Reverse Circulation


For Holes 5¼” to 38” (133 to 965 mm)

Leading the Industry for Reverse Circulation Systems

Numa has led the industry in the innovative design of Reverse Circulation (RC) hammers and bits for exploration, dewatering, caissons, piles/rock sockets, and foundation drilling where large volume of rock excavation is required.

Numa is the world’s leading drilling technology provider, with the highest value in products, performance and service in the entire drilling industry.

Our RC products exhaust all cuttings up the center of the hammer and drill string to be safely collected at the surface, which reduces the risk of hole erosion and is better suited for environmentally sensitive applications.

The deep channel ways and side exhaust holes on our RC bits flush more air over the bit face resulting in a greater recovery and accurate down hole sample at the surface – all at a much faster drilling rate.

Numa’s Reverse Circulation System is a DTH hammer for use in environmentally challenging or confined work sites where contamination or risks of damaging close-by piles or other infrastructure. It uses a modified RC concept where water and/or bezonite are used for flushing the hole instead of pressurized air that can impact the surrounding area.

RC Products to meet your needs:

Benefits of Numa’s Reverse Circulation offerings include:

  • Five valveless hammer models. 
  • Cuttings exhaust up a collection tube in the center of the hammer and drill string to be safely collected at the surface.
  • Environmentally sensitive – no foam required for hole cleaning and lubricants are not free to contaminate the formation.
  • Exceptional performance against high heads of water.
  • Hole erosion dramatically reduced.
  • Faster and more efficient than rotary drilling.

Reverse Circulation

More Details

Patriot RC50

Hole Size: 5.25 to 5.75" (133mm to 146mm)

Challenger RC100

Hole Size: 10 to 15" (254mm to 381mm)

Champion RC160

Hole Size: 16 to 20" (406mm to 508mm)

Champion RC210

Hole Size: 21 to 28" (533mm to 711mm)

Champion RC300

Hole Size: 30 to 36" (762mm to 914mm)


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Learn more about our groundbreaking capabilities.

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