Straight stroke valve rod structure with protective sleeve

Abstract

A valve rod structure of a straight stroke valve with a protective sleeve relates to the technical field of valve rods of straight stroke valves with protective sleeves, and comprises a packing box body, a packing assembly, a packing gland, a valve rod and a valve rod protective sleeve, a packing groove is arranged in the packing box body, an installation groove of the valve rod protective sleeve is arranged on the inner circle of the upper end of the packing gland, and the valve rod protective sleeve is arranged in the installation groove. The packing assembly is installed in a packing groove formed in the packing box body, the valve rod protection sleeve is installed in an installation groove of the valve rod protection sleeve, the section provided with the valve rod protection sleeve forms a concentricity hole structure between the packing gland and the valve rod and between the packing pressing plate and the valve rod, and the valve rod protection sleeve is made of polytetrafluoroethylene materials and cannot damage the surface of the valve rod. The valve rod has the advantages of prolonging the service life of the valve rod and being convenient to operate, the arranged valve rod protection sleeve is of a large-small head structure, the packing gland and the packing pressing plate are installed on the valve rod, and when the valve rod moves up and down, the valve rod protection sleeve cannot move up and down along with up-down movement of the valve rod due to blocking of the packing pressing plate.

Description

Technical Field

[0001] A linear-stroke valve stem structure with a protective sleeve is used for protecting the surface of the linear-stroke valve stem and relates to the technical field of design and manufacturing of a linear-stroke valve stem provided with a protective sleeve. Background Art

[0002] Valves are indispensable fluid control equipment in various sectors of the national economy, such as petroleum, chemical industry, power station, long-distance pipeline, shipbuilding, nuclear industry, various cryogenic projects, aerospace and marine oil production. The valve core of the linear control valve generally reciprocates in a straight line, including high-pressure linear valves that move in a spiral manner. Typical products include single-seat valves, double-seat valves, sleeve valves, three-way valves, angle valves, Y-type valves, axial flow valves, etc. In linear valves, the movement of valve adjustment is very ordinary. Due to the needs of the production process, the valve stem moves up and down at a high frequency. Therefore, the valve opening is adjusted up and down continuously, which increases the valve Wear of the packing used for sealing in the stem; in the prior art, when workers conduct on-site inspections and find leakage at the valve stem, they will tighten the valve cover nut on the packing of the valve stem and tighten the packing bolts to solve the leakage caused by the wear of the packing at the valve stem; however, due to the harsh on-site environment, workers can easily use excessive force and press the packing gland to the side, which will cause the packing gland to directly contact the valve stem. Then, when the valve is running up and down, the surface of the valve stem will be damaged due to direct metal friction with the packing gland, causing greater leakage at the packing, which will seriously affect production safety.

[0003] With the comprehensive upgrade of the intelligent chemical industry, users have put forward new and higher-level requirements for the use of valves. Although my country's valve production technology level has made great progress through innovation, there are still some problems. The leading products of many valve companies are still low-end mass products that cannot meet the needs of modern production. Utility Model Content

[0004] The utility model aims to provide a straight-stroke valve stem structure with a protective sleeve, which can effectively solve the problem that the packing pressure plate and the packing pressure cover are worn, the packing pressure cover is pressed off-center when tightened, and the valve stem surface is damaged.

[0005] The technical solution adopted by the utility model is as follows: The utility model provides a straight-stroke valve stem structure with a protective sleeve, including a packing box, a packing assembly, a packing gland, a valve stem protective sleeve, a packing pressure plate, a hexagonal nut, a stud bolt, and a valve stem;

[0006] A packing gland and a packing pressure plate are arranged at the upper end of the packing box, and the packing gland and the packing pressure plate are fixed by hexagonal nuts and stud bolts;

[0007] A packing groove and a bolt hole are arranged on the packing box body, and a valve stem protection sleeve installation groove is arranged on the upper end of the packing gland;

[0008] The packing assembly is installed in a packing groove provided in the packing box; the packing gland is installed on the upper end of the packing assembly; the valve stem protection sleeve is installed on the upper end of the packing gland; the packing pressure plate is sleeved on the outer circle of the valve stem protection sleeve;

[0009] The valve stem protective sleeve is made of polytetrafluoroethylene material, and the inner diameter of the valve stem protective sleeve is tightly matched with the outer diameter sliding clearance of the valve stem;

[0010] The valve stem protection sleeve is installed in the installation groove of the valve stem protection sleeve arranged at the upper end of the packing gland, and a section of the valve stem protection sleeve is arranged to form a concentricity hole structure between the packing gland and the packing pressure plate and the valve stem.

[0011] The upper and lower ends of the valve stem protective sleeve are respectively installed in the packing gland and the packing pressure plate;

[0012] The valve stem protection sleeve is installed in the valve stem protection sleeve installation groove arranged at the upper end of the packing gland;

[0013] The valve stem protective sleeve is a large-small head structure, and the diameter of the lower end arranged in the packing gland is larger than the diameter of the upper end arranged in the packing pressure plate;

[0014] Furthermore, the inner hole diameter of the packing pressure plate is larger than the outer circle diameter of the valve stem, and the valve stem protection sleeve is installed between the inner hole of the packing pressure plate and the outer circle of the valve stem.

[0015] Advantages or positive effects of the utility model

[0016] 1. Since the inner hole diameter of the packing plate is larger than the outer diameter of the valve stem, a valve stem protective sleeve is arranged between the inner hole of the packing plate and the outer circle of the valve stem. With this arrangement, even if the packing plate is biased under the extrusion of the hexagonal nut and the stud bolt, it will not cause metal contact between the valve stem and the packing plate. Only the valve stem protective sleeve can contact the valve stem. Because the valve stem protective sleeve is made of polytetrafluoroethylene, it will not damage the surface of the valve stem. Therefore, it has the advantages of extending the service life of the valve stem and being very convenient to operate.

[0017] 2. The valve stem protection sleeve is set to a large and small head structure. The diameter of the lower end set in the packing gland is larger than the diameter of the upper end set in the packing pressure plate. The valve stem protection sleeve is set with a small upper end and a large lower end. When the valve stem is equipped with the packing gland and the packing pressure plate, the valve stem protection sleeve will not move up and down with the up and down movement of the valve stem due to the obstruction of the packing pressure plate during the up and down movement of the valve stem. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1It is a schematic diagram of the installation structure of the utility model.

[0019] Legend

[0020] Packing box-1, packing assembly-2, packing gland-3, valve stem protection sleeve-4, packing pressure plate-5, hexagonal nut-6, stud bolt-7, valve stem-8. DETAILED DESCRIPTION

[0021] In order to further clearly demonstrate the structure of the utility model, the best embodiment of the utility model is given below:

[0022] See attached Figure 1 The utility model provides a straight-stroke valve stem structure with a protective sleeve, comprising a stuffing box 1, a stuffing assembly 2, a stuffing gland 3, a stem protective sleeve 4, a stuffing pressure plate 5, a hexagonal nut 6, a stud bolt 7, and a valve stem 8. A stuffing groove and a bolt hole are provided on the stuffing box 1 to facilitate the insertion of stuffing, which is then tightened by bolts to achieve the purpose of sealing the valve stem. During installation, the stuffing assembly 2 is now installed into the stuffing groove provided in the stuffing box 1, and then the stuffing gland 3 is installed, and then the stem protective sleeve 4 is installed, and then the stuffing pressure plate 5 is installed, and finally the stuffing assembly 2 is tightened using the hexagonal nut 6 and the stud bolt 7 to make the stuffing assembly 2 and the valve stem 8 closely connected to achieve a sealing effect. An installation groove for the stem protective sleeve 4 is provided at the upper end of the stuffing gland 3; since the stem protective sleeve 4 is made of polytetrafluoroethylene material, the inner diameter of the stem protective sleeve 4 is tightly matched with the outer diameter sliding clearance of the valve stem 8, so after installation, the inner diameter of the stem protective sleeve 4 and the outer diameter of the valve stem 8 can be completely sealed.

[0023] Furthermore, since the valve stem protection sleeve 4 arranged between the upper end of the packing gland 3 and the inner circle of the packing gland 5 is an integral structure, after the valve stem 8 is installed in the valve stem protection sleeve 4, it takes the valve stem 8 as the center of the circle and corrects the concentricity of the two independent components, the packing gland 3 and the packing gland 5, and the valve stem 8. A concentric circle structure with the valve stem as the center is formed between the two independent components, the packing gland 3 and the packing gland 5, and the valve stem 8. Therefore, during installation, the installation of the parts can be on a concentricity line, which can ensure that when the valve stem 8 moves up and down, it can prevent external dust and particles from entering the valve stem surface and causing damage to the valve stem surface.

[0024] The upper and lower ends of the valve stem protection sleeve 4 are respectively installed in the packing gland 3 and the packing pressure plate 5. The valve stem protection sleeve 4 is installed in the valve stem protection sleeve installation groove set at the upper end of the packing gland 3. The inner circle sleeve of the packing pressure plate 5 is set at the upper end of the valve stem protection sleeve 4. The valve stem protection sleeve 4 is a large and small head structure. The diameter of the lower end set in the packing gland 3 is larger than the diameter of the upper end set in the packing pressure plate 5. The large and small diameter structure of the valve stem protection sleeve 4 with a small upper end and a large lower end, when the valve stem 8 is installed with the packing gland 3 and the packing pressure plate 5, during the up and down movement of the valve stem, the valve stem protection sleeve will not move up and down with the up and down movement of the valve stem due to the obstruction of the packing gland 5.

[0025] Furthermore, the inner hole diameter of the packing pressure plate 5 is larger than the outer diameter of the valve stem 8, and a valve stem protection sleeve 4 is arranged between the inner hole of the packing pressure plate 5 and the outer circle of the valve stem 8. In this way, even if the packing pressure plate 5 is pressed off-center under the extrusion of the hexagonal nut 6 and the stud bolt 7, it will not cause metal contact between the valve stem 8 and the packing pressure plate 5. Only the valve stem protection sleeve 4 can contact with the valve stem 8. Because the valve stem protection sleeve 4 is made of polytetrafluoroethylene material, it will not cause damage to the surface of the valve stem 8, can extend the service life of the valve stem, and is very convenient to operate.

[0026] Furthermore, the utility model relates to the structure between the valve stem and the protective cover of a straight-stroke valve. The other structures of the straight-stroke valve are existing technologies. Ordinary technicians in this field can easily realize the connection between the utility model and other components of the existing straight-stroke valve, and complete the design and manufacture of the overall structure of the valve. The overall design of other components of the valve will not be elaborated here.

Claims

1. A straight-stroke valve stem structure with a protective sleeve, comprising a packing box (1), a packing assembly (2), a packing gland (3), a valve stem (8) and a valve stem protective sleeve (4), characterized in that: A packing gland (3) and a packing pressure plate (5) are provided at the upper end of the packing box (1), and the packing gland (3) and the packing pressure plate (5) are fixed by a hexagonal nut (6) and a stud bolt (7); A packing groove is provided in the packing box (1), a bolt hole is provided on the upper end surface of the packing box (1), and a mounting groove for a valve stem protective sleeve (4) is provided on the inner circle of the upper end of the packing gland (3); The packing assembly (2) is installed in a packing groove provided in the packing box (1); The packing gland (3) is installed at the upper end of the packing assembly (2); The valve stem protection sleeve (4) is installed in a mounting groove of the valve stem protection sleeve (4) arranged at the upper end of the packing gland (3), and a section of the valve stem protection sleeve (4) is provided to form a concentricity hole structure between the packing gland (3) and the packing pressure plate (5) and the valve stem (8).

2. A linear valve stem structure with a protective sleeve according to claim 1, characterized in that: The packing pressure plate (5) is sleeved on the outer circle of the valve stem protection sleeve (4).

3. A linear valve stem structure with a protective sleeve according to claim 1, characterized in that: The valve stem protection sleeve (4) is made of polytetrafluoroethylene material.

4. A linear valve stem structure with a protective sleeve according to claim 1, characterized in that: The inner diameter of the valve stem protection sleeve (4) is tightly matched with the outer diameter sliding clearance of the valve stem (8).

5. The linear valve stem structure with a protective sleeve according to claim 1, characterized in that: The upper and lower ends of the valve stem protection sleeve (4) are respectively mounted in the packing gland (3) and the packing pressure plate (5).

6. A linear valve stem structure with a protective sleeve according to claim 1, characterized in that: The valve stem protection sleeve (4) is a large-small head structure, and the diameter of the lower end arranged in the packing gland (3) is larger than the diameter of the upper end arranged in the packing pressure plate (5).

7. The linear valve stem structure with a protective sleeve according to claim 1, characterized in that: The inner hole diameter of the packing pressure plate (5) is larger than the outer diameter of the valve stem (8), and the valve stem protection sleeve (4) is installed between the inner hole of the packing pressure plate (5) and the outer diameter of the valve stem (8).

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