Installing Bits and Reaming shells

1. Install the inner tube stabilizer into the counter bore of a new reaming shell. This stabilizer centers the inner tube.

2. If assembling an extended core barrel, insert an inner tube stabilizer into the box of the second length of outer tube and thread it to the first. To extend the inner tube, insert an inner tube coupler and a second inner tube between the first inner tube and the core lifter case. Alternatively, an "extenda" inner tube is available in certain sizes which combines a coupler and an inner tube into one length.

3. Thread both the reaming shell and the diamond bit to the outer tube.

4. If using a stabilized reaming shell, add the appropriate inner tube extension between the inner tube and the core lifter case. If using a stabilized reaming shell with an extended core barrel, use the appropriate extended inner tube coupling.

5. Wipe the inner tube assembly clean and lightly oil the outside surface. Insert the inner tube assembly into the outer tube. For Wireline Coring Systems, ensure the landing shoulder is firmly seated on the landing ring.

6. Check the bit gap, the space between the beveled shoulder inside of the bit and lower end of the core lifter case. The gap should measure 3–5 mm (1/8”–3/16”). If the gap setting is not within the limits specified above:

1). Extract the inner tube assembly.
2). Loosen the lock nut.
3). Adjust the spindle to attain the proper gap.
4). Insert the inner tube.
5). Check the gap again.

A bit gap that exceeds 4.8 mm (3/16”) may cause poor recovery or short core runs. If it is less than 3.2 mm (1/8”) then high fluid pressure, reduced flow to the bit, and mis-latching of the inner tube assembly may result. Whenever a new bit or reaming shell is first installed, or if the inner tube or a core lifter case is replaced, check the bit gap between the core lifter case and the bit to assure proper adjustment.

7. Latch Clearance Check (Wireline Systems) Suspend the entire assembly and recheck the bit gap. Remove the bit and push upward on the core lifter case to check latch clearance. Movement should be slight, approximately 1.5–3 mm (1/16”–1/8”). When using more than one inner tube assembly, check the bit gap and latch clearance in all the assemblies used with the same outer tube assembly.

8. Tighten all thread joints using Guizhou Vilong inner tube and outer tube wrenches.