168-DHD350 concentric drill bits with casing tube for water well drilling

Concentric Casing System

Working Principle of Drill:

1. Ring bit and casing shoe assembly is welded to casing prior to drilling. Lock the assembly into pilot bit with hammer. The pilot bit' shoulder engages the shoulder of the casing shoe.

2. Hammer's percussive energy is transferred through the pilot and ring bit, crusing rock. Part of impact energy advances casing.

3. On completion of drilling and casing, the drill string wit pilot bit is retrieved by a slight reverse rotation to unlock the bayonet coupling. The ring bit stays in the hole, and can be recovered only if the casing is retrieved.

4. If further drilling is required on the bedrock, the pilot bit is simply replaced by an appropriate size of standard DTH bit.

Advantages of Concentric Drilling:

1. Drilling straight and fast.

2.The torque for Concentric drilling is much less than for eccentric drilling

3. Easily unlocking-relocking.

4. Drilling in any angle.

5. Effective cuttings discharge.

6. Easy-to-operate and system security.

7. Economical and cost-effective.

---------------------------------------------------------------------------FAQ-----------------------------------------------------------------

Q: Can you supply related drilling tools except Concentric Drill Bits ?

A: Yes, we can supply full set of drilling tools, such as drill pipe, tricone bit, PDC bit, drag bit, DTH Hammer. Moreover, we have drilling equipments like rigs, mud pump, air compressor, etc.as well.

Q: How can you ensure the quality of concentric drill bits ?

A: We have our professional QC and all the products will be strict inspection and testing for every order before shipping out.

Q: Can you do other sizes of concentric drill bits?

A: We do all common specifications, if you have special requirements,we can also provide

Q: How is your delivery time?

A: This will depend on your purchasing quantity. Normally we can deliver 3-5 days.