Application criterion Design and manufacture£ºto ANSI B16.34;API602 2Size of coupling end: (1).Size of socket joint hole:to ANSI B16.11,JIS B23.6 (2).Size of threaded end :to ANSI B1.20.1:BS21:JIS BO203:S107/1 3Valve inspection and test£ºto API 598 4Structure characteristics£ºB.B;OS&Y OR W.B;OS&Y 5Material:to AIS/ASTM 6Materiare fo main body