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2019

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11

Classification and selection of fluorine-lined valves

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Fluorine-lined valves, also known as fluorine-lined plastic corrosion-resistant valves, use molding (or inlay) method to place polytetrafluoroethylene resin on the inner wall of the valve pressure-bearing parts or the outer surface of the valve internal parts. (The same method is applicable to all types of valves. (lining of pressure vessels and pipeline accessories), a special corrosion-resistant valve made by taking advantage of its unique performance in resisting highly corrosive media. To put it simply, fluorine-lined valves use lining technology for all places within the valve body that can be reached by the medium.

Fluorine-lined valves, also known as fluorine-lined plastic corrosion-resistant valves, use molding (or inlay) method to place polytetrafluoroethylene resin on the inner wall of the valve pressure-bearing parts or the outer surface of the valve internal parts. (The same method is applicable to all types of valves. (lining of pressure vessels and pipeline accessories), a special corrosion-resistant valve made by taking advantage of its unique performance in resisting highly corrosive media. To put it simply, fluorine-lined valves use lining technology for all places within the valve body that can be reached by the medium.

 

The lining materials of fluorine-lined valves generally use fluoroplastics such as FEP (F46) and PCTFE (F3), which can be applied to various concentrations of sulfuric acid, hydrochloric acid, hydrofluoric acid, aqua regia and various organic acids, strong acids, strong oxidants and others Corrosive media and other pipelines, but fluorine-lined valves are subject to greater temperature limitations and are only suitable for media between -50°C and 150°C.

 

Categories of fluorine-lined valves and corrosion-resistant special valves:

Common fluorine plastic lined valves include: fluorine lined back pressure valve, fluorine lined diaphragm damper, fluorine lined butterfly valve, fluorine lined ball valve, fluorine lined globe valve, fluorine lined diaphragm valve, fluorine lined gate valve, fluorine lined plug valve, etc.

 

1. Fluorine lined back pressure valve

Fluorine-lined back pressure valves can only be made in flange type, and all areas where the medium flows are lined with ECTFE material. Able to withstand strong acid and alkali.

 

2. Fluorine-lined diaphragm damper

The upper shell of the diaphragm damper does not contact the medium and generally does not need to be lined; the side of the diaphragm that contacts the medium is a PTFE surface, and the lower shell and flange are lined.

 

 

3. Fluorine lined ball valve

The ball valve with fluoroplastic lining has extremely high chemical stability and is suitable for any highly corrosive chemical medium. Its structure is a full-pass floating ball valve structure, which can perform elemental leakage closure within the entire pressure range to facilitate the passage of the pipeline system. Ball sweep line and pipeline maintenance.

 

4. Fluorine lined butterfly valve

Used where reliable sealing and good regulating characteristics are required. The body of the fluorine-lined butterfly valve adopts a split type. The sealing of the current end of the valve shaft is controlled by adding fluorine rubber to the rotating base surface between the butterfly plate and the valve seat, so as to achieve a compact product structure, beautiful appearance, reasonable technology and reliable performance. The fluorine-lined butterfly valve ensures that the valve shaft does not come into contact with the fluid medium in the cavity. It is very convenient to replace the valve shaft. The fluorine-lined butterfly valve can be completed without disassembling the pipeline.

5. Fluorine lined gate valve

One of the most common opening and closing valves uses wedge-shaped gates with seals on both sides to connect or cut off the medium in the pipeline. The wedge gate valve does not allow micro-opening and is used as a throttling device in the pipeline to avoid high-speed flow. The erosion of the medium will accelerate the damage of the sealing surface.

6. Fluorine lined plug valve

The structure is compact and reasonable, with the smallest cavity space in the valve body, reducing medium retention. In addition, the special molding process makes the sealing surface dense, and the herringbone annular PTFE packing combination enables the valve to achieve zero leakage; this series is suitable for various Designed for automatic opening and closing control of pipelines with highly corrosive media.

7. Fluorine lined stop valve

The valve is opened or blocked by lifting the valve disc. The valve disc and the inner side of the valve body are all made of fluoroplastic lining technology. It has the advantages of light switch, small size, reliable sealing, simple structure, convenient maintenance, and wide range of use.

8. Fluorine lined check valve

The fluorine-lined check valve only allows the medium to flow in one direction and prevents the flow in the opposite direction. Usually, this fluorine-lined check valve works automatically. Under the pressure of flow in one direction, the valve disc opens and the liquid flows in the opposite direction. There is liquid pressure and the self-weight of the valve disc, and the valve disc acts on the valve weight to cut off the flow. Fluorine lined check valves include lift check valves, swing check valves, wafer check valves, etc. H41F46 fluorine lined check valve is suitable for various concentrations of aqua regia, sulfuric acid, hydrochloric acid, hydrofluoric acid and various organic acids, strong acids and strong oxidants at -50℃~150℃. FEP is also suitable for various concentrations of strong alkali. Used on pipelines with organic solvents and other corrosive gases and liquid media.