Valves occur with the creation of fluid lines. People have been using valves for nearly 4,000 years. In ancient my country, when absorbing brine from Yanjing Town to produce salt, bottle plug valves were used in bamboo pipelines. In 1800 AD, in order to avoid the flooding of the White Nile River in ancient Egypt, large-scale water conservancy and hydropower projects were built. Similar wooden plug valves were also used to control the distribution of flowing water. This is all the development process of the valve. Many applications of industrial valves began after Thales invented the steam engine. Valves of cast steel, forged steel and forged welded construction occurred in the early twentieth century.
