The history of the development of single screw pump was invented by the French engineer Moineau in 1932 by the German PCM pump products. Three screw pump was invented and manufactured by the Swedish IMO company in 1931. China's Tianjin Industrial Pump Factory in the early 60's developed a high-pressure marine small-volume three-screw pump, and expanded to single, double and triple screw pump professional factory. Shenyang Pump Factory in the mid-60s development and production of double and triple screw pump, the success of the 1970s developed five screw pump. Tianjin Industrial Pump Factory in 1984 to introduce Allweiler's manufacturing technology and the British company Holroyd 2AC screw milling machine and ancillary equipment, China began mass production of screw pumps. Than 20 years behind foreign full. After more than a decade of business development in 1984, there are currently about 30 professional screw pump manufacturers in China. The main manufacturers are: * Tianjin Industrial Pump Factory: In 1984 the introduction of Allweiler manufacturing technology, the United Kingdom Holroyd 2AC screw milling machine and its supporting equipment, in 1993 the introduction of Germany's Bornemann company technology, Austria Linsinger CNC screw whirlwind milling machine Taiwan, And 2AC - L, 5AC screw milling machine each one, in 1998 the introduction of Germany Klingelnberg company HNC35SL all controlled high precision screw grinder one. With an annual output of single, double, three screw pump about 6000 Taiwan. * Shishou pump factory: In 1989 the introduction of Czechoslovakia technology and hollow-tube single screw pump rotor equipment. * Xian Far East Machinery Manufacturing Company curved rod pump plant: an annual output of about 600 units with a single screw pump. * Other single screw pump plant are: Hangzhou Pump Plant, Lanzhou Pump Factory, Zhejiang Dongyang Screw Pump Factory, Shanghai Light Industry Machinery Technology Research Institute, Jingjiang Chemical Machinery Factory, Wuxi Liangzhong Screw Pump Factory, Beijing Petroleum Machinery Factory, Jiaxing Oil Machinery Factory, Zhongcheng Machinery Manufacturing Co., Ltd. and so on. * Twin Screw Pumping Plant: In addition to the day pump and sink pump, there are Jiangsu Huaiyin General Machinery Factory and Guangzhou Shipyard Machinery Factory. Annual production is generally in the hundreds of units. * Three screw pump plant: In addition to the day pump, Shen pump, blue pump, as well as Nanjing Industrial Pump Factory, Shanghai Hydraulic Machinery Factory. After the two annual output less. * Five screw pump plant: the only production plant - pump plant will be transferred to the days of pumping plant. Products China's single, double, three, five screw pump annual output of a total of about 10,000 units to the largest three screw pump production, accounting for more than half, followed by single and twin screw pump. Five screw pump production is very small. Materials and manufacturing technology Screw pump rotor due to harsh working conditions, the selection of air compressor, refrigerator screw is better, such as the choice of 38CrMoAl, 40Cr, 20Cr13, 16Mn, CrS5, often subject to nitriding (HRc56-65). There are also selected CrNi, CrMo, CrNiMo stainless steel, MnCrS steel. General manufacturing technology plant is coarse, fine milling -> nitriding. Only the domestic industrial pump factory in Tianjin using rough milling -> nitriding -> rough grinding process. Professional collaboration In addition to the pump industry day pump, pump and a few other plants, screw production equipment is very simple, so urgent need to establish a well-equipped, advanced technology professional screw factory.