Fluorine-lined pumps are industrial equipment that is widely used in the chemical industry. Pump valves are the most important basic equipment unit and are the power guarantee for the circulation of the overall process flow. The difference in performance of fluorine-lined pump and valve equipment directly affects the continuity and stability of the production process.
Process characteristics of fluorine-lined pump valve material:
1. At present, there are more than ten kinds of fluorine-containing resins commonly used in the world, such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), polyperfluoroethylene propylene (FEP) Etc., its performance characteristics are excellent strong corrosion resistance (most acids, alkalis, salts and organic solvents can not corrode them), excellent electrical insulation properties, outstanding anti-adhesive properties (almost all substances are Can not adhere to its surface), high resistance to atmospheric aging and non-combustibility, excellent self-lubricating and dynamic and static friction characteristics (the lowest friction coefficient among all solid materials), high thermal stability, no toxin decomposition and no creep Variable characteristics (the substance with the highest long-term stable use temperature among various engineering resin materials). Fluorine-lined materials have excellent chemical resistance and weather resistance, which not only far exceed metal materials, but also are the best among organic polymer materials. Therefore, they are widely used in chemistry, pharmaceuticals, metallurgy, energy, electronics, electrical, and aviation. Anti-corrosion coating and sealing in aerospace and military industries.
Due to the complex composition of industrial wastewater, especially complex wastewater, the chemical reaction time in the treatment process is quite long, which causes serious scaling of the entire system and must be cleaned regularly to avoid serious impact on the operation of the system. After the fluorine-lined pump and corrosion-resistant pipeline are used, the entire system can be cleaned with acid, instead of expending a lot of manpower for disassembly and assembly and mechanical descaling, which greatly saves maintenance and cleaning costs.
2. Fluorine-lined materials have excellent surface non-stickiness, non-wetting to water, oil and most organic solvents, and low friction to solid materials. The thermal stability of fluororesin is the best among various polymer materials, but it is the lowest compared to metallic materials and inorganic non-metallic materials. The main reasons for the degradation of its high-temperature performance are recrystallization, thermal softening and thermal decomposition. Fluorine-lined materials are prone to cold brittleness or even cracking at very low temperatures, which limits the minimum operating temperature of such products. Among various fluoroplastics, polytetrafluoroethylene (PTFE) has the widest long-term use temperature (-250℃~260℃). Fluorine-containing resins all have excellent electrical insulation. Among them, polytetrafluoroethylene (PTFE) and polyperfluoroethylene propylene (FEP) have the best performance and can be widely used as coating materials for electronic and electrical components or components. The coefficient of linear expansion of fluorine-lined plastics is about three orders of magnitude higher than that of ordinary metal materials, ranging from 5×103 to 1.9×10/℃. Although fluoroplastics have good plasticity and can accommodate larger expansion and contraction deformations, fluorine-containing resins with smaller linear expansion coefficients should be used as metal or non-metal surface coatings and linings, which is good for improving coatings or linings. The surface quality and fatigue life of the alloy are of great significance.
3. Although fluorine-lined materials have excellent corrosion resistance, surface non-stickiness, weather resistance, electrical insulation, and aging resistance, their mechanical properties are relatively low compared to metal materials. The stiffness and strength of fluoroplastics are generally lower. More than an order of magnitude lower (the yield strength of plain carbon steel is 235MPa, the tensile strength of H62 copper alloy is 370MPa, the tensile strength of austenitic stainless steel is greater than 500MPa, the tensile strength of ultra-high-strength alloy steel is greater than 1200MPa, and the tensile strength of fluoroplastics The tensile strength is only 15-50MPa). The modulus of elasticity of fluoroplastics is very low, the modulus of elasticity is about 4×10MPa, which is only 1/50 of steel materials, and the strength is only 1/10 of steel materials, but the toughness is very excellent, and the elongation is one higher than that of steel materials. More than orders of magnitude.
Therefore, fluorine-containing resins generally cannot be used as the main material of engineering components, but mainly used as surface composite (covering or lining) materials, coating or lining on the surface of rigid metal materials or inorganic non-metallic materials. Metal materials have high rigidity, strength and other mechanical properties, while fluoroplastics have excellent engineering characteristics such as strong corrosion resistance, anti-adhesion, low friction, noise reduction and consumption reduction. The two are organically combined, and the metal substrate surface is used. New equipment such as pump valves, pipe fittings, tower vessels, etc. required by the composite fluorine-containing resin coating or lining manufacturing process industry has a broad market application prospect.
