Welcome~Guizhou Vilong Equipment Co,.Ltd
When drilling in loose, unconsolidated so-called overburden formations, It is difficult to retrieve the drill strings after the hole has been drilled, the bore hole is often lost before a casing tube can be inserted to support it, currently there are Eccentric and Concentric two types of Overburden drilling systems represent the latest technology in simultaneous casing advancement.
Concentric casing drilling system or called Symmetrix system by Atlas copco and Centrex system by Sandvik, which enables you to drill and case deep holes simultaneously in all types of formation, even those with large boulders. The Symmetrix system are made up of a central pilot bit, a casing shoe and a symmetrical ring bit, casing diameters from 114 mm (Symmetrix 114) to 1220 mm (Symmetrix 1220) can be used.
Symmetrix drilling steps:
1). The integrated casing shoe and ring bits assembly is welded to casing prior drilling, then lock the assembly into pilot bits with hammer to start drilling.
2). When casing is installed in required overburden bedrock, simply unlock pilot bits with reverse rotation to retrieve the drill strings with pilot bits out, leave the casing, casing shoe and ring bits in the hole.
3). Continue drilling with a conventional drill strings or retrieve the casing, casing shoe and ring bits out for next processes.
|
Model |
Casing O.D |
Casing I.D |
Ring Bit O.D |
Ring Bit I.D |
Normal bit max O.D |
Hammer |
|
Symmetrix 114 |
114 mm |
94 mm |
122 mm |
86 mm |
84 mm |
3.5" |
|
126 mm |
||||||
|
Symmetrix 127 |
127 mm |
107 mm |
136 mm |
95 mm |
93 mm |
|
|
142 mm |
||||||
|
Symmetrix 140 |
140 mm |
120 mm |
148 mm |
100 mm |
97 mm |
4" |
|
161 mm |
||||||
|
Symmetrix 146 |
146 mm |
126 mm |
154 mm |
112 mm |
110 mm |
|
|
165 mm |
||||||
|
Symmetrix 168 |
168 mm |
142.6 mm |
180 mm |
130 mm |
127 mm |
5" |
|
188 mm |
||||||
|
Symmetrix 178 |
178 mm |
152.6 mm |
186 mm |
133 mm |
131 mm |
|
|
196 mm |
||||||
|
Symmetrix 194 |
194 mm |
168.6 mm |
202 mm |
147 mm |
145 mm |
6" |
|
214 mm |
||||||
|
Symmetrix 219 |
219 mm |
193.6 mm |
228 mm |
172 mm |
170 mm |
|
|
243 mm |
||||||
|
Symmetrix 245 |
245 mm |
219.6 mm |
254 mm |
198 mm |
195 mm |
8" |
|
268 mm |
||||||
|
Symmetrix 254 |
254 mm |
228.6 mm |
265 mm |
205 mm |
203 mm |
|
|
276 mm |
||||||
|
Symmetrix 273 |
273 mm |
247.6 mm |
285 mm |
225 mm |
223 mm |
|
|
298 mm |
||||||
|
Symmetrix 325 |
325 mm |
299.6 mm |
338 mm |
278 mm |
276 mm |
|
|
350 mm |
||||||
|
Symmetrix 406 |
406 mm |
380.6 mm |
420 mm |
352 mm |
350 mm |
12" |
|
442 mm |
||||||
|
Symmetrix 508 |
508 mm |
482.6 mm |
522 mm |
418 mm |
416 mm |
|
|
545 mm |
Contact: Mr. Peter Chan
Phone: +86 851 8577 3056 / 8569
Email：sales@rotarypercussivedrill.com
Add：No.17, 21 floor, unit 1, 1 building, M district, xiaochehe street flower orchard project, Nanming district, Guiyang City, Guizhou Province, China.
