China Scratch Mat

Natural oxidation and corrosion of the valve stem, because the surface of the valve stem packing is oxidized, and ferroferric oxide (rust) is formed, which will cause the valve stem to become thin and cause leakage; For example, the use temperature of pure PTFE must be 150℃, filled with PTFE250℃, and PTFE particle filler The compensation performance is poor, and it is only suitable for low-pressure valves, PTFE fiber, carbon fiber or the mixed filler of the two, and the price is too high to be unfavorable for promotion. A valve that relies on exteal force to rotate and drive to open and close is designed with a sealing device that is used to install a certain number of packing seals in the packing culvert to achieve a sealing effect, but how about the sealing? Leakage at the PTFE fiberglass fabric high temperature cloth packing of the valve is one of the most prone to leakage failure in the valve, but there are roughly two reasons for it. Synthetic resins and synthetic fibers, some of these products are restricted in the scope of use. Corrosion problems can also be caused by one aspect., serious threats to personal safety, property safety and environmental pollution accidents. Asbestos, because the asbestos material has chloride ions that corrode the valve stem, and the asbestos contains carcinogens, which are harmful to human health. The country has banned or seldom used the parts of the product; 2. Expanded graphite will cause severe electrochemical corrosion. If the water valve leaks, it will lead to serious consequences, such as poisonous, harmful, flammable, explosive and Corrosive media leakage, etc. Reasons for fillers The main fillers currently used are:  Corrosion situations include: 1.Valve leakage is very common in life and production, and it will cause waste or danger to life at the slightest. Leakage caused by chloride ion corrosion of asbestos packing; ,PTFE fiberglass fabric high temperature cloth ...ادامه مطلب

The reactivity of these compounds is very high. The principle is: Na transfers the outermost electrons to the empty orbital of naphthalene to form anionic radicals; then forms an ion pair with Na+, releasing a large amount of resonance energy, and forming a mixed solution of dark green metal organic compounds.064nm) is greater than that of hydrogen atoms (0. The helical conformation just surrounds the PTFE's carbon chain skeleton, which is vulnerable to chemical attack, forming a tight and complete;fluorinated; protective layer, so that the PTFE main chain is not attacked by any exteal reagents, so that PTFE has other materials Unmatched solvent resistance, chemical stability, and low cohesive energy density; at the same time, the carbon-fluorine bond is extremely strong, with a bond energy of 460.05~1u0026mu;m, the surface tension of PTFE is 18. Because the radius of fluorine atoms (0. When in contact with PTFE, sodium can break the CF bond, tear off part of the fluorine atoms on the surface of PTFE, and leave a carbonized layer on the surface , Polar groups such as COOH; the depth of the carbonized layer is about 0. Structural analysis of PTFE properties: In PTFE, fluorine atoms replace hydrogen atoms in polyethylene. The unbranched symmetrical main chain structure of PTFE also makes it highly crystalline, so processing is more difficult.1.2 High temperature melting method The advantage of this method is that it has better weather resistance and heat resistance than other methods, and is suitable for long-term outdoor use; the disadvantage is that PTFE will release a toxic substance during high temperature sintering, and the shape of the PTFE membrane is not easy to maintain. Reducing agent method (sodium-naphthalene solution replacement method) The sodium-naphthalene solution replacement method is the sodium-naphthalene solution replacement method that has better effect and wider application among the various modification methods currently known.2kJ,Gas Stove Top Protectors ...ادامه مطلب