DOUBLE WALL DRILL PIPES
Dual Wall HDD Drill Pipe
Reverse Circulation RC Drilling Rods
Reverse Circulation RC Drilling Rods is also called Double wall drill pipe, double drill pipe or Dual Wall drill pipe. It consists of two layers of inner and outer drill pipes (called inner pipe and outer pipe). The inner and outer pipes constitute an annular gap, which is a channel for pumping the flushing medium to the bottom of the hole when hydraulic rock drilling and center sampling drilling. The central hole of the inner tube is fixed as a whole by discharging the flushing medium, and each double-walled drill pipe is connected with the screw of the outer tube to ensure transmission of torque and pressure. The inner tube is usually connected by a plug-in method, which generally only serves as a flushing medium. Therefore, a sealing device is required at the plug-in place.
Double Wall Drill Pipes are used in drilling of wells with diameter 84 and 93 mm and depth up to 300 m in soils of II-V drill ability classes with seams of soils up to VII drill ability class in the fulfilment of all necessary prospecting and geochemical operations, in geological mapping and exploration of deposits of solid minerals.
Drilling of wells is carried out with hydro-transport of the core delivered on the surface along the internal channel of the double drill string.
| Reverse circulation drill pipe/Double wall drill pipe/Dual Wall drill pipe | ||||
| Outer tube O/D in | Inner tube in | Lerngth m | Type of thread | Range of drill in |
| 3 1/2 | 1 1/2 | 3 ~ 6 | Remet, Metzke, Matrix, others | 4-1/8-4-3/4 |
| 4 | 2 | 3 ~ 6 | Remet, Metzke, Matrix, others | 4-3/4-5-1/2 |
| 4 1/2 | 2 & 2-1/2 | 3 ~ 6 | Remet, Metzke, Matrix, others | 5-1/8-6 |
| 6 5/8 | 3 | 3 ~ 6 | Remet, Metzke, Matrix, others | 7-7/8-15 |
| 10 3/4 | 5 | 3 ~ 6 | Remet, Metzke, Matrix, others | Over 15 |
| * Roschen offers reverse circulation drill string components in accordance with the requirements of the customer. Reverse circulation drill pipes available in different model, diameters and length. | ||||
| REVERSE CIRCULATION DRILL ROD SPECIFICATIONS | |||||||
| Type / Thread | Remet | Remet | Remet | Metzke | Metzke | Matrix | Matrix |
| Rod O.D. | 3 1/2" | 4" | 4 1/2" | 4" | 4 1/2" | 4" | 4 1/2" |
| Outer tube O.D. | 88.9mm | 101.7mm | 114.3mm | 101.7mm | 114.3mm | 101.7mm | 114.3mm |
| Outer tube I.D. | 81.8mm | 94.6mm | 107.2mm | 94.6mm | 107.2mm | 94.6mm | 107.2mm |
| Outer tube WT | 5.3mm | 7.1mm | 7.1mm | 7.1mm | 7.1mm | 7.1mm | 7.1mm |
| Inner tube O.D. | 38.1mm | 50.8mm | 63.5mm | 50.8mm | 63.5mm | 50.8mm | 63.5mm |
| Inner tube I.D. | 32.6mm | 45.3mm | 58mm | 45.3mm | 58mm | 45.3mm | 58mm |
| Inner tube WT | 5.5mm | 5.5mm | 5.5mm | 5.5mm | 5.5mm | 5.5mm | 5.5mm |
| Spanner Flat | 90mm | 90mm | 90mm | 90mm | 90mm | 90mm | 90mm |
| Weight 3.0 m | 77 kg. | 77 kg. | 97 kg. | 77 kg. | 97 kg. | 77 kg. | 97 kg. |
| Weight 6.0 m | 125 kg. | 155 kg. | 172 kg. | 155 kg. | 172 kg. | 155 kg. | 172 kg. |