CN112049941A

CN112049941A - Pressure reducing regulating valve

Info

Publication number: CN112049941A
Application number: CN202010738861.5A
Authority: CN
Inventors: 孙志强; 胡庆斌; 王新成; 王阳; 彭仁杰; 陈礼敏; 乔元
Original assignee: Beijing Aerospace Propulsion Institute
Current assignee: Beijing Aerospace Petrochemical Technology and Equipment Engineering Corp Ltd
Priority date: 2020-07-28
Filing date: 2020-07-28
Publication date: 2020-12-08

Abstract

The invention discloses a pressure reducing regulating valve, which comprises: the valve comprises a valve body, a main valve seat, a valve core assembly and a packing box; the valve body is of a three-way structure with a hollow interior; the main valve seat is arranged at the bottom of the valve body, and the stuffing box is arranged at the top of the valve body; the valve core assembly passes through the inner cavity of the stuffing box and the inner cavity of the main valve seat to be installed; wherein the internal cavity of the main valve seat serves as a main valve passage. The invention can be applied to the pressure/flow regulation of high pressure difference liquid medium, and is particularly suitable for occasions requiring large adjustable ratio at the same time.

Description

Pressure reducing regulating valve

Technical Field

The invention belongs to the technical field of valves, and particularly relates to a pressure reducing regulating valve.

Background

Under large pressure difference, when the regulating valve adopts a single-seat throttling mode, when a medium flows through a throat part, the flow velocity of the medium is rapidly increased due to the rapid reduction of the overflowing area, the static pressure is reduced due to the conversion into kinetic energy according to the conservation of energy, and when the static pressure is reduced to be lower than the saturated vapor pressure of the current temperature of the medium, the liquid medium is converted into bubbles, and the process is called flash evaporation; after the medium flows through the throat, the flow rate is gradually reduced due to the increase of the flow area, the static pressure is recovered, and when the static pressure is recovered to be higher than the saturated vapor pressure, bubbles are broken, and the process is called cavitation erosion. The flash evaporation and the cavitation erosion can cause serious damage to the valve internals, and simultaneously, the expansion and the interaction of two-phase flow cause noise because the medium flash evaporation forms gas-liquid two-phase flow; after the pressure of the medium in the pipeline behind the valve is recovered, the breakage of the bubbles aggravates the noise and brings about severe vibration.

And, with the industrial development, the occasions requiring large adjustable ratio at the same time under large pressure difference are more and more. The difficulty of realizing large adjustable ratio by using a single valve is higher due to the factors of the machining accuracy, the sealing capability of the valve, the sensitivity of a control system in micro flow and the like.

To solve the above problems, there is a combination of a multi-stage sleeve/labyrinth and a pilot structure, which is used to provide a large adjustable ratio in an attempt to solve flash evaporation and cavitation using the multi-stage sleeve/labyrinth. However, this method has the following disadvantages:

1) the processing of the sleeve and the labyrinth is relatively complex;

2) the size of the flow channel is small, and the flow channel is easy to block by a medium;

3) the pilot structure does not have a multi-stage pressure reduction function, and is easily damaged when the opening degree is small.

And a duplex control means is also adopted, namely two pressure reducing valves are connected in parallel, one valve is used in small flow, the other valve is used in large flow, and the use cost is increased invisibly.

Therefore, it is urgently needed to develop a more suitable valve type to deal with the occasions requiring large pressure difference adjustment and large adjustable ratio.

Disclosure of Invention

The technical problem of the invention is solved: the pressure reducing regulating valve can be applied to pressure/flow regulation of high-pressure-difference liquid media, and is particularly suitable for occasions requiring large adjustable ratio.

In order to solve the above technical problem, the present invention discloses a pressure reducing regulating valve, comprising: the valve comprises a valve body, a main valve seat, a valve core assembly and a packing box;

the valve body is of a three-way structure with a hollow interior;

the main valve seat is arranged at the bottom of the valve body, and the stuffing box is arranged at the top of the valve body; wherein, the main valve seat is coaxial with the stuffing box;

the valve core assembly passes through the inner cavity of the stuffing box and the inner cavity of the main valve seat to be installed; wherein the internal cavity of the main valve seat serves as a main valve passage.

In the above-described reduced-pressure regulator valve, further comprising: the packing machine comprises a middle flange, a packing assembly, a packing press plate, a middle flange bolt nut, a packing press plate bolt nut, a valve seat set screw, a packing box winding pad and a pressing valve seat winding pad;

the stuffing box is sleeved on the top of the valve body and is tightly pressed by the middle flange, and the middle flange is fastened on the valve body through a middle flange bolt and a middle flange nut; a stuffing box winding pad is arranged between the contact surfaces of the stuffing box and the valve body;

the main valve seat is sleeved at the bottom of the valve body and is fixedly connected with the valve body through a valve seat set screw; a pressing valve seat winding pad is arranged between the contact surfaces of the main valve seat and the valve body.

The packing assembly is arranged between the valve core assembly and the inner cavity of the packing box, the top of the packing assembly is connected with the packing press plate, and the packing press plate is connected with the top of the packing box through a bolt and a nut of the packing press plate.

In the above pressure reducing regulator valve, the inner chamber structure of the main valve seat includes: the valve seat is characterized by comprising at least three uniformly distributed guide ribs, at least two throttling cavities, a valve seat throttling surface and a valve seat sealing surface, wherein the throttling cavities are different in flow area, are arranged in series, and are connected with the circular truncated cone in shape.

In the pressure reducing regulator valve described above, the spool assembly includes: the main valve core, the guide valve core, the spring gland and the elastic component;

the elastic component, the spring gland and the main valve core are sequentially arranged from top to bottom;

a main valve spool mounted in the internal cavity of the main valve seat forming a main valve flow path for adjusting the flow area of the main valve passage;

the pilot valve core is arranged in the main valve core to form a pilot valve flow path;

the spring gland is fixed on the main valve core through a bolt.

In the pressure reducing regulator valve described above, the main spool includes: the valve core comprises a guide valve seat sealing surface, a throttling core, a main valve core sealing surface, a main valve core head, a valve core throttling surface and a main valve core internal flow passage;

the guide valve seat sealing surface and the main valve core sealing surface are respectively positioned on two end surfaces of the main valve core;

the number of the throttling cores is not less than two, and the throttling cores are distributed on the outer side of the main valve core along the axial direction;

the head of the main valve core is positioned at the top of the main valve core; the head of the main valve core is always positioned in the uniformly distributed guide ribs so as to ensure the stability of the valve rod under the medium scouring working condition;

the valve core throttling surface is positioned on the side surface of the main valve core;

the hollow inner cavity of the main valve core forms the main valve core internal flow passage, and the guide valve core is arranged in the main valve core internal flow passage and can move up and down in the main valve core internal flow passage.

In the above-mentioned pressure-reducing regulating valve,

when the main valve flow path is closed, the valve core throttling surface is correspondingly attached to the valve seat throttling surface of the same stage, the sealing surface of the main valve core and the sealing surface of the valve seat form a sealing pair, and the main valve flow path is cut off;

when the flow path of the pilot valve and the flow path of the main valve are closed simultaneously, the sealing surface of the pilot valve seat is in sealing fit with the sealing surface of the pilot valve core, and the valve is sealed.

In the pressure reducing regulator valve described above, the pilot valve body includes: the guide valve core comprises a flow channel window at the end part of the guide valve core, a seal surface of the guide valve core, a guide valve balance hole, a valve rod, a guide valve core limiting block and an opening and closing guide ring;

one end of the valve rod is connected with an external actuating mechanism, and the other end of the valve rod is connected with the opening and closing guide ring; the valve rod drives the valve core assembly to move up and down axially through the force provided by the external actuating mechanism, so that the valve is opened, closed and adjusted;

the opening and closing guide ring is connected with the guide valve core limiting block through an elastic part;

the pilot valve balance hole is arranged on the pilot valve core limiting block;

the sealing surface of the guide valve core is arranged between the flow channel window at the end part of the guide valve core and the guide valve core limiting block and is used for sealing the internal flow channel of the main valve core.

In the above-mentioned pressure-reducing regulating valve,

the guide valve core adjusts the opening or closing of a flow channel window at the end part of the guide valve core under the control of the valve rod;

when the guide valve core moves towards the direction far away from the internal flow passage of the main valve core, the main valve core is driven to move in the same direction through the spring gland and the guide valve core limiting block so as to open the main valve passage.

In the pressure reducing regulating valve, a stuffing box bottom runner window is arranged on the stuffing box; the shapes of a flow channel window at the bottom of the stuffing box and a flow channel window at the end part of the guide valve core are symmetrical along the axial direction and are increased and decreased in equal proportion in size; in the moving process of the guide valve core, the medium flow areas of a flow channel window 51 at the bottom of the stuffing box and a flow channel window at the end part of the guide valve core are increased and decreased in equal proportion;

the flow channel window at the bottom of the stuffing box is the medium flow inlet of the pilot valve flow path and is controlled by the opening and closing guide ring on the valve rod to realize opening or closing.

In the pressure-reducing regulator valve, the elastic member is a compression spring or a disc spring.

The invention has the following advantages:

(1) the invention discloses a pressure reduction regulating valve, which can ensure that a medium is not subjected to cavitation under high pressure difference, can realize a valve with a large adjustable ratio, and has a simple structure and easy processing; the main valve and the pilot valve have a multi-stage pressure reduction function; and the circulation diameter is larger, and the medium can not block the flow channel.

(2) The invention discloses a pressure reduction regulating valve which is provided with a pilot valve and a main valve, wherein the flow passage area of the pilot valve is smaller by one order of magnitude relative to the flow area of the main valve, so that the minimum flow passing through the pilot valve can be greatly reduced, and the adjustable ratio of the valve is improved.

Drawings

FIG. 1 is a schematic diagram of a pressure reducing regulator valve according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of a main valve seat in an embodiment of the present invention;

FIG. 3 is a schematic view of a valve cartridge assembly in both a natural state and a compressed state (pilot valve closed) in accordance with an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of an integrated valve stem and guide valve core in an embodiment of the invention;

FIG. 5 is a schematic illustration of a stuffing box flow passage portion in an embodiment of the invention;

FIG. 6 is an enlarged view of a bottom channel window and an end channel window of a pilot valve core of an embodiment of the present invention;

FIG. 7 is a schematic diagram of the flow of the medium when the pressure reducing regulating valve is opened to a small degree in the embodiment of the invention;

fig. 8 is a schematic diagram of the medium flow when the pressure reducing regulating valve is opened to a large degree in the embodiment of the invention.

Detailed Description

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

The invention provides a pressure-reducing regulating valve which comprises a valve body, a main valve seat and a packing box. Wherein, a valve rod controlled by external power is arranged in the stuffing box; and the stuffing box is provided with a stuffing box bottom runner window which is used as a medium inflow port of the flow path of the pilot valve; the opening or closing of the flow channel window at the bottom of the stuffing box is controlled by an opening and closing guide ring on the valve rod. The valve core assembly: the main valve core and the pilot valve core are provided with an internal flow passage of the main valve core and are used for forming a main valve flow passage and a pilot valve flow passage; the main valve core is arranged in the inner cavity of the main valve seat to form a main valve flow path for adjusting the flow area of the main valve channel; the guide valve core is arranged in the main valve core and is controlled by the valve rod to adjust the opening or closing of a flow passage window at the end part of the guide valve core; when the guide valve core moves towards the direction far away from the internal flow passage of the main valve core, the main valve core is driven to move in the same direction by the limiting structures of the main valve core and the guide valve core to open the main valve passage.

As shown in fig. 1, in the present embodiment, the pressure reduction regulating valve includes: the valve comprises a valve body 1, a main valve seat 2, a valve core assembly 3 and a packing box 5.

The valve body 1 is used as a shell structure of the pressure reducing regulating valve and is of a three-way structure with a hollow interior. The main valve seat 2 is arranged at the bottom of the valve body 1, the stuffing box 5 is arranged at the top of the valve body 1, and the main valve seat 2 is coaxial with the stuffing box 5. The valve core assembly 3 is installed by penetrating an inner cavity of the stuffing box 5 and an inner cavity of the main valve seat 2; wherein the inner cavity of the main valve seat 2 acts as a main valve passage.

In this embodiment, the reduced-pressure regulator valve may further include a fastening seal member; wherein, the fastening sealing component is used for fastening the sealing valve body 1, the main valve seat 2 and the stuffing box 5, and specifically comprises: the packing machine comprises a middle flange 6, a packing assembly 10, a packing press plate 11, a middle flange bolt nut 12, a packing press plate bolt nut 13, a valve seat fastening screw 14, a packing box winding pad 15 and a pressing valve seat winding pad 16.

Preferably, the stuffing box 5 is sleeved on the top of the valve body 1 and is tightly pressed through the middle flange 6, the middle flange 6 is fastened on the valve body 1 through the middle flange bolt and nut 12, and the stuffing box winding pad 15 is arranged between the contact surface of the stuffing box 5 and the valve body 1, so that the medium is prevented from leaking from the gap between the valve body 1 and the stuffing box 5.

Preferably, the main valve seat 2 is sleeved at the bottom of the valve body 1 and is fixedly connected with the valve body 1 through a valve seat fastening screw 14, and a pressing valve seat winding pad 16 is arranged between the contact surface of the main valve seat 2 and the valve body 1, so that the medium is prevented from leaking from a gap between the valve body 1 and the valve seat 2.

Preferably, the packing assembly 10 is arranged between the valve core assembly 3 and the inner cavity of the stuffing box 5, the top of the packing assembly 10 is connected with the packing press plate 11, and the packing press plate 11 is connected with the top of the stuffing box 5 through a packing press plate bolt nut 13. In the process of screwing the bolt and the nut 13 of the packing pressing plate, the packing pressing plate 11 transmits force to the packing assembly 10, and the packing assembly 10 is compressed, so that the packing assembly 10 is tightly attached to the valve rod 324 and the inner wall of the packing box 5 respectively, and the medium is prevented from leaking from the gap between the three.

In an embodiment of the present invention, as shown in fig. 2, the inner cavity structure of the main valve seat 2 may specifically include: the valve seat comprises at least three uniformly distributed guide ribs 21, at least two throttling cavities 22 which are different in flow area, arranged in series and connected with the circular truncated cone in shape, a valve seat throttling surface 23 and a valve seat sealing surface 24.

In the embodiment of the present invention, as shown in fig. 3 and 4, the spool assembly 3 may specifically include: main spool 31, pilot spool 32, spring gland 33, and resilient member 34. Wherein, the elastic component 34, the spring gland 33 and the main valve core 31 are sequentially arranged from top to bottom; a main valve spool 31 is installed in the inner cavity of the main valve seat 2, forming a main valve flow path for adjusting the flow area of the main valve passage; the pilot valve core 32 is installed in the main valve core 31 to form a pilot valve flow path; the spring gland 33 is fixed on the main valve core 31 through bolts; an elastic member 34 is installed between the open/close guide ring 326 and the spring cover 33, and the elastic member 34 is used for maintaining the relative position of the pilot valve core 32 and the main valve core 31 stable during the movement process, and making the main valve core 31 have the tendency to move toward the main valve seat 2 when the main valve is not opened.

In the embodiment of the present invention, main spool 31 may specifically include: a pilot seat sealing surface 311, a spool 312, a main spool sealing surface 313, a main spool head 314, a spool throttle surface 315, and a main spool internal flow passage 316.

Guide valve seat sealing surface 311 and main valve element sealing surface 313 are respectively located on two end surfaces of main valve element 31; the number of the throttling cores 312 is not less than two, and the throttling cores are distributed on the outer side of the main valve core 31 along the axial direction; the main valve core head 314 is positioned at the top of the main valve core 31, and the main valve core head 314 is always positioned in the uniformly distributed guide ribs 21 so as to ensure the stability of the valve rod 324 under the medium flushing working condition; spool restriction surface 315 is located on the side of main spool 31; the hollow interior of main spool 31 defines main spool internal flow passage 316. pilot spool 32 is mounted within main spool internal flow passage 316 so as to be movable up and down within main spool internal flow passage 316.

Preferably, when the main valve flow path is closed, the valve body throttling surface 315 is correspondingly attached to the valve seat throttling surface 23 of the same step, the main valve body sealing surface 313 forms a sealing pair with the valve seat sealing surface 24, and the main valve flow path is cut off; when the pilot valve flow path and the main valve flow path are closed at the same time, the pilot valve seat sealing surface 311 is in sealing contact with the pilot valve core sealing surface 322 of the pilot valve core 32, and the valve is sealed.

In the embodiment of the present invention, the pilot valve core 32 may specifically include: a pilot valve core end flow passage window 321, a pilot valve core sealing surface 322, a pilot valve balancing hole 323, a valve rod 324, a pilot valve core limiting block 325 and an opening and closing guide ring 326.

One end of the valve rod 324 is connected with an external actuating mechanism, and the other end is connected with an opening and closing guide ring 326; the valve rod 324 drives the valve core assembly 3 to move axially up and down by the force provided by the external actuator, so as to open, close and adjust the valve. The pilot valve balancing hole 323 is arranged on the pilot valve core limiting block 325; the pilot valve element sealing surface 322 is disposed between the pilot valve element end flow passage window 321 and the pilot valve element stopper 325, and is used for sealing the main valve element internal flow passage 316. The open/close guide ring 326 is connected to the guide spool stopper 325 via the elastic member 34.

As mentioned above, the pilot valve element 32 can slide up and down in the main valve element internal flow passage 316, up until contacting the spring gland 33, and down until the pilot valve element sealing surface 322 is attached to the pilot valve seat sealing surface 311; accordingly, the elastic member 34 is gradually compressed during the upward movement of the guide valve body 32, and the amount of compression is reduced during the downward movement, so that the spring cover 33 guides the elastic member 34 during the movement. The elastic member 34 may be a cylindrical compression spring or a disc spring.

Preferably, the pilot valve core 32 adjusts the opening or closing of the pilot valve core end flow passage window 321 under the control of the valve rod 324; when the pilot valve spool 32 moves away from the main valve spool internal flow passage 316, the main valve spool 31 is driven to move in the same direction by the spring gland 33 and the pilot valve spool stopper 325, so as to open the main valve passage.

In this embodiment, as shown in fig. 5, a stuffing box 5 is provided with a stuffing box bottom flow channel window 51, and the stuffing box bottom flow channel window 51 is a medium flow inlet of a pilot valve flow path and is controlled by an opening and closing guide ring 326 on a valve rod 324 to open or close. Wherein, the shape of the flow channel window 51 at the bottom of the stuffing box and the flow channel window 321 at the end part of the guide valve core are symmetrical along the axial direction and are increased and decreased in equal proportion in size; in the moving process of the guide valve core 32, the medium flow areas of the stuffing box bottom flow passage window 51 and the guide valve core end flow passage window 321 are increased and decreased in equal proportion. For example, during the upward movement of the stem 324, the stuffing box bottom flow passage window 51 is gradually exposed from the bottom to the top, and the guide valve core end flow passage window 321 is gradually exposed from the top to the bottom, with the exposed area always maintaining a certain ratio, as shown in fig. 6. When the pilot valve is closed, the opening and closing guide ring 326 is driven by the valve rod 324 to shield the flow channel window 51 at the bottom of the stuffing box, and the sealing surface 322 of the pilot valve core is attached to the sealing surface 311 of the pilot valve seat to form sealing; when the pilot valve is opened, the flow channel window 51 at the bottom of the stuffing box is gradually exposed and is communicated with the flow channel window 321 at the end part of the pilot valve core exposed at the same time, the sealing surface 322 of the pilot valve core is separated from the sealing surface 311 of the pilot valve seat, and a medium flows in from the flow channel window 51 at the bottom of the stuffing box and flows out after passing through the valve rod balancing hole 323, the flow channel window 321 at the end part of the pilot valve core and the internal flow channel 316. The flow characteristics of the valve can be changed by changing the shapes of the two windows, namely the stuffing box bottom flow channel window 51 and the pilot valve core end flow channel window 321, and the common flow characteristics comprise linearity, equal percentage, quick opening and the like.

In the embodiment of the present invention, as can be seen from fig. 1 to 8, the main valve flow path is formed by matching the main valve seat 2 and the main valve core 31, the inner cavity of the main valve seat 2 has not less than two throttling cavities 22 with different flow areas and a group of not less than three evenly distributed guide ribs 21, the throttling cavities 22 are in a cylindrical and circular truncated cone shape, and not less than two throttling cavities 22 with different flow areas are axially arranged in series. Corresponding to the main valve seat 2, at least two truncated cone-shaped throttling cores 312 are arranged on the outer side of the main valve core 31, the at least two truncated cone-shaped throttling cores 312 can axially move in the throttling cavity 22, and meanwhile, the flow areas of all stages of the main flow path are changed, so that the adjustment and pressure reduction of the main flow path are realized. When the main valve flow path is closed, the valve body orifice surface 315 is brought into contact with the valve seat orifice surface 23 of the same step, and the end seal surface 313 of the main valve body 31 forms a seal pair with the seal surface 24 of the main valve seat 2 to shut off the main valve flow path, as shown in fig. 7.

When the valve is closed, the pilot valve flow path is closed simultaneously with the main valve flow path. The guide valve core sealing surface 322 is attached to the guide valve seat sealing surface 311, the main valve core sealing surface 313 is attached to the valve seat sealing surface 24, and the valve is sealed. When the valve is adjusted at a small flow rate (from the separation of the sealing surface 322 of the pilot valve core and the sealing surface 311 of the pilot valve seat to the moment that the upper surface of the limit block 325 does not touch the lower surface of the spring gland 33), as shown in fig. 7, due to the acting force of the elastic component 34, the sealing surface 313 of the main valve core and the sealing surface 24 of the valve seat are still attached, the main valve flow path is still closed, the valve stem 324 drives the pilot valve core 32 to slide in the main valve core 31 in a guiding manner, only the flow area of the pilot valve flow path is changed for flow rate adjustment, and the flow channel window 51 at the bottom of the stuffing box and the; when the valve flow further increases to the maximum opening (after the upper surface of the limit block 325 touches the lower surface of the spring gland 33), as shown in fig. 8, the pilot valve flow path is completely opened, the valve rod 324 continues to move upwards, the limit block 325 drives the spring gland 33 and the main valve element 31 fixed together to move upwards together, the main valve element sealing surface 313 is separated from the main valve seat sealing surface 24, the main valve flow path is opened, and at this time, the medium passes through the multi-stage channel 4 formed by the main valve element and the main valve seat; similarly, as the valve rod moves axially, the flow area of the multistage flow passage 4 increases or decreases proportionally, and the possibility of cavitation is reduced. In the upward movement process of the valve core assembly 3, the head position 314 of the main valve core is always inside the uniformly distributed guide ribs 21, so that the stability of the valve rod under the medium scouring working condition can be ensured. Conversely, when the flow rate is reduced, the opening degree of the main valve is reduced along with the flow rate until the main valve is closed (at the moment, the pilot valve is still opened), and the opening degree of the pilot valve is gradually reduced along with the further reduction of the flow rate until the pilot valve is closed.

When the valve core assembly 3 moves to a certain opening degree, different positions of the throttling cavity 22 and the throttling surfaces 315 of the valve cores at the same level form throttling rings with different flow areas, the flow capacity of the valve at the opening degree is determined, and the flow resistance coefficient of the valve is changed by changing the opening degree, so that the pressure/flow of the valve is adjusted. A medium enters a multistage flow passage 4 formed by the valve core assembly 3 and the main valve seat 2, the flow capacity of the multistage flow passage 4 is dynamic variable quantity, the valve core assembly 3 moves upwards, and the flow capacity is increased; the valve core assembly 3 moves downwards, and the flow capacity is reduced. At any opening of the valve core component 3, the expansion flow channel 41 in the multistage flow channel 4 decelerates the medium, the contraction flow channel 42 turns and accelerates the medium, and the differential pressure is distributed on the multistage in the processes of continuous deceleration, direction change and acceleration. Compared with single-seat throttling, the pressure difference born by each stage is small, and the static pressure can be stably maintained above the saturated vapor pressure, so that the generation of cavitation and cavitation is effectively prevented, and the noise and vibration of a pipeline behind the valve are eliminated; meanwhile, the flow velocity of the medium is low, the valve internals are not washed greatly, and the service life of the valve internals is prolonged.

When the main valve core 31 acts, because the pilot valve core 32 is opened, the pressure on the upper surface of the main valve core can be partially discharged from the pilot valve flow passage 43, the pressure difference between the upper surface and the lower surface of the main valve is reduced, the unbalanced force of the valve switch is reduced, and the actuating mechanism can be reduced; when the valve is closed, because the pilot valve is closed, the medium force completely acts on the upper surface of the main valve, the sealing specific pressure of the valve is increased, and the sealing grade of the valve is improved.

It should be noted that, in this embodiment, the number of the main valve core flow passages may be set according to an actual working condition, so as to ensure that the medium does not flash; meanwhile, a larger flow area is reserved, and the valve is ensured not to be jammed in action.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make variations and modifications of the present invention without departing from the spirit and scope of the present invention by using the methods and technical contents disclosed above.

Those skilled in the art will appreciate that the invention may be practiced without these specific details.

Claims

1. A pressure reducing regulator valve, comprising: the valve comprises a valve body (1), a main valve seat (2), a valve core assembly (3) and a packing box (5);

the valve body (1) is of a three-way structure with a hollow interior;

the main valve seat (2) is arranged at the bottom of the valve body (1), and the stuffing box (5) is arranged at the top of the valve body (1); wherein the main valve seat (2) is coaxial with the stuffing box (5);

the valve core assembly (3) is installed by penetrating through an inner cavity of the stuffing box (5) and an inner cavity of the main valve seat (2); wherein the inner cavity of the main valve seat (2) serves as a main valve passage.

2. The reduced pressure regulator valve according to claim 1, further comprising: the packing machine comprises a middle flange (6), a packing assembly (10), a packing press plate (11), a middle flange bolt nut (12), a packing press plate bolt nut (13), a valve seat set screw (14), a packing box winding pad (15) and a pressing valve seat winding pad (16);

the stuffing box (5) is sleeved on the top of the valve body (1) and is tightly pressed through the middle flange (6), and the middle flange (6) is fastened on the valve body (1) through a middle flange bolt nut (12); a stuffing box winding pad (15) is arranged between the contact surfaces of the stuffing box (5) and the valve body (1);

the main valve seat (2) is sleeved at the bottom of the valve body (1) and is fixedly connected with the valve body (1) through a valve seat fastening screw (14); a pressing valve seat winding pad (16) is arranged between the contact surfaces of the main valve seat (2) and the valve body (1).

The packing component (10) is arranged between the inner cavity of the valve core component (3) and the packing box (5), the top of the packing component (10) is connected with the packing press plate (11), and the packing press plate (11) is connected with the top of the packing box (5) through a packing press plate bolt nut (13).

3. The pressure reducing regulating valve according to claim 1, wherein the internal cavity structure of the main valve seat (2) comprises: the valve seat is characterized by comprising at least three uniformly distributed guide ribs (21), at least two throttling cavities (22) which are different in flow area, arranged in series and connected with the circular truncated cone in shape, a valve seat throttling surface (23) and a valve seat sealing surface (24).

4. The pressure reducing regulator valve according to claim 3, wherein the spool assembly (3) includes: a main valve core (31), a pilot valve core (32), a spring gland (33) and an elastic component (34);

the elastic component (34), the spring gland (33) and the main valve core (31) are sequentially arranged from top to bottom;

a main valve spool (31) mounted in the internal cavity of the main valve seat (2) forming a main valve flow path for adjusting the flow area of the main valve passage;

the pilot valve core (32) is arranged in the main valve core (31) to form a pilot valve flow path;

the spring gland (33) is fixed on the main valve core (31) through bolts.

5. The pressure reducing regulator valve according to claim 4, wherein the main spool (31) includes: a guide valve seat sealing surface (311), a throttling core (312), a main valve core sealing surface (313), a main valve core head (314), a valve core throttling surface (315) and a main valve core internal flow passage (316);

the guide valve seat sealing surface (311) and the main valve core sealing surface (313) are respectively positioned on two end surfaces of the main valve core (31);

the number of the throttling cores (312) is not less than two, and the throttling cores are distributed on the outer side of the main valve core (31) along the axial direction;

the main valve core head (314) is positioned at the top of the main valve core (31); the head (314) of the main valve core is always positioned in the uniformly distributed guide ribs (21) so as to ensure the stability of the valve rod (324) under the medium flushing working condition;

the valve core throttling surface (315) is positioned on the side surface of the main valve core (31);

the hollow inner cavity of the main valve core (31) forms the main valve core internal flow passage (316), and the valve core (32) is installed in the main valve core internal flow passage (316) and can move up and down in the main valve core internal flow passage (316).

6. The reduced-pressure regulator valve according to claim 5,

when the main valve flow path is closed, the valve core throttling surface (315) is correspondingly attached to the valve seat throttling surface (23) of the same grade, the main valve core sealing surface (313) and the valve seat sealing surface (24) form a sealing pair, and the main valve flow path is cut off;

when the pilot valve flow path and the main valve flow path are closed simultaneously, the sealing surface (311) of the pilot valve seat is in sealing joint with the sealing surface (322) of the pilot valve core (32) of the pilot valve, and the valve is sealed.

7. The pressure reducing regulator valve according to claim 5, wherein the pilot spool (32) includes: the device comprises a pilot valve core end flow channel window (321), a pilot valve core sealing surface (322), a pilot valve balancing hole (323), a valve rod (324), a pilot valve core limiting block (325) and an opening and closing guide ring (326);

one end of the valve rod (324) is connected with an external actuating mechanism, and the other end of the valve rod is connected with the opening and closing guide ring (326); the valve rod (324) drives the valve core assembly (3) to move up and down axially through the force provided by the external actuating mechanism, so that the valve is opened, closed and adjusted;

the opening and closing guide ring (326) is connected with the guide valve core limiting block (325) through an elastic component (34);

the pilot valve balance hole (323) is arranged on the pilot valve core limiting block (325);

the guide valve core sealing surface (322) is arranged between the guide valve core end flow passage window (321) and the guide valve core limiting block (325) and is used for sealing the main valve core internal flow passage (316).

8. The reduced-pressure regulator valve according to claim 7,

the pilot valve core (32) is controlled by the valve rod (324) to adjust the opening or closing of a flow channel window (321) at the end part of the pilot valve core;

when the guide valve core (32) moves towards the direction far away from the main valve core internal flow passage (316), the main valve core (31) is driven to move in the same direction through the spring gland (33) and the guide valve core limiting block (325) so as to open the main valve passage.

9. The pressure-reducing regulating valve according to claim 7, characterized in that the stuffing box (5) is provided with a stuffing box bottom runner window (51); wherein, the shape of the flow channel window (51) at the bottom of the stuffing box and the shape of the flow channel window (321) at the end part of the guide valve core are symmetrical along the axial direction and are increased and decreased in equal proportion in size; in the moving process of the guide valve core (32), the medium flow areas of a flow channel window (51) at the bottom of the stuffing box and a flow channel window (321) at the end part of the guide valve core are increased and decreased in equal proportion;

the stuffing box bottom flow channel window (51) is a medium inlet of a pilot valve flow path and is controlled by an opening and closing guide ring (326) on a valve rod (324) to realize opening or closing.

10. The pressure-reducing regulator valve according to claim 4, wherein the elastic member (34) is a compression spring or a disc spring.