Dual Wall Reverse Circulation Tricone Rotary System

When the ground is too soft, too broken or too wet for an RC hammer, a dual wall RC tricone system keeps your program drilling and your samples clean.

Black Diamond Drilling supplies the complete tricone RC string, from the top head adaptor down to the bit adaptor. It’s backed by stock and technical support from our Perth and Kalgoorlie branches.

How does the Dual Wall Reverse Circulation Tricone Rotary System work?

A tricone RC system uses the same dual wall pipe as RC hammer drilling, but cuts the rock by rotation instead of percussion.

  1. Rotation from the top. The rig’s top head drive turns the entire dual wall string, with a tricone roller bit on the end.
  2. Air down the outside. Compressed air is fed through the swivel into the gap between the outer pipe and the inner tube, and travels down to the bit.
  3. Samples up the middle. At the bit face, the air picks up the cuttings and carries them up the inner tube, through a bit with an open centre, to the cyclone at surface.

The cuttings never touch the wall of the hole on the way up. You get a sample from the depth you’re actually drilling, not material that has fallen in from higher up the hole.

How do Drillers use Tricone RC?

  • Keeps drilling in wet ground. Water that would stall a hammer is far less of a problem for a tricone.
  • Clean, depth-accurate samples. The sealed inner tube keeps samples separate from the hole wall, with no mud or additives.
  • Lower air demand. Rotary RC can run on smaller air packages than hammer drilling, which saves fuel.
  • Quick switch to a hammer. It uses the same dual wall pipe as RC hammer drilling, so changing methods mid-hole is straightforward.
  • Real-time geology. Continuous samples tell your geologist what’s being drilled within minutes.

Black Diamond Drilling Top Head Adaptor

 

Top Head Adaptor

5.5" to 4"

Black Diamond Drilling RC Top Head Adaptor Inner Tube

Swivel Adaptor Inner Tube

Inner Tube 32 1/4"

Inner Tube 34 1/4"

Inner Tube 36 7/8"

Black Diamond Drilling RC Saver Sub

Saver Sub

Black Diamond Drilling RC Dual Tube Pipes
 

Dual Wall RC Drill Pipes

 
RC Drill Pipes 5'
 
RC Drill Pipes 10'
 
RC Drill Pipes 15'
 
RC Drill Pipes 20'

Black Diamond Drilling Rock Bit Adaptor

Tricone Bit Adaptor

2 3/8"

2 7/8"

Best Practice for Tricone RC?

  • Check inner tube O-rings at every rod change. A leaking seal lets air short-circuit and can mix samples.
  • Replace the saver sub before it’s worn out. A worn saver sub passes damage on to your top drive.
  • Use thread protectors when pipes are stored or moved.
  • Clear wet sample blockages promptly. This prevents build-up and corrosion inside the inner tube.
  • Match the bit to the ground. Choose open or sealed bearings and the cutting structure to suit the formation.