What is fluorine-lined butterfly valve?

Fluorine-lined butterfly valve is a metal valve body (such as carbon steel, stainless steel) lined with fluorine plastic (such as PTFE, FEP), butterfly valve, valve seat and other media contact parts are also fluorine plastic or fluorine lining material, through the rotation of the butterfly plate to achieve strong corrosion medium (such as concentrated acid, alkali, organic solvent) cut off, on or flow adjustment of the valve, can be matched with manual, electric or pneumatic actuators. Its core advantage is "metal valve body strength + fluorine plastic corrosion resistance" : metal valve body to ensure structural strength, fluorine plastic lining resistance to almost all strong corrosive media (in addition to molten alkali metal, element fluorine), and excellent sealing performance, widely used in chemical, pharmaceutical, metallurgical and other industries in the strong corrosion of low pressure pipeline system.

Fluorine lining material parameters: Commonly used fluorine plastics are divided into PTFE (polytetrafluorethylene, temperature resistance -200-260 ℃, optimal corrosion resistance, universal type), FEP (ethylene fluoride propylene copolymer, temperature resistance -200-200 ℃, good workability, suitable for complex structures), PFA (perfluoroalkoxyl, temperature resistance -200-260 ℃, excellent creep resistance, Suitable for high voltage scenarios); The thickness of the lining should be ≥2mm, and there should be no pinholes and bubbles (the resistance voltage should be ≥15kV after EDM detection); The butterfly plate is mostly carbon steel lined PTFE or pure PTFE material, and the valve seat is PTFE or PTFE + elastane composite structure (improving the sealing elasticity).

Performance and sealing parameters: nominal pressure PN0.6-2.5MPa (mainly medium and low pressure, conventional selection PN1.0-1.6MPa, high pressure to strengthen the lining and the valve body bonding strength); Nominal diameter DN50-600 (mainly small and medium caliber, DN600 or more need special lining technology); Working temperature -200-260 ℃ (depending on the fluorine lining material, PTFE/PFA temperature limit); The leakage rate was ≤1×10⁻⁶MPa · m³/s.

Operation and structure parameters: operation mode: separate dynamic (with turbo worm transmission, labor-saving, suitable for small and medium caliber), electric (action time ≤30 seconds, with anti-corrosion coating, suitable for remote control), pneumatic (action time ≤15 seconds, anti-corrosion cylinder, suitable for explosion-proof scene); The structural form is mostly wafer type (the center of the butterfly plate and the valve shaft are concentric, and the seal is reliable). The connection method is mainly flange. The valve body material can be carbon steel (low cost) or stainless steel (suitable for strong corrosion scenes with clean requirements).

Fluorine-lined butterfly valve application scenario: in the chemical industry, used for concentrated nitric acid, concentrated sulfuric acid delivery pipeline, PTFE lining resistance to strong corrosion, to ensure the safety of raw material transportation; Pharmaceutical industry, used for acid and alkaline liquid reaction kettle feed pipeline; Metallurgy industry, used for electroplating wastewater treatment pipeline (including chromic acid, hydrochloric acid), fluorine-lined butterfly valve resistance to electroplating solution corrosion, to avoid corrosion of the valve body pollution wastewater; Environmental protection industry, used for desulfurization denitrification system slurry delivery pipeline (containing sulphuric acid, ammonia), PTFE lining slurry corrosion resistance, prolong the service life of the valve; In addition, in pesticide (phosphorous pesticide synthesis), dye (strong acid dye production) and other fields, also used for strong corrosive medium control, taking into account corrosion resistance and sealing.