CN205479466U - Unsteady ball valve seating structure - Google Patents

Abstract

The utility model discloses an unsteady ball valve seating structure, it includes the disk seat of two intervals settings and establishes the spheroid between two disk seats, all is equipped with interior sphere on two disk seats and is connected with the spheroid, the microcephaly of sphere serves the fluting structure that is equipped with more than the round in the disk seat, and the structure of should slotting is constituteed for the ring channel or by a plurality of intervals and the arc wall on a concentric circles. Structure more than adopting under the condition that does not improve dish spring pretightning force, realizes the separation of high low pressure seal through changing valve holder structure, guarantees during low pressure that there is more abundant sealed specific pressure in the low pressure seal district, and it has sufficient sealed face width degree to satisfy material specific pressure requirement allowable to guarantee during the high pressure.

Description

Floating ball valve seat structure

technical field

The utility model relates to the field of soft sealing of ball valves with medium and small diameters, in particular to a valve seat structure of a floating ball valve.

Background technique

Small and medium caliber floating ball valves are currently widely used in petroleum, chemical, municipal, electric power and other fields, with the advantages of small size, simple maintenance, and convenient operation. With the development of science and technology and the improvement of industrial technology, higher requirements are put forward for the durability and reliability of ball valves. Leakage is the main manifestation of impermanence and unreliability. For floating valves, low pressure seat seal leakage is the main cause of valve leakage and unreliability. In order to improve the service life of the valve, most of the floating balls at home and abroad currently use a compensating seat design to ensure reliable sealing of the ball valve. At low pressure, sealing is achieved by the seat disc spring loaded seat. Under high pressure, the valve ball moves downstream under the action of the medium, which deflects the downstream seat and enhances the seal. Although this type of structure has better wear durability, there is still a lot of room for improvement. The main problems are: (1) Due to the high rigidity of the soft seat of the high-pressure valve, the initial pre-tightening force of the disc spring cannot be well acted on the sealing surface of the valve ball through the deformed seat. (2) In order to ensure the allowable sealing specific pressure of the valve seat material, the valve seat design must have a certain sealing pressure width. The larger the sealing width, the smaller the sealing specific pressure, which is easy to cause leakage; (3) In order to improve low-pressure sealing, individual manufacturers continuously increase the initial preload of the disc spring, which eventually leads to an increase in the operating torque of the valve, and may also cause the valve seat to "strangle" the valve ball, resulting in failure of opening and closing, and even damage to the valve seat .

Contents of the invention

In order to solve the deficiencies in the prior art, the purpose of this utility model is to provide a valve seat structure without increasing the preload of the disc spring to realize the separation of high and low pressure seals. Sealing specific pressure, the seat structure of the floating ball valve is guaranteed to have sufficient sealing surface width to meet the allowable specific pressure requirements of the material at high pressure.

In order to achieve the above object, the utility model adopts the following technical solutions:

The seat structure of the floating ball valve includes two valve seats arranged at intervals and a ball between the two seats. Both seats are provided with an inner spherical surface connected to the ball. The small end of the inner spherical surface of the valve seat There is more than one ring of slotted structure on the top, and the slotted structure is an annular slot or is composed of a plurality of arc-shaped slots at intervals on a concentric circle.

The valve seat is molded from PEEK material.

The sphere is formed of stainless steel.

The utility model adopts the above technical scheme, and the groove structure divides the inner spherical surface on the valve seat into two parts. The part located at the large end of the inner spherical surface and having the largest area is the outer ring, which is a high-pressure sealing area, while the other inner spherical parts Both are inner rings, and the inner ring is a low-pressure sealing area; because the contact area of the inner ring is greatly reduced, the sealing specific pressure is increased, the low-pressure sealing is more reliable, and the service life of the valve is greatly increased; The elastic deformation deflection of the ring increases, the seal pre-tightening force becomes larger, and the low-pressure seal is more reliable. In addition, the high-pressure sealing area of the inner spherical surface of the valve seat is relatively large to ensure that the stress on the pressure-bearing surface of the material is within the allowable stress range, so that the valve seat will not be deformed too much and fail.

Description of drawings

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail:

Fig. 1 is the sectional schematic diagram of the valve seat structure of the utility model floating ball valve;

Fig. 2 is embodiment 1 of grooved structure in the utility model;

Fig. 3 is embodiment 2 of slotting structure in the utility model;

Fig. 4 is a schematic diagram of the inner spherical surface of the valve seat in the utility model.

detailed description

As shown in one of Figures 1 to 4, the utility model comprises two valve seats 1 arranged at intervals and a ball 2 arranged between the two valve seats 1, and the two valve seats 1 are provided with inner spherical surfaces 4 and The sphere 2 is connected, and the small end of the inner spherical surface 4 of the valve seat 1 is provided with more than one circle of grooved structures 3 . As shown in FIG. 2 , the groove structure 3 is an annular groove, or as shown in FIG. 3 , the groove structure 3 can also be composed of a plurality of arc-shaped grooves at intervals on a concentric circle.

In addition, the valve seat 1 is made of PEEK material. PEEK material has the characteristics of both toughness and rigidity. At the same time, it has excellent fatigue resistance to alternating stress. It can effectively improve the service life of the valve seat when applied to the valve seat. In addition, the spherical body 2 is formed of stainless steel.

The slotted structure 3 divides the inner spherical surface 4 on the valve seat 1 into two parts. The part located at the big end of the inner spherical surface 4 and having the largest area is the outer ring 41, which is a high-pressure sealing area, while the other inner spherical surface 4 parts are is the inner ring 42, and the inner ring 42 is a low-pressure sealing area.

After grooved on the inner spherical surface 4 of the valve seat 1, the flexural stiffness of the inner ring 42 of the inner spherical surface 4 of the valve seat 1 is greatly reduced, and the sealing force of the valve seat 1 acting on the inner spherical surface 4 is increased by 20%. The stress point with the valve seat 1 is on the inner ring 42 of the inner spherical surface 4 of the valve seat 1. Under low pressure, the sealing area of the valve seat 1 will move to the inner ring 42, and the outer ring 41 on the inner spherical surface 4 of the valve seat 1 is basically No force. Since the sealing of the inner ring 42 on the inner spherical surface 4 of the valve seat 1 reduces the low-pressure sealing width while the pre-tightening force is increased, the specific pressure of the low-pressure sealing is greatly improved. In the case of high pressure, due to the increase of upstream medium pressure, the high-pressure sealing area of the outer ring 41 on the inner spherical surface 4 of the rear valve seat 1 begins to be under pressure, increasing the pressure-bearing area, so the specific pressure acting on the surface of the rear valve seat 1 is not large. Exceeds the allowable specific pressure value of the material.

When the other conditions of the existing non-grooved valve seat and the utility model slotted valve seat are consistent, the low-pressure sealing pretightening force of the existing non-grooved valve seat is 26.2N, while the utility model grooved valve seat The low-pressure sealing pretightening force of the valve seat is 31.3N, which can effectively improve the low-pressure sealing pretightening force of the grooved valve seat, so the sealing performance is better.

In addition, the local contact stress of the inner spherical surface of the existing non-grooved valve seat is 25.8MPa, while the local contact stress of the inner spherical inner ring of the utility model grooved valve seat is 52.2MPa, thereby increasing the low-pressure sealing specific pressure , making the low-pressure seal more reliable and greatly increasing the wear life.

Claims (3)

1. The seat structure of the floating ball valve includes two valve seats arranged at intervals and a ball between the two seats. Both seats are provided with an inner spherical surface connected to the ball. It is characterized in that: the valve seat The small head end of the inner spherical surface is provided with more than one ring of slotting structures, which are annular slots or composed of multiple arc-shaped slots at intervals on a concentric circle. 2. The valve seat structure of the floating ball valve according to claim 1, wherein the valve seat is formed of PEEK material. 3. The seat structure of the floating ball valve according to claim 1 or 2, characterized in that: the ball is made of stainless steel.