Regulating valve with stable sealing structure

Abstract

According to the technical scheme, the adjusting valve is characterized by comprising a valve body, a valve seat located in the valve body, a valve element capable of forming hard sealing with the valve seat and a valve cage arranged outside the valve element in a sleeved mode, and the valve element comprises a middle portion located in the valve cage and a sealing portion capable of forming sealing with the valve seat. The valve cage comprises a ring body abutting against the valve seat and a circulation portion located above the ring body, the diameter of the middle portion is close to the inner diameter of the ring body, the middle portion is in a circular truncated cone shape, the small-diameter end of the middle portion is connected with the sealing portion, and the height of the ring body is larger than or equal to the total height of the middle portion and the sealing portion. The flow of a medium flowing to the sealing part is reduced through the gap between the middle part and the ring body, so that the medium impact on the sealing part and the valve seat is reduced, and the problem that the sealing surface is easy to damage due to large scouring force in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of governing valve, more specifically relates to a governing valve with stable sealing structure. BACKGROUND

[0002] The governing valve is the final control element in the industrial automation process control field, which changes the medium flow, pressure, temperature, liquid level and other process parameters by accepting the control signal output by the control unit and operating with power. The sealing performance of the governing valve directly affects the quality and economic benefit of the final product. One common structure of the governing valve is a single seat plunger structure (see Figure 1 ), but this type of governing valve has defects. The sealing surface of this type of governing valve is located at the outlet of the medium, and the flow rate of the medium flowing through the sealing surface is the highest. The scouring force of the medium on the sealing surface is large, which can easily damage the sealing surface and affect the sealing performance. SUMMARY

[0003] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a governing valve that can reduce the scouring of the medium on the sealing surface and has a stable sealing surface structure.

[0004] To achieve the above purpose, the utility model provides the following technical scheme: a governing valve with stable sealing structure, comprising a valve body, a valve seat positioned in the valve body, a valve core capable of forming a hard seal with the valve seat, and a valve cage sleeved outside the valve core, the valve core comprises a middle part located in the valve cage and a sealing part capable of forming a seal with the valve seat, the valve cage comprises a ring body in contact with the top of the valve seat and a flow-through part above the ring body, the diameter of the middle part is similar to the inner diameter of the ring body, the middle part is in the shape of a circular truncated cone with a small diameter end connected to the sealing part, the height of the ring body is greater than or equal to the total height of the middle part and the sealing part, and the flow of the medium to the sealing part is reduced through the gap between the middle part and the ring body, so that the impact of the medium on the sealing part and the valve seat is reduced.

[0005] As a further improvement of the utility model, the inclination angle of the peripheral wall of the middle part relative to the vertical plane is smaller than the inclination angle of the peripheral wall of the sealing part relative to the vertical plane.

[0006] As a further improvement of the utility model, the peripheral wall of the middle part is provided with a plurality of ring grooves distributed along the height direction of the middle part.

[0007] The utility model discloses beneficial effect: through the gap between the middle part and ring body reduces the flow of medium to the flow of sealing part makes the medium impact that sealing part and valve seat bear reduces, such design compared with prior art can utilize the clearance rate between the middle part and ring body and first regulate and control medium flow and flow rate, thereby ensure the medium flow constant and flow rate alleviation that follow through sealing part and valve seat between, effectively slow down the scouring degree between medium and sealing part and valve seat, prevent the occurrence of cavitation, the structure stability of sealing part and valve seat, indirectly guarantee the stability of sealing. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 It is the main sectional view of prior art;

[0009] Figure 2 It is the main sectional view of the utility model;

[0010] Figure 3 It is Figure 2 The enlarged view of middle A.

[0011] Reference signs: 1, valve body;2, valve seat;3, valve core;31, middle part;32, sealing part;33, ring groove;4, valve cage;41, ring body;42, flow-through part. DETAILED DESCRIPTION

[0012] The utility model is further explained in detail below in combination with the drawings and examples. Wherein same parts are expressed with same reference signs.

[0013] Referring to Figures 1 to 3 The sealing structure stable regulating valve of the embodiment, including valve body 1, the valve seat 2 positioned in valve body 1, the valve core 3 can with valve seat 2 form hard sealing and the valve cage 4 of setting in valve core 3 outside, valve core 3 includes the middle part 31 in valve cage 4 and the sealing part 32 can with valve seat 2 form sealing, middle part 31 is more cylindrical body, valve cage 4 includes with the ring body 41 of valve seat 2 top touch and the flow-through part 42 located ring body 41 top;

[0014] Based on the foregoing prior art, the diameter of the middle part 31 is first machined to be close to the inner diameter of the ring body 41, and then the peripheral wall of the middle part 31 is cut to make the peripheral wall of the middle part 31 inclined relative to the vertical surface. The middle part 31 is machined from a cylindrical body to a circular truncated cone. The small end of the middle part 31 is coaxially connected to the sealing part 32. The height of the ring body 41 is greater than or equal to the total height of the middle part 31 and the sealing part 32.

[0015] During operation, the medium enters the valve body 1 from the right and flows successively through the flow section 42, the ring body 41, and the valve seat 2. When it is necessary to block the flow of the medium, the sealing part 32 first enters the inner cavity of the ring body 41. As the valve core 3 continues to move downward, the middle part 31 gradually enters the inner cavity of the ring body 41. The gap between the peripheral wall of the middle part 31 and the ring body 41 gradually decreases. The flow rate of the medium entering the ring body 41 from the flow section 42 decreases and the flow velocity increases. The medium flowing through the outer wall of the middle part 31 is turned at the end face of the valve seat 2 and flows towards the gap between the sealing part 32 and the valve seat 2. The flow velocity of the medium decreases due to the change in flow direction. As the middle part 31 completely enters the ring body 41... Within 1, the flow rate of the medium flowing between the middle part 31 and the ring body 41 reaches its minimum until the sealing part 32 and the valve seat 2 are tightly fitted to form a hard seal, and the medium is in a blocked and static state; when the medium needs to be converted to a flow state, the valve core 3 moves upward, the sealing part 32 separates from the valve seat 2, and the flow rate of the medium flowing between the ring body 41 and the middle part 31 is small. As the valve core 3 continues to move upward, the middle part 31 gradually moves out of the ring body 41, the gap between the middle part 31 and the ring body 41 gradually increases, the medium flow rate increases and the flow velocity decreases, until the middle part 31 and the sealing part 32 completely exit the ring body 41, and the medium is in a fully flow state;

[0016] Compared with existing technologies, this design can utilize the gap between the middle part 31 and the ring body 41 to regulate the flow rate and velocity of the medium in advance, thereby ensuring that the flow rate of the medium flowing between the sealing part 32 and the valve seat 2 is constant and the velocity is gentle. This effectively reduces the degree of erosion of the sealing part 32 and the valve seat 2 by the medium, prevents cavitation, and ensures the structural stability of the sealing part 32 and the valve seat 2, thus indirectly guaranteeing the stability of the seal.

[0017] As one specific implementation method of the improvement, refer to Figure 3 As shown, the inclination angle of the peripheral wall of the middle part 31 relative to the vertical plane is smaller than the inclination angle of the peripheral wall of the sealing part 32 relative to the vertical plane. Therefore, the flow rate change between the middle part 31 and the ring body 41 is smaller, and the medium tends to be gentle. At the same time, it ensures that the flow velocity and flow direction of the medium flowing through the outer wall of the middle part 31 and the outer wall of the sealing part 32 are different, thereby further reducing the scouring effect of the medium on the sealing part 32.

[0018] As one specific implementation method of the improvement, refer to Figure 3 As shown, several annular grooves 33 are provided on the peripheral wall of the middle part 31, which are distributed along the height direction of the middle part 31. This design changes the peripheral wall of the middle part 31 from flat to uneven. As a result, the gap width between the middle part 31 and the ring body 41 varies irregularly in the height direction of the middle part 31, thereby effectively changing the flow direction and velocity of the medium when it flows through the outer wall of the middle part 31. Due to the multiple changes in speed and direction, the scouring effect of the medium on the sealing surfaces of the sealing part 32 and the valve seat 2 becomes worse, further ensuring the structural stability and sealing stability of the sealing surfaces of the sealing part 32 and the valve seat 2.

[0019] The above merely describes preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments. Any technical solution falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that, for ordinary skilled persons in the art, some improvements and refinements without departing from the principles of the present application shall also be considered as falling within the protection scope of the present application.

Claims

1. A regulating valve with a stable sealing structure, comprising a valve body (1), a valve seat (2) positioned within the valve body (1), a valve core (3) capable of forming a hard seal with the valve seat (2), and a valve cage (4) sleeved outside the valve core (3), wherein the valve core (3) includes a central portion (31) located within the valve cage (4) and a sealing portion (32) capable of forming a seal with the valve seat (2), and the valve cage (4) includes an annular body (41) contacting the valve seat (2) and a flow portion (42) located above the annular body (41), characterized in that: The diameter of the middle part (31) is similar to the inner diameter of the ring (41). The middle part (31) is frustum-shaped and the end with the smaller diameter is connected to the sealing part (32). The height of the ring (41) is greater than or equal to the total height of the middle part (31) and the sealing part (32). The gap between the middle part (31) and the ring (41) reduces the flow of medium to the sealing part (32), thereby reducing the impact of medium on the sealing part (32) and the valve seat (2).

2. The regulating valve with a stable sealing structure according to claim 1, characterized in that: The angle of inclination of the peripheral wall of the middle part (31) relative to the vertical surface is smaller than the angle of inclination of the peripheral wall of the sealing part (32) relative to the vertical surface.

3. A regulating valve with a stable sealing structure according to claim 1 or 2, characterized in that: The peripheral wall of the middle part (31) is provided with a number of annular grooves (33) distributed along the height direction of the middle part (31).

Images