Polit Bit
Application Range
It is suitable for drilling water wells,geothermal wells, short mircopiles medium mini-type grouting hole of building, dam and harbour project.
Design Principles
Make the casing follow easy and the equipment and operation simple
Outstanding Advantages
Simple structure,simple operation,reliable quality,retrievable drilling tools,long service life.
Operation Procedure:
1. As soon as the drilling starts, the reamer opens and enlarges the hole to drive the casing shoe and casing tube down.
2.When drilling in over-burden formation is done, Start reverse circulation to close the reamer, and then pull up the assembly through the casing tube.
3.The casing tube can be left in the hole, or can be pulled out by means of grout sealing material.
4.Use the normal drilling tools to drill and achieve to the desired depth.
Specifications
| A | B | C | D | E | F |
| Outer Dia. of Casing Tube | Inner Dia. of Casing Tube | Reamed Dia. | Min. Inner Dia.of Casing Shoe | Hammer Type | Drill Pipes |
| mm | mm | mm | mm | mm | |
| 108 | 93-99 | 118 | 86 | TDS79 | 76 |
| 114 | 101-103 | 127 | 91 | R56,T38,TDS79 | 76 |
| 127 | 114-116 | 136 | 101 | TDS79 | 76 |
| 140 | 124-127 | 152 | 117 | TDS98 | 76 |
| 146 | 127-132 | 154 | 117 | TDS98 | 76 |
| 168 | 149-155 | 184 | 140 | TDS122 | 76,89 |
| 178 | 159-165 | 194 | 150 | TDS122 | 76,89 |
| 193 | 173-180 | 206 | 166 | TDS139 | 89,114 |
| 219 | 199-206 | 234 | 193 | TDS139,TDS180 | 89,114 |
| 245 | 224-231 | 260 | 210 | TDS180,TDS220 | 114 |
| 273 | 251-257 | 300 | 241 | TDS180 |
114,127 |
Usage:
1. In not stable rock formation, the casing is necessary to follow.
2. Usually in water well drilling, for large hole boring.
3. Drilling depth is better less than 40 metres to control the hole well.
4. Match to 6" hammer and 194mm casing tube.
5. Air pressure is 20 Bar and air volumn is 500 cfm.
6. The tools is fetched out to use in the next holes.
