Reverse circulation (RC ) drilling represents a fast,economical and efficient way. The RC drilling method will reduce dramatically both overall drilling costs and impact on the environ-ment. It not only prevents cross contamination but also enables a large number of sample bags in a short amount of time. The two ends of the pipe body are internally thickened, tempered after friction welding, quenched and tempered after rough machining of drill pipe joints, phosphating or nitriding after finishing. It effectively eliminates the failure probability of gluing, broken buckles, outer diameter swelling and cracking, is more wear-resistant and easy to disassemble.
