Applied to over burden formation with complex topographic and geological conditions, such as gravel, fissured formation, boulder, landfill of construction etc.
D | h | H | C | G | ||||
Specification | O. D. of Casing Tube (mm) | I.D. of Casing Tube(mm) | Wall thickness of casing (mm) | Max. O.D. of pilot bit (mm) | Ring Bit O.D. (mm) | Max. O.D. of Normal Bit (mm) | Hammer Type | Weight(kg) |
TOP hammer type | ||||||||
P76/7-39 | 76 | 62 | 7 | 57 | 88 | 39 | R32 | 3.2 |
P89/8-58 | 89 | 73 | 8 | 70 | 100 | 58 | T38 | 5.8 |
P114/9-84 | 114 | 94 | 10 | 92 | 126 | 84 | T45 | 7.5 |
P127/10-93 | 127 | 107 | 10 | 105 | 142 | 93 | T45 | 10 |
P140/10-97 | 140 | 120 | 10 | 116 | 161 | 97 | T45,T51 | 15 |
DTH hammer type | ||||||||
P114/9-84 | 114 | 94 | 10 | 94 | 126 | 84 | COP34/COP32/DHD3.5 | 12 |
P127/10-93 | 127 | 107 | 10 | 105 | 142 | 93 | COP34/COP32/DHD3.5 | 16 |
P140/10-97 | 140 | 120 | 10 | 116 | 161 | 97 | COP44/DHD340/M40/SD4/QL40 | 21 |
P146/10-110 | 146 | 126 | 10 | 124 | 165 | 110 | 22 | |
P168/12.7-127 | 168 | 142.6 | 12.7 | 141 | 188 | 127 | COP54/DHD350/M50/SD5/QL50 | 27 |
P178/12.7-131 | 178 | 152.6 | 12.7 | 150 | 196 | 131 | 32.5 | |
P194/12.7-145 | 194 | 168.6 | 12.7 | 166 | 214 | 145 | COP64/DHD360/M60/SD6/QL60 | 42.5 |
P219/12.7-170 | 219 | 193.6 | 12.7 | 191 | 243 | 170 | 58 | |
P245/12.7-195 | 245 | 219.6 | 12.7 | 214 | 268 | 195 | DHD380/COP84/SD8/QL80 | 78 |
P254/12.7-203 | 254 | 228.6 | 12.7 | 224 | 276 | 203 | 84.5 | |
P273/12.7-223 | 273 | 247.6 | 12.7 | 241 | 305 | 223 | 100 | |
P325/12.7-276 | 325 | 299.6 | 12.7 | 292 | 350 | 276 | 135 | |
P406/12.7-350 | 406 | 380.6 | 12.7 | 377 | 442 | 350 | DHD112/QL120/SD12/N120 | 280 |
P508/12.7-416 | 508 | 482.6 | 12.7 | 478 | 545 | 416 | 522 | |
P560/12.7-475 | 560 | 534.6 | 12.7 | 528 | 595 | 475 | NUMA180SD18/Numa180/TH18/TS18/TK18 | 620 |
P610/12.7-513551 | 610 | 584.6 | 12.7 | 558 | 645 | 513 | NUMA180 | 710 |
Step1: The drilling in over burden formation is finished.
Step2: Reverse rotation of the hammer and pull the pilot bit out from the hole.
Step3: Replace the pilot bit with normal bit to continue drilling down.