①. In oil refining equipment, most of the valves used in oil refining equipment are pipeline valves, mainly gate valves, stop valves, check valves, safety valves, ball valves, butterfly valves, and traps. Among them, gate valves account for about 80% of the total number of valves. (Valves account for 3% to 5% of the total investment of the device); ②. Chemical fiber device, chemical fiber products mainly include polyester, acrylic and vinylon. The ball valve and jacket valve (jacketed ball valve, jacketed gate valve, jacketed stop valve) of the valves needed; ③. Acrylonitrile device. The device generally requires standard valves, mainly gate valves, globe valves, check valves, ball valves, traps, needle globe valves, and plug valves. Among them, gate valves account for about 75% of the total valve; ④. Synthetic ammonia device . Because the ammonia source and purification method are different, the process flow is different, and the technical function of the required valve is also different. At present, domestic ammonia plants mainly need gate valves, globe valves, check valves, traps, butterfly valves, ball valves, diaphragm valves, regulating valves, needle valves, safety valves, high temperature and low temperature valves;