... class:AA-HH 4)Spec level:PSL1-4,PR1-2.. Function: During drilling operation, casing head is ... /8,7Nominal Diameter of Side Outlet (in)2-1/16,2-9/16,3-1/81. Casing Head ... Slip ConnectionCharacteristics:(1) Connect surface casing by type WD slip.(2) Adopt type BT secondary seal structure.(3) ... for the connection between casing head and surface casing.2. Casing Head-Bottom thread connection(1)Bottom of ...