Pilot operated safety valve

Abstract

The invention relates to the technical field of pilot operated safety valves, in particular to a pilot operated safety valve which comprises a main valve, a pilot valve and a connecting piece used for connecting the main valve with the pilot valve. An air inlet cavity communicated with the inlet cavity is formed in the main valve, and an output cavity communicated with the air chamber cavity is formed in the main valve; a lower gas path and an upper gas path are arranged in the connecting piece; the pilot valve is internally provided with an air inlet groove communicated with the pilot valve lower cavity, the pilot valve is internally provided with an air outlet groove communicated with the pilot valve upper cavity, and the air inlet cavity of the main valve and the air inlet groove of the pilot valve are connected through a lower air path on the connecting piece. According to the pilot operated safety valve, the output cavity of the main valve and the air outlet groove of the pilot valve are connected through the upper air channel on the connecting piece, a channel is built in, the connecting strength between structures can be effectively improved, the shaking phenomenon is avoided, then the overall shock resistance of the pilot operated safety valve is improved, and safe operation of equipment can be guaranteed when an earthquake happens.

Description

Technical Field

[0001] The invention relates to the technical field of pilot-operated safety valves, in particular to a pilot-operated safety valve. Background Art

[0002] A safety valve is a reclosable overpressure protection device that can discharge the rated flow of fluid using the pressure of the medium itself, thereby releasing part of the pressure in pressure-bearing devices and equipment such as pressure vessels, pressure pipes or boilers, preventing damage to the system or equipment due to overpressure, and ensuring the normal operation of the device and equipment and the safety of operators.

[0003] The passage between the main valve and the pilot valve of a conventional pilot-operated safety valve is usually connected through a steel pipe, and the main valve and the pilot valve are fixed by a bracket. This connection method is prone to loose connection between the main valve and the pilot valve under earthquake conditions, and the pilot valve shakes under earthquake conditions, thereby causing the steel pipe to break. Therefore, a pilot-operated safety valve is proposed. Summary of the invention

[0004] In view of the problem in the above or prior art that the connection between the main valve and the pilot valve is easily loosened under earthquake conditions, the pilot valve shakes under earthquake conditions, thereby causing the steel pipe to break, the present invention is proposed.

[0005] Therefore, an object of the present invention is to provide a pilot operated safety valve.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a pilot-operated safety valve, comprising a main valve and a pilot valve, and a connecting piece for connecting the main valve and the pilot valve; the main valve is provided with an air inlet cavity connected to an inlet cavity, and the main valve is provided with an output cavity connected to an air chamber cavity; the connecting piece is provided with a lower air path and an upper air path; the pilot valve is provided with an air inlet groove connected to a lower cavity of the pilot valve, and the pilot valve is provided with an air outlet groove connected to an upper cavity of the pilot valve.

[0007] As a preferred solution of the pilot-operated safety valve of the present invention, wherein: a lower fan-shaped cavity and an upper fan-shaped cavity are provided in the main valve, and a connecting cavity is provided in the main valve; a flow guide is provided in the main valve; the flow guide includes a rotating ring provided in the main valve, and a straight-through groove and a conveying groove provided in the rotating ring.

[0008] As a preferred solution of the pilot-operated safety valve of the present invention, the flow guide member further comprises a baffle plate arranged on the rotating ring; an expansion chamber is arranged in the lower fan-shaped cavity; and a resistance member is also slidably arranged in the main valve.

[0009] As a preferred solution of the pilot-operated safety valve of the present invention, a flow guide cavity is provided in the main valve, and a booster piston is slidably provided in the air chamber cavity of the main valve.

[0010] As a preferred solution of the pilot-operated safety valve of the present invention, the flow guide member further comprises a sector-shaped shielding block arranged on the rotating ring.

[0011] As a preferred solution of the pilot-operated safety valve of the present invention, the outer wall size of the fan-shaped shielding block matches the inner wall size of the upper fan-shaped cavity; the outer wall size of the baffle matches the inner wall size of the lower fan-shaped cavity.

[0012] As a preferred solution of the pilot-operated safety valve of the present invention, the diameter of the lower fan-shaped cavity is larger than that of the upper fan-shaped cavity.

[0013] As a preferred solution of the pilot-operated safety valve of the present invention, the upper diameter of the air chamber cavity of the main valve is larger than the lower diameter.

[0014] As a preferred solution of the pilot-operated safety valve of the present invention, the abutment member comprises a top sleeve slidably disposed in the main valve, and a chamfered surface disposed at the end of the top sleeve.

[0015] As a preferred solution of the pilot-operated safety valve of the present invention, a vent hole is provided on the outer wall of the top sleeve.

[0016] The beneficial effects of the pilot-operated safety valve of the present invention: the present invention connects the air inlet chamber of the main valve and the air inlet groove of the pilot valve through the lower air path on the connecting piece, connects the output chamber of the main valve and the air outlet groove of the pilot valve through the upper air path on the connecting piece, builds the channel in, and uses a connecting piece to connect the main valve and the pilot valve, which can effectively improve the connection strength between the structures and avoid the occurrence of shaking, thereby improving the overall seismic resistance of the pilot-operated safety valve, and ensuring the safe operation of the equipment when an earthquake occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the overall structure of the pilot-operated safety valve.

[0019] Figure 2 This is a schematic diagram of the internal structure of a pilot-operated safety valve.

[0020] Figure 3 This is an enlarged view of the structure of the resistance and guide parts of the pilot-operated safety valve.

[0021] In the figure: 100, main valve; 101, air inlet chamber; 102, output chamber; 103, lower fan-shaped chamber; 104, upper fan-shaped chamber; 105, connecting chamber; 106, expansion chamber; 107, guide chamber; 108, booster piston; 200, connecting piece; 201, lower air path; 202, upper air path; 300, guide valve; 301, air inlet groove; 302, air outlet groove; 400, resistance piece; 401, top sleeve; 402, chamfered surface; 403, vent; 500, guide piece; 501, rotating ring; 502, straight groove; 503, conveying groove; 504, baffle; 505, fan-shaped shielding block. DETAILED DESCRIPTION

[0022] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0023] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0024] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0025] Example 1, reference Figures 1 to 3 , which is the first embodiment of the present invention, provides a pilot-operated safety valve, including a main valve 100 and a pilot valve 300, and a connecting piece 200 for connecting the main valve 100 and the pilot valve 300; the main valve 100 is provided with an air inlet cavity 101 connected to the inlet cavity, and the main valve 100 is provided with an output cavity 102 connected to the air chamber cavity; the connecting piece 200 is provided with a lower air path 201 and an upper air path 202; the pilot valve 300 is provided with an air inlet groove 301 connected to the lower cavity of the pilot valve, and the pilot valve 300 is provided with an air outlet groove 302 connected to the upper cavity of the pilot valve.

[0026] It should be noted that in the prior art, an inlet cavity, an outlet cavity and an air chamber cavity are provided in the main valve 100, and the inlet cavity, the outlet cavity and the air chamber cavity are connected. A main valve piston is slidably provided in the air chamber cavity, a main valve spring is provided above the main valve piston, and the cross-section of the upper end surface of the main valve piston is larger than the cross-section of the lower end surface. A pilot valve lower cavity, a pilot valve upper cavity and a pilot valve exhaust port are provided in the pilot valve 300. A slidable pilot valve piston is provided in the pilot valve 300, and a pilot valve spring is provided above the pilot valve piston. The air inlet cavity 101 of the main valve 100 and the air inlet groove 301 of the pilot valve 300 are connected by a steel pipe, and the output cavity 102 of the main valve 100 and the air outlet groove 302 of the pilot valve 300 are connected by a steel pipe.

[0027] In the present invention, the air inlet chamber 101 of the main valve 100 and the air inlet groove 301 of the pilot valve 300 are connected through the lower air path 201 on the connecting piece 200, and the output chamber 102 of the main valve 100 and the air outlet groove 302 of the pilot valve 300 are connected through the upper air path 202 on the connecting piece 200. The channel is built-in, and the main valve 100 and the pilot valve 300 are connected by the connecting piece 200. This can effectively improve the connection strength between the structures and avoid the occurrence of shaking, thereby improving the overall seismic resistance of the pilot safety valve, and ensuring the safe operation of the equipment during an earthquake.

[0028] Example 2, reference Figure 1 to Figure 3 , which is the second embodiment of the present invention. Different from the previous embodiment, a lower fan-shaped cavity 103 and an upper fan-shaped cavity 104 are provided in the main valve 100 , and a connecting cavity 105 is provided in the main valve 100 ; the connecting cavity 105 is connected to the upper gas path 202 .

[0029] A flow guide 500 is provided in the main valve 100; the flow guide 500 includes a rotating ring 501 provided in the main valve 100, and a straight groove 502 and a conveying groove 503 provided in the rotating ring 501. The rotating ring 501 is rotatably provided in the main valve 100, and the straight groove 502 and the conveying groove 503 are vertically arranged, and the straight groove 502 passes through the rotating ring 501.

[0030] Specifically, the flow guide 500 further includes a baffle 504 disposed on the rotating ring 501 ; an expansion chamber 106 is disposed in the lower fan-shaped chamber 103 ; and further includes a resistance member 400 slidably disposed in the main valve 100 .

[0031] Furthermore, a flow guide cavity 107 is provided in the main valve 100 , and a booster piston 108 is slidably provided in the air chamber cavity of the main valve 100 .

[0032] The guide member 500 also includes a fan-shaped baffle block 505 arranged on the rotating ring 501; the outer wall size of the fan-shaped baffle block 505 matches the inner wall size of the upper fan-shaped cavity 104; the outer wall size of the baffle 504 matches the inner wall size of the lower fan-shaped cavity 103; the diameter of the lower fan-shaped cavity 103 is larger than the upper fan-shaped cavity 104; the upper diameter of the air chamber cavity of the main valve 100 is larger than the lower diameter.

[0033] The resisting member 400 comprises a top sleeve 401 slidably disposed in the main valve 100 , and a chamfered surface 402 disposed at the end of the top sleeve 401 ; an air vent 403 is disposed on the outer wall of the top sleeve 401 .

[0034] The rest of the structure is the same as that of Example 1.

[0035] After the main valve 100 and the pilot valve 300 are connected, the connecting member 200 will be able to abut against the end of the abutment member 400, and the abutment member 400 will abut against the baffle 504, referring to Figure 2 , the connection between the main valve 100 and the pilot valve 300 can be completed.

[0036] When the pilot safety valve is working, gas enters from the inlet chamber. Due to the action of the main valve spring, the main valve piston will block the inlet chamber, and the gas enters the air inlet chamber 101, enters the lower fan-shaped chamber 103 through the expansion chamber 106, and then enters the lower air path 201 through the resistance member 400. It should be noted that the beveled surface 402 of the resistance member 400 and the arrangement of the vent hole 403 can facilitate the flow of gas. The gas enters the lower chamber of the pilot valve through the lower air path 201. There is a gap between the pilot valve piston and the inner wall of the pilot valve 300, and the gas flows into the upper chamber of the pilot valve. And enter the upper gas path 202, pass through the connecting chamber 105, flow out from the conveying groove 503 through the straight groove 502, and then flow into the output chamber 102 through the upper fan-shaped chamber 104, and enter the interior of the air chamber. Since the cross-section of the upper end face is larger than that of the lower end face, the area is large and the pressure is large when the gas pressure is equal. Therefore, the main valve piston can block the inlet cavity. In addition, even if there is a gap between the guide member 500 and the upper fan-shaped cavity 104 and the lower fan-shaped cavity 103, so that the gas enters the guide cavity 107, it will not affect the closing of the main valve piston.

[0037] During operation, when the gas pressure is too high, due to the increase in gas pressure, the pilot valve piston is pressurized by force, compressing the pilot valve spring, and the pilot valve piston slides up to the pilot valve exhaust port to open. The gas pressure on one side of the gas chamber cavity is reduced. After the pilot valve exhaust port is exhausted, the pressure in the gas chamber cavity is not enough to close the main valve piston. Therefore, the main valve piston slides up and opens, and the outlet cavity also exhausts and releases pressure until the pressure is released to the pilot valve piston reset, and the pilot valve exhaust port is closed. At this time, under the action of gas pressure, the main valve piston is closed.

[0038] When working under earthquake conditions, the pilot valve 300 may be smashed down and the connecting piece 200 may be separated from the main valve 100. After the connecting piece 200 is separated, the gas pushes the baffle 504, and the baffle 504 pushes out the resistance piece 400, causing the resistance piece 400 to fall. Since the baffle 504 is relatively long, it is easier to push the rotating ring 501 to rotate through the lever principle, so as to facilitate the pushing of the resistance piece 400. After the baffle 504 is slightly deflected, since the baffle 504 leaves the expansion chamber 106, the air pressure will be able to act on the surface of the baffle 504, increasing the pushing pressure, and finally the baffle 504 rotates to fit the side of the lower fan-shaped chamber 103 away from the air inlet chamber 101, and the fan-shaped shielding block 505 will cover the output chamber 102 after the deflection. After the ring 501 rotates, the straight groove 502 connects the lower fan-shaped cavity 103 and the guide cavity 107, and a new gas channel is formed in the main valve 100. The gas enters the lower fan-shaped cavity 103 from the air inlet cavity 101, and enters the guide cavity 107 through the straight groove 502, acting on the booster piston 108. The booster piston 108 slides in the air chamber cavity to compress the main valve spring. After the main valve spring is compressed, the pressure on the main valve piston is increased. In addition, the upper diameter of the air chamber cavity of the main valve 100 is larger than the lower diameter, and the area of ​​the booster piston 108 is larger than the upper end surface, which can increase the pressure. After the pilot valve 300 falls, the main valve 100 itself can also relieve pressure to a certain extent, and at the same time, it can also avoid the phenomenon of low pressure caused by gas leakage.

[0039] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A pilot-operated safety valve, characterized in that: It comprises a main valve (100) and a pilot valve (300), and a connecting piece (200) for connecting the main valve (100) and the pilot valve (300); The main valve (100) is provided with an air inlet cavity (101) in communication with the inlet cavity, and the main valve (100) is provided with an output cavity (102) in communication with the air chamber cavity; The connecting member (200) is provided with a lower air path (201) and an upper air path (202); The pilot valve (300) is provided with an air inlet groove (301) in communication with the lower cavity of the pilot valve, and the pilot valve (300) is provided with an air outlet groove (302) in communication with the upper cavity of the pilot valve.

2. The pilot operated safety valve according to claim 1, characterized in that: The main valve (100) is provided with a lower fan-shaped cavity (103) and an upper fan-shaped cavity (104), and the main valve (100) is provided with a connecting cavity (105); A flow guide member (500) is provided in the main valve (100); The flow guide member (500) comprises a rotating ring (501) arranged in the main valve (100), and a straight-through groove (502) and a conveying groove (503) arranged in the rotating ring (501).

3. The pilot operated safety valve according to claim 2, characterized in that: The flow guide (500) further comprises a baffle (504) arranged on the rotating ring (501); An expansion cavity (106) is provided in the lower fan-shaped cavity (103); It also includes a resistance member (400) slidably disposed in the main valve (100).

4. The pilot operated safety valve according to claim 3, characterized in that: A flow guide cavity (107) is provided in the main valve (100), and a pressure-boosting piston (108) is slidably provided in the air chamber cavity of the main valve (100).

5. The pilot operated safety valve according to claim 4, characterized in that: The flow guide (500) further comprises a fan-shaped shielding block (505) arranged on the rotating ring (501).

6. The pilot operated safety valve according to claim 5, characterized in that: The outer wall size of the fan-shaped shielding block (505) and the inner wall size of the upper fan-shaped cavity (104) match each other; The outer wall size of the baffle (504) and the inner wall size of the lower fan-shaped cavity (103) match each other.

7. The pilot operated safety valve according to claim 6, characterized in that: The diameter of the lower fan-shaped cavity (103) is larger than that of the upper fan-shaped cavity (104).

8. The pilot operated safety valve according to claim 7, characterized in that: The upper diameter of the air chamber cavity of the main valve (100) is larger than the lower diameter.

9. The pilot operated safety valve according to any one of claims 3 to 8, characterized in that: The resisting member (400) comprises a top sleeve (401) slidably disposed in the main valve (100), and a chamfered surface (402) disposed at the end of the top sleeve (401).

10. The pilot operated safety valve according to claim 9, characterized in that: The outer wall of the top sleeve (401) is provided with a vent hole (403).

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