Low-dissipation valve rod filler
By designing the upper and lower packing rings of the middle filler rings of the circular rings of the polygonal cross-sectional structure, the sealing ability of the valve filler is enhanced, and the problem that existing fillers are difficult to meet the low dispersion standards are solved, and effective volatile organic compounds are achieved. .
Patent Information
- Application Number
- CN202323541626.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-25
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2033-12-25
AI Technical Summary
Existing valve packing is difficult to meet the harsh low dissipation standards, resulting in leakage of volatile organic compounds in the petrochemical industry and causing air pollution.
A low-escape valve stem packing including an upper filler ring, a middle filler ring and a lower filler ring is designed. The cross-section of the middle filler ring is polygonal, and is provided with an outer circle lower ring plane, an outer circle upper ring plane, and an inner circle. The upper ring plane, outer conical surface, inner conical surface, outer cylindrical surface and inner cylindrical surface are used to increase sealing capacity under the action of axial force.
By increasing the deformation amount of the filler ring, the sealing capacity is enhanced, and the escape of volatile organic matter is effectively suppressed, meeting the requirements of low ejaculation standards.
Smart Images
Figure CN222163773U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of sealing, and in particular relates to a low-emission valve stem packing. Background Art
[0002] Petrochemical industry is a large industry, and its manufacturing process is a complex chemical engineering. The gas composition is complex and contains a large number of volatile organic compounds (VOCS). Once these volatile organic compounds leak out, they will cause serious pollution to the atmosphere. According to relevant statistical data reports, 60% of VOCS in the petrochemical industry are caused by valve leakage, among which the valve stem packing is the main source of leakage. In order to effectively control the leakage of valves, the valve industry has introduced fugitive measurement for valve measurement. The American Petroleum Institute has promulgated API624 and API641 standards, which respectively stipulate fugitive test for gate valves, stop valves, ball valves and butterfly valves; the International Organization for Standardization has promulgated ISO 15848-1: "Industrial Valves - Fugitive Measurement, Testing and Qualification Procedures Part 1: Valve Type Test Classification System and Assessment Method"; my country has also promulgated GB / T 26481-2011 "Valve Fugitive Test" standard. These standards are extremely demanding for low fugitive detection of packing, which is difficult to achieve with existing packing.
[0003] The packing ring is subjected to axial force, which causes the packing to deform radially. The outer cylindrical surface of the packing ring fits the inner wall of the stuffing box, and the inner cylindrical surface of the packing ring fits the valve stem to achieve sealing pressure. The cross section of the existing sealing ring structure is rectangular, and the deformation of the rectangular sealing ring is limited after being compressed. In addition, the allowable deformation of both flexible graphite packing and polytetrafluoroethylene materials is very small. Therefore, the packing and the valve stem will fail to seal if they are slightly worn. If the valve is to meet the stringent low emission standard requirements, the valve stem packing is the key. Utility Model Content
[0004] The utility model aims to overcome the deficiencies of the prior art and provide a low-emission valve stem packing, which has a large radial deformation, increases the sealing ability and can meet the low-emission standard requirements.
[0005] The purpose of the utility model is achieved through the following technical solutions: a low-emission valve stem packing, comprising an upper packing ring, a middle packing ring and a lower packing ring, a plurality of middle packing rings are arranged between the upper packing ring and the lower packing ring, and the upper packing ring, the middle packing ring and the lower packing ring are axially overlapped; the cross-section of the middle packing ring is a polygon, and the middle packing ring is provided with an outer circle lower ring plane, an outer circle upper ring plane, an inner circle upper ring plane, an outer cone surface, an inner cone surface, an outer cylindrical surface and an inner cylindrical surface; the upper end of the outer cylindrical surface is connected to the outer end of the outer circle upper ring plane, and the inner end of the outer circle upper ring plane is connected to the outer end of the outer cone surface; the inner end of the outer cone surface is connected to the outer end of the inner circle upper ring plane, and the inner end of the inner circle upper ring plane is connected to the inner cylindrical surface; the lower end of the inner cylindrical surface is connected to the upper end of the inner cone surface; the inner circle The lower end of the conical surface is connected to the inner end of the lower annular plane of the outer circle; the other end of the lower annular plane of the outer circle is connected to the lower end of the outer cylindrical surface; the upper annular plane of the inner circle is higher than the upper annular plane of the outer circle; specifically, the middle packing ring includes an outer cylindrical surface, the upper end of the outer cylindrical surface is provided with an outer cylindrical surface upper plane, and one end of the outer cylindrical surface plane is provided with an outer conical surface; the outer conical surface is arranged at the end of the outer cylindrical surface plane away from the outer cylindrical surface, and the other end of the outer conical surface is provided with an inner circle upper annular plane, and the horizontal plane of the inner circle upper annular plane is higher than the horizontal plane of the outer cylindrical surface plane; the other end of the inner circle upper annular plane is provided with an inner cylindrical surface; the lower end of the inner cylindrical surface is provided with an inner conical surface, and the lower end of the inner conical surface is provided with an outer cylindrical surface lower plane; the other end of the outer cylindrical surface lower plane is connected to the lower end of the outer cylindrical surface.
[0006] Through the above scheme, according to the fact that in a right triangle, the length of the hypotenuse is greater than the adjacent side, the intermediate ring in the packing structure is like the hypotenuse of a right triangle. Under the action of axial force, the acute angle of the triangle decreases, the length of the hypotenuse remains unchanged, and the additional deformation stress applied to the inner wall of the stuffing box and the valve stem increases, which is converted into enhanced sealing ability.
[0007] Preferably, the outer conical surface forms an angle b with the upper annular plane of the inner circle; the inner conical surface forms an angle a with the lower plane of the inner cylindrical surface; the angle a is greater than the angle b, and both the angle a and the angle b are acute angles.
[0008] Through the above scheme, under the action of axial force, the angle a of the packing is reduced, the length of the hypotenuse remains unchanged, and the additional deformation stress applied to the inner wall of the stuffing box and the valve stem is increased, thereby effectively improving the sealing ability of the packing.
[0009] Preferably, the upper packing ring and the lower packing ring are both circular ring structures, the upper packing ring and the lower packing ring are flexible graphite braided packing rings, and the middle packing ring is made of any one of high-density flexible graphite, polytetrafluoroethylene, and modified polytetrafluoroethylene materials.
[0010] Through the above solution, the upper packing ring and the lower packing ring are respectively located at the two ends of the middle ring, and are mainly used to scrape off dirt on the surface of the valve stem.
[0011] Preferably, the inner diameters of the upper packing ring, the middle packing ring and the lower packing ring are equal.
[0012] Preferably, the cross-section of the middle packing ring is a polygonal structure, the outer conical surface is located above the inner conical surface, the inner cylindrical surface is located above the outer cylindrical surface, the inner circle upper ring plane is located above the upper plane of the outer cylindrical surface, the outer conical surface and the inner conical surface are both arranged to gradually tilt upward along the direction of the outer cylindrical surface toward the inner cylindrical surface, and the middle packing ring is a flexible graphite ring.
[0013] Through the above solution, the middle packing ring realizes low-emission sealing performance of the packing.
[0014] Preferably, the inner diameters of the outer packing ring and the middle packing ring are equal.
[0015] Through the above solution, the inner walls of the outer packing ring and the middle packing ring can be easily abutted against the valve stem, thereby ensuring the sealing performance of the packing.
[0016] The beneficial effect of the utility model is that the utility model arranges the structure of the middle packing ring so that the angle a is greater than the angle b, and then by means of the principle that the hypotenuse of a right triangle is greater than the adjacent side, the deformation of the packing ring is increased, and the sealing ability of the packing sealing ring is enhanced, thereby achieving low-emission sealing performance of the packing ring. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the structure of the utility model;
[0018] Figure 2 It is the structural schematic diagram of the middle packing ring;
[0019] Figure 3 It is a schematic diagram of the geometric shape of the cross section of the middle packing ring;
[0020] In the figure, 1-upper packing ring, 2-middle packing ring, 3-lower packing ring, 4-outer cylindrical surface, 5-outer circle upper ring plane outer cylindrical surface, 6-outer conical surface, 7-inner circle upper ring plane, 8-inner cylindrical surface, 9-inner conical surface, 10-outer circle lower ring plane. DETAILED DESCRIPTION
[0021] The technical solution of the present utility model is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present utility model is not limited to the following. Example
[0022] like Figure 1-Figure 3 As shown, a low-emission valve stem packing comprises an upper packing ring 1, a middle packing ring 2 and a lower packing ring 3; a plurality of middle packing rings 2 are arranged between the upper packing ring 1 and the lower packing ring 3, and the upper packing ring 1, the middle packing ring 2 and the lower packing ring 3 are axially overlapped; the cross section of the middle packing ring 2 is a polygon, and the middle packing ring 2 is provided with an outer lower circular ring plane 10, an outer upper circular ring plane 5, an inner upper circular ring plane 7, an outer conical surface 6, an inner conical surface 9, an outer cylindrical surface 4 and an inner cylindrical surface 8; the upper end of the outer cylindrical surface 4 is aligned with the outer The outer ends of the upper annular planes 5 are connected, and the inner end of the outer circle upper annular plane 5 is connected to the outer end of the outer conical surface 6; the inner end of the outer conical surface 6 is connected to the outer end of the inner circle upper annular plane 7, and the inner end of the inner circle upper annular plane 7 is connected to the inner cylindrical surface 8; the lower end of the inner cylindrical surface 8 is connected to the upper end of the inner conical surface 9; the lower end of the inner conical surface 9 is connected to the inner end of the outer circle lower annular plane 10; the other end of the outer circle lower annular plane 10 is connected to the lower end of the outer cylindrical surface 4; the inner circle upper annular plane 7 is higher than the outer circle upper annular plane 5. The middle packing ring 2 includes an outer cylindrical surface 4, the upper end of the outer cylindrical surface 4 is provided with an outer cylindrical surface upper plane 5, and one end of the outer cylindrical surface plane 5 is provided with an outer conical surface 6; the outer conical surface 2 is arranged at the end of the outer cylindrical surface plane 5 away from the outer cylindrical surface 4, and the other end of the outer conical surface 6 is provided with an inner circle upper annular plane 7, and the horizontal plane of the inner circle upper annular plane 7 is higher than the horizontal plane of the outer cylindrical surface upper plane 5; the other end of the inner circle upper annular plane 7 is provided with an inner cylindrical surface 8; the lower end of the inner cylindrical surface 8 is provided with an inner conical surface 9, and the lower end of the inner conical surface 9 is provided with an outer cylindrical surface lower plane 10; the other end of the outer cylindrical surface lower plane 10 is connected to the lower end of the outer cylindrical surface 4. The outer conical surface 6 forms an angle b with the inner circle upper annular plane 7; the inner conical surface 9 forms an angle a with the lower plane of the inner cylindrical surface 8; the angle a is greater than the angle b, and both the angle a and the angle b are acute angles. The upper packing ring 1 and the lower packing ring 3 are both annular structures, the upper packing ring 1 and the lower packing ring 3 are flexible graphite braided packing rings, and the middle packing ring 2 is a flexible graphite ring. The inner diameters of the upper packing ring 1, the middle packing ring 2 and the lower packing ring 3 are equal; the upper plane 5 of the outer cylindrical surface, the upper annular plane 7 of the inner circle and the lower plane 10 of the outer cylindrical surface are all arranged horizontally; the inner conical surface 9 is arranged below the outer conical surface 6.
[0023] During specific implementation, the upper packing ring 1, the middle packing ring 2 and the lower packing ring 3 are sleeved on the valve stem and installed in the stuffing box. According to the principle that the length of the hypotenuse of a right triangle is greater than the adjacent side, the middle packing ring 2 is like the hypotenuse of a right triangle in the packing structure. Under the action of the axial force, the angle a of the packing is reduced, and the length of the hypotenuse remains unchanged. The additional deformation stress applied to the inner wall of the stuffing box and the valve stem is increased, thereby increasing the sealing ability, thereby suppressing the escape of volatile organic compounds VoCs and achieving low-emission sealing.
[0024] The above is only a preferred embodiment of the utility model. It should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.
Claims
1. A low-emission valve stem packing, comprising an upper packing ring (1), a middle packing ring (2) and a lower packing ring (3), characterized in that: A plurality of middle packing rings (2) are arranged between the upper packing ring (1) and the lower packing ring (3); the upper packing ring (1), the middle packing ring (2) and the lower packing ring (3) are arranged to overlap axially; the cross section of the middle packing ring (2) is polygonal; the middle packing ring (2) is provided with an outer lower annular plane (10), an outer upper annular plane (5), an inner upper annular plane (7), an outer conical surface (6), an inner conical surface (9), an outer cylindrical surface (4) and an inner cylindrical surface (8); the upper end of the outer cylindrical surface (4) is connected to the outer end of the outer upper annular plane (5); The inner end of the outer circle upper annular plane (5) is connected to the outer end of the outer conical surface (6); the inner end of the outer conical surface (6) is connected to the outer end of the inner circle upper annular plane (7); the inner end of the inner circle upper annular plane (7) is connected to the inner cylindrical surface (8); the lower end of the inner cylindrical surface (8) is connected to the upper end of the inner conical surface (9); the lower end of the inner conical surface (9) is connected to the inner end of the outer circle lower annular plane (10); the other end of the outer circle lower annular plane (10) is connected to the lower end of the outer cylindrical surface (4); the inner circle upper annular plane (7) is higher than the outer circle upper annular plane (5).
2. A low-emission valve stem packing according to claim 1, characterized in that: The outer conical surface (6) and the upper annular plane (7) of the inner circle form an angle b; the inner conical surface (9) and the lower plane of the inner cylindrical surface (8) form an angle a; the angle a is greater than the angle b, and both the angle a and the angle b are acute angles.
3. A low-emission valve stem packing according to claim 1, characterized in that: The upper packing ring (1) and the lower packing ring (3) are both circular ring structures, and the upper packing ring (1) and the lower packing ring (3) are flexible graphite braided packing rings.
4. A low-emission valve stem packing according to any one of claims 1 and 3, characterized in that: The inner diameters of the upper packing ring (1), the middle packing ring (2) and the lower packing ring (3) are equal.