Application: Series NKVW vacuum pumping system is composed of vacuum pump and Roots pump, Roots pump automatically works by the controlling of relays or electrical-contact vacuum gauge. NKVW equips an electrical control system and a cooling water system. It is quick start, big capacity of vacuum evacuating etc, widely used in vacuum smelting, welding, chemical, pharmaceutical and electric power system, particularly suitable for transformer vacuum operation. Contact:David JoyoSkype:joyooilpurifierTEL: +86 23 68645069Fax:+86 23 68089506Mobile:+86 13658335577Website:http://www.nkoilpurifier.comhttp://www.cqnkoilpurifier.en.ec21.comhttp://cqnkoilpurifier.diytrade.comhttp://coilpurifier.company.frbiz.comhttp://cqnkoilpurifier.bossgoo.com/http://www.flickr.com/photos/oilpurifier/