C-22 Casing Heads use a straight-bore bowl design that prevents damage to sealing areas from drilling tools and prevents test-plug and bowl-protector wedging problems under pressure. This straightbore design also reduces maintenance costs and permits suspension of heavy casing loads. C-22 Casing Heads normally are furnished with 2-inch threaded outlets, but optional sizes and studded outlets are available upon request. Bottom connections can be furnished slip-on-weld, threaded or slip-n-lock. C-22 Casing Heads permit interchangeability of casing hangers C-22 and C-21.
The C-29 Casing Head uses a straight bore based on the same reliable design as the C-22, except the bowl is 2 inches deeper, permiting the acceptance of the minimal-deflection C-29 Casing Hanger.This allows extreme-load casing-hanging capacity compared with the C-22 profile.