Asbestos used in weak acid and alkali, ammonia, water, oil medium, valves, for static sealing anti-corrosion seal works best. Fiber packing with a good thermal conductivity, acid and alkali resistance, suitable for all kinds of solvents, gasoline, water, pumps, valves, liquid nitrogen medium reactor sealing (another good thermal conductivity, acid and alkali resistance, high temperature resistant, suitable for high-speed operation under the condition of static and dynamic seals). PTFE packing is pure PTFE dispersing resin as raw material, raw films made, and then through the twisting, woven packing. This PTFE is no other additives, can be widely used in food, pharmaceutical, paper fiber with high cleanliness requirements, and have a strong corrosive medium of valves, not suitable for use on the pump.
Aramid fiber packing with excellent high speed, high modulus properties of numbers (known as synthetic metal wire) is the wire three times its strength, light weight wire five times. Therefore, compared with other types of packing, it can resist particle crystallization medium and higher temperatures can be used separately or in combination with other packing, suitable for medium containing solid particles are easy to wear, recommended for superheated steam, solvents, liquefied gas, sugar syrup and other grinding fluid. Pump system on asbestos, which is a very good alternative.