Pilot operated single call valve for cryogenic service

Abstract

This utility model relates to the field of pilot-operated single-call valves, specifically disclosing a pilot-operated single-call valve for operation in low-temperature environments. It includes a valve body, a steam pipe, and a pressure relief assembly. The valve body has an inner valve cylinder connected to an inlet flange. A positive pressure valve plate is located at the top of the inner valve cylinder, and a valve stem connected to the positive pressure valve plate to open and close the inner valve cylinder. A drive shaft is connected to the upper end of the valve stem, and a diaphragm is connected to the upper end of the drive shaft. The steam pipe is fitted against the inner wall of the valve body and located above the positive pressure valve plate. The pressure relief assembly includes a pressure bladder and a pressure guiding pipe. The pressure bladder is annularly fitted against the inner wall of the inlet flange, and the pressure guiding pipe is located on the outer side of the valve body, with its upper end connected to the diaphragm and its lower end connected to the pressure bladder. This utility model has good sensitivity and is suitable for use in low-temperature environments of -30 to -10°C. It avoids the operational hazards caused by the condensation of material vapor into solids, blockage, and adhesion of the valve's mechanical mechanism, which can lead to failure, as seen in existing technologies.

Description

Technical Field

[0001] This utility model relates to the field of pilot-operated single-call valves, specifically a pilot-operated single-call valve that operates in low-temperature environments. Background Technology

[0002] In the field of chemical material storage and transportation, a wide variety of tank accessories are used to meet different requirements. In particular, the pilot-operated single-call valve, as a pressure relief safety device that maintains the tank at normal pressure, is widely used. Under normal circumstances, when the pressure inside the tank is lower than the set value, the pilot valve remains closed under the force of a spring or the action of a diaphragm. The pressure in the main valve control chamber is balanced with the internal pressure of the tank, and the main valve disc is sealed under its own weight or the action of an auxiliary spring to prevent gas escape. When the pressure in the tank becomes too high during operation, the gas pressure sent to the diaphragm through the pressure guide pipe reaches the valve's opening pressure threshold. The valve actuates, lifting the valve stem, thereby opening the pilot valve. High-pressure gas is quickly discharged through the pilot valve. When the pressure drops below the threshold, the pilot valve closes again.

[0003] However, in the winter environment of -30 to -10℃ in northern my country, when materials such as naphthalene, isobutyraldehyde, formaldehyde, and neopentyl glycol are stored in the tank, some pilot-operated single-call valves in the existing technology are prone to condensation of material vapor into solids at low ambient temperatures. This causes the material to condense at the opening of the inner valve cylinder and at the gas pressure guiding pipe. During use, the condensed material can cause the positive pressure valve plate to stick and the pressure guiding pipe to become blocked, which in turn leads to the failure of the pilot-operated single-call valve, causing the tank to pressurize and creating a safety hazard.

[0004] To overcome this defect of easily condensable materials at low temperatures during storage, this application proposes a new structural design for a pilot-operated single-call valve. Summary of the Invention

[0005] The purpose of this invention is to provide a pilot-operated single-call valve that operates in low-temperature environments, suitable for use in environments with temperatures ranging from -30°C to -10°C. This avoids the operational risks caused by the condensation of material vapor into solids at low temperatures, leading to blockages and adhesions that could cause valve mechanical failure. It also overcomes the defects of easily condensable materials during storage at low temperatures, ensuring the normal use of the pilot-operated single-call valve and improving safety during operation.

[0006] To solve the above-mentioned technical problems, this utility model provides a pilot-operated single-call valve for operation in low-temperature environments, including a valve body, a steam pipe and a pressure relief assembly. The bottom and one side of the valve body are respectively provided with an inlet flange and an outlet flange. The valve body is provided with an inner valve cylinder communicating with the inlet flange. The top of the inner valve cylinder is provided with a positive pressure valve plate. A valve stem that can open and close the inner valve cylinder is connected to the positive pressure valve plate. The upper end of the valve stem is connected to a drive shaft, and the upper end of the drive shaft is connected to a diaphragm.

[0007] The steam pipe is disposed in the valve body and above the positive pressure valve plate. The inlet and outlet ends of the steam pipe extend out of the valve body. The pressure relief assembly includes a pressure bladder and a pressure guiding pipe. The pressure bladder is annularly fitted to the inner wall of the inlet flange. The pressure guiding pipe is located on the outside of the valve body, with its upper end connected to the diaphragm and its lower end connected to the pressure bladder.

[0008] Furthermore, the steam pipe is ring-shaped and installed in the valve body via a support frame, with its inlet and outlet ends located on the same side.

[0009] Furthermore, a reducing pipe is provided at the connection between the pressure bladder and the pressure guiding pipe. The reducing pipe is embedded in the inner wall of the valve body and its inner diameter decreases from large to small. The large diameter end of the reducing pipe is connected to the pressure bladder, and the small diameter end of the reducing pipe is connected to the pressure guiding pipe.

[0010] Furthermore, the pressure bladder has a flat, annular structure and is filled with nitrogen gas.

[0011] Furthermore, an adjusting bolt is provided at the top of the diaphragm, and a spring is fitted onto the adjusting bolt.

[0012] The beneficial effects of this utility model are:

[0013] 1. The pilot-operated single-call valve of this utility model, which operates in low-temperature environments, has good sensitivity and is suitable for use in low-temperature environments of -30~-10℃. It avoids the condensation of material vapor into solids in low-temperature environments, which leads to condensation between the positive pressure diaphragm and the inner valve cylinder and in the pressure guiding pipe, as in the prior art. It overcomes the defects of easily condensable materials in the storage process at low temperatures, avoids the operational hazards caused by valve mechanical failure due to blockage and adhesion, ensures the normal use of the pilot-operated single-call valve, and improves the safety during use.

[0014] Specifically, the design of the steam pipe allows high-temperature steam to be introduced into the pipe, keeping the valve body cavity at a high temperature and preventing material condensation. This also prevents interference with emergency pressure relief when the valve body is under excessive pressure. Furthermore, the design of the pressure relief component's pressure bladder and pressure guide pipe prevents material from entering the pressure guide pipe and condensing at the source. The pressure bladder deforms under pressure, allowing the gas inside to be quickly guided to the diaphragm through the pressure guide pipe, thus enabling rapid valve opening and improving the safety of this invention during use.

[0015] This invention utilizes a ring-shaped design for the steam pipe to increase the heat exchange area with the valve body cavity, facilitating better heat transfer, preventing material condensation inside the valve body, and improving the safety of this invention.

[0016] This invention reduces stress concentration in the pipeline through the design of a reduced-diameter tube. Combined with the design of a flat, annular pressure bladder structure that fits snugly against the inner wall of the valve body, the pressure-bearing area and pressure sensitivity of the pressure bladder are increased. Thus, when the pressure inside the valve body is too high, the pressure bladder deforms under pressure, allowing the gas inside the pressure bladder to enter the pressure-conducting tube from the reduced-diameter tube. This causes the diaphragm to deform, moving the valve stem upward and opening the positive pressure valve plate, allowing the material to flow out from the outlet flange, thus achieving emergency pressure relief. Attached Figure Description

[0017] To more clearly illustrate the technical solution of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the pilot-operated single call valve for operation in low-temperature environments according to this utility model;

[0019] Figure 2 This is a schematic diagram of the steam pipeline structure of the pilot-operated single-call valve for low-temperature operation according to this utility model.

[0020] Figure 3 This is a schematic diagram of the pressure relief assembly of the pilot-operated single-call valve that operates in a low-temperature environment according to this utility model.

[0021] In the diagram: 1-valve body, 2-steam pipe, 3-pressure relief assembly, 11-inlet flange, 12-outlet flange, 13-inner valve cylinder, 14-positive pressure valve plate, 15-valve stem, 16-drive shaft, 17-diaphragm, 18-adjusting bolt, 19-spring, 31-pressure bladder, 32-pressure guide pipe, 33-reducing diameter pipe. Detailed Implementation

[0022] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] In one specific embodiment of this utility model, such as Figure 1-3As shown, a pilot-operated single-call valve for operation in low-temperature environments includes a valve body 1, a steam pipe 2, and a pressure relief assembly 3. The bottom and one side of the valve body 1 are respectively provided with an inlet flange 11 and an outlet flange 12. The valve body 1 is provided with an inner valve cylinder 13 that communicates with the inlet flange 11. The top of the inner valve cylinder 13 is provided with a positive pressure valve plate 14. A valve stem 15 that can open and close the inner valve cylinder 13 is connected to the positive pressure valve plate 14. The upper end of the valve stem 15 is connected to a drive shaft 16, and the upper end of the drive shaft 16 is connected to a diaphragm 17.

[0024] Steam pipe 2 is installed inside valve body 1 and above positive pressure valve plate 14. Both the inlet and outlet ends of steam pipe 2 extend outside valve body 1. Pressure relief assembly 3 includes pressure bladder 31 and pressure guiding pipe 32. Pressure bladder 31 is annularly fitted on the inner wall of inlet flange 11. Pressure guiding pipe 32 is located outside valve body 1 and its upper end is connected to diaphragm 17, and its lower end is connected to pressure bladder 31.

[0025] This invention relates to a pilot-operated single-call valve that operates in low-temperature environments. It is suitable for use in low-temperature environments of -30 to -10℃, avoiding the condensation of material vapor into solids in low-temperature environments, which leads to condensation between the positive pressure diaphragm and the inner valve cylinder, and in the pressure guiding pipe, thus ensuring the normal use of the pilot-operated single-call valve and improving safety during use.

[0026] Specifically, the design of the steam pipe allows high-temperature steam to be introduced into the pipe, keeping the valve body cavity at a high temperature and preventing material condensation. Furthermore, the design of the pressure relief assembly's pressure bladder and pressure guide pipe prevents material condensation from the source, thus improving the safety of this invention during use.

[0027] like Figure 1-2 As shown, the steam pipe 2 is ring-shaped and installed inside the valve body 1 through a support frame (not shown in the figure), with its inlet and outlet ends located on the same side; the ring-shaped design of the steam pipe can increase the heat exchange area with the inner cavity of the valve body, which facilitates better heat transfer, avoids the phenomenon of material condensation inside the valve body, and improves the safety of this utility model.

[0028] like Figure 1 and 3As shown, a reducing pipe 33 is provided at the connection between the pressure bladder 31 and the pressure guiding pipe 32. The reducing pipe 33 is embedded in the inner wall of the valve body 1 and its inner diameter decreases from large to small. The large diameter end of the reducing pipe 33 is connected to the pressure bladder 31, and the small diameter end of the reducing pipe 33 is connected to the pressure guiding pipe 32. In this embodiment, the pressure bladder 31 is preferably a flat annular structure and is filled with nitrogen. Here, the design of the reducing pipe can reduce the stress concentration in the pipeline. Combined with the design of the flat annular pressure bladder structure fitting against the inner wall of the valve body, the pressure-bearing area and pressure sensitivity of the pressure bladder are increased. Thus, when the pressure inside the valve body is too high, the pressure bladder is deformed under pressure, allowing the gas inside the pressure bladder to enter the pressure guiding pipe from the reducing pipe. This causes the diaphragm to deform and move the valve stem upward, opening the positive pressure valve plate. The material flows out from the outlet flange, achieving emergency pressure relief.

[0029] Specifically, in this embodiment, the top of the diaphragm 17 is provided with an adjusting bolt 18, and a spring 19 is sleeved on the adjusting bolt 18; by rotating the adjusting bolt, the pre-compression of the spring can be changed, thereby precisely adjusting the initial elastic force acting on the diaphragm. The adjusting bolt is exposed for easy manual adjustment on site, and the pressure setting can be completed without disassembling the valve.

[0030] The above-disclosed embodiment is merely a preferred embodiment of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the claims of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A pilot-operated single-call valve for operation in low-temperature environments, characterized in that, The device includes a valve body (1), a steam pipe (2), and a pressure relief assembly (3). The bottom and one side of the valve body (1) are respectively provided with an inlet flange (11) and an outlet flange (12). The valve body (1) is provided with an inner valve cylinder (13) that communicates with the inlet flange (11). The top of the inner valve cylinder (13) is provided with a positive pressure valve plate (14). A valve stem (15) that can open and close the inner valve cylinder (13) is connected to the positive pressure valve plate (14). The upper end of the valve stem (15) is connected to a drive shaft (16). The upper end of the drive shaft (16) is connected to a diaphragm (17). The steam pipe (2) is located inside the valve body (1) and above the positive pressure valve plate (14). The inlet and outlet ends of the steam pipe (2) extend outside the valve body (1). The pressure relief assembly (3) includes a pressure bladder (31) and a pressure guide pipe (32). The pressure bladder (31) is annularly fitted on the inner wall of the inlet flange (11). The pressure guide pipe (32) is located outside the valve body (1) and its upper end is connected to the diaphragm (17), and its lower end is connected to the pressure bladder (31).

2. The pilot-operated single-call valve for operation in low-temperature environments according to claim 1, characterized in that, The steam pipe (2) is ring-shaped and installed inside the valve body (1) through a support frame, with its inlet and outlet ends located on the same side.

3. The pilot-operated single-call valve for operation in low-temperature environments according to claim 1, characterized in that, A reducing pipe (33) is provided at the connection between the pressure airbag (31) and the pressure guiding pipe (32). The reducing pipe (33) is embedded in the inner wall of the valve body (1) and its inner diameter decreases from large to small. The large diameter end of the reducing pipe (33) is connected to the pressure airbag (31), and the small diameter end of the reducing pipe (33) is connected to the pressure guiding pipe (32).

4. The pilot-operated single-call valve for operation in low-temperature environments according to claim 1, characterized in that, The pressure bladder (31) is a flat, ring-shaped structure filled with nitrogen.

5. A pilot-operated single-call valve for operation in low-temperature environments according to claim 1, characterized in that, The top of the diaphragm (17) is provided with an adjusting bolt (18), and a spring (19) is sleeved on the adjusting bolt (18).

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