BB OS & Y structure Flanged or Butt-welding endsManufacture in accordance with API 6D or API 600Face to Face/End dimensions to ANSI B16.10Flange dimensions to ANSI B16.5Butt-welding end dimensions to ANSI B16.25Valve tested to API 6D or API598 Standard Material specification Shell ASTM A216-WCB ASTM A351-CF8 Disc WCB CF8 CF8M Monel Stem F6a F304 F316 Monel F304 Disc facing 13Cr 13Cr STL 304 STL 304 STL Monel F304 F304 STL Seat facing 13Cr STL STL 304 STL 304 STL Monel 304 STL STL Shell ASTM A351-CF3 ASTM A351-CF8M ASTM A351-CF3M Disc Stem F304L F316 F316L Disc facing 304L 304L STL 316 316 STL 316L 316L STL Seat facing 304L STL STL 316 STL STL 316L STL STL