1、Design and manufacture conform to BS5351 MSS SP-118; 2、Connection ends conform to: 1)Scoket wdled ends conform to ANSI B16.11;JB/T1751 2)Screw ends conform to ANSI B16.11;JB/T1751 3)Butt-welded ends conform to ANSI B16.25;JB/T12224 4)Flanged ends conform to ANSI B16.5;JB79 3、Test and inspection conform to:API 598;GB/T13927;JB/T9092 4、Structure features:Bolted bonnet; three-piece 5、Materials conform to ANSI/ASTM 6、Main materials:A105;LF2;F304(L);F316(L);F51.