Sealing structure of safety valve of railway tank car

Abstract

The utility model relates to a safety valve, in particular to a sealing structure of a safety valve of a railway tank car, and aims to solve the problems that an existing sealing piece is easy to fall off or fail and is not easy to overhaul under the working condition that the discharge capacity of the safety valve is large. The check valve comprises the valve body and the valve element arranged in the valve body, the gland connected with the sealing section of the valve element in a sealed mode is arranged on the sealing section of the valve element, the gland is further fixed to the valve element through the locking nut arranged on the guide rod on the upper portion of the valve element, the sealing section of the valve element is connected with the upper end face of the valve body in a sealed mode, and therefore the sealing effect is guaranteed. When maintenance is needed, the gland can be taken out and the sealing piece arranged on the sealing section of the valve element can be replaced only by dismounting the locking nut, so that the maintenance efficiency is improved.

Description

Technical Field

[0001] This utility model relates to a safety valve, specifically to a sealing structure for a safety valve on a railway tank car. Background Technology

[0002] The pressure inside railway tank cars is regulated by safety valves. Currently, the industry uses breather-type safety valves for railway tank cars, with seals embedded in tenons on the sealing surface. This sealing structure has the following problems under conditions of large valve discharge and during safety valve maintenance: First, the seals may fall off under conditions of large valve discharge; second, the seals may fail if the valve core has some oscillation; and third, replacing the seals requires disassembling the entire valve, which is not easy to maintain. Utility Model Content

[0003] The main purpose of this utility model is to solve the technical problems of easy detachment or failure of seals and difficulty in maintenance in the existing technology, and to provide a sealing structure for a safety valve of a railway tank car.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A sealing structure for a safety valve in a railway tank car, comprising a valve body and a valve core disposed within the valve body, is characterized by:

[0006] The valve core consists of a guide rod, a sealing section, and a pull rod connected sequentially from top to bottom. The sealing section is a stepped circular boss, consisting of a first sealing section and a second sealing section from top to bottom, with the outer diameter of the first sealing section being smaller than that of the second sealing section. A pressure cap is sealed to the upper end face of the first sealing section, and the pressure cap is simultaneously sealed to the outer edge of the second sealing section and the upper end face of the valve body. The lower end face of the second sealing section is sealed to the upper end face of the valve body.

[0007] A locking nut is provided on the guide rod of the valve core to press the gland onto the sealing section of the valve core.

[0008] Furthermore, an annular secondary sealing ring is provided on the outer side of the first sealing section, and the inner diameter of the secondary sealing ring is adapted to the outer diameter of the first sealing section. The upper end face of the first sealing section is sealed to the lower end face of the gland through the secondary sealing ring. A first annular groove is provided on the outer side of the second sealing section along the circumference. An annular main sealing ring is provided in the first annular groove, and the inner diameter of the main sealing ring is adapted to the inner diameter of the groove. An annular boss is provided on the outer side of the central hole of the valve body. The gland is sealed to the outer edge of the second sealing section and the upper end face of the annular boss on the valve body through the main sealing ring. When the valve core is offset in the central hole of the valve body, a stable seal can still be achieved.

[0009] Furthermore, the lower end face of the gland is provided with a positioning boss that matches the outer diameter of the annular boss on the valve body, and the inner wall of the positioning boss is a conical surface. A second annular groove is provided on the inner wall at the position corresponding to the main sealing ring. An annular sealing surface is provided on the upper surface of the annular boss. The main sealing ring is located between the first annular groove, the second annular groove and the annular sealing surface. The inner wall of the positioning boss on the gland is simultaneously sealed and connected to the outer edge of the second sealing section and the upper surface of the annular boss on the valve body through the main sealing ring.

[0010] Furthermore, the guide rod of the valve core is provided with a first mounting boss and a second mounting boss from top to bottom; the second mounting boss is located in the central hole of the gland, and its cross-sectional shape is rectangular, which matches the cross-sectional shape of the central hole of the gland; a locking nut is installed on the outside of the first mounting boss, and its shape matches the shape of the central hole of the locking nut; the rectangular cross-section of the second mounting boss cooperates with the central hole of the gland, thereby ensuring that the valve core and the gland will not rotate when the locking nut is tightened.

[0011] Furthermore, an oblong boss is provided on the outer side of the center hole of the cover. Let the distance between the upper surface of the oblong boss and the lower surface of the cover be L, the distance between the lower surface of the first mounting boss and the upper surface of the second mounting boss be L1, and the height of the second mounting boss be L2. Then L, L1 and L2 satisfy L1+L2=L.

[0012] Furthermore, an annular vent is provided on the outer side of the annular boss on the valve body.

[0013] Furthermore, an annular stepped limiting boss is provided on the outer side of the annular ventilator, and multiple mounting bosses are also uniformly provided on the outer side along the circumference for mounting the guide frame; multiple water guiding channels extending axially are uniformly provided on the limiting boss along the circumference for draining rainwater falling into the annular ventilator.

[0014] Furthermore, the outer side of the limiting boss is provided with multiple mounting holes evenly distributed circumferentially for mounting the valve body on the railway tank car.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] 1. The sealing structure of the safety valve of the railway tank car provided by this utility model allows for replacement of the two sealing rings without disassembling the spring. Simply remove the anti-loosening nut and take out the pressure cap to replace them, thereby improving maintenance efficiency.

[0017] 2. The sealing structure of the safety valve for railway tank cars provided by this utility model is such that the main sealing ring and the auxiliary sealing ring are fixed by the gland and the valve core, and are not easy to fall off under the condition of large exhaust volume, and its sealing effect is stable and reliable.

[0018] 3. The sealing structure of the safety valve for railway tank cars provided by this utility model can still achieve a stable and reliable seal even when the valve core has a certain degree of oscillation, because the rounded corner of the valve body is embedded in the main sealing ring. Attached Figure Description

[0019] Figure 1 This is a half-sectional three-dimensional structural schematic diagram of an embodiment of the sealing structure of a safety valve for a railway tank car according to the present invention;

[0020] Figure 2 This is a three-dimensional structural diagram of the valve core in an embodiment of the sealing structure of a safety valve for a railway tank car according to the present invention, wherein (a) is a schematic diagram of the overall structure of the valve core, and (b) is a partially enlarged schematic diagram of the sealing section of the valve core;

[0021] Figure 3 This is a three-dimensional structural diagram of the gland in an embodiment of the sealing structure of a safety valve for a railway tank car according to the present invention, wherein (a) is a three-dimensional structural diagram of the gland and (b) is a half-sectional structural diagram of the gland.

[0022] Figure 4 This is a three-dimensional structural diagram of the valve body in an embodiment of the sealing structure of a safety valve for a railway tank car according to the present invention, wherein (a) is a three-dimensional structural diagram of the upper side of the valve body, and (b) is a half-sectional structural diagram of the valve body.

[0023] Figure 5 This is a schematic diagram showing the installation positions of the main sealing ring and the auxiliary sealing ring in an embodiment of the sealing structure of a safety valve for a railway tank car according to this utility model.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1-Valve body; 11-Annular vent; 12-Limiting boss; 13-Mounting boss; 14-Mounting hole; 2-Main sealing ring; 3-Secondary sealing ring; 4-Gland; 41-Oval boss; 42-Second annular groove; 5-Locking nut; 6-Valve core; 61-Guide rod; 62-First mounting boss; 63-Second mounting boss; 64-First sealing section; 65-Second sealing section; 66-Pull rod; 67-First annular groove. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0027] This utility model provides a sealing structure for a safety valve on a railway tank car, the overall structure of which is as follows: Figure 1 As shown, it includes a valve body 1 and a valve core 6 disposed in the central hole of the valve body 1; the specific structure of the valve core 6 is as follows. Figure 2As shown, the valve body 1 consists of a guide rod 61, a sealing section, and a pull rod 66 connected sequentially from top to bottom. The sealing section is a stepped circular boss, consisting of a first sealing section 64 and a second sealing section 65 from top to bottom, with the outer diameter of the first sealing section 64 being smaller than that of the second sealing section 65. An annular secondary sealing ring 3 is provided on the outer side of the first sealing section 64, and the inner diameter of the secondary sealing ring 3 matches the outer diameter of the first sealing section 64. A first annular groove 67 is circumferentially formed on the outer surface of the second sealing section 65, and an annular main sealing ring 2 is provided within the first annular groove 67. An annular boss is provided on the outer side of the central hole of the valve body 1, and the main sealing ring 2 is sealed to the annular boss on the valve body 1.

[0028] A gland 4 is sealingly connected to the main sealing ring 2 and the secondary sealing ring 3. The specific structure of the gland 4 is as follows: Figure 3 As shown, a positioning boss is provided on the lower end face of the valve body 1 with an outer diameter that matches the outer diameter of the annular boss. The inner wall of the positioning boss is a tapered surface. A second annular groove 42 is provided on the inner wall at the position corresponding to the main sealing ring 2. An annular sealing surface is provided on the upper surface of the annular boss of the valve body 1. The main sealing ring 2 is located between the first annular groove 67, the second annular groove 42 and the annular sealing surface. The inner wall of the positioning boss on the pressure cap 4 is simultaneously sealed and connected to the outer edge of the second sealing section 65 and the upper surface of the annular boss on the valve body 1 through the main sealing ring 2.

[0029] The guide rod 61 of the valve core 6 is provided with a first mounting boss 62 and a second mounting boss 63 from top to bottom. The second mounting boss 63 is a rectangular boss, which is located in a rectangular hole in the center of the cover 4 that matches its shape. The first mounting boss 62 is a cylindrical boss, on which a locking nut 5 is installed to further fix the cover 4 to the valve core 6. The second mounting boss 63 with a rectangular cross section fits with the center hole of the cover 4, thereby ensuring that the valve core 6 and the cover 4 will not rotate when the locking nut 5 is tightened. An oblong boss 41 is provided on the outside of the center hole of the cover 4. Let the distance between the upper end face of the oblong boss 41 and the lower end face of the cover 4 be L, the distance between the lower end face of the first mounting boss 62 and the upper end face of the second mounting boss 63 be L1, and the height of the second mounting boss 63 be L2. Then L, L1, and L2 satisfy L1 + L2 = L.

[0030] The specific structure of valve body 1 is as follows: Figure 4 As shown, an annular vent 11 is provided on the outer side of the annular boss; an annular stepped limiting boss 12 is provided on the outer side of the annular vent 11, and multiple mounting bosses 13 are evenly provided on the outer side of the boss along the circumference for mounting the guide frame; multiple water guiding channels extending axially are evenly provided on the limiting boss 12 along the circumference for draining rainwater falling into the annular vent 12; multiple mounting holes 14 are evenly provided on the outer side of the limiting boss along the circumference for mounting the valve body 1 on the railway tank car.

[0031] The positional relationship of the various components of this utility model during operation is as follows: Figure 5 As shown, a spring is fitted on the pull rod 66 of the valve core 6, and the spring is fixed and pressed against the lower end face of the valve body 1 by a spring seat set on the pull rod 66. At this time, the locking nut 5 and the valve core 6 are connected by threads to press the cover 4, and the cover 4 presses the two sealing rings. The annular sealing surface machined on the upper end of the annular boss of the valve body 1 fits with the main sealing ring 2 to achieve external sealing. The secondary sealing ring 3 is between the cover 4 and the lower end face of the valve core 6 to achieve end face sealing. When the pressure inside the railway tank car increases, the spring is compressed upward, and the valve core 6 and the cover 4 move upward as a whole. At this time, the main sealing ring 2 separates from the annular sealing surface machined on the upper end of the annular boss of the valve body 1, releasing the pressure to the outside of the tank and balancing the pressure inside and outside the tank. After the pressure is released, the spring is stretched downward to its original position. At this time, the valve core 6 and the cover 4 move downward as a whole, and the main sealing ring 2 re-contacts the annular sealing surface machined on the upper end of the annular boss of the valve body 1 to achieve internal sealing of the tank.

[0032] When the safety valve needs maintenance, simply unscrew the locking nut 5 to remove the gland and replace the main sealing ring 2 and the auxiliary sealing ring 3. The entire valve does not need to be disassembled, thus improving maintenance efficiency.

[0033] In other embodiments, the guide rod 61 of the valve core 6 and the sealing section can also be designed separately. A hole is made on the upper surface of the valve core 6, and the guide rod 61 is screwed into it and fixed with a nut. When the guide rod 61 is worn, only the guide rod 61 needs to be replaced, instead of replacing the entire valve core 6. This makes it easier to replace during maintenance, reduces costs, and improves maintenance efficiency.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. For those skilled in the art, modifications can be made to the specific technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions protected by this utility model.

Claims

1. A sealing structure for a safety valve of a railway tank car, comprising a valve body (1) and a valve core (6) disposed in the valve body (1), characterized in that: The valve core (6) consists of a guide rod (61), a sealing section, and a pull rod (66) connected sequentially from top to bottom. The sealing section is a stepped circular boss, consisting of a first sealing section (64) and a second sealing section (65) from top to bottom. The outer diameter of the first sealing section (64) is smaller than that of the second sealing section (65). A pressure cap (4) is sealed to the upper end face of the first sealing section (64), and the pressure cap (4) is also sealed to the outer edge of the second sealing section (65) and the upper end face of the valve body (1). The lower end face of the second sealing section (65) is sealed to the upper end face of the valve body (1). A locking nut (5) is provided on the guide rod (61) of the valve core (6) to press the gland (4) onto the sealing section of the valve core (6).

2. The sealing structure of a railway tank car safety valve according to claim 1, characterized in that: An annular secondary sealing ring (3) is provided on the outer side of the first sealing section (64), and the inner diameter of the secondary sealing ring (3) is adapted to the outer diameter of the first sealing section (64). The upper end face of the first sealing section (64) is sealed to the lower end face of the gland (4) through the secondary sealing ring (3). The second sealing section (65) has a first annular groove (67) circumferentially formed on its outer side. The first annular groove (67) is provided with an annular main sealing ring (2), and the inner diameter of the main sealing ring (2) is matched with the inner diameter of the first annular groove (67). The valve body (1) has an annular boss on its outer side of the center hole. The pressure cap (4) is sealed to the outer edge of the second sealing section (65) and the upper end face of the annular boss on the valve body (1) through the main sealing ring (2).

3. The sealing structure of a railway tank car safety valve according to claim 2, characterized in that: The lower end face of the pressure cap (4) is provided with a positioning boss that matches the outer diameter of the annular boss on the valve body (1). The inner wall of the positioning boss is a conical surface. The inner wall is provided with a second annular groove (42) at the position corresponding to the main sealing ring (2). The upper surface of the annular boss is provided with an annular sealing surface. The main sealing ring (2) is located between the first annular groove (67), the second annular groove (42) and the annular sealing surface. The inner wall of the positioning boss on the pressure cap (4) is simultaneously sealed and connected to the outer edge of the second sealing section (65) and the upper surface of the annular boss on the valve body (1) through the main sealing ring (2).

4. The sealing structure of a railway tank car safety valve according to any one of claims 1-3, characterized in that: The lower part of the guide rod (61) of the valve core (6) is provided with a first mounting boss (62) and a second mounting boss (63) from top to bottom; the second mounting boss is located in the center hole of the pressure cap (4), and its cross-sectional shape is rectangular. The cross-sectional shape of the center hole of the pressure cap (4) is adapted to the cross-sectional shape of the second mounting boss (63); a locking nut (5) is installed on the outside of the first mounting boss (62), and its shape is adapted to the shape of the center hole of the locking nut (5).

5. The sealing structure of a railway tank car safety valve according to claim 4, characterized in that: An oblong boss (41) is provided on the outside of the center hole of the pressure cap (4). Let L be the distance between the upper end face of the oblong boss (41) and the lower end face of the pressure cap (4), L1 be the distance between the lower end face of the first mounting boss (62) and the upper end face of the second mounting boss (63), and L2 be the height of the second mounting boss (63). Then L, L1 and L2 satisfy L1+L2=L.

6. The sealing structure of a railway tank car safety valve according to claim 4, characterized in that: An annular vent (11) is provided on the outer side of the annular boss on the valve body (1).

7. The sealing structure of a railway tank car safety valve according to claim 6, characterized in that: The outer side of the annular ventilation channel is provided with an annular stepped limiting boss (12), and a number of mounting bosses (13) are also uniformly provided on the outer side along the circumference for mounting the guide frame; a number of water guiding channels extending axially are uniformly opened on the limiting boss along the circumference for draining rainwater falling into the annular ventilation channel.

8. The sealing structure of a railway tank car safety valve according to claim 7, characterized in that: The outer side of the limiting boss is provided with multiple mounting holes (14) evenly distributed along the circumference, for mounting the valve body (1) on the railway tank car.

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