A relief manhole with two-stage opening pressure

Abstract

The utility model provides a kind of pressure relief manhole with two-stage opening pressure, it is specifically related to petroleum chemical industry field.The pressure relief manhole includes valve body, guide screw and counterweight disc;Three lugs and three guide rods are set on the outer wall of valve body along its circumference equidistantly;Guide rod top is fixed with rain cover through nut;Two-stage valve disc is movably arranged at the top of valve body, and two-stage valve disc is slidably connected with three guide rods;One-stage valve seat is arranged in the middle of the top of two-stage valve disc;Fixed seat is arranged at the center position of one-stage valve seat;Spring sleeve is arranged at the bottom of fixed seat;One-stage valve disc is movably arranged in the middle of the top of one-stage valve seat, and guide screw is arranged at the bottom of one-stage valve disc;Guide screw is sequentially penetrated into fixed seat and spring sleeve inner cavity downwards;Reset spring is sleeved on the surface of guide screw located in spring sleeve inner cavity.The utility model can realize low-pressure opening and rapid pressure relief in emergency, to solve the problem that traditional pressure relief manhole cannot meet two-stage pressure relief requirement.

Description

Technical Field

[0001] This utility model relates to the field of petrochemical technology, specifically to a pressure relief manhole with two-stage opening pressure. Background Technology

[0002] Pressure relief manholes are safety emergency ventilation devices installed on petrochemical and other equipment and storage tanks. They are usually used in conjunction with breather valves installed on the top of the tank to maintain normal pressure inside the tank and prevent accidents caused by sudden overpressure inside the tank due to unexpected reasons.

[0003] Utility model patent CN215795984U discloses a novel pressure relief manhole, including a flat-welded flange and a pressure relief cylinder. It only has a single-stage opening pressure and typically needs to be used in parallel with a breather valve or a single-call valve. The low-pressure opening function is achieved through the breather valve or single-call valve; the pressure relief manhole only enables rapid pressure relief in emergency situations.

[0004] To address the problem that traditional pressure relief manholes cannot meet the two-stage pressure relief requirements and need to be used in conjunction with a breathing valve, this utility model proposes a pressure relief manhole with two-stage opening pressure, which can realize the low-pressure opening function of the breathing valve or single exhalation valve, and also realize rapid pressure relief in emergency situations. Utility Model Content

[0005] To overcome the shortcomings of the prior art, this utility model provides a pressure relief manhole with two-stage opening pressure, the specific technical solution of which is as follows: A pressure relief manhole with two-stage opening pressure includes a valve body, a rain cover, a guide screw, and a counterweight plate. Three lifting lugs are evenly spaced along the circumference of the outer wall of the valve body. A guide rod is positioned near the side wall of each lifting lug. The top of each guide rod is fixed to the top wall of the rain cover by a nut. A secondary valve disc is movably mounted on the top of the valve body, and the secondary valve disc is sleeved on and slidably connected to the three guide rods. A primary valve seat is positioned at the center of the top of the secondary valve disc. A fixed seat is positioned at the center of the primary valve seat via a connecting rod. A spring sleeve is positioned at the bottom of the fixed seat. The counterweight plate is sleeved on the primary valve seat. A primary valve disc is movably mounted at the center of the top of the primary valve seat, and a guide screw is positioned at the center of the bottom of the primary valve disc. The guide screw passes downwards through the fixed seat, the inner cavity of the spring sleeve, and a gasket, and its bottom is threaded with a nut. A return spring is sleeved on the surface of the guide screw located between the fixed seat and the gasket. The primary valve disc can drive the guide screw to move up and down along the spring sleeve.

[0006] Preferably, the primary valve seat is fixedly connected to the secondary valve disc by a number of screws arranged at equal intervals along its circumference.

[0007] Preferably, a bird net is fitted onto the outer surface of the valve body, and the height of the bird net is flush with the bottom of the rain cover.

[0008] Preferably, the outer dimensions of the bird net are adapted to the inner dimensions of the rain cover to the side wall of the valve body.

[0009] Preferably, a pipe connection flange is provided at the bottom of the valve body.

[0010] Preferably, the outer diameter of the primary valve disc is larger than the inner diameter of the primary valve seat; and the outer diameter of the secondary valve disc is larger than the inner diameter of the valve body.

[0011] More preferably, the inner diameter of the spring sleeve is larger than the outer diameter of the washer and the nut.

[0012] The beneficial effects of this utility model are: This invention can simultaneously achieve primary and secondary pressure relief: the primary opening pressure is determined by the spring preload and the self-weight of the primary valve disc, and the secondary opening pressure is determined by the total weight of the secondary valve disc and the primary pressure relief related components located above it. It can achieve both low-pressure relief of small-scale gas volume and rapid pressure relief of large-scale gas volume in emergency situations. Attached Figure Description

[0013] The accompanying drawings constituting this utility model are provided to further understand this application and do not constitute an undue limitation on this application.

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 for Figure 1 Side view; Figure 3 for Figure 2 Sectional view at point AA; Figure 4 This is a schematic diagram of the internal structure of the rain cover; Figure 5 This is a schematic diagram of the structure of the primary valve seat; In the diagram, 1-valve body; 101-pipeline connection flange; 102-lifting lug; 103-guide rod; 2-rain cover; 3-nut; 4-guide screw; 401-gasket; 5-first-stage valve disc; 6-first-stage valve seat; 601-connecting rod; 602-fixed seat; 7-counterweight disc; 8-second-stage valve disc; 9-bird net; 10-spring sleeve. Detailed Implementation

[0015] The specific implementation of a pressure relief manhole with two-stage opening pressure provided by this utility model will be further described with reference to the accompanying drawings and embodiments.

[0016] like Figures 1-4 As shown, a pressure relief manhole with two-stage opening pressure includes a valve body 1, a rain cover 2, a guide screw 4, and a counterweight plate 7. Specifically, the outer wall of the valve body 1 is provided with three lifting lugs 102 at equal intervals along its circumference; each lifting lug 102 is provided with a guide rod 103 near the side wall of the valve body 1; the top of the guide rod 103 is fixed to the top wall of the rain cover 2 by a nut.

[0017] Preferably, a secondary valve disc 8 is movably disposed on the top of the valve body 1. The secondary valve disc 8 is sleeved on three guide rods 103 and slidably connected to the three guide rods 103, which can guide and limit the up and down movement of the secondary valve disc 8 during the opening or sealing process.

[0018] Preferably, the primary valve seat 6 is fixedly connected to the top center of the secondary valve disc 8 by a plurality of screws evenly spaced along its circumference. Figure 5 As shown, a fixed seat 602 is provided at the center of the first-stage valve seat 6 via a connecting rod 601; a spring sleeve 10 is fixed at the bottom of the fixed seat 602; the counterweight plate 7 is movably sleeved on the first-stage valve seat 6, and the opening pressure of the second-stage pressure relief can be adjusted by selecting counterweight plates 7 of different weights.

[0019] Preferably, a primary valve disc 5 is movably disposed at the top center of the primary valve seat 6, and a guide screw 4 is disposed at the bottom center of the primary valve disc 5. The guide screw 4 passes downward through the inner cavity of the fixed seat 602, the spring sleeve 10, and the gasket 401 in sequence, and a nut (not marked in the figure) is threadedly fixed at its bottom. It is worth noting that a return spring is sleeved on the surface of the guide screw 4 located between the fixed seat 602 and the gasket 401, and the primary valve disc 5 can drive the guide screw 4 to move up and down along the spring sleeve 10.

[0020] Preferably, a bird net 9 is fitted onto the outer surface of the valve body 1. It is worth emphasizing that the height of the bird net 9 is flush with the bottom of the rain cover 2; the outer dimensions of the bird net 9 are adapted to the inner dimensions of the rain cover 2 and the side wall of the valve body 1, thus achieving multiple layers of protection without affecting the pressure relief / ventilation function, preventing external foreign objects from interfering with the normal operation of the equipment, ensuring equipment safety and media purity. A dust filter can also be laid on the outer surface of the bird net to further prevent small dust particles and impurities from entering the equipment.

[0021] Preferably, the bottom of the valve body 1 is provided with a pipe connection flange 101, and the pressure relief manhole is connected to the pressure relief device through the pipe connection flange 101.

[0022] It is worth emphasizing that the outer diameter of the first-stage valve disc 5 is larger than the inner diameter of the first-stage valve seat 6; the outer diameter of the second-stage valve disc 8 is larger than the inner diameter of the valve body 1. In order not to affect the guide screw 4 moving up and down along the spring sleeve 10 with the first-stage valve disc 5, the inner diameter of the spring sleeve 10 needs to be slightly larger than the outer diameter of the gasket 401 and the nut.

[0023] In use, when the internal pressure of the pressure relief device exceeds the first-stage opening pressure, the first-stage valve disc 5 is lifted upwards, simultaneously driving the guide screw 4 to move upwards along the spring sleeve 10. At this time, the return spring is compressed between the fixed seat 602 and the gasket 401, and the pressure relief manhole performs low-pressure, small-scale first-stage pressure relief. After the first-stage pressure relief is completed, the tension of the return spring will assist the first-stage valve disc 5 to reset and close, and improve the tightness between the first-stage valve disc 5 and the first-stage valve seat 6. When the pressure relief device continues to increase and reaches the second-stage opening pressure after the low-pressure, small-scale first-stage pressure relief, the second-stage valve disc 8 is lifted and moves upwards along the guide rod 103 (at this time, other first-stage pressure relief related components installed on the top of the second-stage valve disc 8 will move upwards together with the second-stage valve disc 8), thereby achieving large-scale second-stage pressure relief.

[0024] The opening pressure of the first-stage pressure relief manhole is related to the preload of the return spring and the weight of the first-stage valve disc 5; the opening pressure of the second-stage pressure relief is related to the overall mass of the second-stage valve disc 8 and other first-stage pressure relief related components mounted on it.

[0025] This invention can simultaneously achieve both primary and secondary pressure relief, effectively solving the problem that traditional pressure relief manholes require additional use with a breather valve to achieve two-stage pressure relief.

[0026] In this utility model, terms such as "upper," "lower," "bottom," and "top" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are merely used to facilitate the description of the structural relationships of the various components or elements of this utility model and do not specifically refer to any part or element of this utility model; they should not be construed as limiting this utility model. Terms such as "connected" and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be determined according to the specific circumstances, and they should not be construed as limiting this utility model.

[0027] Of course, the above description is not intended to limit the present utility model, and the present utility model is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present utility model should also fall within the protection scope of the present utility model.

Claims

1. A pressure relief manhole with two-stage opening pressure, characterized in that, Includes valve body, rain cover, guide screw and counterweight plate; The outer wall of the valve body is provided with three lifting lugs at equal intervals along its circumference; each of the lifting lugs is provided with a guide rod near the side wall of the valve body; the top of the guide rod is fixed to the top wall of the rain cover by a nut; A secondary valve disc is movably mounted on the top of the valve body, and the secondary valve disc is sleeved on three guide rods and slidably connected to the three guide rods; A primary valve seat is provided at the top center of the secondary valve disc; a fixed seat is provided at the center of the primary valve seat via a connecting rod; a spring sleeve is provided at the bottom of the fixed seat; and the counterweight disc is fitted onto the primary valve seat. A primary valve disc is movably disposed at the top center of the primary valve seat, and a guide screw is disposed at the bottom center of the primary valve disc; The guide screw passes through the fixed seat, the inner cavity of the spring sleeve, and the washer in sequence, and a nut is threaded at its bottom; a return spring is sleeved on the surface of the guide screw located between the fixed seat and the washer. The primary valve disc can drive the guide screw to move up and down along the spring sleeve.

2. The pressure relief manhole with two-stage opening pressure as described in claim 1, characterized in that, The primary valve seat is fixedly connected to the secondary valve disc by a number of screws that are equally spaced along its circumference.

3. The pressure relief manhole with two-stage opening pressure as described in claim 1, characterized in that, The valve body is covered with a bird net, the height of which is flush with the bottom of the rain cover.

4. The pressure relief manhole with two-stage opening pressure as described in claim 3, characterized in that, The outer dimensions of the bird net are adapted to the inner dimensions of the rain cover to the side wall of the valve body.

5. The pressure relief manhole with two-stage opening pressure as described in claim 1, characterized in that, A pipe connection flange is provided at the bottom of the valve body.

6. The pressure relief manhole with two-stage opening pressure according to claim 1, characterized in that, The outer diameter of the first-stage valve disc is larger than the inner diameter of the first-stage valve seat; The outer diameter of the secondary valve disc is larger than the inner diameter of the valve body.

7. The pressure relief manhole with two-stage opening pressure according to claim 1, characterized in that, The inner diameter of the spring sleeve is larger than the outer diameter of the washer and nut.

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