Ultralow-temperature ball valve

Abstract

The utility model belongs to the technical field of ball valve sealing, and discloses an ultralow-temperature ball valve. The ultralow-temperature ball valve comprises a ball body, a valve body and a valve seat arranged between the ball body and the valve body, one side of the valve seat is a valve body contact side, the other side of the valve seat is a ball body contact side, a sealing ring is installed on the valve body contact side wall of the valve seat, and the sealing ring and the valve body are tightly attached to form sealing. The sealing ring comprises a fluoroplastic O-shaped ring coating layer and a metal spring inner core, and the fluoroplastic O-shaped ring coating layer is arranged outside the metal spring in a sleeving mode to form the composite sealing ring of a hollow structure. The inner core of the sealing ring of the ultra-low-temperature-resistant metal spring is adopted by the ultra-low-temperature-resistant metal spring, the outer O-shaped ring coating layer is made of fluoroplastic with the low temperature resistance capable of reaching-250 DEG C, and the whole ball valve can meet the ultra-low-temperature sealing requirements of liquefied natural gas (-162 DEG C), liquid oxygen (-183 DEG C) and liquid hydrogen (-253 DEG C).

Description

Technical Field

[0001] The utility model belongs to the technical field of ball valve seals, and particularly relates to an ultra-low temperature ball valve. Background Art

[0002] With the gradual wide promotion and popularization of natural gas, a clean energy source, in the industrial and civil fields in China, the oil and gas industry has been developing continuously and rapidly. The excavation and pipeline transportation projects have become important links in construction. A large number of valves that control the passage and blockage of media are used, especially the quality and stability of large-size high-pressure ball valves in long-distance pipeline transportation are particularly important. The main seal of a ball valve refers to the seal between the ball and the valve body, and this seal is mainly achieved by a sealing seat.

[0003] Rubber materials are widely used in valve seals, but the low-temperature resistance of rubber materials is limited. Most rubbers cannot meet the sealing environment with a temperature lower than -60°C. Although silicone rubber has excellent low-temperature resistance, especially phenyl silicone rubber can reach -120°C at low temperatures. For example, the patent document CN216200781U discloses a valve seat for a low-temperature ball valve. The core material of the sealing ring on the valve seat is phenyl silicone rubber solid rubber, and the low-temperature resistance of the valve seat can reach -120°C. However, in actual use, the valve seat in this patent document still cannot meet the ultra-low temperature requirements of liquefied natural gas (-162°C), liquid oxygen (-183°C), and liquid hydrogen (-253°C); for low-temperature environments with a temperature lower than -120°C, most existing valve sealing technologies use lip seals, but lip seals have a complex structure, extremely high requirements for the machining accuracy and roughness of valves, and cannot be disassembled and reused, which brings great troubles to valve manufacturing enterprises. Summary of the Utility Model

[0004] In order to solve the technical problems that the phenyl silicone rubber solid rubber used in the ball valve sealing ring in the prior art cannot meet the ultra-low temperature requirements and the sealing ring has a complex structure, the present application provides an ultra-low temperature ball valve.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0006] An ultra-low temperature ball valve includes a ball, a valve body, and a valve seat disposed between the two. One side of the valve seat is the valve body contact side, and the other side is the ball contact side. A sealing ring is installed on the valve body contact side wall of the valve seat. The sealing ring is closely attached to the valve body to form a seal. The sealing ring includes a fluoroplastic O-ring coating layer and a metal spring inner core. The fluoroplastic O-ring coating layer is sleeved outside the metal spring to form a composite sealing ring with a hollow structure.

[0007] Further, an open groove is provided on the valve body contact side wall of the valve seat, and the sealing ring is installed in the groove.

[0008] Further, the metal spring is a stainless steel spring or an alloy spring.

[0009] Further, the fluoroplastic O-ring is made of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer or perfluoroethylene propylene copolymer.

[0010] A support ring is further installed on the side wall of the sphere contact of the valve seat of the present application, and the support ring is closely attached to the sphere to form a seal.

[0011] Compared with the prior art, for a cryogenic ball valve provided by the present application, the plastic O-ring coating of the sealing ring is sleeved outside the metal spring to form a composite sealing ring with a hollow structure. The inner core uses a super cryogenic-resistant metal spring, and the outer O-ring coating is made of a fluoroplastic with a cryogenic resistance of up to -250°C, especially prepared from tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer (PFA) or perfluoroethylene propylene copolymer (FEP). In this way, the entire ball valve can meet the cryogenic sealing requirements of liquefied natural gas (-162°C), liquid oxygen (-183°C), and liquid hydrogen (-253°C). Moreover, the hollow structure of the sealing ring can provide a large compression amount, making the sealing effect of the sealing ring better.

[0012] Secondly, compared with most valve seats with lip seals on the outer layer, the fluoroplastic O-ring coating used in the present application has a simpler structure than the lip seal, requires lower processing precision and roughness for the valve, and can also be disassembled and reassembled repeatedly. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural diagram of the cryogenic ball valve provided by the present utility model;

[0014] Figure 2 is a schematic structural diagram of the sealing ring of the cryogenic ball valve provided by the present utility model;

[0015] Wherein, Figure 1 - Figure 2 in:

[0016] 1, sealing ring; 2, support ring; 3, valve body; 4, valve seat; 5, sphere; 101, fluoroplastic O-ring; 102, metal spring inner core. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0018] Combined with Figure 1 As shown, the present utility model provides a cryogenic ball valve, which includes a ball 5, a valve body 3, and a valve seat 4 disposed therebetween. One side of the valve seat 4 is the valve body contact side, and the other side is the ball contact side. A sealing ring 1 is installed on the valve body contact side wall of the valve seat 4, and the sealing ring 1 is in close fit with the valve body 3 to form a seal. Specifically, as Figure 2 shown, the sealing ring 1 includes a fluoroplastic O-ring 101 coating layer and a metal spring inner core 102. The fluoroplastic O-ring 101 coating layer is sleeved outside the metal spring to form a composite sealing ring with a hollow structure.

[0019] For the sealing ring 1 of the present application, its inner core uses a super cryogenic-resistant metal spring, and the outer O-ring coating layer is made of fluoroplastic with a low-temperature resistance of up to -250°C. The ball valve with this structure of the sealing ring can meet the cryogenic sealing requirements of liquefied natural gas (-162°C), liquid oxygen (-183°C), and liquid hydrogen (-253°C). The composite sealing ring 1 with a hollow structure has a hollow structure that can provide a large compression amount, making the sealing effect of the sealing ring better.

[0020] In addition, compared with most valve seats with lip-shaped sealing rings on the outer layer, the fluoroplastic O-ring 101 coating layer used in the present application has a simpler structure than the lip-shaped sealing ring, has lower requirements for the machining accuracy and roughness of the valve, and can also be disassembled and reused repeatedly.

[0021] Such as Figure 1 shown, in an embodiment, an open groove is provided on the valve body contact side wall of the valve seat 4, and the sealing ring 1 is installed in the groove.

[0022] In a preferred embodiment, the metal spring is a stainless steel spring or an alloy spring; the fluoroplastic O-ring 101 is made of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer or perfluoroethylene propylene copolymer.

[0023] Such as Figure 1 shown, in another embodiment, a support ring 2 is further installed on the ball contact side wall of the valve seat 4, and the support ring 2 is in close fit with the ball 5 to form a seal.

[0024] The preferred embodiments of the present utility model disclosed above are only used to help illustrate the present utility model. The preferred embodiments do not describe all the details in detail, nor do they limit the present utility model to only the specific embodiments. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification in order to better explain the principle and practical application of the present utility model, so that those skilled in the relevant technical field can well understand and utilize the present utility model. The present utility model is only limited by the claims and their full scope and equivalents.

Claims

1. A cryogenic ball valve, comprising a ball, a valve body and a valve seat arranged therebetween, wherein one side of the valve seat is a valve body contact side and the other side is a ball contact side, a sealing ring is installed on the valve body contact side wall of the valve seat, and the sealing ring is tightly fitted with the valve body to form a seal, characterized in that: The sealing ring comprises a fluoroplastic O-ring coating layer and a metal spring inner core. The fluoroplastic O-ring coating layer is sleeved outside the metal spring to form a composite sealing ring with a hollow structure.

2. The cryogenic ball valve according to claim 1, characterized in that: An open groove is provided on the valve body contacting side wall of the valve seat, and the sealing ring is installed in the groove.

3. The cryogenic ball valve according to claim 1, characterized in that: The metal spring is a stainless steel spring or an alloy spring.

4. The cryogenic ball valve according to claim 1, characterized in that: The fluoroplastic O-ring is made of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer or perfluoroethylene propylene copolymer.

5. The cryogenic ball valve according to claim 1 or 2, characterized in that: A support ring is also installed on the ball contact side wall of the valve seat, and the support ring is tightly fitted with the ball to form a seal.

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