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[China]
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Address: No. 33 Jinsuo Road, High-tech Zone, Zhengzhou, Henan
Contact name:Robin
Henan Rancheng Machinery Co., Ltd. |
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Concentric Bit for DTH Water Drilling Projects Drilling Rig Tools
Product Description
The concentric / symmetrical drilling system is an efficient integrated drilling and casing technology, especially suitable for environments with unstable formations. This system uses a removable or reusable ring drill bit to speed up the drilling process and maintain the straightness of the borehole. Its internal flush tank and casing shoe design provide excellent sealing while reducing formation disturbance.
This system is widely used in the construction of water wells, geothermal wells, building foundations, dams and ports, etc. It is mainly used for drilling short holes and small and medium - sized grouting holes.
Technical Parameters
| Outer Dia. of Casing Tube | Inner Dia. of Casing Tube | Reamed Dia. | Min. Inner Dia. of Casing Shoe | Drill Pipes | Max. Outer Dia. of Normal Bit |
| mm | mm | mm | mm | mm | mm |
| 108 | 93-99 | 118 | 86 | 76 | 77 |
| 114 | 101-103 | 127 | 91 | 76 | 82 |
| 127 | 114-116 | 136 | 101 | 76 | 92 |
| 140 | 124-127 | 152 | 117 | 76 | 105 |
| 146 | 127-132 | 154 | 117 | 76 | 105 |
| 168 | 149-155 | 184 | 140 | 76,89 | 125 |
| 178 | 159-165 | 194 | 150 | 76,89 | 140 |
| 193 | 173-180 | 206 | 164 | 89,114 | 150 |
| 219 | 199-206 | 234 | 184 | 89,114 | 165 |
| 244 | 224-231 | 260 | 210 | 114 | 190 |
| 273 | 251-257 | 305 | 240 | 114,127 | 220 |
| 323 | 301-310 | 348 | 284 | 127 | 255 |
| 406 | 382-388 | 440 | 364 | 140 | 340 |
| 457 | 433-439 | 488 | 413 | 140 | 385 |
| 508 | 484-490 | 538 | 464 | 140 | 440 |
Operation Process
1 . Weld the trephine bit and casing shoe to the casing and lock it firmly on the pilot bit by tapping.
2 . The impact energy is transmitted through the pilot bit and the trephine bit, effectively breaking the rock and advancing the casing.
3 . After drilling and casing operations are completed, remove the drill string with the pilot bit by gentle counter-rotation and unlock the latch connection. The trephine bit remains in the hole and is only removed when retrieving the casing.
4 . Finally, continue drilling into the bedrock to the predetermined depth using traditional drilling techniques.
The advantages of this drilling system are its integrated design and efficient operating procedures, making it ideal for drilling in unstable formation conditions.
Machine Pictures
