. 14 shows the first axis a1 and the second axis a2 of the lumen 07. As shown in fig. 14, the inner chamber 07 includes a horizontal chamber 0701 and a vertical chamber 0702.

For example, as shown in fig. 11 and 14, the inner cavity of the valve housing 70 has a T-shaped structure, the inner cavity 07 is divided into a low pressure cavity 07a, an alternating cavity 07b and a high pressure cavity 07c according to the installation positions of the first valve assembly and the second valve assembly, and the intersection of the inner cavities 07 is designed in a "bell mouth" shape and is smoothly transited, so that the stress concentration effect can be effectively improved.

Compared with a common hydraulic end valve box, the hydraulic end valve box provided by the embodiment of the disclosure has the characteristics as described above, and is not described in detail herein.

The hydraulic end provided by the embodiment of the disclosure does not have the problem of inconvenient maintenance, the axis of the plunger coincides with the first axis (horizontal axis) of the valve box, the suction side is provided with the first pressure-bearing assembly M1 and the second pressure-bearing assembly M1, the axis of the first pressure-bearing assembly M1 and the axis of the second pressure-bearing assembly M1 both coincide with the axis of the plunger, and the hydraulic end can be maintained by normal operation of a well site.

For example, as shown in fig. 11, the alternating pressure cover 13 is a rotary body structure, and is horizontally placed inside the valve box 70, the left side is in contact with the first valve assembly V1, the right side is in contact with the alternating pressure cap 23, and the alternating pressure cap 23 is screwed into the valve box 70.

For example, as shown in fig. 11 and 12B, the hydraulic end includes a plunger 81. The plunger 81 is a rotary body, one end of the plunger 81 reciprocates in contact with the liquid in the valve housing 70, and the other end is connected to the power end of the plunger pump via a yoke 86.

For example, as shown in fig. 11 and 12B, the hydraulic end further includes a packing assembly 82, the packing assembly 82 includes a packing 821, a spacer ring 822, and a compression ring 823.

For example, as shown in fig. 11 and 12B, the packing set 821 includes three packing rings, but the number of packing rings is not limited to that shown in the drawings and may be determined as needed. For example, the material of the packing ring includes, but is not limited to, rubber.

For example, as shown in fig. 11 and 12B, the plunger side 70c of the valve housing 70 is provided with a lubricating oil passage 7007 for lubricating a packing set 821 (rubber) to make the reciprocating motion of the plunger 81 smoother; the plunger 81 is surrounded by a packing 821, and the packing 821 plays a sealing role to prevent liquid from leaking when the plunger 81 reciprocates.

For example, as shown in fig. 11 and 12B, the inner wall of the packing set 821 is in interference fit with the plunger 81 to perform a sealing function; the plunger 81 reciprocates to rub against the inner wall of the packing 821 with forced lubrication to reduce friction.

For example, as shown in fig. 11 and 12B, the hydraulic end also includes a packing cap 83, the packing cap 83 configured to press against the packing assembly 82.

For example, as shown in fig. 11 and 12B, the packing 821 is fixed by a packing cap 83, and the packing cap 83 is screwed to the valve housing 70. The packing gland 83 functions as: when the plunger 81 reciprocates, the packing 821 is prevented from moving axially, and the packing 821 is expanded by screwing and pressing, which is advantageous for sealing. Packing package 821's both ends are equipped with spacer ring 822 and clamping ring 823 respectively, and spacer ring 822 keeps apart packing package 821 and valve box 70, and clamping ring 823 keeps apart packing package 821 and packing pressure cap 83, and protection packing package 821 prolongs packing package 821's life. For example, the spacer ring 822 and the pressure ring 823 may be metal pieces.

For example, as shown in fig. 11 and 12B, the hydraulic end further includes a packing sleeve 84 and a packing sleeve pressure cap 85, the plunger cavity 07d is configured to receive the plunger 81, the packing sleeve 84 is positioned between the packing assembly 82 and the valve housing 70, and the packing sleeve pressure cap 85 is configured to press the packing sleeve 84.

For example, as shown in fig. 11 and 12B, the packing sleeve 84 is axially retained by a shoulder and packing sleeve gland 85.

For example, as shown in fig. 11 and 12B, at least one of the packing set 84 and the packing set gland 85 is welded to the valve housing 70.

For example, as shown in fig. 11 and 12B, the packing set 84 has a hardness greater than that of the valve housing 70. Because the packing set 84 has a hardness higher than that of the valve housing 70, the packing set 84 is not damaged when the valve housing 70 is damaged, and therefore the packing set 84 and the valve housing 85 can be fixed by welding.

For example, as shown in fig. 11 and 12B, the packing set 821 has an outer diameter that contacts the packing sleeve 84 and an inner diameter that contacts the plunger 81; the front end of the packing sleeve 84 is provided with a sealing piece 7008, so that high-pressure liquid is prevented from entering a gap to cause liquid leakage and damage to a valve box; the packing set 84 is a wear-resistant member and is in interference fit with the valve housing 70, and the hardness of the packing set 84 is higher than that of the valve housing. The packing sleeve 84 is arranged to prevent the packing package 821 from being damaged due to friction, and the service life of the valve box is prolonged.

For example, as shown in fig. 11 and 12B, both the inner and outer diameters of the packing set pressing cap 85 are provided with threads, the external threads of the packing set pressing cap 85 are engaged with the valve housing 70, and the internal threads of the packing set pressing cap 85 are engaged with the packing set pressing cap 83, so that the packing set pressing cap 85 can be fixed to the valve housing 70 by welding in order to prevent the packing set pressing cap 85 from becoming loose when the plunger 81 reciprocates.

Fig. 11, 14 and 15 also show the discharge side 70b of the fluid end. As shown in fig. 11 and 15, the suction side 70a of the valve box 70 is provided with a liquid supply hole 700, and the discharge side 70b is provided with a discharge hole 7005. For example, the upper liquid hole 700 is connected with an upper water manifold, and low-pressure liquid flows inside; the outlet orifice 7005 may be connected to the outlet flange and internally communicate a high pressure fluid.

For example, as shown in fig. 10, 11, and 14, the valve housing 70 is provided with a suction-side screw 7001, a discharge-side screw 7002, and a plunger-side screw 7003. The suction cap 43 is connected to the valve housing 70 by suction side threads 7001. The pressure cap 50 is connected to the valve housing 70 via the discharge side screw 7002. The packing set pressure cap 85 is connected to the valve housing 70 by the plunger-side threads 7003.

For example, as shown in fig. 10 and 11, the first valve assembly V1 and the second valve assembly V2 are both one-way valves. For example, as shown in fig. 10 and 11, the first valve assembly V1 and the second valve assembly V2 may be interchanged. For example, the second valve assembly V2 is positioned vertically, the first valve assembly V1 is positioned horizontally, and the axial directions of the first valve assembly V1 and the second valve assembly V2 are perpendicular to each other.

For example, as shown in fig. 10 and 11, the second valve assembly V2 is vertically placed, the first valve assembly V1 is horizontally placed, and the valve seats of the first valve assembly V1 and the second valve assembly V2 are both matched and fixed with the valve box through the conical surfaces, but the first valve assembly V1 shown in fig. 10 is limited by the hole diameter, so that the plunger cannot be pulled out from the suction side during maintenance and needs to be pulled out from the opposite side, and the maintenance is complicated. The valve body with the embedded seal constitutes a valve body assembly and the valve seat and the base constitute a valve seat assembly. The valve body assembly is matched with the valve seat assembly through an inclined plane, the valve body is in rigid contact with the valve seat, the sealing piece in the valve assembly is in non-rigid contact with the base, and the sealing piece in the valve assembly plays a sealing role.

As shown in fig. 11, with the first valve assembly V1, the valve seat 1c is disposed in the valve seat groove of the alternating pressure cover 13, and the left side of the alternating pressure cover 13 serves as a base of the valve seat 1c for fixing the valve seat 1 c. For example, the alternating gland 13 is used in cooperation with the valve body 1a, the seal 1b, the spring 1d and the spring holder 1e to form a check valve. For example, the axis of the first valve assembly V1 coincides with the axis of the crossover gland 13. When the plunger returns, the valve body 1a is opened, and low-pressure liquid enters the valve box 70; during plunger travel, the valve body 1a closes, preventing low pressure fluid from entering the valve housing 70.

For example, referring to fig. 11, taking the fluid entering the fluid end as fracturing fluid as an example, the working principle of the fluid end is as follows.

During liquid suction, the plunger 81 returns (moves leftwards), the first valve assembly V1 is opened, the second valve assembly V2 is closed, and fracturing fluid flows into the alternating cavity 07b from the suction manifold through the upper fluid hole 700, the low-pressure fluid channel 230 and the low-pressure fluid channel 130 until the alternating cavity 07b is filled with the fracturing fluid, wherein the fluid in the inner cavity 07 is low-pressure fluid.

FIG. 19 is a schematic illustration of a second valve assembly in a hydraulic end provided by an embodiment of the present disclosure. As shown in fig. 19, the valve body 2a includes a boss a1 and a claw a2, the boss a1 has a function of limiting the spring 2d and preventing the spring 2d from moving radially, the boss a1 also has a function of limiting the opening height of the valve body 2a, and when the second valve assembly V2 is opened, the boss a1 of the valve body 2a is in rigid contact with the boss of the discharge gland 40, so that the uniform height of each opening is realized.

As shown in fig. 19, the inner hole of the base 2f is in clearance fit with the jaw a2, and plays a role in guiding the jaw a2 to prevent the valve body 2a from deflecting under the impact of high-pressure liquid; valve seat 2c and base 2f are split type structure, and the hardness of base 2f is higher than the hardness of base 2f, and when the purpose prevented that valve body 2a from slapping valve seat 2c, the inclined plane of valve seat 2c took place wearing and tearing, and it is relatively poor to avoid wearing and tearing valve seat 2c to cause the leakproofness, also avoids reducing the life of valve seat and valve body simultaneously.

The structure and function of the first valve assembly can be referred to the above description. Except that the boss of the valve body 1a is in rigid contact with the boss of the spring holder.

Fig. 20 is a schematic diagram of a valve housing on the discharge side of a hydraulic end provided by an embodiment of the present disclosure. Fig. 21 is a schematic view of a sealing structure on a discharge side of a fluid end according to an embodiment of the present disclosure. Fig. 22 is a schematic diagram of a valve housing on the suction side of a hydraulic end provided by an embodiment of the present disclosure. Fig. 23 is a schematic view of a sealing structure on the suction side of a fluid end according to an embodiment of the present disclosure.

Fig. 19 shows a seal 1021, where the seal 1021 comprises a sealing ring with a sealing groove at the corresponding position of the base 2 f. As shown in fig. 10 and 11, a seal 1021 is provided to effect a seal between the second valve assembly V2 and the valve box 70.

Fig. 20 shows a seal groove 901 and fig. 21 shows a seal 902. A seal 902 is provided to effect a seal against the high pressure chamber of the inner chamber.

Fig. 22 shows seal groove 903 and fig. 23 shows seal 904. A seal 904 is provided to effect a seal against the low pressure chamber of the internal chamber.

For example, the seal and the groove for disposing the seal may be referred to as a seal structure. For example, the seal 904 and the groove for disposing the seal 904 may be referred to as a second seal structure, and the seal 902 and the groove for disposing the seal 902 may be referred to as a third seal structure. The seal comprises a seal ring.

For example, in an embodiment of the present disclosure, the fluid end includes: the valve box comprises an inner cavity, and the inner cavity comprises an alternating cavity and a low-pressure cavity; a first valve assembly located in the inner chamber and configured to open to communicate the low pressure chamber and the alternating chamber or to close to isolate the low pressure chamber and the alternating chamber; a pressure-bearing structure 99, at least a portion of the pressure-bearing structure 99 being located in the low-pressure chamber, and a first seal structure located between the pressure-bearing structure 99 and the valve box; at least one of the valve box and the pressure-containing structure 99 has a bleed passage configured to communicate fluid upon failure of a portion of the first seal structure. For example, a pressure bearing structure 99 is located in the internal cavity.

For example, the vent path may be vent path 1000 or vent path 7000, as described above.

For example, in some embodiments, as shown in fig. 7 and 9, the pressure-bearing structure 99 may include the gland 10 described above. In this case, the drain passage 1000 is provided in the gland 10.

For example, as shown in fig. 7 and 9, the pressure-bearing structure 99 includes a gland 10 and a pressure cap 20, the pressure cap 20 is screwed with the valve housing 70, and the drain passage 100 is located in the gland 10.

For example, in other embodiments, as shown in FIG. 11, the bearing structure 99 may include the first bearing assembly M1 described above. In this case, the bleed flow path 7000 is provided in the valve housing 70.

For example, the first seal structure may be the first seal structure 101s or the first seal structure SE described above.

For example, as shown in fig. 9, the first seal structure 101s includes a first seal SL1 and a second seal SL2, the drain passage 1000 includes a first drain 1001 and a second drain 1002, the first drain 1001 is closer to the first seal structure 101s than the second drain 1002, and the first drain 1001 is located between the first seal SL1 and the second seal SL 2.

For example, as shown in fig. 12A, the first seal structure SE includes a first seal SE1 and a second seal SE2, the drain passage 1000 includes a first drain 1001 and a second drain 1002, the first drain 1001 is closer to the first seal structure 101s than the second drain 1002, and the first drain 1001 is located between the first seal SE1 and the second seal SE 2.

For example, as shown in fig. 11, the bearing structure 99 includes a first bearing assembly M1 and a second bearing assembly M2, and the first valve assembly V1, the first bearing assembly M1 and the second bearing assembly M2 are sequentially arranged along the extending direction of the first axis a1 of the inner cavity.

The arrangement of the packing assembly 82, the packing pressing cap 83, the packing sleeve 84, the packing sleeve pressing cap 85 and the like on the left side portion of the hydraulic end shown in fig. 10 and 11 can be referred to the above description, and the description thereof is omitted.

For example, the fluid end and plunger pump described above may be used in a fracturing/cementing apparatus for an oil and gas field.

The above description is only for the specific embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present disclosure, and all the changes or substitutions should be covered within the scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. A liquid end, comprising:

a valve box, including an inner cavity, the inner cavity includes an alternating cavity and a low pressure cavity;

a first valve assembly, located in the inner chamber, configured to open to communicate the low pressure chamber and the alternating chamber or configured to close to separate the low pressure chamber and the alternating chamber;

a pressure-bearing structural member, at least a portion of which is located in the low-pressure cavity, and

a first sealing structure, located between the pressure-bearing structural member and the valve box;

Wherein, at least one of the valve box and the pressure-receiving structural member has a relief passage, and the relief passage is configured to flow fluid when a portion of the first sealing structure fails.

2. The hydraulic end according to claim 1, wherein the first sealing structure comprises a first seal and a second seal, and the leakage channel comprises a first leakage port and a second leakage port, The first leak opening is closer to the first sealing structure than the second leak opening, and the first leak opening is located between the first seal and the second seal.

3 . The hydraulic end of claim 1 , wherein the drain passage is provided in the valve box, and the drain passage is arranged obliquely with respect to the first axis of the inner cavity. 4 .

4. The hydraulic end of claim 3, wherein an acute angle formed by the drain passage and the first axis of the lumen is greater than or equal to 30 degrees and less than or equal to 60 degrees.

5. The hydraulic end according to claim 3, wherein the pressure-bearing structural member comprises a first pressure-bearing assembly and a second pressure-bearing assembly, the first valve assembly, the first pressure-bearing assembly, and the The second pressure bearing components are arranged in sequence along the extending direction of the first axis of the inner cavity.

6. The hydraulic end of claim 5, wherein the first pressure bearing assembly includes an alternating pressure cap and an alternating pressure cap, the alternating pressure cap being closer to the alternating pressure cap than the alternating pressure cap In the first valve assembly, the alternating pressure cap is connected with the valve box through threads.

7 . The hydraulic end according to claim 1 , wherein the pressure-bearing structural member comprises a pressure cap and a pressure cap, the pressure cap is connected with the valve box by screws, and the relief channel is located in the pressure cap. 8 . cover.

8. The fluid end of claim 7, wherein the gland comprises:

a body, the body is cylindrical, and the body includes a first end, a second end, and a side surface connecting the first end and the second end;

a main flow channel extending along the axis of the body;

a plurality of secondary flow channels, each of which is communicated with the main flow channel;

a first opening, located at the first end, in communication with the main channel; and

A plurality of second openings are located on the side surface of the body, and the secondary flow channel is communicated with at least one of the plurality of second openings.

9. The liquid end of claim 8, wherein the gland has a low pressure fluid passage that communicates with an upper fluid hole of the valve box.

10. The hydraulic end according to any one of claims 1-9, wherein the inner cavity of the valve box is in an inverted T-shaped structure, and the alternating cavity and the low-pressure cavity are located along the first line of the inner cavity. The extension direction of an axis is set.

11. The hydraulic end according to claim 10, wherein the valve box further comprises a high-pressure chamber; the alternating chamber and the high-pressure chamber are arranged along the extension direction of the second axis of the inner chamber, the The first axis intersects the second axis.

12 . The hydraulic end according to claim 11 , wherein the valve box has an upper liquid hole, and the upper liquid hole and the high pressure chamber are staggered in the extending direction of the first axis. 13 .

13. The hydraulic end according to any one of claims 1-9, further comprising a plunger, a packing pack assembly, a packing press cap, a packing sleeve and a packing sleeve press cap, wherein the inner cavity is further includes a plunger cavity configured to receive the plunger, the packing sleeve is located between the packing pack assembly and the valve box, and the packing sleeve gland is configured to The packing sleeve applies pressure, and the packing pressure cap is configured to apply pressure to the packing pack assembly.

14. The hydraulic end according to claim 13, wherein the hardness of the packing sleeve is greater than that of the valve box, and the packing sleeve pressing cap is welded to the valve box.

15. The hydraulic end of claim 13, wherein the packing gland is welded to the valve box.

16. A plunger pump comprising a fluid end according to any one of claims 1-15.