GB / T12230-2005 General valves austenitic steel castings JB / T5300-2008 industrial valves material selection guidelines JB / T6438-1992 valve sealing surface plasma arc welding technical requirements JB / T7248-2008 valve with low temperature steel castings PAW technical conditions JB / T7744-1995 valve sealing surface surfacing alloy powder GB / T12234-2007 universal valve flange and butt weld steel gate valves GB / T12235-2007 General valves Flanged steel globe valves and lift check GB / T12236-2008 General valve steel swing check valves GB / T12237-2007 universal valve flange and welded steel ball valves GB / T12238-2008 common valve flange and wafer butterfly GB / Universal Valve Diaphragm T12239-2008 GB / T12240-2008 General valve Iron Plug GB / T12241-2005 valve general requirements GB / T12243-2005 Spring loaded safety valves Shanghai Guanlong Valve Machinery Co., Ltd. Shanghai Guanlong valve Machinery Limited, valves, valve out of Hong Kong, the Hong Kong provided by the Dongguan 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!