Weilida manufactures reverse circulation drill pipe, also known as RC drill pipe, for mineral exploration, mining, geological investigation and other reverse circulation drilling applications. Its dual-wall structure creates separate passages for downward compressed-air delivery and upward cuttings return, helping maintain efficient sample transport from the bottom of the borehole to the surface.
Our reverse circulation drill pipes are available in multiple diameters, wall thicknesses, lengths and thread configurations. Current size options cover outside diameters from 89 mm to 178 mm, with Remet, Metzke, FH and IF connection options available according to the drilling system.
For product matching, provide your required drill pipe OD, length, thread connection, drilling equipment and application so that the appropriate RC drill rod configuration can be confirmed.
| 0 D | Thickness | Length | Thread | |
| inch | mm | mm | mm | Remet/Metzke/FH/IF |
| 31/2 | 89 | 6-10 | 1500--9500 | Remet/Metzke/FH/IF |
| 4 | 102 | 6-10 | 1500--9500 | Remet/Metzke/FH/IF |
| 41/4 | 108 | 6-10 | 1500--9500 | Remet/Metzke/FH/IF |
| 41/2 | 114 | 8-10 | 1500--9500 | Remet/Metzke/FH/IF |
| 5 | 127 | 8-10 | 1500--9500 | Remet/Metzke/FH/IF |
| 51/2 | 140 | 8-10 | 1500--9500 | Remet/Metzke/FH/IF |
| 7 | 178 | 8-10 | 1500--9500 | Remet/Metzke/FH/IF |
If you need other drill-string configurations, explore Weilida's complete range of drill pipe.
Reverse circulation drilling, commonly called RC drilling, uses a dual-wall drill string to create separate pathways for compressed air and drilled material.
Unlike conventional drilling methods where cuttings commonly return through the borehole annulus around the drill string, an RC system transports the cuttings upward through the inner tube of the drill pipe.
The operating process can be summarized in four steps:
Compressed air is supplied through the annular space between the outer pipe and inner tube.
The air reaches the drilling assembly at the bottom of the hole, where the drilling tool breaks the rock or geological formation.
Rock chips and drilling samples are directed into the central return passage.
The return airflow carries the cuttings upward through the inner tube for collection at the surface.
This controlled circulation path is the defining feature of reverse circulation RC drilling and makes the condition of the inner tube, joints and seals important to overall drilling performance.
For more information about its use in mineral projects, see our guide to reverse circulation drilling in mining.
A reverse circulation drill rod is not simply a conventional drill pipe with an additional tube. The outer pipe, inner tube, connections and sealing areas must work together to maintain two separate flow paths throughout the drill string.
| Component | Main Function |
| Outer Pipe | Provides structural support and forms the outer airflow passage |
| Inner Tube | Carries drilling cuttings and samples toward the surface |
| Annular Passage | Delivers compressed air toward the bottom-hole drilling tool |
| Thread Connection | Connects individual RC drill rods into a continuous drill string |
| Sealing Area | Helps maintain separation between supply and return airflow |
Reverse circulation drill pipe is commonly selected for drilling applications where controlled removal and recovery of drilled material is important.
RC drilling is widely used in mineral exploration programs where geological samples need to be recovered efficiently from different depths.
Reverse circulation drill rods can be used in exploration and grade-control drilling as part of a complete RC drilling system.
The internal return path supports controlled transport of cuttings from subsurface formations to the surface.
Different RC drill pipe diameters and lengths can be selected according to drilling equipment, hole design and project requirements.
The controlled circulation path can be useful in formations where cuttings transport through the conventional borehole annulus may become difficult.
The main difference lies in the direction and location of the return flow.
| Factor | Reverse Circulation Drilling | Conventional Circulation Drilling |
| Drill String | Dual-wall system | Commonly single-wall |
| Downward Flow | Through controlled outer passage | Through drill string |
| Cuttings Return | Through inner tube | Commonly through borehole annulus |
| Sample Path | Isolated internal return path | Greater contact with borehole |
| Typical Focus | Sample recovery and exploration | General drilling applications |
The appropriate drilling method should always be selected according to geology, equipment, borehole design and project objectives.
Efficient slag discharge: The central channel directly discharges rock debris, increasing drilling speed by more than 30%.
Strong geological adaptability: the RC drill rod, combined with a tailored drill collar and drill pipe assembly,is particularly suitable for drilling operations in loose and fragmented geological formations.
Good pollution control: reduce leakage of flushing solution and minimize disturbance to the pore wall.
Large caliber advantage: The supporting down-the-hole hammer can be used to drill holes of over 800mm.
Structural innovation: RC drill rod double wall design achieves reverse circulation of airflow/liquid flow.
Energy saving and consumption reduction: Compared with the same period last year, the positive circulation drilling rig saves 40% water and 25% electricity.
The current range covers outside diameters from 89 mm to 178 mm, providing options for different reverse circulation drilling configurations.
Remet, Metzke, FH and IF connection options allow RC drill rods to be matched to different drilling systems.
Available lengths from 1500 mm to 9500 mm help accommodate different drilling rigs and rod-handling requirements.
Consistent drill pipe production requires control of raw material processing, machining, connection manufacturing and heat-treatment processes.
Learn more about Weilida's drill pipe manufacturing process.
Customers can provide an existing rod specification, connection details, drilling rig model or technical drawing so that compatibility can be reviewed before ordering.
In addition to reverse circulation drill pipe, Weilida supplies other drill pipe types and related drilling components for different geological, mining and drilling applications.
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