Gas pressure regulator adopting double-balance structure

Abstract

The utility model discloses a gas pressure regulator adopting a double-balance structure, which relates to the technical field of natural gas pipeline network transmission and distribution equipment, and comprises a valve body and a pressure regulating device, the pressure regulating device is provided with an upper pressure regulating cavity and a lower pressure regulating cavity which are separated by a regulating diaphragm, and the lower pressure regulating cavity is communicated with the downstream of a gas pipeline to introduce low-pressure gas after pressure regulation; the upper pressure adjusting cavity is communicated with the atmosphere, and a pressure adjusting spring with the bottom end abutting against the adjusting diaphragm is arranged in the upper pressure adjusting cavity; a balance assembly is arranged in the valve body and comprises a positioning seat installed in the valve body, a piston arranged in the positioning seat and a valve rod connected with the piston and the adjusting diaphragm, a balance cavity is formed in the positioning seat, and the piston seals the balance cavity to form a sealed space. An air hole for air of an upstream pipeline to enter the balance cavity is formed between the valve rod and the positioning seat; first-stage pressure balance is formed between the lower pressure adjusting cavity and the balance cavity, second-stage pressure balance is formed between the lower pressure adjusting cavity and the upper pressure adjusting cavity, and the stability and safety of the pressure adjusting device can be improved.

Description

Technical Field

[0001] This utility model relates to the field of natural gas pipeline transmission and distribution equipment technology, and in particular to a gas pressure regulator with a dual-balance structure. Background Technology

[0002] Gas pressure regulators are widely used in key components of gas transmission and distribution networks, such as pressure regulating stations, pressure regulating cabinets, and pressure regulating skids. They are crucial equipment for pressure regulation in gas transmission and distribution systems. Especially in large pressure regulating stations, as the core hub for gas transmission, pressure regulators face challenges under various complex operating conditions.

[0003] Chinese Patent No. CN208107282U, published on September 21, 2017, discloses an integrated pressure regulating and shut-off gas regulator. This regulator includes a valve body with an inlet, an outlet, a shut-off chamber, and a regulating chamber. The regulating chamber is divided into an upper regulating chamber and a lower regulating chamber by a diaphragm. An adjusting spring is installed in the upper regulating chamber, and a balancing diaphragm is installed in the lower regulating chamber. A valve stem connected to the diaphragm at its top passes through the balancing diaphragm and a valve stem guide sleeve. A valve disc matching the valve port is installed at the bottom of the valve stem. The outlet and the lower regulating chamber are connected by a signal pipe. A flared, speed-increasing shroud is installed at the bottom of the valve stem guide sleeve. When the gas regulator operates at high flow rates, the gas velocity at the valve port is high, and a negative pressure can be formed inside the speed-increasing shroud. This reduces the closing force exerted by the inlet pressure on the balancing diaphragm, helping to open the distance between the valve port and the valve disc, thus increasing the effective flow rate of the regulator.

[0004] The internal balancing components of the pressure regulator use balancing diaphragms as balancing elements, all made of rubber. If the balancing diaphragms fail under various complex working conditions, the pressure regulator will shut off or lose its pressure regulating function, thereby affecting the gas supply to downstream users of the gas transmission and distribution network. Therefore, the pressure regulating stations of the gas transmission and distribution network all have defects such as difficult maintenance and long maintenance cycles.

[0005] Therefore, if the single-balance component fails during the use of this single-balance structure pressure regulator, the gas transmission and distribution network will affect downstream gas consumption. Utility Model Content

[0006] In view of the lack of stability of the single-balance structure of the gas pressure regulator in the above-mentioned prior art, which leads to the failure of the single-balance component and its impact on downstream gas consumption, this utility model provides a gas pressure regulator with stability and safety using a double-balance structure.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a gas pressure regulator with a dual-balance structure, comprising a valve body and a pressure regulating device disposed on the valve body. The pressure regulating device has an upper pressure regulating chamber and a lower pressure regulating chamber separated by an adjusting diaphragm. The lower pressure regulating chamber is connected to the downstream of the gas pipeline to introduce low-pressure gas after pressure regulation. The upper pressure regulating chamber is connected to the atmosphere. A pressure regulating spring with its bottom end abutting against the adjusting diaphragm is disposed in the upper pressure regulating chamber. A balancing assembly is disposed in the valve body. The balancing assembly includes a positioning seat installed in the valve body, a piston disposed in the positioning seat, and a valve stem connecting the piston and the adjusting diaphragm. The positioning seat forms a balancing chamber, and the piston closes the balancing chamber to form a sealed space. There is a vent between the valve stem and the positioning seat for gas from the upstream pipeline to enter the balancing chamber. A first-stage pressure balance is formed between the lower pressure regulating chamber and the balancing chamber, and a second-stage pressure balance is formed between the lower pressure regulating chamber and the upper pressure regulating chamber.

[0008] Furthermore, a balance diaphragm is provided above the positioning seat. The balance diaphragm moves axially back and forth with the valve stem and is used to seal the sealing space between the piston and the balance chamber.

[0009] Furthermore, the balancing assembly also includes a limiting block located above the piston, and the valve stem passes through the piston to connect the limiting block and the adjusting diaphragm.

[0010] Furthermore, a pad is connected between the limiting block and the adjusting diaphragm.

[0011] Furthermore, the pressure regulating device includes a lower valve cover connected to the valve body and an upper valve cover mounted opposite to the lower valve cover. The lower valve cover and the regulating diaphragm form the lower pressure regulating chamber, and the upper valve cover and the regulating diaphragm form the upper pressure regulating chamber.

[0012] Furthermore, the lower valve cover is connected to the lower pressure regulating chamber by an air guide pipe.

[0013] Furthermore, the upper valve cover is connected to the upper pressure regulating chamber via a breather nozzle.

[0014] Furthermore, the lower valve cover is provided with a pressure plate for pressing the positioning seat onto the valve body, the inner side of the balance diaphragm is pressed between the limiting block and the piston, and the outer side of the balance diaphragm is pressed between the pressure plate and the positioning seat.

[0015] Furthermore, the limiting block, the balancing diaphragm, and the pressure plate form an auxiliary balancing cavity with the piston and the positioning seat.

[0016] Furthermore, a sealing ring is provided between the piston and the inner wall of the positioning seat.

[0017] In summary, this utility model has the following beneficial effects:

[0018] (1) Compared with the single-balance structure, the gas pressure regulator using the dual-balance structure of this utility model has certain limitations in pressure bearing capacity due to the rubber diaphragm as the balancing element in the single-balance structure, and the rubber element is prone to aging and needs to be replaced regularly. However, with the dual-balance structure, the main balancing function is played by the metal balancing piston, which can withstand higher pressure than the balancing diaphragm, and there is no risk of aging and failure, thus improving the adjustment range and service life of the gas pressure regulator.

[0019] (2) The balancing diaphragm serves as an auxiliary balancing element and also as a safety element of the balancing structure. When the sealing relationship between the piston and the positioning seat fails, the balancing diaphragm replaces the piston to play a balancing role. The balancing diaphragm can prevent high-pressure gas from directly entering the lower pressure regulating chamber, which would cause the pressure difference between the lower pressure regulating chamber and the balancing chamber and the upper pressure regulating chamber to change. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a gas pressure regulator.

[0021] Figure 2 for Figure 1 Enlarged view of the balancing component of the gas pressure regulator.

[0022] The reference numerals in the attached drawings are explained as follows: 1. Valve body; 2. Pressure regulating device; 20. Adjusting diaphragm; 21. Upper pressure regulating chamber; 211. Pressure regulating spring; 22. Lower pressure regulating chamber; 23. Upper valve cover; 24. Lower valve cover; 3. Balance assembly; 31. Positioning seat; 311. Balance chamber; 32. Piston; 321. Sealing ring; 33. Valve stem; 34. Limiting block; 35. Balance diaphragm; 36. Pad; 4. Pressure plate; 5. Air guide tube; 6. Breathing nozzle. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the embodiments.

[0024] Example 1

[0025] like Figure 1 and Figure 2 As shown, this embodiment provides a gas pressure regulator with a dual-balance structure, including a valve body 1 and a pressure regulating device 2 disposed on the valve body 1. The pressure regulating device 2 has an upper pressure regulating chamber 21 and a lower pressure regulating chamber 22 separated by an adjusting diaphragm 20. The lower pressure regulating chamber 22 is connected to the downstream of the gas pipeline. After the lower pressure regulating chamber 22 is connected to the downstream pipeline, it can introduce low-pressure gas after pressure regulation. The upper pressure regulating chamber 21 is connected to the atmosphere and can be connected to atmospheric pressure. At this time, the upper pressure regulating chamber 21 is at atmospheric pressure, and the lower pressure regulating chamber 22 is at low-pressure gas. The upper pressure regulating chamber 21 is provided with a pressure regulating spring 211 whose bottom end abuts against the adjusting diaphragm 20.

[0026] The valve body 1 is provided with a balancing component 3. The balancing component 3 includes a positioning seat 31 installed in the valve body 1, a piston 32 disposed in the positioning seat 31, and a valve stem 33 connecting the piston 32 and the adjusting diaphragm 20. The positioning seat 31 forms a balancing chamber 311, and the piston 32 closes the balancing chamber 311 to form a sealed space. A first-stage pressure balance is formed between the lower pressure regulating chamber 22 and the balancing chamber 311, and a second-stage pressure balance is formed between the lower pressure regulating chamber 22 and the upper pressure regulating chamber 21.

[0027] The gas enters the pressure regulator from the inlet flange. There is a vent between the valve stem 33 and the positioning seat 31 for the gas from the upstream pipeline to enter the balance chamber 311. The high-pressure gas from the upstream pipeline enters the balance chamber 311 formed by the positioning seat 31 and the piston 32 through the vent between the positioning seat 31 and the valve stem 33. The piston 32 and the positioning seat 31 are sealed to form the balance chamber 311, preventing the high-pressure gas entering the pressure regulator from entering the lower pressure regulating chamber 22. The lower pressure regulating chamber 22 is connected to the downstream pipeline of the pressure regulator, and the low-pressure gas after pressure regulation is introduced into the lower pressure regulating chamber 22. At this time, there is a pressure difference between the gas in the lower pressure regulating chamber 22 and the balance chamber 311. This pressure difference is used to form a balancing force. Since the upper pressure regulating chamber 21 is connected to the atmosphere, it is at atmospheric pressure, while the lower pressure regulating chamber 22 contains low-pressure gas. This pressure difference creates another balancing force. When the downstream pipeline pressure changes, the pressure in the lower pressure regulating chamber 22 changes accordingly, and the pressure difference in the upper pressure regulating chamber 21 also changes. The regulating diaphragm 20 drives the valve stem 33 and piston 32 to reciprocate up and down, thus achieving pressure balance. Therefore, the two-stage balancing pressure regulator is more stable, and its pressure regulation accuracy and shut-off pressure rating are higher than those of a single-balancing pressure regulator.

[0028] Example 2

[0029] According to Embodiment 1, a gas pressure regulator with a dual-balance structure includes a valve body 1 and a pressure regulating device 2 disposed on the valve body 1. The pressure regulating device 2 has an upper pressure regulating chamber 21 and a lower pressure regulating chamber 22 separated by an adjusting diaphragm 20. The lower pressure regulating chamber 22 is connected to the downstream of the gas pipeline, and the upper pressure regulating chamber 21 is connected to the atmosphere. The upper pressure regulating chamber 21 is provided with a pressure regulating spring 211 whose bottom end abuts against the adjusting diaphragm 20. The valve body 1 is provided with a balancing component 3.

[0030] The pressure regulating device 2 includes a lower valve cover 24 connected to the valve body 1 and an upper valve cover 23 mounted opposite to the lower valve cover 24. The lower valve cover 24 and the regulating diaphragm 20 form the lower pressure regulating chamber 22, and the upper valve cover 23 and the regulating diaphragm 20 form the upper pressure regulating chamber 21. The lower valve cover 24 and the lower pressure regulating chamber 22 are connected by an air guide tube 5, and the upper valve cover 23 and the upper pressure regulating chamber 21 are connected by a breathing nozzle 6.

[0031] During implementation, a sealing ring 321 is provided between the piston 32 and the inner wall of the positioning seat 31. The sealing ring 321 is an O-ring. The piston 32 fits into the positioning seat 31, and the sealing of the balance chamber 311 is ensured by the sealing ring 321.

[0032] like Figure 2 As shown, the balancing assembly 3 also includes a limiting block 34 located above the piston 32. The valve stem 33 passes through the piston 32 and connects the limiting block 34 and the adjusting diaphragm 20. The limiting block 34 is used to limit the axial reciprocating motion of the piston 32. The piston 32 is made of metal materials including aluminum alloy and stainless steel. A balance diaphragm 35, made of flexible rubber, is provided above the positioning seat 31. The limiting block 34, balance diaphragm 35, and pressure plate 4 form an auxiliary balance cavity with the piston 32 and positioning seat 31. The inner side of the balance diaphragm 35 presses against the limiting block 34 and piston 32, while the outer side presses against the pressure plate 4 and positioning seat 31. The inner side of the balance diaphragm 35 moves with the piston 32 and limiting block 34, while the outer side remains fixed. When the valve stem 33 reciprocates axially, it seals the space between the piston 32 and the balance cavity 311. The balance diaphragm 311 is housed within the auxiliary balance cavity, which provides space for the inner side of the balance diaphragm to move axially with the valve stem assembly. A pressure plate 4, which presses the positioning seat 31 against the valve body 1, is provided on the lower valve cover 24. The balance diaphragm 35 is located on the limiting block 34.

[0033] The advantage of using a two-stage balanced pressure regulator is that the gas enters the intake chamber through the inlet of valve body 1 and enters the outlet chamber through the valve port. Even if the seal between piston 32 and sealing ring 321 fails, the high-pressure gas enters the cavity of the balance diaphragm 35. At this time, the balance diaphragm 35 replaces piston 32 to play a balancing role, preventing high-pressure gas from directly entering the lower pressure regulating chamber 22, which would cause the pressure difference between the lower pressure regulating chamber 22 and the balance chamber 311 and the upper pressure regulating chamber 21 to change, thereby causing the pressure regulator to leak pressure and the pressure regulator to fail to work properly, affecting the normal gas supply of the downstream gas pipeline network.

[0034] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A gas pressure regulator employing a dual-balance structure, characterized in that, The system includes a valve body (1) and a pressure regulating device (2) disposed on the valve body (1). The pressure regulating device (2) has an upper pressure regulating chamber (21) and a lower pressure regulating chamber (22) separated by a regulating diaphragm (20). The lower pressure regulating chamber (22) is connected to the downstream of the gas pipeline to introduce low-pressure gas after pressure regulation. The upper pressure regulating chamber (21) is connected to the atmosphere. The upper pressure regulating chamber (21) is provided with a pressure regulating spring (211) whose bottom end abuts against the regulating diaphragm (20). The valve body (1) is provided with a balancing assembly (3). The balancing assembly (3) includes a positioning seat (31) installed in the valve body (1) and a... The piston (32) is located in the positioning seat (31) and the valve stem (33) connects the piston (32) and the regulating diaphragm (20). The positioning seat (31) forms a balance chamber (311), and the piston (32) closes the balance chamber (311) to form a sealed space. There is a vent between the valve stem (33) and the positioning seat (31) for gas from the upstream pipeline to enter the balance chamber (311). A first-stage pressure balance is formed between the lower pressure regulating chamber (22) and the balance chamber (311), and a second-stage pressure balance is formed between the lower pressure regulating chamber (22) and the upper pressure regulating chamber (21).

2. The gas pressure regulator with a dual-balance structure according to claim 1, characterized in that, A balance diaphragm (35) is provided above the positioning seat (31). The balance diaphragm (35) moves axially back and forth with the valve stem (33) and is used to seal the sealing space between the piston (32) and the balance chamber (311).

3. The gas pressure regulator with a dual-balance structure according to claim 2, characterized in that, The balancing assembly (3) also includes a limiting block (34) located above the piston (32), and the valve stem (33) passes through the piston (32) and connects the limiting block (34) and the adjusting diaphragm (20).

4. The gas pressure regulator with a dual-balance structure according to claim 3, characterized in that, A pad (36) is connected between the limiting block (34) and the adjusting diaphragm (20).

5. The gas pressure regulator with a dual-balance structure according to claim 3, characterized in that, The pressure regulating device (2) includes a lower valve cover (24) connected to the valve body (1) and an upper valve cover (23) mounted opposite to the lower valve cover (24). The lower valve cover (24) and the regulating diaphragm (20) form the lower pressure regulating chamber (22), and the upper valve cover (23) and the regulating diaphragm (20) form the upper pressure regulating chamber (21).

6. The gas pressure regulator with a dual-balance structure according to claim 5, characterized in that, The lower valve cover (24) is connected to the lower pressure regulating chamber (22) by an air guide pipe (5).

7. The gas pressure regulator with a dual-balance structure according to claim 5, characterized in that, The upper valve cover (23) is connected to the upper pressure regulating chamber (21) and has a breathing nozzle (6).

8. The gas pressure regulator with a dual-balance structure according to claim 5, characterized in that, The lower valve cover (24) is provided with a pressure plate (4) for pressing the positioning seat (31) onto the valve body (1). The inner side of the balance diaphragm (35) is pressed between the limiting block (34) and the piston (32), and the outer side of the balance diaphragm (35) is pressed between the pressure plate (4) and the positioning seat (31).

9. The gas pressure regulator with a dual-balance structure according to claim 8, characterized in that, The limiting block (34), the balancing diaphragm (35) and the pressure plate (4) form an auxiliary balancing cavity with the piston (32) and the positioning seat (31).

10. The gas pressure regulator with a dual-balance structure according to claim 9, characterized in that, A sealing ring (321) is provided between the piston (32) and the inner wall of the positioning seat (31).

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