CN111637261A

CN111637261A - Reset safety valve and method for releasing fluid pressure by using same

Info

Publication number: CN111637261A
Application number: CN202010544539.9A
Authority: CN
Inventors: 郭谊民
Original assignee: Nanyang Ruige Industrial Co ltd
Current assignee: Nanyang Ruige Industrial Co ltd
Priority date: 2020-06-15
Filing date: 2020-06-15
Publication date: 2020-09-08

Abstract

The invention provides a reset safety valve, and belongs to the technical field of valves. The reset safety valve comprises a three-way valve body, a valve cap, a valve cover, a base, a piston and a sealing retainer ring; the valve cover is fixedly connected with the three-way valve body through a fastener; the valve cap is fixedly connected with the valve cover through a fastener; the base is fixedly connected with the three-way valve body through a fastener; the inner cavity of the three-way valve body is provided with the sealing retainer ring; the piston and the sealing retainer ring form a piston balance cavity, the piston balance cavity is not limited by the surfaces of a valve rod bushing or other parts of a valve cover, the overall pressure resistance value of the valve is improved by 1-1.5 times, and fluid leakage at the part interface is minimized.

Description

Reset safety valve and method for releasing fluid pressure by using same

Technical Field

The invention belongs to the technical field of valves, and particularly relates to a reset safety valve and a method for releasing fluid pressure by using the reset safety valve.

Background

Quick opening reset relief valves are commonly used in systems that encounter acute or transient pressure spikes that exceed system operating or design limits. Depending on the application, such valves may experience overpressure only a limited number of times, or may recur. When an overpressure condition is encountered, a reset relief valve is required to open quickly to prevent system failure. In addition, as the system operating pressure increases, the pressure on the valve member increases, which may result in loss of seal integrity and compromise valve function.

Patent No. ZL201610828401 discloses a spring type reset safety valve, in which a return spring is used to realize the safety opening function of the valve. The patent well solves the problem of resetting the safety valve when the fluid pressure is below 35 Mpa. However, for high pressure systems exceeding 35Mpa, this single piston structure can result in accidental opening of the valve, affecting the proper functioning of the valve or causing malfunction, thereby compromising the integrity and safety of the system.

The hydraulic valve piston or valve member that is subjected to system pressure will only be subjected to the above-mentioned rapid increase or decrease in force during pressure relief caused by overpressure. However, it is important that the reset relief valve not only function properly during venting, but also not leak during normal system operation. Typical reset relief valves install seals made of elastomeric material at the interface between the valve components to prevent fluid leakage. Loss of valve integrity due to seal rupture or other failure can compromise the integrity and safety of the system.

As shown in patent No. ZL201610828401, to reduce leakage of liquid in the valve chamber. The patent uses a rubber damping sleeve for damping as the piston approaches its travel limit, attenuating the initial rapid rate of movement of the vent opening member/piston while minimizing the rebound forces in the piston movement.

Additionally, the invention patent No. ZL201610828401 utilizes threads to rotate the flange piston into position to engage the seal (note that the installer can remove the nut from the valve body and expose the valve member seal). If the engagement surface of the flange piston is damaged or does not meet the specifications required to mate with the sealing surface, a seal failure may occur and the valve member may be damaged. It is also noted that the torque applied by the installer may over compress and damage the seal, also leading to failure.

Disclosure of Invention

In view of the above, an object of the present invention is to provide a reset safety valve and a method for releasing fluid pressure using the same, which can work in a high-pressure environment, have better sealing performance, longer service life and more convenient maintenance, can be widely applied to a high-pressure system higher than 35Mpa, and is used to improve safety performance and maintain overall stability of the system.

In order to achieve the purpose, the invention provides the following technical scheme: a reset safety valve comprises a three-way valve body, a valve cap, a valve cover, a base, a piston, a sealing retainer ring and a closed valve cavity; the valve cover is fixedly connected with the three-way valve body through a fastener; the valve cap is fixedly connected with the valve cover through a fastener; the base is fixedly connected with the three-way valve body through a fastener; the sealing retainer ring is sealed in the inner cavity of the three-way valve body; the base is internally provided with a first flow passage; the first flow passage has a first flow passage inlet and a first flow passage outlet; the three-way valve body is provided with a second flow passage; the second flow passage having a discharge end and an exhaust port; the piston is positioned in the three-way valve body; the piston comprises a valve stem and a valve head; the valve rod extends out of the valve head and penetrates through the sealing retainer ring and the valve cover, and is fixedly connected with the valve cap through a fastener; the lower surface of the valve cover, the sealing retainer ring and the upper surface of the valve head jointly enclose to form the closed valve cavity; the upper surface of the valve head is provided with at least one channel; the upper surface of the sealing retainer ring is connected with the lower surface of the valve cover in a sealing manner; the outer surface of the sealing retainer ring is hermetically connected with the inner cavity of the three-way valve body; the first flow passage outlet is connected with the second flow passage in a sealing mode.

Preferably, a first boss is arranged at the top of the sealing retainer ring; the lower surface of the valve cover is provided with a first counter bore matched with the first boss; the first boss is connected with the first counter bore in a sealing mode.

Preferably, the outer surface of the sealing retainer ring is provided with a second boss; a second counter bore matched with the second boss is formed in the inner cavity of the three-way valve body; the second boss is connected with the second counter bore in a sealing mode.

Preferably, a third boss is arranged at the outlet of the first flow channel; a third counter bore matched with the third boss is formed in the lower portion of the second flow channel; the third boss is connected with the third counter bore in a sealing mode.

Preferably, the first fastener and the second fastener are both bolts or studs.

Preferably, the bonnet and the bonnet are threadedly connected by bolts.

Preferably, the base is provided with at least one threaded hole and at least one flange; the second fastener is connected with the three-way valve body in a sealing mode through the threaded hole and the flange.

Preferably, the base is in a shape of a Chinese character 'tu'.

The invention also provides a method for releasing fluid pressure by using the reset safety valve, which comprises the following steps:

step 1, a piston of a reset safety valve is in a closed state, and the closed state is a first position;

step 2, introducing fluid with preset pressure from an inlet of the first flow channel; when the piston bears the pressure of the fluid in the first flow passage, the piston moves upwards, and the piston is in an opening state, namely a second position;

and 3, when the piston is at the second position, the fluid flows into the second flow channel and is discharged through the discharge end and the discharge port.

Preferably, the method further comprises the steps of moving the piston upward when the pressure of the fluid in the first flow passage exceeds a predetermined pressure value, and discharging a portion of the fluid into the second flow passage through the discharge end and the discharge port; and the other part of the fluid flows into the piston and flows out through the through hole on the upper surface of the piston, so that the piston occupies the closed valve cavity and opens the flow passage.

Compared with the prior art, the invention has the following beneficial effects:

1. the reset safety valve comprises a set of balance piston and a sealing retainer ring structure thereof which are arranged in a valve body, so that high-pressure fluid is sealed in a closed cavity made of special high-strength materials, and the pressure-resistant grade of the valve is improved by 2 times under the condition that the overall mass of the valve is only increased by 25%. Under the condition of ensuring safety, the maximum safety pressure grade of the reset safety valve is increased to 70Mpa (10000 psi). The valve housing is not subjected to high pressures. The valve member moves into engagement with the seal to close the valve fluid passage and moves out of engagement with the seal to open the valve fluid passage. The sealing retainer ring is fixed in the valve body through the valve cover and provides sufficient power for sealing, so that the reset safety valve can work under a high-pressure environment, the sealing is better, the service life is longer, and the maintenance is more convenient. The safety valve is reset to be in an integral design, and internal welding threads are not arranged, so that the defect of leakage at the thread is overcome, and the valve body is prevented from being damaged due to corrosion or scouring of the threads.

2. The piston balance cavity is added by closing the valve cavity rather than limiting by using the surfaces of other parts of a valve rod bushing or a valve cover, so that the overall pressure resistance value of the valve is improved by 1-1.5 times, and the fluid leakage at the interface of the parts is minimized; improving the sealing function, durability, and maintainability of the valve, minimizing fluid leakage from the pressurized chamber; eliminating the threaded configuration of the lower flange piston, not using threaded rotation to engage, and the seal is no longer subject to significant rotational torque forces during installation, minimizing the possibility of leakage; the seal of this reset relief valve can withstand normal system operating pressures: (56-70MPa) 8000-; after the seal fails, fluid will not remain in the sealing valve cavity and will be carried out of the valve through the outlet or the stem bushing and the bonnet; the base is in the form of a letter of earth, thereby reducing or eliminating the possibility of damaging the seal and valve member during installation.

Drawings

FIG. 1 is a schematic view of the reset relief valve of the present invention;

FIG. 2 is an enlarged view of the sealed connection of the boss and the recess of the present invention;

FIG. 3 is a diagram of the piston opening state of the present invention under fluid pressure;

reference numerals: 1. the valve comprises a valve cap, a valve cover, a first fastener, a valve cover through hole, a valve body, a valve cover, a valve body, a valve cover, a.

The specific implementation mode is as follows:

as shown in fig. 1, the reset safety valve comprises a base 4 fixed on a three-way valve body 3 by bolts or studs or other means, a piston 5 positioned in the three-way valve body 3, a bonnet 2 fixed on the three-way valve body 3 by bolts or studs or other means, and a bonnet 1 fixed on the bonnet 2 by bolts or studs or other means. The bonnet 1 is connected with the first thread groove 34 in a threaded mode through the bonnet through hole 22 through bolts or studs and other fastener connection modes.

In the present invention, the bonnet 2, which is connected to the three-way valve body 3 by a fastener, receives an upward force generated by the pressure of the fluid in the second flow passage 31 and the sealed valve chamber 6, rather than the bonnet 1 receiving the pressure of the fluid. Thus, the valve closure 2 may vary in size and accessory configuration depending on the mechanical specifications and design requirements. The sealing valve cavity 6 is formed by the lower surface of the valve cover, the sealing retainer 7 and the upper surface of the piston valve head 52 which are enclosed together. The sealing retainer ring 7 is sealed with the inner cavity of the three-way valve body 3.

In the invention, the valve cover 2 is fixed on the three-way valve body 3 by 8 bolts. The other fastener design is that a stud is screwed into the three-way valve body 3, and only a nut needs to be disassembled when the three-way valve body is disassembled. Furthermore, the use of the bonnet 2 in the present invention enables better access to the seal located in the three-way valve body 3. Another advantage of the present invention is that the bonnet 1 assembly is connected to the bonnet 2 instead of to the three-way valve body 3, so that the pressure generated by the fluid acts on the bonnet 2 instead of on the bonnet 1, ensuring the safety of the bonnet 1 assembly.

In the present invention, the base 4 has a first flow passage 41, a first flow passage inlet 42 for receiving fluid, a first flow passage outlet 43 connected to the three-way valve body 3, and a flange 47. The upper surface of the flange 47 is connected to the lower surface of the three-way valve body 3. One or more base through holes 46 extend through the flange 47 at right angles to the upper surface of the flange 47 for the attachment of bolts, studs or other fasteners. The bolts pass through the base through holes 46 and connect to the second threaded recesses 35 on the three-way valve body 3 so that the base 4 is secured to the three-way valve body 3 to seal the flange seal against the upper surface of the flange 47 and the lower surface of the three-way valve body 3.

In the present invention, the three-way valve body 3 has the second flow passage 31, and the lower portion of the second flow passage 31 has a third counterbore that cooperates with the first flow passage outlet 43, the discharge end 32, and the discharge port 33 of the base 4. A third boss 44 is designed at the first flow passage outlet 43 of the base 4, and the third boss 44 is in sealing connection with a third counter bore so as to tightly engage the outer side of the valve head 52 of the piston 5. The piston 5 in the three-way valve body 3 is movable between two positions, as shown in fig. 1 and 3, the first position being a valve-closed position, i.e. the position of the valve head 52 of the piston 5 in fig. 1, the valve head 52 cooperating with the third boss 44 and the third counter bore and being in tight engagement with the seat 4 for closing the fluid passage. The second position is an open position as shown in fig. 3, the piston 5 is disengaged from the base 4, and the second flow path 31 is opened. The use of a matrix 4 with a zig-zag pattern may reduce or eliminate the possibility of damaging the seals and valve components during installation.

In the present invention, the piston 5 passing through the three-way valve body 3 includes a valve head 52, a valve stem 51 projecting from the valve head 52, an upper surface formed by a difference between an outer diameter of the valve stem 51 and an outer diameter of the valve head 52, and a lower surface facing the first flow passage 41. The valve stem 51 extends from the valve head 52 and is reversibly attached to the bonnet 1 by pins or other fasteners through the sealing collar 7 and the bonnet 2. The upper surface of the valve head 52 is the bottom end of the closed valve chamber 6 and is further defined by the inner wall of the sealing collar 7. One or more through holes 53 are provided through the valve head 52 to allow fluid to pass through the first flow passage 41 into the closed valve chamber 6 to provide a restricted flow of fluid at fluid pressure. The importance of this confined fluid is readily apparent. When the pressure in the first flow passage 41 exceeds a set pressure relief value, the piston 5 moves to the valve-open position, as shown in fig. 3, and fluid flows from the first flow passage 41 in the base 4 into the second flow passage 31 in the three-way valve body 3 through the discharge end 32 to the discharge port 33. When the piston 5 is moved by the release of the valve cap 1, the presence of the restricted fluid in the closed valve chamber 6 limits the speed of movement of the piston 5, since this restricted fluid must flow out through the through hole 53 under the pressure of the first flow passage 41 to allow the piston 5 to occupy the closed valve chamber 6 and open the second flow passage 31, thereby absorbing and reducing the acceleration and deceleration forces encountered by the piston 5 when releasing the pressure.

In the invention, the sealing retainer ring 7 is detachable, the boss on the outer surface of the sealing retainer ring is engaged with the counter bore on the side wall of the inner cavity of the three-way valve body 3, and the first boss 71 on the upper surface of the sealing retainer ring 7 is combined with the first counter bore of the valve cover 2. The end of the sealing retainer ring 7 is designed with a second boss 72 to seal with a second counter bore of the three-way valve body 3.

In the present invention, the upper surface of the three-way valve body 3 is connected to the lower surface of the bonnet 2, and one or more bonnet through holes 22 are connected to the upper surface of the three-way valve body 3 through the bonnet 2 at approximately right angles for receiving bolts, studs or other fasteners. Bolts or studs and other fasteners are passed through the bonnet throughbore 22 to engage the first threaded groove 34 in the three-way valve body 3, thus tightly securing the bonnet 2 to the three-way valve body 3. The bonnet 1 is reversibly attached to the upper surface of the bonnet 2 and is pinned to the valve stem 51 to secure the valve element within the flow passage.

In another embodiment of the invention, no projection is provided on the outside of the sealing collar 7, so that different types of seals can be used between the valve head 52 and the inner wall of the second flow passage 31, and between the valve stem 51 and the inner wall of the bonnet 2.

Those skilled in the art will recognize from the above description that the relief valve can be disassembled by removing the support bolts in the first screw grooves 34 of the three-way valve body 3, thereby detaching the bonnet 2 and the sealing collar 7 from the three-way valve body 3. By removing the bonnet 2 and the sealing collar 7 in this way, and removing the base 4 from the three-way valve body 3 in the same way, the seals of the first boss 71, the second boss 72 and the third boss 44 can be easily removed, thereby facilitating replacement when resetting the safety valve for maintenance. In addition, the reset safety valve can conveniently disassemble the seal of each boss, so that the installation and the fixed seal are more convenient than the traditional reset safety valve. In the reset relief valves used today and before, it is not uncommon that some of the seals must be pressed or otherwise deformed during seal installation, which may cause damage to the seals, even if the seals are placed in the reset relief valve, it is difficult to secure them in place in the corresponding seal grooves. It will also be clear to those skilled in the art that the seal need not be folded, rolled or otherwise deformed during installation of the seal of the reset relief valve of the present invention, and that a seal made of a harder material may be used to better withstand the pressure of the fluid in the flow passage. In addition to the presently known commercially available seals, the reset relief valve of the present invention may also utilize U-seals, V-spring loaded seals, and often polymeric seals. Although not specifically required at times, the present invention may also optionally employ a seal reinforced with a metallic material for increased durability and pressure resistance. For the reasons stated above and in connection with the related design of the invention, the inventive reset relief valve can be advantageously used in high-pressure working systems with high efficiency.

The device embodying the invention in the reset relief valve further comprises means mounted in the bonnet 1 for pushing the piston 5 into the first position, i.e. the reset relief valve closed position, as shown in fig. 1, and resetting means, i.e. after the piston 5 has been moved to the second position, as shown in fig. 3, for resetting the piston 5 to the first position, thereby re-closing the reset relief valve. Such reset mechanisms are well known in the art and will not be described in detail herein.

as shown in fig. 1, step 1, the piston 5 of the safety valve is reset to a closed state, which is a first position.

As shown in fig. 3, step 2. passing a fluid at a predetermined pressure from the first channel inlet 42; when the piston 5 is subjected to pressure from the fluid in the first flow passage 41, the piston 5 moves upward, with the piston in an open state, which is a second position.

Step 3, when the piston is in the second position, fluid flows into the second flow passage 31 and is discharged through the discharge end 32 and the discharge port 33.

The piston 5 has at least one through hole 53 on the upper surface thereof, and when the fluid pressure in the first flow passage 41 exceeds a predetermined pressure value, the piston 5 moves upward, and a part of the fluid enters the second flow passage 31, and is discharged through the discharge end 32 and the discharge port 33. The other part of the fluid flows into the piston 5 and flows out through a through hole 53 on the upper surface of the piston 5, so that the piston 5 occupies the closed valve cavity 6 and opens a flow passage,_fromWhile absorbing and reducing the acceleration and deceleration forces encountered by the piston 5 when releasing pressure.

In the method of the present invention for releasing the pressure of the fluid using the reset relief valve, when the piston 5 is moved by the release of the valve cap 1, the presence of the restricted fluid in the closed valve chamber 6 limits the moving speed of the piston 5 because the restricted fluid must flow out through the second flow passage 31 under the pressure of the first flow passage 41 to allow the piston to occupy the closed valve chamber 6 and open the flow passage, thereby absorbing and reducing the acceleration and deceleration forces encountered by the piston 5 when releasing the pressure.

The method comprises allowing a portion of the fluid in the flow passage to pass through the through-holes 53 in the upper surface of the piston 5 into the closed valve chamber 6 above the piston 5, holding the piston in engagement with the outside of the top of the piston by means of a sealing gasket 7, securing the sealing gasket 7 in the three-way valve body 3, attaching the valve cap 2 to the three-way valve body 3, the valve cap 2 being subjected to the force generated by the pressure of the fluid in the closed valve chamber 6, the piston 5 being subjected to the force generated by the pressure of the fluid in the flow passage, and the piston being moved from the first position to the second position when the pressure of the fluid in the flow passage exceeds.

To test the pressure rating of the present invention providing a reset relief valve and a method of releasing fluid pressure using the reset relief valve, the present invention provides the following examples and comparative examples.

Example 1

By adopting the reset safety valve and the method for releasing the fluid pressure, provided by the invention, the preset pressure is 50 Mpa; the fluid pressure in the first flow channel 41 is 56Mpa (the fluid pressure in the first flow channel 41 is 56Mpa measured by the 2D1SY electric pressure test pump), the piston 5 moves upward, and a part of the fluid enters the second flow channel 31 and is discharged through the discharge end 32 and the discharge port 33. Another part of the fluid flows into the piston 5 and out through the through holes 53 in the upper surface of the piston 5 to allow the piston 5 to occupy the closed valve chamber 6 and open the flow passage, thereby absorbing and reducing the acceleration and deceleration forces encountered by the piston 5 when releasing pressure. A part of fluid in the flow passage enters a closed valve cavity 6 above a piston 5 through a through hole 53 on the upper surface of the piston 5, the closed valve cavity is kept jointed with the outer side of the top of the piston by a sealing retainer ring 7, the sealing retainer ring 7 is fixed in a three-way valve body 3, a valve cover 2 is connected on the three-way valve body 3, the valve cover 2 bears the force generated by the fluid pressure in the closed valve cavity 6, and the piston 5 bears the force generated by the fluid pressure in the flow passage.

Example 2

The same as in example 1, except that the pressure of the fluid introduced into the first flow passage 41 was measured to be 65Mpa by using a 2D1SY electric pressure test pump.

Example 3

The same as in example 1, except that the pressure of the fluid introduced into the first flow passage 41 was measured to be 70Mpa by using a 2D1SY electric pressure test pump.

Comparative example 1

By adopting the spring type reset safety valve mentioned in the background technology of the invention, the preset pressure is 20Mpa, and the pressure of the fluid introduced into the flow passage is 25Mpa measured by adopting a 2D1SY electric pressure test pump.

Comparative example 2

The same as comparative example 1, except that the predetermined pressure was 30Mpa, the pressure of the fluid introduced into the flow passage was 35Mpa as measured by a 2D1SY electric pressure test pump.

Comparative example 3

The same as comparative example 1, except that the predetermined pressure was 35Mpa, the pressure of the fluid introduced into the flow passage was 37Mpa as measured by a 2D1SY electric pressure test pump.

TABLE 1 pressure ratings for measured reset relief valves for examples 1-3 and comparative examples 1-3

As can be seen from the contents of table 1, the pressure rating of the spring type reset relief valve provided in comparative example 1 is suitable for a pressure rating of 35Mpa or less; the pressure grade of the balance buffer cavity of the reset safety valve with the pressure grade of more than 35MPa reaches 56-70 MPa.

Claims

1. A reset safety valve is characterized by comprising a three-way valve body, a valve cap, a valve cover, a base, a piston, a sealing check ring and a closed valve cavity; the valve cover is fixedly connected with the three-way valve body through a fastener; the valve cap is fixedly connected with the valve cover through a fastener; the base is fixedly connected with the three-way valve body through a fastener; the sealing retainer ring is sealed in the inner cavity of the three-way valve body; the base is internally provided with a first flow passage; the first flow passage has a first flow passage inlet and a first flow passage outlet; the three-way valve body is provided with a second flow passage; the second flow passage having a discharge end and an exhaust port; the piston is positioned in the three-way valve body; the piston comprises a valve stem and a valve head; the valve rod extends out of the valve head and penetrates through the sealing retainer ring and the valve cover, and is fixedly connected with the valve cap through a fastener; the lower surface of the valve cover, the sealing retainer ring and the upper surface of the valve head jointly enclose to form the closed valve cavity; the upper surface of the valve head is provided with at least one channel; the upper surface of the sealing retainer ring is connected with the lower surface of the valve cover in a sealing manner; the outer surface of the sealing retainer ring is hermetically connected with the inner cavity of the three-way valve body; the first flow passage outlet is connected with the second flow passage in a sealing mode.

2. The reset safety valve of claim 1 wherein the top of the gasket is provided with a first boss; the lower surface of the valve cover is provided with a first counter bore matched with the first boss; the first boss is connected with the first counter bore in a sealing mode.

3. The reset safety valve of claim 1 wherein the gasket outer surface is provided with a second boss; a second counter bore matched with the second boss is formed in the inner cavity of the three-way valve body; the second boss is connected with the second counter bore in a sealing mode.

4. The reset relief valve of claim 1, wherein a third boss is provided at the first flow passage outlet; a third counter bore matched with the third boss is formed in the lower portion of the second flow channel; the third boss is connected with the third counter bore in a sealing mode.

5. The reset relief valve of claim 1, wherein the first and second fasteners are each bolts or studs.

6. The reset safety valve of claim 1 wherein the bonnet is threadably connected to the bonnet by a bolt.

7. The reset relief valve of claim 1, wherein the seat is provided with at least one threaded hole and at least one flange; the second fastener is connected with the three-way valve body in a sealing mode through the threaded hole and the flange.

8. The reset safety valve of claim 1 wherein the seat is a letter-of-earth.

9. A method of releasing fluid pressure using the reset relief valve of any of claims 1-8, comprising the steps of:

10. A method of releasing fluid pressure according to claim 9, further comprising the step of moving the piston upwardly when the fluid pressure in the first flow passage exceeds a predetermined pressure value, a portion of the fluid entering the second flow passage and being discharged through the discharge end and the discharge outlet; and the other part of the fluid flows into the piston and flows out through the through hole on the upper surface of the piston, so that the piston occupies the closed valve cavity and opens the flow passage.