Program-controlled valve balanced cylinder seal structure

Abstract

The utility model relates to program control valve discloses a kind of program control valve balance cylinder sealing structure, program control valve includes valve body, valve rod, valve core and balance cylinder, valve rod and the sealing cooperation of cylinder sleeve of balance cylinder, inner sealing gland and outer sealing gland are successively sleeved on valve rod;Valve rod is sealed with cylinder sleeve by inner sealing gland and outer sealing gland, and the sealing between valve rod and the inner sealing gland includes third high-pressure dustproof ring, second fluorine ring, which are arranged in sequence;The sealing between valve rod and the outer sealing gland includes fluorine glue sealing ring, first fluorine rubber O-ring, the sealing between the inner sealing gland, outer sealing gland and cylinder sleeve all use fluorine rubber O-ring, and valve core and the sealing cooperation of cylinder barrel of balance cylinder, and the sealing between the two includes first high-pressure dustproof ring, first fluorine ring and support ring, second high-pressure dustproof ring, which are arranged in sequence;It scrapes dust by high-pressure dustproof ring, and increases lubricating oil groove in suitable position, to prolong the service life of sealing element.

Description

Technical Field

[0001] This utility model relates to a programmable valve, and in particular to the sealing structure of its balance cylinder. Background Technology

[0002] The programmable valve includes a valve body and a balance cylinder fixed to the valve body. A grid-shaped support frame is connected to the balance cylinder. The piston of the balance cylinder passes through the balance cylinder and connects to the detection rod. The valve rod connected to the piston passes through the balance cylinder and connects to the valve core. Figure 1 As shown, the balance cylinder body is provided with a cylinder barrel and a cylinder liner for sealing purposes. The valve core is sealed to the cylinder barrel of the balance cylinder, and the valve stem is sealed to the cylinder liner of the balance cylinder.

[0003] like Figure 3 As shown, in most programmable valves, the sealing components used between the valve stem and the cylinder liner of the balance cylinder are a packing support cover, a spring, packing, and a packing gland. The packing is usually made of multiple layers of rubber V-rings stacked together. Rubber O-rings are used between the packing support cover and the packing gland and the inner wall of the cylinder liner. When the spring fails, it will affect the sealing performance, and the rubber is prone to aging. Figure 2 As shown, in most currently used programmable valves, the seal between the valve core and the cylinder is a rubber YX sealing ring, consisting of one upper seal and one lower seal, with a support ring between the upper and lower seals. There is no lubrication groove, making the seal prone to damage during use. During disassembly and inspection, it was found that the sealing lip was almost completely worn away, with fine powder present. This powder significantly impacts the sealing ring. During system operation, the valve core inevitably absorbs process media, generating a small amount of dust, which is the main cause of internal leakage in the programmable valve. In production systems using this programmable valve, the purity and yield of the product will be affected. Therefore, it is necessary to frequently inspect the seals of the programmable valve's balance cylinder to overcome its adverse effects on the product, which may disrupt normal production.

[0004] Therefore, it is necessary to improve the sealing structure of the programmable valve balance cylinder to minimize its adverse effects on the product. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a sealing structure for a programmable valve balance cylinder, which has a longer service life.

[0006] The technical solution adopted by this utility model to solve its technical problem is: a programmable valve balance cylinder sealing structure. The programmable valve includes a valve body, a valve stem, a valve core, and a balance cylinder fixed on the valve body. The valve stem is sealed to the cylinder liner of the balance cylinder, and the valve core is sealed to the cylinder barrel of the balance cylinder. The seal between the valve core and the cylinder barrel includes a first high-pressure dustproof ring, a first PTFE sealing ring and a support ring, and a second high-pressure dustproof ring arranged sequentially. By arranging two high-pressure dustproof rings to scrape away dust and replacing the sealing rings with PTFE sealing rings, their wear resistance and self-lubricating properties are increased, thereby extending the service life of the seal between the valve core and the cylinder liner.

[0007] The valve stem is fitted with an inner sealing cap and an outer sealing cap in sequence. The valve stem seals with the cylinder liner through the inner and outer sealing caps. The seal between the valve stem and the inner sealing cap includes a third high-pressure dustproof ring and a second PTFE sealing ring arranged in sequence. The seal between the valve stem and the outer sealing cap includes a fluororubber sealing ring and a first fluororubber O-ring. The seals between the inner and outer sealing caps and the cylinder liner are both made of fluororubber O-rings. An additional high-pressure dustproof ring is arranged on the valve stem near the valve core to scrape off dust, and the sealing ring is replaced with a PTFE sealing ring to increase its wear resistance and self-lubricating properties, thereby extending the service life of the seals between the valve stem and the cylinder liner.

[0008] A first lubricating oil groove is provided between the first high-pressure dustproof ring and the first PTFE sealing ring. A second lubricating oil groove is provided on the outside of the first second PTFE sealing ring. A third lubricating oil groove is provided between the fluororubber sealing ring and the first fluororubber O-ring. By filling the lubricating oil grooves at the corresponding positions with suitable lubricating oils such as grease, the coefficient of friction is reduced and the sealing effect is increased.

[0009] Two layers of second PTFE sealing rings are respectively provided at both ends of the second lubricating oil groove, and the first PTFE sealing ring (23) also has two layers. By increasing the number of sealing rings, the sealing performance is further improved, the service life of the overall sealing structure is increased, and the risk of production stoppage for maintenance is reduced.

[0010] The beneficial effects of this utility model are: it reduces the adverse effects of dust carried by the process medium attached to the valve core of the programmable valve on the seal of the balance cylinder, resulting in a better sealing effect and an extended overall effective service life of the seal. It can be used for the manufacture or modification of programmable valves. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the sealing structure of an existing programmable valve balance cylinder.

[0012] Figure 2 yes Figure 1 A schematic diagram of the sealing structure between the valve core and the cylinder barrel of the balance cylinder.

[0013] Figure 3 yes Figure 1 A schematic diagram of the sealing structure between the valve stem and the cylinder liner of the balance cylinder.

[0014] Figure 4 This is a schematic diagram of the sealing structure of the balance cylinder of the programmable valve of this utility model.

[0015] Figure 5 yes Figure 4 A schematic diagram of the sealing structure between the valve core and the cylinder barrel of the balance cylinder.

[0016] Figure 6 yes Figure 4 A schematic diagram of the sealing structure between the valve stem and the cylinder liner of the balance cylinder.

[0017] The components in the diagram are labeled as follows: 1-Valve body, 2-Valve core, 3-Cylinder barrel, 4-Cylinder liner, 5-Valve stem, 6-Piston, 7-Support bracket, 8-Spring, 9-Packing, 11-Support ring, 12-Valve core sealing ring, 13-YX sealing ring, 14-Detection rod, 15-Sensor mounting hole, 21-First high-pressure dustproof ring, 22-First lubricating oil groove, 23-First PTFE sealing ring, 24-Second high-pressure dustproof ring, 50-Inner sealing gland, 51-Third high-pressure dustproof ring, 52-Second PTFE sealing ring, 53-Second lubricating oil groove, 54-Fluororubber sealing ring, 55-Third lubrication groove, 56-First fluororubber O-ring, 57-Outer sealing gland, 58-Second fluororubber O-ring, 91-Packing support cover, 92-V-ring, 93-Packing gland, 94-Rubber O-ring. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Example: Original Figures 1 to 3 The programmable valve shown is pressed Figures 4 to 6 The design was modified to incorporate the sealing structure of the programmable valve balance cylinder of this invention.

[0020] like Figure 4 and Figure 5As shown, the present invention discloses a programmable valve balance cylinder sealing structure. The programmable valve includes a valve body 1, a valve stem 5, a valve core 2, and a balance cylinder fixed on the valve body 1. The valve stem 5 is sealed to the cylinder sleeve 4 of the balance cylinder, and the valve core 2 is sealed to the cylinder barrel 3 of the balance cylinder. The seal between the valve core 2 and the cylinder barrel 3 includes a first high-pressure dustproof ring 21, two layers of first PTFE sealing rings 23, a support ring 11, and a second high-pressure dustproof ring 24 arranged sequentially. A first lubricating oil groove 22 is provided between the first high-pressure dustproof ring 21 and the first PTFE sealing ring 23. Considering the influence of dust carried by the process medium adhering to the valve core, two high-pressure dustproof rings are arranged to scrape off the dust, and a lubricating oil groove is added to increase the sealing effect. The sealing rings used are PTFE sealing rings, which improve the wear resistance and self-lubricating performance of the seal itself, thereby greatly reducing the wear of the sealing rings by dust and greatly increasing the reliability of the sealing structure between the valve core and the cylinder barrel.

[0021] like Figure 4 and Figure 6 As shown, an inner sealing cap 50 and an outer sealing cap 57 are sequentially fitted onto the valve stem 5. The valve stem 5 is sealed to the cylinder liner 4 through the inner sealing cap 50 and the outer sealing cap 57. The seal between the valve stem 5 and the inner sealing cap 50 includes a third high-pressure dustproof ring 51 and four second PTFE sealing rings 52. A second lubricating oil groove 53 is provided between the two middle second PTFE sealing rings 52. The seal between the valve stem 5 and the outer sealing cap 57 includes a fluororubber sealing ring 54 and a first fluororubber O-ring 56. A third lubricating oil groove 55 is provided between the fluororubber sealing ring 54 and the first fluororubber O-ring 56. The seal between the inner sealing cap 50, the outer sealing cap 57 and the cylinder liner 4 also uses fluororubber O-rings, namely the second fluororubber O-ring 58. The above structure no longer uses the traditional "spring + packing" sealing method. Instead, it uses a double-layer sealing gland as the mounting base for the seal between the valve stem and cylinder liner. The skeleton material of the inner sealing gland 50 and the outer sealing gland 57 is aviation aluminum, and the inner / outer sealing material is PTFE + rubber, which has strong sealing performance, high and low temperature resistance, aging resistance, media resistance, and weather resistance. The positioning method at both ends can be the same as the original packing method, eliminating the influence of spring failure on the seal. The above structure can also reduce the frictional resistance of the valve stem. On one side of the inner wall of the sealing gland, a high-pressure dustproof ring structure is arranged in conjunction with a lubricating oil groove structure to further reduce the impact of dust on the seal. The use of PTFE sealing rings improves the wear resistance and self-lubricating performance of the seal itself. The outer wall of the sealing gland also uses fluororubber O-rings as the sealing element, realizing the performance improvement and service life extension of the overall sealing structure.

[0022] Considering their application scenarios, both the first PTFE sealing ring 23 and the second PTFE sealing ring 52 are bidirectional PTFE sealing rings.

[0023] Fluororubber sealing rings are high-performance sealing elements with several outstanding advantages: High temperature resistance – capable of continuous and stable operation in environments ranging from 200°C to 250°C. Even at temperatures as high as 300°C, it can maintain its function for a short period of time; Aging resistance – after 10 years of natural storage, its performance still maintains a satisfactory level, ensuring stable sealing performance during long-term use; Corrosion resistance – fluororubber is a special synthetic rubber, mainly composed of fluoropolymers, which can effectively resist the erosion of various acids, alkalis, and solvents. In chemical production, it can be used to make seals, gaskets, and pipe linings; Oil resistance – exhibiting good resistance to oils, maintaining stable performance in oily environments, and not easily dissolved or swollen by oils.

[0024] After the above modifications, the average failure period of the balance cylinder seal of the programmable valve was extended from 24 months to 36 months.

Claims

1. A programmable valve balance cylinder sealing structure, wherein the programmable valve includes a valve body (1), a valve stem (5), a valve core (2), and a balance cylinder fixed on the valve body (1), wherein the valve stem (5) is sealed to the cylinder sleeve (4) of the balance cylinder, and the valve core (2) is sealed to the cylinder barrel (3) of the balance cylinder, characterized in that: The seal between the valve core (2) and the cylinder (3) includes a first high-pressure dustproof ring (21), a first PTFE sealing ring (23), a support ring (11), and a second high-pressure dustproof ring (24) arranged in sequence.

2. The sealing structure of the programmable valve balance cylinder as described in claim 1, characterized in that: The valve stem (5) is fitted with an inner sealing cap (50) and an outer sealing cap (57) in sequence; the valve stem (5) is sealed to the cylinder liner (4) through the inner sealing cap (50) and the outer sealing cap (57). The seal between the valve stem (5) and the inner sealing cap (50) includes a third high-pressure dustproof ring (51) and a second PTFE sealing ring (52) arranged in sequence; the seal between the valve stem (5) and the outer sealing cap (57) includes a fluororubber sealing ring (54) and a first fluororubber O-ring (56). The seal between the inner sealing cap (50), the outer sealing cap (57) and the cylinder liner (4) is made of fluororubber O-ring.

3. The sealing structure of the programmable valve balance cylinder as described in claim 2, characterized in that: A first lubricating oil groove (22) is provided between the first high-pressure dustproof ring (21) and the first PTFE sealing ring (23), a second lubricating oil groove (53) is provided on the outside of the first second PTFE sealing ring (52), and a third lubricating oil groove (55) is provided between the fluororubber sealing ring (54) and the first fluororubber O-ring (56).

4. The sealing structure of the programmable valve balance cylinder as described in claim 3, characterized in that: The second lubricating oil groove (53) is provided with two layers of second PTFE sealing rings (52) at both ends, and the first PTFE sealing ring (23) is also provided with two layers.

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