The selection of valves in the chemical industry should be set according to the requirements of production (including normal production, start-stop and special working conditions), maintenance and safety requirements, and economic rationality should also be considered. Chemical industry process materials and public materials pipeline at the boundary of the device, chemical plant all the public material pipeline main branch pipe root valve setting, public material station (public engineering station), tower and reboiler, heat exchanger, steam heating equipment, water cooling equipment, air cooler, device contents and storage tank, compressor and compressor auxiliary system, chemical valve not only suitable range, but also more dosage, of course, chemical valve than the general valve requirements are higher. Chemical valves generally use the medium is relatively simple corrosion, simple chlor-alkali industry, to large petrochemical enterprises, there are high temperature, high pressure, corrosion resistance, wear resistance, temperature and pressure difference is very large, for this kind of acute high valve, in the selection and use of the process should be strictly in accordance with chemical standards.