... B16.5 Flanged or Butt-Welding Ends, Plug Type Disk, Straight Pattern, Bolted Bonnet, Integral Body ... and Yoke, Rising Stem, Rising Handwheel, Gearbox, or Power Actuator Operated, Complete with a Machined Conical Backseat in ... Bonnet -------------------------------------------------------------------------------- • Design : BS 1873 • Testing : API 598 / BS 6755-1 • ANSI Class 150 : 2" to ...