... black steel spiral-casing , thickness 7mm Weight : 69kg/m- casing 8 5/8 : galvanized steel casing , thickness 5mm collapse pressure 450 psi.Weight ... : 26.4kg/m- - screen 8 5/8 : galvanized bridge slotted screen , slot opening 1.5mm , open ... steel casing , thickness 7mm Weight : 47.8kg/mscreen pipes 10 5/8 : galvanized bridge slotted screen , slot opening 1.5mm , ...