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 / T12224-2005 steel valves - General requirements GB / T12247-1989 steam traps classification GB / T12250-2005 steam traps term, sign, structure length GB / T12712-1991 steam heating system Condensate Recovery and steam trap management requirements of GB / T12221-2005 metal valve structure length JB / T74-1994 pipe flange technical conditions JB / T7928-1999 common valve supply requirements JB / T8530-1997 valve electric device model preparation method Zhuhai high-pressure valve valve manufacturer | valve out of Hong Kong (Online) | Zhuhai, Dongguan Ming valve provided by the Hong Kong Science and Technology Co., Ltd. valve. Valve Co., Ltd., Dongguan Ming Kong (www.gdmgfm.com) is Dongguan, butterfly leaders, over the years, the company implement the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Ming Kong valve leadership with the staff warmly welcome all inquiries negotiations to create a better valve out of Hong Kong in the future.