CN112984207A

CN112984207A - Pressure reducing valve

Info

Publication number: CN112984207A
Application number: CN202110384358.9A
Authority: CN
Inventors: 张正凯; 陈震翔; 刘青青
Original assignee: Ackam Jiangsu Industrial Technology Co ltd
Current assignee: Ackam Jiangsu Industrial Technology Co ltd
Priority date: 2021-04-09
Filing date: 2021-04-09
Publication date: 2021-06-18

Abstract

The invention relates to the technical field of valves, in particular to a pressure reducing valve which comprises a valve body, wherein a liquid inlet flow passage and a liquid outlet flow passage are arranged on the valve body, a middle flow passage is arranged between the liquid inlet flow passage and the liquid outlet flow passage in the valve body, a valve seat is arranged on the middle flow passage, a valve core is arranged in the valve seat in a sliding manner, the end face of one end, matched with the valve seat, of the valve core is drawn inwards to form a first hollow cavity, and a small hole for communicating the liquid inlet flow passage and the liquid outlet flow passage is formed in the side wall of the first hollow cavity.

Description

Pressure reducing valve

Technical Field

The invention relates to the technical field of valves, in particular to a pressure reducing valve.

Background

The existing high-temperature high-pressure steam pressure reducing valve adopts a self-sealing structure, a throttling pressure reducing element adopts a porous sleeve type, the upper end of a sleeve is provided with a flange outer ring, the lower end of the sleeve is provided with an inner circle which is positioned with a valve seat, the valve seat is fixed on a valve body, and a similar sleeve part with a throttling small hole is fixed on the lower end face, see patents with patent numbers of CN201166191, CN104179989A and the like, and has the following problems:

the radial constraints of the sleeve are: the upper part is constrained by the valve cover and the lower part is constrained by the valve seat. The sleeve is axially unconstrained and can be compressed upwards along with the valve cover to generate displacement with the self-sealing ring along with the pressure rise of the medium in the valve cavity. The larger the pressure is, the larger the displacement is, and when the valve is subjected to a shell strength test, the upward displacement generated by the valve is maximum; because the sleeve can generate displacement upwards, and the maximum displacement after the valve shell test can not be accurately controlled, the distance between the lowest row of throttling small holes of the sleeve and the sealing surface of the valve core is increased and is uncontrollable, a stroke blind area of the valve is generated, and the flow characteristic curve of the valve is changed, so that the regulation performance of the pressure reducing valve is seriously influenced, the rated flow capacity of the pressure reducing valve is seriously influenced, the rated effective stroke of the pressure reducing valve is seriously influenced, and particularly the pressure reducing valve with equivalent percentage flow characteristic is seriously influenced;

in addition, the elastic force of a common spring is small, the friction force generated by the flange surface of the pilot valve core and the valve core cover is not large, the valve core is easy to twist under the convection of high-speed steam entering small holes on the periphery of the sleeve, the rigidity of the spring can be influenced, and the performance and the service life of the spring are reduced.

Disclosure of Invention

The invention provides a pressure reducing valve without a stroke blind area, which aims to solve the problem that a dead area is formed on a pressure reducing valve in a sleeve form to influence a flow characteristic curve in the prior art.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the utility model provides a pressure reducing valve, includes the valve body, the valve body on be equipped with feed liquor runner and go out the liquid flow way, the valve body in be equipped with middle runner between feed liquor runner and the liquid flow way, be equipped with the disk seat on the middle runner, the disk seat in slide and be equipped with the case, the terminal surface of case and disk seat complex one end inwards take out the shell and form first cavity, and first hollow lateral wall is equipped with the aperture that is used for communicateing feed liquor runner and liquid flow way.

Furthermore, the side wall of the valve core is provided with a bulge for limiting the position of the valve core in a closed state, the edge of the bulge extends out of a first conical surface to serve as a sealing surface of the valve core, and the valve seat is provided with a second conical surface matched with the first conical surface.

Furthermore, the included angle between the oblique line of the longitudinal section of the first conical surface and the motion direction of the valve core is 25-35 degrees. The valve core sealing surface adopts a conical surface form, the thrust of the actuating mechanism is smaller than that of a plane sealing surface, the conical surface sealing surface is larger than pressure, the self-centering function is realized, and the valve seat can be better aligned for sealing.

Furthermore, the valve body on still be equipped with self sealss valve gap, self sealss valve gap have the centre bore, it is equipped with the valve rod that is used for pulling case motion to slide in the centre bore, the case cover on the valve rod, and have the spring that is used for the case reset between valve rod and the case, self-sealing valve has the guiding hole on covering, the case keep away from the one end of disk seat and slide in the guiding hole.

Furthermore, the end face of one end, far away from the valve seat, of the valve core is drawn inwards to form a second hollow, the side wall of the second hollow, close to the end, is fixed with a valve core cover, the valve rod is provided with a shaft collar, the shaft collar is arranged on the inner side of the valve core cover, and the spring is arranged between the shaft collar of the valve rod and the bottom wall of the second hollow.

Furthermore, the hollow lateral wall of second be equipped with the keyway, the keyway in be equipped with and prevent changeing the key, the lateral wall of collar be equipped with prevent changeing the spout that the key matches, the valve body on be fixed with the stand, the valve rod on be fixed with the stand assorted prevent changeing the clamp splice.

Further, the stand on be fixed with the support upper cover jointly, be equipped with support upper cover axle sleeve between support upper cover and the valve rod, the support on cover and be fixed with electric support, be fixed with electric actuator on the electric support, electric actuator's flexible end is connected with the valve rod through clamp splice and second gland nut.

Further, the valve body is internally provided with a step, the valve body is connected with a valve seat pressing ring for pressing the valve seat to the step through threads, and a metal winding pad is arranged between the valve seat and the step.

Further, the tip that is close to the guiding hole of centre bore lateral wall of self sealss valve gap be equipped with first annular, first annular in be equipped with the valve gap axle sleeve, the tip of the centre bore lateral wall of self sealss valve gap keeping away from the guiding hole be equipped with the second annular, the second annular in from inside to outside be equipped with packing pad, filler spacer ring and packing pressure cover in proper order, packing pad and all be equipped with the filler between the spacer ring and between filler spacer ring and the packing pressure cover, the packing pressure cover outside press the packing clamp plate, the packing clamp plate fix on the self-sealing valve cover through first full-thread double-screw bolt and first gland nut.

Further, case and self sealss valve gap's guiding hole lateral wall between be equipped with the guide ring, the valve body in seted up the holding tank, the holding tank inside callipers have four ring-openings, four ring-openings one side be equipped with and be used for the sealed valve body and the self sealss valve gap between the self sealss valve gap circle, four ring-openings and self sealss are pressed between the circle and have the self sealss clamping ring, four ring-openings opposite side be equipped with the valve gap pull ring, valve gap pull ring and self sealss valve body between be connected through second full thread double-screw bolt and first gland nut.

Has the advantages that:

(1) the invention has no stroke blind area, and the flow capacity, flow characteristic curve and adjusting performance of the valve are more ensured;

(2) the valve core type of the single seat is equivalent to the mode that the original sleeve is arranged on the valve core in a modified mode, and the valve core type of the single seat is simple in structure, convenient to install and maintain and capable of balancing the sleeve;

(3) the valve core sealing surface of the invention adopts a conical surface form, the thrust of the actuating mechanism is smaller than that of a plane sealing surface, the sealing specific pressure of the conical surface sealing surface is larger, and the valve core has a self-centering function and can better align the valve seat for sealing;

(4) the anti-rotation clamping block ensures that the actuator does not rotate and plays a role in protecting the actuator;

(5) the valve inner part is connected without bolts, so that the phenomenon of bolt loosening or bolt falling-in is avoided, and the operation is safer and more reliable.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is a state diagram of a prior art pressure reducing valve prior to pressure testing;

FIG. 2 is a state diagram of a prior art pressure reducing valve after a pressure test;

FIG. 3 is a diagram of a closed state of a prior art pressure relief valve during operation;

fig. 4 is a structural view of the pressure reducing valve of the present invention.

The valve comprises a valve body 1, a valve body 2, a metal winding pad 3, a valve core 301, a first hollow 302, a second hollow 4, a valve seat 5, a valve seat press ring 6, a spring 7, a valve rod 8, a guide ring 9, a valve core cover 10, a self-sealing valve cover 101, a guide hole 11, a self-sealing ring 12, a self-sealing press ring 13, a four-open ring 14, a valve cover pull ring 15, a packing pad 16, a packing 17, a packing spacer ring 18, a packing press sleeve 19, a packing press plate 20, a first full-thread stud 21, a first compression nut 22, a column 23, a first inner hexagonal socket head screw 24, a support upper cover 25, a support upper cover shaft sleeve 26, a clamping block 27, an electric support 28, an electric actuator 29, a first bolt 30, a first fastening nut 31, a first elastic pad 32, a first flat pad 33, a second compression nut 34, a first elastic pad 34, a second elastic pad 33, a packing nut, a packing press sleeve, the anti-rotation valve comprises a second stud 35, a second fastening nut 36, a second elastic cushion 37, a second flat cushion 38, a second hexagon socket head cap screw 39, an anti-rotation clamping block 40, a second full-thread stud 41, a valve cover shaft sleeve 42 and an anti-rotation key.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

As shown in fig. 1-3, a self-sealing structure is adopted for the existing high-temperature and high-pressure steam pressure reducing valve, a porous sleeve type is adopted for the throttling pressure reducing element, a flange outer ring is arranged at the upper end of the sleeve, an inner circle is arranged at the lower end of the sleeve in a positioning way with a valve seat, the valve seat is screwed and pressed on the valve body by a pressing ring thread, the sleeve is fixed on the lower end face of the valve cover by a bolt, and the following problems exist:

(1) the radial constraints of the sleeve are: the upper part is constrained by the valve cover and the lower part is constrained by the valve seat. The sleeve is axially unconstrained and can be compressed upwards along with the valve cover to generate displacement with the self-sealing ring along with the pressure rise of the medium in the valve cavity. The larger the pressure is, the larger the displacement is, and when the valve is subjected to a shell strength test, the upward displacement L' -L generated by the valve reaches the maximum; because the sleeve can generate displacement upwards, and the maximum displacement after the valve shell test can not be accurately controlled, the distance between the lowest row of throttling small holes of the sleeve and the sealing surface of the valve core is increased and is uncontrollable, a stroke blind area of the valve is generated, and the flow characteristic curve of the valve is changed, so that the regulation performance of the pressure reducing valve is seriously influenced, the rated flow capacity of the pressure reducing valve is seriously influenced, the rated effective stroke of the pressure reducing valve is seriously influenced, and particularly the pressure reducing valve with equivalent percentage flow characteristic is seriously influenced;

(2) after the valve cover is connected with the sleeve, the size in the height direction is increased, so that the hoisting height is higher, and difficulty is brought to the disassembly and assembly during field maintenance to a certain extent;

(3) the valve rod is connected with the pilot valve core by screwing a pin tightly through threads. The valve cover and the sleeve are connected by bolts, and due to different materials, different shapes and different wall thicknesses of workpieces, the three workpieces have different thermal expansion coefficients under the high-temperature and high-pressure steam environment, so that the bolts are loosened or disengaged; the fastening pin of the valve rod and the pilot valve core is easy to be disengaged, so that the threads of the valve rod and the pilot valve core are loosened.

(4) Because the elastic force of the spring F1 is small, the friction force generated by the flange surface of the pilot valve core and the valve core cover is not large, the valve core is easy to twist under the convection of high-speed steam entering the small holes on the periphery of the sleeve, the rigidity of the spring can be influenced, and the performance and the service life of the spring are reduced

As shown in fig. 4, the pressure reducing valve of the present invention includes a valve body 1, a liquid inlet flow channel and a liquid outlet flow channel are disposed on the valve body 1, a middle flow channel is disposed between the liquid inlet flow channel and the liquid outlet flow channel in the valve body 1, a valve seat 4 is disposed on the middle flow channel, a valve core 3 is slidably disposed in the valve seat 4, an end surface of one end of the valve core 3, which is matched with the valve seat 4, is drawn inward to form a first hollow 301, and a small hole for communicating the liquid inlet flow channel and the liquid outlet flow channel is disposed on a side.

The side wall of the valve core 3 is provided with a bulge for limiting the position of the valve core 3 in a closed state, the edge of the bulge extends out of a first conical surface to be used as a sealing surface of the valve core 3, and the valve seat 4 is provided with a second conical surface matched with the first conical surface.

The included angle between the oblique line of the longitudinal section of the first conical surface and the motion direction of the valve core 3 is 25-35 degrees.

Still be equipped with self sealss valve gap 10 on the valve body 1, self sealss valve gap 10 has the centre bore, and it is equipped with the valve rod 7 that is used for the motion of pulling case 3 to slide in the centre bore, and case 3 overlaps on valve rod 7, and has between valve rod 7 and the case 3 and be used for the spring 6 that case 3 resets, has guiding hole 101 on the self sealss valve gap 10, and the one end that valve seat 4 was kept away from to case 3 slides in guiding hole 101.

The end face of one end of the valve core 3 far away from the valve seat 4 is drawn inwards to form a second hollow 302, the side wall of the second hollow 302 is close to the end part and is fixed with a valve core cover 9, a shaft ring is arranged on the valve rod 7 and is arranged on the inner side of the valve core cover 9, and the spring 6 is arranged between the shaft ring of the valve rod 7 and the bottom wall of the second hollow 302.

The lateral wall of second cavity 302 is equipped with the keyway, is equipped with in the keyway and prevents changeing key 42, and the lateral wall of collar is equipped with the spout that matches with preventing changeing key 42, is fixed with stand 22 on the valve body 1, is fixed with on the valve rod 7 and prevents changeing clamp block 39 with stand 22 matching.

The upright column 22 is jointly fixed with a support upper cover 24, a support upper cover shaft sleeve 25 is arranged between the support upper cover 24 and the valve rod 7, an electric support 27 is fixed on the support upper cover 24, an electric actuator 28 is fixed on the electric support 27, and the telescopic end of the electric actuator 28 is connected with the valve rod 7 through a clamping block 26 and a second compression nut 33.

Have the step in the valve body 1, threaded connection has the disk seat clamping ring 5 that is used for pressing disk seat 4 to the step on the valve body 1, is equipped with metal winding pad 2 between disk seat 4 and the step.

The end part of the side wall of the central hole of the self-sealing valve cover 10, which is close to the guide hole 101, is provided with a first ring groove, a valve cover shaft sleeve 41 is arranged in the first ring groove, the end part of the side wall of the central hole of the self-sealing valve cover 10, which is far away from the guide hole 101, is provided with a second ring groove, the second ring groove is internally provided with a filler 16 pad 15, a filler spacer ring 17 and a filler pressure sleeve 18 from inside to outside in sequence, filler 16 is arranged between the filler 16 pad 15 and the filler spacer ring 17 and between the filler spacer ring 17 and the filler pressure sleeve 18, a filler pressure plate 19 is pressed on the outer side of the filler pressure sleeve 18, and the filler pressure plate 19 is fixed on.

Be equipped with guide ring 8 between case 3 and the guiding hole 101 lateral wall of self sealss valve gap 10, the holding tank has been seted up in the valve body 1, the card has four ring openings 13 in the holding tank, 13 one side of four ring openings is equipped with and is used for the self sealss circle 11 in the clearance between sealed valve body 1 and the self sealss valve gap 10, it has self sealss clamping ring 12 to press between 13 and the self sealss circle 11 of four ring openings, 13 opposite sides of four ring openings are equipped with valve gap pull ring 14, be connected through second full thread stud 40 and first gland nut 21 between valve gap pull ring 14 and the self seal.

The invention keeps the original self-sealing structure and the valve seat fixing structure; sleeve workpieces are cancelled; the length below the sealing surface of the valve core is increased, the length-increased part is fully inserted into the inner hole of the valve seat 4, the length is increased to meet the requirement of full opening of the rated stroke of the valve, and the overlapping length of the inner circle of the valve seat 4 and the outer circle of the valve core 3 is ensured to be 40mm when the valve is fully opened; the length increasing part is provided with a part with the excircle wall thickness which is completely turned to be 5mm higher than the sealing surface (the uppermost end of the sealing surface) of the valve core; distributing all throttling and pressure reducing small holes of the rated flow coefficient of the valve on the increased length of the valve core 3 according to the requirements of flow and stroke, and keeping the edge of the small hole at the uppermost row and the lowermost end of the sealing surface of the valve core 3 at 2 mm; equivalently, the original sleeve is arranged on the valve core 3; the size of the excircle above the sealing surface of the valve core 3 is increased; the size of the second hollow 302 is slightly larger than the excircle of the spring by 2mm, and the depth of the second hollow 302 is required by the spring H1; key slots are inserted at the upper end of the side wall of the second hollow 302, one key is arranged at one side, and the size of the lower end face of the over-travel slot is the same as the length of the flat key; the valve core cover 9 is changed into a round nut form; machining threads on the outer circle of the valve core cover 9 to be matched with the valve core 3, and machining 4 through holes with the diameter of 8mm on the annular surface of the valve core cover 9 for mounting and dismounting; the valve rod 7 and the valve core 3 are combined into a one-piece valve rod; the inner circle of the pilot hole 101 may be nitrided or built-up to increase surface hardness.

The upright column 22 and the support upper cover 24 are fixed through a first inner hexagonal socket head cap screw 23, the electric actuator 28 and the electric support 27 are fixed through a first bolt 29 and a first fastening nut 30, a first elastic pad 31 and a first flat pad 32 are arranged between the first fastening nut and the electric support 27, the electric support 27 and the support upper cover 24 are fixed through a second stud 34 and a second fastening nut 35, a second elastic pad 36 and a second flat pad 37 are arranged between the second fastening nut 35 and the electric support 27, anti-rotation clamping blocks 39 are arranged in pairs, the anti-rotation clamping blocks 39 on two sides of the valve rod 7 are connected through a second inner hexagonal socket head cap screw 38, and the valve rod 7 is clamped in the middle.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical scope of the present invention and the equivalent alternatives or modifications according to the technical solution and the inventive concept of the present invention within the technical scope of the present invention.

Claims

1. The pressure reducing valve is characterized by comprising a valve body (1), wherein a liquid inlet flow channel and a liquid outlet flow channel are arranged on the valve body (1), a middle flow channel is arranged between the liquid inlet flow channel and the liquid outlet flow channel in the valve body (1), a valve seat (4) is arranged on the middle flow channel, a valve core (3) is arranged in the valve seat (4) in a sliding mode, a first hollow cavity (301) is formed by inward shell drawing of the end face of one end, matched with the valve seat (4), of the valve core (3), and a small hole used for communicating the liquid inlet flow channel with the liquid outlet flow channel is formed in the side wall of the first hollow cavity (.

2. A pressure reducing valve according to claim 1, wherein: the side wall of the valve core (3) is provided with a bulge for limiting the position of the valve core (3) in a closed state, the edge of the bulge extends out of a first conical surface to serve as a sealing surface of the valve core (3), and the valve seat (4) is provided with a second conical surface matched with the first conical surface.

3. A pressure reducing valve according to claim 2, wherein: the included angle between the oblique line of the longitudinal section of the first conical surface and the motion direction of the valve core (3) is 25-35 degrees.

4. A pressure reducing valve according to claim 1, wherein: the valve body (1) on still be equipped with self sealss valve gap (10), self sealss valve gap (10) have the centre bore, it is equipped with valve rod (7) that are used for pulling case (3) motion to slide in the centre bore, case (3) cover on valve rod (7), and have between valve rod (7) and case (3) and be used for case (3) spring (6) that reset, self sealss valve gap (10) is last to have guiding hole (101), case (3) keep away from the one end of disk seat (4) and slide in guiding hole (101).

5. The pressure reducing valve according to claim 4, wherein: the end face of one end, far away from the valve seat (4), of the valve core (3) is drawn inwards to form a second hollow cavity (302), the side wall of the second hollow cavity (302) is close to the end part and is fixed with a valve core cover (9), the valve rod (7) is provided with a shaft collar, the shaft collar is arranged on the inner side of the valve core cover (9), and the spring (6) is arranged between the shaft collar of the valve rod (7) and the bottom wall of the second hollow cavity (302).

6. The pressure reducing valve according to claim 5, wherein: the lateral wall of second cavity (302) be equipped with the keyway, the keyway in be equipped with and prevent commentaries on classics key (42), the lateral wall of collar be equipped with prevent the spout that commentaries on classics key (42) match, valve body (1) on be fixed with stand (22), valve rod (7) on be fixed with the anti-rotation clamp splice (39) that match with stand (22).

7. The pressure reducing valve according to claim 6, wherein: the support is characterized in that a support upper cover (24) is jointly fixed on the upright column (22), a support upper cover shaft sleeve (25) is arranged between the support upper cover (24) and the valve rod (7), an electric support (27) is fixed on the support upper cover (24), an electric actuator (28) is fixed on the electric support (27), and the telescopic end of the electric actuator (28) is connected with the valve rod (7) through a clamping block (26) and a second compression nut (33).

8. A pressure reducing valve according to claim 1, wherein: the valve body (1) is internally provided with a step, the valve body (1) is connected with a valve seat pressing ring (5) for pressing a valve seat (4) to the step through threads, and a metal winding pad (2) is arranged between the valve seat (4) and the step.

9. The pressure reducing valve according to claim 4, wherein: self sealss valve gap (10) the centre bore lateral wall be equipped with first annular near the tip of guiding hole (101), first annular in be equipped with valve gap axle sleeve (41), the tip of keeping away from guiding hole (101) of the centre bore lateral wall of self sealss valve gap (10) be equipped with the second annular, the second annular in from inside to outside be equipped with in proper order and pack (16) pad (15), pack spacer ring (17) and pack and press cover (18), pack (16) pad (15) and pack between spacer ring (17) and pack and all be equipped with between pressing cover (18) filler (16), pack and press cover (18) outside to have pressed packing clamp plate (19), packing clamp plate (19) fix on self sealss valve gap (10) through first full thread double-screw bolt (20) and first gland nut (21).

10. The pressure reducing valve according to claim 4, wherein: case (3) and guiding hole (101) lateral wall of self sealss valve gap (10) between be equipped with guide ring (8), valve body (1) in seted up the holding tank, the holding tank inside callipers have four ring openings (13), four ring openings (13) one side be equipped with be used for sealed valve body (1) and self sealss valve gap between valve gap from sealing washer (11), four ring openings (13) and self sealss have self sealss clamping ring (12) between ring (11), four ring openings (13) opposite side be equipped with valve gap pull ring (14), valve gap pull ring (14) and self sealss valve body (1) between be connected through second full thread stud (40) and first gland nut (21).