Valve sleeve type blow-down valve

Abstract

The invention belongs to the field of hydraulic valves, and particularly relates to a valve sleeve type blow-down valve which comprises a valve body, a valve cover, a valve rod, a valve seat, a valve sleeve and a valve element assembly. The valve seat is arranged in the valve body, the valve sleeve is arranged at the upper end of the valve seat, a plurality of throttling holes are evenly formed in the side, close to the valve seat, of the valve sleeve along the peripheral face, and the valve element assembly is installed in an inner space formed by the valve sleeve and the valve seat. The outer circumferential face of the valve element assembly is in sliding fit with the inner circumferential face of the valve sleeve so that the throttling hole can be opened or closed. Wherein the valve element assembly is provided with a guiding part, the valve seat is provided with a valve seat guiding face used in cooperation with the guiding part, and the guiding part and the valve seat guiding face are used for guiding fluid media to scour impurities deposited on the valve seat or the throttling hole. According to the blow-down valve, impurities deposited at the sealing structure can be effectively washed out, and the sealing performance of the blow-down valve is improved.

Description

Technical Field

[0001] The present invention belongs to the field of hydraulic valves, and particularly relates to a valve sleeve type blowdown valve. Background Art

[0002] Valve sleeve type blowdown valves are widely used in pipelines of natural gas, liquefied gas, petroleum, aviation kerosene, water, and corrosive and non-corrosive media, and are mainly used for blowdown of pipeline devices and closing of media. When the blowdown valve is opened for blowdown, the medium will flow through the sealing structure, and most of the media flowing through the blowdown valve contain particulate impurities. Since the existing blowdown valves are prone to deposit impurities at the sealing structure, even when the valve is opened, the fluid medium cannot effectively wash away the impurities. In addition, in the existing blowdown valves, the sealing pair is located at the end of the valve core. When the valve is opened, the fluid medium is not easy to wash the sealing pair in this area. Due to the above-mentioned defects of the existing blowdown valves, the sealing performance of the blowdown valve will be seriously affected. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, the object of the present invention is to provide a valve sleeve type blowdown valve, which can effectively wash away the impurities deposited at the sealing structure and improve the sealing performance of the blowdown valve.

[0004] In order to achieve the above invention object, the present invention provides the following technical solutions: A valve sleeve type blowdown valve, the blowdown valve comprising: a valve body, a valve cover, a valve rod, a valve seat, a valve sleeve, and a valve core assembly; the valve cover is located at the upper end of the valve body, a bracket is installed at the upper end of the valve cover, and the lower end of the valve rod sequentially passes through the bracket and the valve cover and is in transmission connection with the valve core assembly; a threaded section is provided at the upper end of the valve rod, a handwheel is installed on the threaded section, and a valve rod nut matching with the threaded section at the upper end of the valve rod is provided in the bracket; A valve seat installation groove is provided in the valve body, the valve seat is provided in the valve seat installation groove, the valve sleeve is provided at the upper end of the valve seat, the outer peripheral surface of the valve sleeve is matched with the valve body, and its top end is matched with the valve cover. A plurality of throttle holes are uniformly provided along the outer peripheral surface of the valve sleeve close to the valve seat. The inner space formed by the valve sleeve and the valve seat is provided with the valve core assembly; the outer peripheral surface of the valve core assembly is in sliding fit with the inner peripheral surface of the valve sleeve to open or close the throttle holes; wherein, a guiding portion is provided on the valve core assembly, and a valve seat guiding surface matching with the guiding portion is provided on the valve seat. The guiding portion and the valve seat guiding surface are used to guide the fluid medium to wash away the impurities deposited at the valve seat or the throttle holes.

[0005] Preferably, the spool assembly includes a spool body, a sealing retaining ring and a throttle shaft which are respectively connected to the spool body; a spool boss is provided at the lower end of the spool body, the guiding portion includes a first guiding surface provided at the spool boss, and a second guiding surface connected to the first guiding surface, and a smooth transition is provided between the first guiding surface and the second guiding surface; wherein, the first guiding surface is an arc-shaped curved surface with an opening facing the valve seat side, the second guiding surface is an inclined surface with an acute angle θ between the horizontal plane, and the angle between the valve seat guiding surface and the horizontal plane is the same as the angle between the second guiding surface and the horizontal plane.

[0006] Preferably, the guiding portion further includes a third guiding surface provided on the outer periphery of the sealing retaining ring, and a fourth guiding surface connected to the third guiding surface; wherein, both the third guiding surface and the fourth guiding surface are inclined surfaces with an acute angle between the horizontal plane, the angle between the third guiding surface and the horizontal plane is α1, the angle between the fourth guiding surface and the horizontal plane is α2, and α1 > α2.

[0007] Preferably, the throttle holes include four U-shaped first throttle holes uniformly distributed along the outer peripheral surface of the valve sleeve, one end of the opening of which is in contact with the valve seat, and a plurality of waist-shaped second throttle holes are uniformly arranged between two adjacent first throttle holes.

[0008] Preferably, an installation boss is provided at the upper end of the valve seat, the installation boss is matched with the valve seat installation groove, and the installation boss has an upper valve seat installation surface and a lower valve seat installation surface, and a valve seat sealing ring is provided between the lower valve seat installation surface and the valve seat installation groove; the thickness of the installation boss is less than the depth of the valve seat installation groove, and the lower end of the valve sleeve is matched with the upper valve seat installation surface, so that the lower end of the valve sleeve is located in the valve seat installation groove.

[0009] Preferably, a threaded hole for installing the throttle shaft and a pin hole for installing the sealing retaining ring are respectively provided along the axial direction of the spool body, a second groove for installing an adjusting pad is provided inside the spool boss, and the adjusting pad is used to adjust the axial relative position between the sealing retaining ring and the spool body; a third groove for installing the sealing retaining ring is also provided between the second groove and the threaded hole, the sealing retaining ring is inserted into the third groove and abuts against the adjusting pad and then is connected to the spool body through a pin, and the throttle shaft passes through the sealing retaining ring and is threadedly connected to the spool body.

[0010] Preferably, a first groove is provided inside the mounting boss, and a gland seal structure is provided in the first groove. A gland seal surface that is in contact with the fourth guiding surface is provided on the outer periphery of the gland seal. Hard alloy layers are provided on the second guiding surface and the valve seat guiding surface. When the valve is in the closed state, the gland seal structure and the gland seal surface cooperate with each other to form a first sealing structure, and the hard alloy layers on the second guiding surface and the valve seat guiding surface cooperate with each other to form a second sealing structure.

[0011] Preferably, a first chamber for accommodating the gland seal and a second chamber for accommodating the throttle shaft are provided inside the valve seat. The first chamber and the second chamber communicate with each other to form a fluid passage for the medium to flow through. When the valve is in the closed state, there is a gap between the first chamber and the outer peripheral surface of the gland seal, and there is a gap between the second chamber and the outer peripheral surface of the throttle shaft.

[0012] Preferably, a valve stem connection portion is formed at the lower end of the valve stem, and a cavity for inserting the valve stem connection portion is formed at the upper end of the valve element. A threaded portion that cooperates with the valve element nut is provided in the cavity. After the valve stem connection portion is inserted into the cavity, the valve stem connection portion and the valve element body are drivingly connected through the valve element nut and the washer.

[0013] Compared with the prior art, a valve sleeve type sewage discharge valve provided by the present invention has the following beneficial technical effects: 1. Since during the use of the sewage discharge valve, particulate impurities in the fluid medium are likely to deposit on the valve seat or the throttle hole. Therefore, the present invention respectively provides guiding structures on the valve seat and the valve element assembly, and uses the guiding structures to guide the fluid medium to effectively flush the impurities deposited on the valve seat or the throttle hole, thereby improving the sealing performance of the sewage discharge valve. Further, by providing a first guiding surface and a second guiding surface at the bottom of the valve element body, and a third guiding surface and a fourth guiding surface on the outer periphery of the gland seal, when the valve is opened, the provided guiding surfaces can effectively guide the flow direction of the fluid medium, reduce the resistance of the fluid medium during the flowing process, and enable it to better flush the impurities deposited on the valve seat or the throttle hole. Moreover, since the angles α1>α2 between the two guiding surfaces respectively provided on the outer periphery of the gland seal and the horizontal plane, on the one hand, it can better guide the fluid medium to flow towards the first guiding surface, and on the other hand, it ensures that the gland seal has sufficient gland seal surface, so that it can form an effective sealing pair with the gland seal structure.

[0014] 2. An adjusting pad is installed on the valve core body of the present invention. The adjusting pad can adjust the relative position in the axial direction between the sealing gland and the valve core body, and further, by adjusting the axial positions of the third guiding surface and the fourth guiding surface provided on the outer periphery of the sealing gland, the fluid medium can flow through the third guiding surface, the fourth guiding surface, the first guiding surface and the second guiding surface, enabling the fluid medium to better wash the impurities deposited at the valve seat or the throttle hole, thereby improving the adaptability of the valve.

[0015] 3. A tiny gap is provided between the first chamber of the valve seat and the outer peripheral surface of the sealing gland, and between the second chamber and the outer peripheral surface of the throttle shaft. Since a sealing pair is formed between the gland sealing structure and the gland sealing surface, the medium is not directly emptied and depressurized at this time, and can effectively play a role in pressure relief. And in the initial stroke of valve opening, due to the small medium flow rate, the pressure in the valve cavity decreases, thus reducing the erosion of the throttle hole when the valve is opened.

[0016] 4. A gland sealing structure is provided on the valve seat of the present invention. Compared with the drain valve in the prior art, when the valve is opened, the medium can effectively wash the gland sealing structure, making it not easy to deposit impurities here, and improving the sealing performance of the sealing structure here.

[0017] 5. A hard alloy layer is provided on the second guiding surface and the valve seat guiding surface. When the valve is in the closed state, the gland sealing structure and the gland sealing surface cooperate with each other to form a first sealing structure, and the hard alloy layers on the second guiding surface and the valve seat guiding surface cooperate with each other to form a second sealing structure. Through the optimized double sealing structure, the sealing performance of the valve in the closed state is improved. Brief Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the valve sleeve type drain valve when it is in the closed state; Figure 2 is a partial enlarged view of the valve sleeve type drain valve; Figure 3 is a schematic structural diagram of the valve sleeve; Figure 4 is a schematic structural diagram of the valve core body; Figure 5 is a schematic structural diagram of the valve seat; Figure 6 is a partial enlarged schematic view of the sealing gland; Figure 7 is a partial enlarged view of the sealing structure of the valve seat and the valve core assembly when the valve sleeve type drain valve is in the open state; Figure 8 is Figure 7 the partial enlarged view at A in

[0019] Among them, the meanings of the reference symbols in the drawings are as follows: 1. Valve body; 2. Valve cover; 3. Valve stem; 4. Handwheel; 5. Valve sleeve; 6. Valve seat; 7. Spool assembly; 8. Bracket; 9. Valve stem nut; 10. Packing gland; 11. Packing ring; 12. Valve seat mounting groove 31. Valve stem connection part; 32. Spool nut; 33. Washer; 34. Balance valve seat 51. First throttle hole; 52. Impurity; 53. Second throttle hole 61. Upper mounting surface of valve seat; 62. Valve seat guiding surface; 63. First groove; 64. Gland seal structure; 65. Lower mounting surface of valve seat; 66. Mounting boss; 67. First chamber; 68. Second chamber 71. Spool body; 72. Seal gland; 73. Throttle shaft 711. First guiding surface; 712. Second guiding surface; 713. Second groove; 714. Adjusting pad; 715. Threaded hole; 716. Pin hole; 717. Spool boss; 718. Third groove; 719. Cavity 721. Third guiding surface; 722. Fourth guiding surface; 723. Gland sealing surface Detailed implementation manners

[0020] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some but not all of the embodiments of the present invention.

[0021] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed present invention, but merely represents some embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0022] It should be noted that, without conflict, the embodiments in the present invention and the features and technical solutions in the embodiments may be combined with each other.

[0023] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0024] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is customarily placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. Such terms are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, terms such as "first" and "second" are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0025] See the attached Figure 1 - attached Figure 8 As shown, the present invention provides a valve sleeve type sewage discharge valve, which includes: a valve body 1, a valve cover 2, a valve stem 3, a valve sleeve 5, a valve seat 6 and a valve core assembly 7. The valve cover 2 is located at the upper end of the valve body 1, and a bracket 8 is installed at the upper end of the valve cover 2. The lower end of the valve stem 3 sequentially passes through the bracket 8 and the valve cover 2 and then is in transmission connection with the valve core assembly 7; a threaded section is provided at the upper end of the valve stem 3, and a handwheel 4 is installed on this threaded section. A valve stem nut 9 that cooperates with the threaded section at the upper end of the valve stem 3 is provided inside the bracket 8. A sealing packing is also provided between the valve stem 3 and the valve cover 2. A packing gland 11 is provided at the upper end of the sealing packing. A packing gland 10 is also provided inside the bracket 8. The lower side of the packing gland 10 abuts against the packing gland 11, and the upper side abuts against the bracket 8 through a threaded fastener. The sealing pre-tightening force of the sealing packing can be adjusted by adjusting the threaded fastener.

[0026] A valve seat installation groove 12 is provided inside the valve body 1, a valve seat 6 is provided inside the valve seat installation groove 12, a valve sleeve 5 is provided at the upper end of the valve seat 6. The outer peripheral surface of the valve sleeve 5 cooperates with the valve body 1, and its top end cooperates with the valve cover 2. A number of throttle holes are evenly provided along the outer peripheral surface of the valve sleeve 5 on the side close to the valve seat 6. The internal space formed by the valve sleeve 5 and the valve seat 6 is installed with a valve core assembly 7. The outer peripheral surface of the valve core assembly 7 is in sliding fit with the inner peripheral surface of the valve sleeve 5 to open or close the throttle holes. Among them, a guiding portion is provided on the valve core assembly 7, and a valve seat guiding surface 62 that cooperates with the guiding portion is provided on the valve seat 6. The guiding portion and the valve seat guiding surface 62 are used to guide the fluid medium to wash away the impurities 52 deposited on the valve seat 6 or the throttle holes.

[0027] During the use of the sewage discharge valve, particulate impurities in the fluid medium are likely to deposit on the valve seat or throttle holes. Therefore, in the above embodiment, guiding structures are respectively provided on the valve seat and the valve core assembly, and the guiding structures are used to guide the fluid medium to effectively wash away the impurities deposited on the valve seat or throttle holes, thereby improving the sealing performance of the sewage discharge valve.

[0028] Preferably, the spool assembly 7 includes a spool body 71, a sealing retainer ring 72 and a throttle shaft 73 which are respectively connected to the spool body 71. A spool boss 717 is provided at the lower end of the spool body 71. The guiding portion includes a first guiding surface 711 provided at the spool boss 717 and a second guiding surface 712 connected to the first guiding surface 711, and a smooth transition is formed between the first guiding surface 711 and the second guiding surface 712. Among them, the first guiding surface 711 is an arc-shaped curved surface with an opening facing the valve seat 6, the second guiding surface 712 is an inclined surface with an acute angle θ between it and the horizontal plane, and the angle between the valve seat guiding surface 62 and the horizontal plane is the same as the angle between the second guiding surface 712 and the horizontal plane.

[0029] Preferably, the guiding portion further includes a third guiding surface 721 provided on the outer periphery of the sealing retainer ring 72 and a fourth guiding surface 722 connected to the third guiding surface 721. Among them, both the third guiding surface 721 and the fourth guiding surface 722 are inclined surfaces with an acute angle between them and the horizontal plane. The angle between the third guiding surface 721 and the horizontal plane is α1, and the angle between the fourth guiding surface 722 and the horizontal plane is α2, and α1 > α2.

[0030] In the above embodiment, by providing the first guiding surface and the second guiding surface at the bottom of the spool body and the third guiding surface and the fourth guiding surface on the outer periphery of the sealing retainer ring, when the valve is opened, the provided guiding surfaces can effectively guide the flow direction of the fluid medium (see the flow path at B in the appendix Figure 8 ), reducing the resistance of the fluid medium during the flow process, so that it can better wash the impurities deposited at the valve seat or the throttle hole. Moreover, since the angles α1 > α2 between the two guiding surfaces respectively provided on the outer periphery of the sealing retainer ring and the horizontal plane, on the one hand, it can better guide the fluid medium to flow towards the first guiding surface, and on the other hand, it ensures that the sealing retainer ring has a sufficient retainer sealing surface, so that it can form an effective sealing pair with the retainer sealing structure.

[0031] Preferably, the throttle holes include four U-shaped first throttle holes 51 evenly distributed on the outer peripheral surface of the valve sleeve 5, one open end of which is in contact with the valve seat 6, and a number of waist-shaped second throttle holes 53 are evenly arranged between two adjacent first throttle holes 51. The long-strip throttle holes improve the flow capacity of the medium, reduce the risk of the throttle holes being blocked, and at the same time reduce the erosion and corrosion of the medium on the throttle holes, improving the throttling and venting performance of the blowdown valve.

[0032] Preferably, an installation boss 66 is provided at the upper end of the valve seat 6. The installation boss 66 cooperates with the valve seat installation groove 12, and the installation boss 66 has a valve seat upper installation surface 61 and a valve seat lower installation surface 65. A valve seat sealing ring is provided between the valve seat lower installation surface 65 and the valve seat installation groove 12. The valve seat sealing ring is used for sealing between the valve seat 6 and the valve body 1. The thickness of the installation boss 66 is less than the depth of the valve seat installation groove 12. The lower end of the valve sleeve 5 cooperates with the valve seat upper installation surface 61, so that the lower end of the valve sleeve 5 is located in the valve seat installation groove 12. Thus, the installation positioning of the valve sleeve 5 is realized by using the inner peripheral wall of the valve body 1 and the valve seat installation groove 12 respectively.

[0033] Preferably, a threaded hole 715 for installing the throttle shaft 73 and a pin hole 716 for installing the seal retainer 72 are respectively formed along the axial direction of the valve core body 71. A second groove 713 for installing the adjusting pad 714 is formed inside the valve core boss 717. The adjusting pad 714 is used to adjust the axial relative position between the seal retainer 72 and the valve core body 71. A third groove 718 for installing the seal retainer 72 is also formed between the second groove 713 and the threaded hole 715. The seal retainer 72 is inserted into the third groove 718 and abuts against the adjusting pad 714 and then is connected to the valve core body 71 through a pin. The throttle shaft 73 passes through the seal retainer 72 and is threadedly connected to the valve core body 71. Of course, other connection methods can also be used to install the seal retainer 72 and the throttle shaft 73 on the valve core body 71, which will not be elaborated here.

[0034] In the above embodiment, an adjusting pad is installed on the valve core body. The adjusting pad can adjust the axial relative position between the seal retainer and the valve core body. Furthermore, by adjusting the axial positions of the third guiding surface and the fourth guiding surface provided on the outer periphery of the seal retainer, the fluid medium can flow through the third guiding surface, the fourth guiding surface, the first guiding surface and the second guiding surface, so that the fluid medium can better wash the impurities deposited at the valve seat or the throttle hole, improving the adaptability of the valve.

[0035] Preferably, a first groove 63 is provided inside the installation boss 66. A seal structure 64 is provided in the first groove 63. A seal surface 723 of the seal retainer 72 that is connected to the fourth guiding surface 722 is provided on the outer periphery of the seal retainer 72. Cemented carbide layers are provided on the second guiding surface 712 and the valve seat guiding surface 62. When the valve is in the closed state, the seal structure 64 in the first groove 63 and the seal surface 723 of the seal retainer 72 cooperate with each other to form a first seal structure, and the cemented carbide layers on the second guiding surface 712 and the valve seat guiding surface 62 cooperate with each other to form a second seal structure. In this embodiment, the seal structure 64 in the first groove 63 can be set as a sealing ring for sealing, but other methods can also be used, such as filling the first groove 63 with a cemented carbide layer. Those skilled in the art can choose according to actual needs.

[0036] Preferably, a first chamber 67 for accommodating the sealing gland 72 and a second chamber 68 for accommodating the throttle shaft 73 are provided inside the valve seat 6. The first chamber 67 and the second chamber 68 communicate to form a fluid passage for the medium to flow through. When the valve is in the closed state, there is a gap between the outer peripheral surface of the first chamber 67 and the outer peripheral surface of the sealing gland 72, and there is a gap between the outer peripheral surface of the second chamber 68 and the outer peripheral surface of the throttle shaft 73.

[0037] In the above embodiment, the present invention provides minute gaps between the first chamber of the valve seat and the outer peripheral surface of the sealing gland, and between the second chamber and the outer peripheral surface of the throttle shaft. Since a sealing pair is formed between the gland seal structure and the gland sealing surface, the medium is not directly vented and depressurized at this time, which can effectively play a pressure-relieving role. And in the initial stroke of valve opening, due to the small medium flow rate, the pressure in the valve cavity decreases, thereby reducing the erosion of the throttle hole when the valve is opened.

[0038] In addition, the present invention provides a gland seal structure on the valve seat. Compared with the drain valve in the prior art, when the valve is opened, the medium can effectively scour the gland seal structure, making it not easy to deposit impurities here and improving the sealing performance of the sealing structure here. At the same time, a cemented carbide layer is provided on the second guiding surface and the valve seat guiding surface. When the valve is in the closed state, the gland seal structure and the gland sealing surface cooperate with each other to form a first sealing structure, and the cemented carbide layers on the second guiding surface and the valve seat guiding surface cooperate with each other to form a second sealing structure. Through the optimized double-sealing structure, the sealing performance of the valve in the closed state is improved.

[0039] Preferably, a valve stem connection part 31 is formed at the lower end of the valve stem 3, and a cavity 719 for inserting the valve stem connection part 31 is formed at the upper end of the valve core body 71. A threaded part cooperating with the valve core nut 32 is provided in the cavity 719. After the valve stem connection part 31 is inserted into the cavity 719, the valve stem connection part 31 and the valve core body 71 are drivingly connected through the valve core nut 32 and the washer 33.

[0040] Preferably, a balance valve seat 34 is further provided in the cavity 719. The balance valve seat 34 is located between the valve core body 71 and the valve stem 3, and a buffer hole is provided on the balance valve seat 34. The balance valve seat 34 can be used to ensure the pressure balance of the upper and lower end faces of the valve core, facilitating the opening and closing of the valve.

[0041] The above embodiments are only used to illustrate the present invention and do not limit the technical solutions described in the present invention. Although this specification has described the present invention in detail with reference to the above respective embodiments, the present invention is not limited to the above specific embodiments. Therefore, any modification or equivalent replacement to the present invention; and all technical solutions and their improvements that do not depart from the spirit and scope of the invention are covered by the scope of the claims of the present invention.

Claims

1. A valve sleeve type sewage discharge valve, characterized in that: The sewage discharge valve includes: a valve body, a valve cover, a valve stem, a valve seat, a valve sleeve and a valve core assembly; the valve cover is located at the upper end of the valve body, a bracket is installed at the upper end of the valve cover, and the lower end of the valve stem sequentially passes through the bracket and the valve cover and is in transmission connection with the valve core assembly; a threaded section is arranged at the upper end of the valve stem, a handwheel is installed on the threaded section, and a valve stem nut that cooperates with the threaded section at the upper end of the valve stem is arranged in the bracket. A valve seat installation groove is arranged in the valve body, the valve seat is arranged in the valve seat installation groove, the valve sleeve is arranged at the upper end of the valve seat, the outer peripheral surface of the valve sleeve cooperates with the valve body, and its top end cooperates with the valve cover. A plurality of throttling holes are uniformly arranged along the outer peripheral surface of the valve sleeve on one side close to the valve seat. The inner space formed by the valve sleeve and the valve seat is installed with the valve core assembly; the outer peripheral surface of the valve core assembly is in sliding fit with the inner peripheral surface of the valve sleeve to open or close the throttling holes; wherein, a guiding part is arranged on the valve core assembly, and a valve seat guiding surface that cooperates with the guiding part is arranged on the valve seat. The guiding part and the valve seat guiding surface are used to guide the fluid medium to wash away the impurities deposited at the valve seat or the throttling holes.

2. The sewage discharge valve according to claim 1, characterized in that: The valve core assembly includes a valve core body, a sealing pressing ring and a throttling shaft that are respectively connected to the valve core body; a valve core boss is arranged at the lower end of the valve core body. The guiding part includes a first guiding surface arranged at the valve core boss and a second guiding surface connected to the first guiding surface, and a smooth transition is made between the first guiding surface and the second guiding surface; wherein, the first guiding surface is an arc-shaped surface with an opening facing the valve seat side, the second guiding surface is an inclined surface with an acute angle θ between the horizontal plane, and the angle between the valve seat guiding surface and the horizontal plane is the same as the angle between the second guiding surface and the horizontal plane.

3. The sewage discharge valve according to claim 2, wherein: The guiding part further includes a third guiding surface arranged on the outer periphery of the sealing pressing ring and a fourth guiding surface connected to the third guiding surface; wherein, both the third guiding surface and the fourth guiding surface are inclined surfaces with an acute angle between the horizontal plane, the angle between the third guiding surface and the horizontal plane is α1, the angle between the fourth guiding surface and the horizontal plane is α2, and α1 > α2.

4. The sewage discharge valve according to claim 3, characterized in that: The throttling holes include four U-shaped first throttling holes uniformly distributed along the outer peripheral surface of the valve sleeve, the opening ends of which are in contact with the valve seat, and a plurality of waist-shaped second throttling holes are uniformly arranged between adjacent two of the first throttling holes.

5. The sewage discharge valve according to claim 4, characterized in that: An installation boss is arranged at the upper end of the valve seat, the installation boss cooperates with the valve seat installation groove, and the installation boss has a valve seat upper installation surface and a valve seat lower installation surface. A valve seat sealing ring is arranged between the valve seat lower installation surface and the valve seat installation groove; the thickness of the installation boss is less than the depth of the valve seat installation groove, and the lower end of the valve sleeve cooperates with the valve seat upper installation surface, so that the lower end of the valve sleeve is located in the valve seat installation groove.

6. The sewage discharge valve according to claim 5, characterized in that: Axially along the spool body, there are respectively a threaded hole for installing the throttle shaft and a pin hole for installing the seal retainer. Inside the spool boss, there is a second groove for installing an adjusting pad, and the adjusting pad is used to adjust the axial relative position between the seal retainer and the spool body. There is also a third groove for installing the seal retainer between the second groove and the threaded hole. The seal retainer is inserted into the third groove and abuts against the adjusting pad, and then is connected to the spool body through a pin. The throttle shaft passes through the seal retainer and is threadedly connected to the spool body.

7. The sewage discharge valve according to claim 6, characterized in that: Inside the installation boss, there is a first groove, and a retainer seal structure is arranged in the first groove. On the outer periphery of the seal retainer, there is a retainer seal surface that is connected to the fourth guiding surface. A cemented carbide layer is arranged on the second guiding surface and the valve seat guiding surface. When the valve is in the closed state, the retainer seal structure and the retainer seal surface cooperate with each other to form a first sealing structure, and the cemented carbide layers on the second guiding surface and the valve seat guiding surface cooperate with each other to form a second sealing structure.

8. The sewage discharge valve according to claim 7, wherein: Inside the valve seat, there is a first chamber for accommodating the seal retainer and a second chamber for accommodating the throttle shaft. The first chamber and the second chamber communicate to form a fluid passage for the medium to flow through. When the valve is in the closed state, there is a gap between the first chamber and the outer peripheral surface of the seal retainer, and there is a gap between the second chamber and the outer peripheral surface of the throttle shaft.

9. The sewage discharge valve according to claim 8, characterized in that: At the lower end of the valve stem, there is a valve stem connection part. At the upper end of the spool, there is a cavity for the valve stem connection part to be inserted. Inside the cavity, there is a threaded part that cooperates with the spool nut. After the valve stem connection part is inserted into the cavity, the valve stem connection part is drivingly connected to the spool body through the spool nut and the washer.

10. The sewage discharge valve according to claim 9, characterized in that: In the cavity of the spool body, there is also a balance valve seat. The balance valve seat is located between the spool body and the valve stem, and a buffer hole is opened on the balance valve seat.

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