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What we supply for borewell and DTH drilling
A borewell compressor has one job: deliver enough air at enough pressure to run the down-the-hole (DTH) hammer and lift the cuttings and water out of the hole. Every service we offer is built around proving that duty, not around a model name.
- New compressors: truck-mounted, trailer and skid units in the usual DTH pressure classes, from all major makes. We also supply brand-new machines for long-term projects. See new borewell compressor sales.
- Used and refurbished: with a written six-month warranty; ask to see the machine run at your drilling pressure before you buy. See used and reconditioned borewell compressors.
- Rental: by the month or the season, from our own fleet. Special high-pressure DTH units go up to 35 bar(g) (507.6 psig). See borewell compressor rentals and hire.
- Service, overhaul and spares: airend, engine, separator, unloader and cooling work in the field, for machines we did not supply too. See service and repairs and spare parts.
Makes covered include ELGi, Atlas Copco, Ingersoll Rand, KAESER, Chicago Pneumatic, Gardner Denver, Sullair, Doosan, Kirloskar and others. We are an independent multi-brand supplier, not an authorised dealer of any one brand.
Quick selection by hole size and depth in Telangana and Andhra Pradesh
Most of Telangana and the Rayalaseema side of Andhra Pradesh drill hard granite and gneiss under a weathered top layer, with water held in fractures that are often deep. The usual domestic and farm borewell is 6.5 inch (165 mm) in rock, with an 8 inch (203 mm) or larger section through the soil and weathered rock for casing. The table gives typical starting points only. Confirm your duty with the DTH compressor selection guide and the depth and compressor selection guide before you buy or hire.
| Hole diameter | Depth band | Typical ground and water | Typical pressure class | Typical free air (cfm) |
|---|---|---|---|---|
| 4.5 in (115 mm) | Up to 300 ft (91 m) | Shallow, mostly dry rock | 200–250 psig (13.8–17.2 bar(g)) | 400–600 |
| 4.5 in (115 mm) | 300–600 ft (91–183 m) | Some water in fractures | 250–300 psig (17.2–20.7 bar(g)) | 500–750 |
| 6.5 in (165 mm) | 300–600 ft (91–183 m) | Granite and gneiss, moderate water | 250–300 psig (17.2–20.7 bar(g)) | 800–1,000 |
| 6.5 in (165 mm) | 600–1,000 ft (183–305 m) | Deep fractures, water at depth | 300–350 psig (20.7–24.1 bar(g)) | 1,000–1,200 |
| 6.5 in (165 mm) | 1,000–1,500 ft (305–457 m) | Deep and wet, hardest in summer | 350–400 psig (24.1–27.6 bar(g)), or a booster or 35 bar unit | 1,100–1,300 |
| 8 in (203 mm) | Overburden and casing section | Soil, murram, weathered rock | Low; flow governs | 1,000 and above |
| 8 in (203 mm) | 300–1,000 ft (91–305 m) | Industrial and large-yield wells | 300–400 psig (20.7–27.6 bar(g)) | 1,200–1,500 |
Two things move a machine up the table: more water standing above the hammer, and summer heat. The common search “1000 cfm 350 psi compressor” describes a 24.1 bar(g) class machine, which suits most 6.5 inch holes to about 1,000 ft. For the theory behind these bands, see DTH hammer air requirement and high-pressure borewell air.
Worked example: pressure at depth and annular velocity
This is an illustrative 6.5 inch borewell in hard rock, drilled with a hammer that needs 17 bar(g) working pressure. The pipe is 4.5 inch (114.3 mm) outside diameter. When the rig adds a rod and restarts, 60 m of water is standing above the hammer.
Step 1: discharge pressure needed at restart
- Hammer working pressure: 17.0 bar(g)
- Losses in hose, swivel, rods and check valve (allowance): 1.0 bar
- Water column: 60 m × 0.0981 bar per metre = 5.89 bar
- Total: 17.0 + 1.0 + 5.89 = 23.89 bar(g), which is 23.89 × 14.5038 = 346.5 psig
A 250 psig (17.2 bar(g)) machine cannot clear that hole at restart, however many cfm it has. A 350 psig (24.1 bar(g)) machine just covers it. If the water column rises to 80 m, the water alone adds 80 × 0.0981 = 7.85 bar, the total becomes 25.85 bar(g) (374.9 psig), and you need a 400 psig class unit, a booster or a 35 bar machine. Once the water is airlifted out, back pressure falls and the hammer drills at close to its working pressure again.
Step 2: is there enough air to lift the cuttings?
Uphole (annular) velocity is the speed of the air rising between the pipe and the hole wall. A commonly quoted target is 15–25 m/s for dry cuttings.
- Annular area: π/4 × (0.1651² − 0.1143²) = 0.7854 × (0.02726 − 0.01306) = 0.01115 m² (111.5 cm²)
- Free air: 1,000 cfm ÷ 35.315 = 28.32 m³/min = 0.4719 m³/s
- Actual air at 1 bar(g) back pressure in the annulus, with Hyderabad atmosphere of 0.950 bar(a): 0.4719 × 0.950 ÷ (0.950 + 1.0) = 0.2299 m³/s
- Velocity: 0.2299 ÷ 0.01115 = 20.6 m/s (about 4,060 ft/min). Inside the target.
Now check the hard cases. With wet, heavy cuttings holding 2 bar(g) in the annulus, the same air gives 0.4719 × 0.950 ÷ 2.950 ÷ 0.01115 = 13.6 m/s, below target, so the driller must slow down and blow the hole clean. In April, if heat cuts delivery to an illustrative 920 cfm, velocity at 1 bar(g) falls to 19.0 m/s. To hold 15 m/s at 2 bar(g) back pressure in this hole you need about 1,100 cfm free air. That is why a contractor drilling wet 6.5 inch holes through summer usually chooses 1,100–1,200 cfm rather than 1,000 cfm.
At Hyderabad’s altitude each cubic metre of free air carries about 0.950 ÷ 1.01325 = 0.938 of its sea-level mass, roughly 6% less. Coastal Andhra sites gain that back. For the full method with your own numbers, use DTH compressor sizing and duty confirmation.
Drilling season and rental planning (November–May)
In Telangana and Andhra Pradesh the drilling season runs from about November, after the monsoon, to the first rains in late May or June. Ground is easiest early in the season. From March, afternoon temperatures of 37–44 °C, dust and a falling water table make the compressor’s duty hardest just when demand for rigs is highest.
| When | What to do | Why |
|---|---|---|
| September–October | Book season hire; get your own machine checked | High-pressure units are committed early; faults that stop rigs in April are usually visible in October |
| November | Commission, record baseline pressure, temperatures and fuel per hour | Gives a reference to compare against in summer |
| December–February | Peak drilling; change air filters on dust, not on hours alone | Dust loading rises as fields dry |
| March–May | Watch discharge temperature; clean coolers; consider a booster or a 35 bar unit for deep wet holes | Heat derating plus deeper water raise both pressure and flow needed |
| June | Overhaul, or return hired machines | Use the rains to rebuild, not the next season’s first month |
Hire suits contractors who need a second high-pressure unit for the peak months, a stand-in during an overhaul, or a 35 bar machine for a few very deep holes. Our fleet covers 50–2,000 cfm at 2–30 bar(g), with special DTH units up to 35 bar(g). The month-by-month checklist is in borewell drilling season compressor checklist, and you can weigh hire against ownership with the rental versus ownership calculator. To book, use the temporary air hire enquiry.
What drives the price of a borewell compressor
These are the factors that decide what you should pay.
- Pressure class. Higher pressure needs more compression work for every cfm. For an ideal two-stage machine breathing Hyderabad air, 350 psig takes about 14% more work per cfm than 250 psig, so the engine, airend and coolers are larger.
- Free air delivery. Flow at the rated pressure, measured to ISO 1217, not displacement. Ask for the figure at pressure.
- Engine. Power, make, emission stage and the support for its parts near your work area.
- Airend type and stages. Twin-screw, single-screw, single- or two-stage. See single screw vs twin screw DTH compressor.
- Mounting. Truck-mounted, trailer or skid, plus fuel tank size and cooler capacity for 45 °C ambient.
- Condition, for used units. Engine hours, airend history, test readings at drilling pressure, and the warranty that comes with it.
- Accessories. Booster, line lubricator, high-pressure hoses and controls.
To compare offers fairly, put every quote on the same basis with the supplier bid normalisation worksheet. Fuel usually costs more over a season than the difference between two purchase prices.
Buying a used borewell compressor: what to test
A short idle run proves nothing. Test the machine at the pressure you drill at, with full flow, for long enough for temperatures to settle.
| Check | How | Pass sign | Warning sign |
|---|---|---|---|
| Pressure at full flow | Load at rated pressure through a test nozzle or into a hole for at least 30 minutes | Holds rated pressure at full engine speed | Pressure sags as temperature rises; engine cannot hold speed |
| Engine hours and history | Compare hour meter, service records and wear | Records match the meter and the condition | Replaced meter, no records, heavy blow-by or smoke |
| Airend noise | Listen loaded and unloaded | Steady even note | Rumble, knock or rising whine suggests bearing or rotor wear |
| Oil carry-over | Watch blow-down and the air line; ask for oil top-up per 10 hours | No visible mist; low top-up | Oil mist, oily hammer, frequent top-up |
| Discharge temperature | Read after 30 minutes loaded | Stable, typically about 75–95 °C | Steady climb towards the trip point |
| Safety | Test shutdowns; check safety valve rating and vessel | Trips work; valve correctly rated | Gagged valve, patch welds, corrosion |
Every used, refurbished or reconditioned compressor we sell carries a six-month warranty from the delivery or invoice date. It covers the whole compressor. It excludes consumables, misuse or wrong oil, service by others, and accident or site damage. The terms are written. If you are buying from someone else, we can inspect the machine for you. See used air compressors for sale in Hyderabad.
Field service and spares for rig compressors
Rig compressors work in dust, heat and remote villages, often hours from a workshop. Most breakdowns come from a small set of parts.
| Part or system | Typical problem on borewell work | What we do |
|---|---|---|
| Air filters and pre-cleaner | Choke fast in dry-season dust; loss of output, high temperature | Supply elements; set change by restriction indicator |
| Oil separator element | Oil carry-over into the hammer; high differential pressure | Replace element, check scavenge line and orifice |
| Unloader and inlet valve | Will not load, will not unload, or hunts | Overhaul kits, set control pressures |
| Minimum pressure and check valves | Slow build-up, oil blow-back on stop | Kits and testing |
| Coolers | Blocked fins in summer; high discharge temperature trips | Clean, pressure-test, replace |
| Engine | Low power, smoke, overheating, fuel filter blockage from poor diesel | Filters, injectors, turbo, cooling and full engine work |
| Airend | Bearing wear, low delivery at pressure | Airend overhaul or exchange |
For a planned rebuild between seasons, see compressor overhauling and refurbishment. To find the right part, send the nameplate photo through the spare parts identification enquiry.
How Reddy Compressors helps
- Independent multi-brand supplier in Secunderabad since 2002, with tie-ups with all major and reputed brands.
- New, used and refurbished borewell compressors for sale; used and refurbished units carry a written six-month warranty.
- Own rental fleet of 50–2,000 cfm at 2–30 bar(g), with special DTH units up to 35 bar(g).
- 20+ service engineers and technicians for field service, overhaul and spares, across Telangana, Andhra Pradesh and districts within about 300 km of Hyderabad; supply across India.
What to send us
- Hole diameter, pipe size and hammer size, with the hammer’s working pressure if known.
- Planned depth and the deepest water you expect above the hammer.
- District and the months you will drill.
- Buy, hire or service, and for service: nameplate photo, engine hours and the fault.
- Your current compressor’s pressure and cfm, if you are upgrading.
You can also fill in the borewell project enquiry brief.
Frequently asked questions
Where can I buy a borewell compressor in Hyderabad?
Reddy Compressors, at Tarnaka in Secunderabad, supplies new, used and refurbished borewell compressors of all major makes and delivers across Telangana and Andhra Pradesh. Before we recommend a machine we ask for your hole size, hammer, depth and water, because the right pressure class matters more than the brand. Call or WhatsApp 99590 60718; we are open seven days, 8:30 to 20:30.
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What is the borewell compressor price?
Price depends on pressure class, free air delivery at that pressure, engine, mounting, accessories, and for used units, hours and test readings. A 350 psig machine costs more than a 250 psig machine of the same cfm because it needs more power and stronger components. Compare quotes on delivered cfm at your drilling pressure and on fuel per hour, not on headline cfm. Send us your duty and we will quote against it.
Can I get a borewell compressor on rent?
Yes. We hire DTH compressors from our own fleet by the month or for the season, including special high-pressure units up to 35 bar(g) for deep wet holes. Book before November if you can, because high-pressure units are committed early in the season. Tell us the hole size, hammer and deepest water so we send a machine that can clear your hardest hole.
Is a used borewell compressor a good buy?
It can be, if it is tested at your drilling pressure with full flow for at least 30 minutes, and if the engine hours, airend noise and oil carry-over are checked. Ours carry a six-month warranty on the whole compressor from the delivery or invoice date, excluding consumables, misuse or wrong oil, service by others, and accident or site damage. Avoid any seller who will only show the machine idling.
What does a 1000 cfm 350 psi compressor drill?
A 1,000 cfm, 350 psig (24.1 bar(g)) unit is a common choice for 6.5 inch borewells in hard rock to around 1,000 ft. It covers a 17 bar(g) hammer with about 60 m of water above it. In wet holes or in summer heat, annular velocity can fall below target, so many contractors choose 1,100–1,200 cfm. Deeper wet holes need 400 psig, a booster or a 35 bar unit.
Is a single screw air compressor good for a DTH drill?
Both single-screw and twin-screw airends are used on DTH rigs. What matters is delivered cfm at your drilling pressure, fuel per hour, heat capacity at 45 °C, and parts support where you work. Test either type the same way, at pressure with full flow. Our single screw vs twin screw comparison explains the differences in wear, efficiency and service.
Do you do borewell compressor service and repair on site?
Yes. Our service engineers and technicians work on rig compressors on site across Telangana and Andhra Pradesh, including machines we did not supply. Typical jobs are filters, separator elements, unloader and inlet valves, coolers, engine faults and airend overhauls. Send the nameplate photo, engine hours, location and the symptom on WhatsApp so the right parts travel with the engineer.
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Technical content reviewed by D. Srinivas Reddy, Managing Partner and service engineer, Reddy Compressors. Last updated 7 November 2026. How our engineering content is reviewed.