Core Barrel Assembly (1) - Inner Tube Assembly
An inner tube Consists of the head assembly, inner tube, stop ring, core lifter, and core lifter case.
1. Apply a light coating of lithium grease to the inside of the core lifter case.
2. Slide the core lifter into the threaded end of the core case, tapered end first. The tapered surfaces of the core lifter and core lifter case act against one another to tighten the grip on the core when the core barrel is pulled back.
3. Snap the stop ring into the core lifter case. The stop ring provides a hardened surface for the core lifter to bear against during coring.
4. Thread the core lifter case onto one end of the inner tube.
5. Thread the head assembly on to the other end of the inner tube.
6. An optional inner tube liner or “split tube” with a pump-out system is available, which is commonly selected when drilling coal, clay bearing or highly fractured formations, a core ejection piston protects the core from pressurized drilling fluid when the split tube, containing the core sample, is pumped out of the inner tube.