タイトルまたは説明

Symmetric overburden casing system Drilling Tools with Casing Tube

Retrievable Symmetric Drilling tools with csing tube step-by-step:
1. When the drilling starts, the central bit drive the ring bit down the hole, meanwhile the casing shoe and casing tube follow down together.
2.When arriving the bedrock, reversly rotate the tools and the central bit is pulled out from the hole.
3. During pouring the concretes through the casing tube, pull out the casing tube with the ring bit synchroly.

Permanent Symmetric Drilling Tools with csing tube step-by-step:
1. When the drilling starts, the central bit drive the ring bit down the hole, meanwhile the casing shoe and casing tube follow down together.
2. When arriving the bedrock, reversly rotate the tools and the central bit is pulled out while leaving ring bit in the hole bottom.
3. Pouring the concretes into the casing tube or move to next field work process.

Symmetric/Centrex/Symmitrix Drilling System
Symmetric is a concentric drilling system with retrievable pilot bits. 
This system drills in any direction and in any type of ground condition. 
It is, in fact, the most flexible and efficient overburden system on the market today. 
The Symmetric components are made up of: 
**-A pilot bits with large internal flushing holes and external flushing grooves
**-Symmetrical ring bit (reamer) with internal bayonet coupling
**-Casing shoe for driving of casing. 
The Pilot bits is attached to any common DTH hammer shank.