Slip-On flanges Type:Slip-On, Welding Neck, Blind, Socket Welding, Threaded, Lap Joint and Plate ... :1/2"to 60"NB 5K,10K,16K Slip-On flanges1. Type: Weld-neck, Slip-on, Blind, Socket Weld, Lap Joint, Spectacles, Ringjoint, Orifcase ... vessel once it has been sealed and must be reopended. Slip-On flanges