国产av综合影院|国产成人久久精品激情|好吊妞人成免费视频观看|国产日韩欧美在线精品观看|亚洲国产欧美日韩综合专区|精品人妻系列无码专区久久|98精品国产高清在线看入口|国产精品∨欧美精品∨日韩精品

Valve is a fluid delivery system in the control of parts, with the cut-off, regulation, diversion, to prevent adverse current, voltage regulator, diversion or overflow relief and other functions. Valves for fluid control systems, from the most simple to the very complex control system used in a variety of valves, the variety and specifications of a considerable variety. Valves can be used to control air, water, steam, a variety of corrosive media, mud, oil, liquid metals and radioactive media and other types of fluid flow. Valve according to the material is divided into cast iron valve, cast steel valves, stainless steel valves (201, 304, 316, etc.), valves in chrome molybdenum steel, chrome molybdenum vanadium steel valve, dual phase steel valves, plastic valves, non-standard custom valve material.