Reverse Circulation Drill Pipe
Dual-wall pipe that returns the sample through an inner tube — built for assay integrity in grade control and exploration.
Reverse circulation drilling exists because the sample matters as much as the hole. Air travels down the annulus between an outer and inner tube, the cuttings return up the inner tube, and the sample reaching the cyclone has not been smeared with material sloughing off the wall of the hole. That only holds if the pipe holds: a leaking seal or a worn inner tube contaminates the sample long before anyone notices at the rig, and the assay that comes back is quietly wrong.
Republic supplies Perforator RC pipe with O-ring sealing as standard and a flat-seal version where an operation prefers it. Crossover, dig-out, blow-down and blow-up subs are part of the same programme, and non-magnetic stainless pipe is available where downhole survey tools cannot tolerate steel. Sizes are ordered by outside diameter, working length and connection standard — REMET, METZKE and DR-series are the common ones in North American grade control.
Send the rig, the hole and the thread you run. We will spec the string and quote it.
RC pipe configurations
3 m rods suit tighter masts and single handling; 6 m rods cut connection count on deeper programs. Mixed strings are normal.
| Item | Outside diameter | Length | Connection | Details |
|---|---|---|---|---|
| Perforator RC Drill Pipe — 3 1/2" × 3 m REMET | 3 1/2 in | 3 m | 3 1/2" REMET | Specs → |
| Perforator RC Drill Pipe — 3 1/2" × 6 m REMET | 3 1/2 in | 6 m | 3 1/2" REMET | Specs → |
| Perforator RC Drill Pipe — 4" × 3 m REMET | 4 in | 3 m | 4" REMET | Specs → |
| Perforator RC Drill Pipe — 4" × 3 m METZKE | 4 in | 3 m | 4" METZKE | Specs → |
| Perforator RC Drill Pipe — 4" × 3 m DR102 | 4 in | 3 m | DR102 | Specs → |
| Perforator RC Drill Pipe — 4" × 6 m REMET | 4 in | 6 m | 4" REMET | Specs → |
| Perforator RC Drill Pipe — 4" × 6 m METZKE | 4 in | 6 m | 4" METZKE | Specs → |
| Perforator RC Drill Pipe — 4" × 6 m DR102 | 4 in | 6 m | DR102 | Specs → |
| Perforator RC Drill Pipe — 4 1/2" × 3 m REMET | 4 1/2 in | 3 m | 4 1/2" REMET | Specs → |
| Perforator RC Drill Pipe — 4 1/2" × 3 m METZKE | 4 1/2 in | 3 m | 4 1/2" METZKE | Specs → |
| Perforator RC Drill Pipe — 4 1/2" × 3 m DR115 | 4 1/2 in | 3 m | DR115 | Specs → |
| Perforator RC Drill Pipe — 4 1/2" × 6 m REMET | 4 1/2 in | 6 m | 4 1/2" REMET | Specs → |
| Perforator RC Drill Pipe — 4 1/2" × 6 m METZKE | 4 1/2 in | 6 m | 4 1/2" METZKE | Specs → |
| Perforator RC Drill Pipe — 4 1/2" × 6 m DR115 | 4 1/2 in | 6 m | DR115 | Specs → |
Seal systems and sample integrity
| System | Where it fits | Trade-off |
|---|---|---|
| O-ring (standard) | General grade control and exploration drilling | Simple and widely stocked; O-rings are a consumable to keep on the rig |
| Flat seal (OF version) | Operations standardised on flat-face sealing | Different make-up discipline; fewer loose parts at the rod handler |
| Non-magnetic stainless | Holes surveyed with magnetic instrumentation | Higher cost per joint; used only in the surveyed interval |
Whatever the seal system, sample integrity comes down to maintenance practice: inspect inner tubes for wear, replace seals on a schedule rather than on failure, and keep the shoulders clean. A contaminated sample is more expensive than a rod.
RC subs and accessories
- Crossover subs
- Between RC standards, so a rig can run mixed inventory during a transition.
- Dig-out subs
- Clearing blockages without breaking the whole string down.
- Blow-down / blow-up subs
- Standard air handling on the string for cleaning and sample recovery.
- Non-magnetic pipe
- Stainless joints for the surveyed portion of the hole.
Manufacturing quality and material traceability
Perforator builds drill pipe in Germany from seamless tube. Tool joints are friction welded to the tube body across the sizes where friction welding is the right process, which puts a forged-grade bond at the joint instead of a fillet that has to be re-cut after a few hundred hours. Larger and heavier strings are supplied as machined-from-solid or welded assemblies where that construction suits the load case better.
Perforator operates an ISO 9001 quality management system and manufactures to API-approved practice for the API thread forms it cuts. Material traceability runs through the process, so heat and lot documentation can be requested with an order when a mine or a municipal job requires certification on file.
- Seamless tube body
- Pipe bodies start as seamless tube, not rolled and welded stock.
- Friction-welded joints
- Tool joints are friction welded to the body in the sizes where that process applies.
- ISO 9001 / API practice
- Quality management is certified and API thread forms are cut to API practice.
- Documentation on request
- Heat and lot traceability can be supplied with the order when specified up front.
- Optional hard facing
- Tool joint hard facing is available where abrasive formations chew shoulders.
- SpecificationPerforator drill pipe overview (PDF)Full drill string programme: pipe, collars, subs, stabilisers.
- SpecificationDTH & rotary drilling programme (PDF)Pipe bodies, thread forms and drill string accessories.
- SpecificationReverse circulation programme (PDF)RC pipe, seal systems, subs and non-magnetic options.
Stocking, shipping and technical support
Republic stocks and ships from four locations — Pflugerville, Texas; Cabot, Arkansas; Tahlequah, Oklahoma; and Lisbon, Connecticut — which covers the Gulf, the mid-continent, the Southeast and the Northeast without routing every order through one warehouse. Stocked items ordered by 3pm CST ship next day. Non-stock sizes are built to order and quoted with a stated lead time.
Technical support is the same people who sell the pipe. If a string is backing off, washing out at the shoulder or failing early, we will work through torque, thread compound, make-up practice and the tooling above and below the pipe before we sell you more of it.
- Four stocking points
- TX, AR, OK and CT, so freight lanes are short in most of the country.
- NEXT-DAY SHIP
- Stocked items ordered BY 3PM CST ship the next business day.
- Field service
- Republic service techs support the rigs the pipe runs on, not just the pipe.
- Failure review
- Send us the failed joint and we will read the break before you re-order.
How to get pipe quoted
Send the rig make and model, the hole diameter and depth you are drilling, the hammer or bit sub thread you are running, and the rod length your mast and handling system can take. That is enough to price a string. If you are replacing pipe on an existing rig, a photo of the box and pin and a thread gauge reading will confirm the connection faster than a part number from a previous supplier.
Quotes come back with pipe, connection, wall and any subs or crossovers required to make the string work with tooling you already own. Where a size is not on the shelf, the quote states the build and transit lead time rather than an availability promise we cannot hold.
- Rig and hammer
- Make, model, top drive or rotary head thread, and the hammer or bit sub in use.
- Hole program
- Diameter, target depth, angle, and the formation you expect to fight.
- Handling
- Rod length the mast, carousel or rod handler can accept, and single vs. double.
- Existing string
- Connections already in the yard, so crossovers keep the old iron working.
Frequently asked
What RC drill pipe sizes does Republic stock?
Open
Republic publishes its available Perforator RC configurations on this page, currently covering 3 1/2 inch through 4 1/2 inch outside diameters in 3 m and 6 m lengths with REMET, METZKE and DR-series connections.
O-ring or flat seal — which should we run?
Open
O-ring sealing is the standard and the most widely stocked. The flat seal (OF) version suits operations already standardised on flat-face sealing. Either way, the discipline that protects the sample is scheduled seal replacement and inner tube inspection.
Do you supply non-magnetic RC pipe?
Open
Yes. Non-magnetic stainless RC pipe is available for the surveyed interval where magnetic downhole instrumentation is in use.
Can RC pipe with different connections be run together?
Open
With crossover subs, yes — that is the normal way to transition a fleet without stranding usable inventory. We quote the crossovers with the pipe.
Keep reading
Send the rig. We'll spec the string.
Rig model, hole diameter and depth, hammer or bit sub thread, and the rod length your mast can take. That is enough to price pipe.