... #--2500# 4: C/S ,S/S , Alloy Steel 5:Marking as Customer design. Carbon Steel Swivel Ring Flange Type Weld Neck,Slip-On ... ,Blind,Socket Weld,Lap Joint,Threaded,Orifice Flange,Swivel Flange,Spectacle Blind ... ,Etc. Size 1/2"-72"Class 150#,300#,400#,600#,900#,1500#,2500# Specification Carbon Steel ASTM ...