JB / T8691-1998 wafer type knife gate valve JB / T8692-1998 flue butterfly JB / T8937-2010 Wafer Check Valve JB / T9093-1999 steam traps technical conditions JB / T9094-1999 LPG equipment emergency shut-off valves for GB / T12242-2005 safety valve performance test method GB / T12245-2006 valve performance test method GB / T12251-2005 steam traps - Test method GB / T13927-2008 Universal valve pressure test JB / T5296-1991 Test methods common valve flow coefficient and flow resistance coefficient Shanghai Guanlong Valve Machinery Co., Ltd. Shanghai Guanlong Valve Machinery Co., Ltd. Hubei valve, the valve provided by the Dongguan Ming Kong, the Hong Kong Science and Technology Co., Ltd. valve. Valve Co., Ltd., Dongguan Ming Kong (www.gdmgfm.com) strong, credible, butterfly and other industries in Dongguan, Guangdong has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead valve and you work out of Hong Kong into the brilliant, for a better future!