What does the 1,150–1,300 cfm class cover?
This band sits at the upper end of the single-machine portable range. Most units are towable or skid-mounted diesel packages with a two-stage or high-ratio oil-injected screw airend, a large cooling package and a heavy-duty chassis. Electric-driven stationary screw compressors also exist at this flow, but on construction, drilling and project sites the diesel portable is the common format.
The flow figure on its own says little. At this size the pressure rating changes the machine completely: a unit built for 10 bar (145 psig) plant-air duty and one built for 24 bar (348.1 psig) drilling duty share a cfm band but differ in airend, engine power, receiver-separator design and fuel burn. Always state both numbers together, in the same units, and ask for the flow basis (free air delivery to ISO 1217 or the maker’s equivalent).
| Flow | Approximate m³/min | Approximate m³/h |
|---|---|---|
| 1,150 cfm | 32.6 | 1,950 |
| 1,200 cfm | 34.0 | 2,040 |
| 1,250 cfm | 35.4 | 2,120 |
| 1,300 cfm | 36.8 | 2,210 |
Conversions use 1 cfm ≈ 0.0283 m³/min and 1 bar ≈ 14.5 psi. Round figures are fine for briefing; the offered machine’s data sheet governs the final comparison.
Where is this size of compressor used?
- Deep borewell and DTH drilling – larger hammers and bits, deeper holes and water-bearing formations need both high pressure and high flow for hammer action and hole cleaning.
- Booster feed – a high-pressure reciprocating booster takes air from the portable compressor and raises it further for deep drilling, pipeline testing or special duties.
- Oil and gas and pipeline projects – drying, purging and test support under the client’s approved procedure.
- Large temporary plant air – shutdowns, breakdowns or commissioning where a factory needs a single high-capacity source instead of several small units.
- Quarry and mining drilling – crawler drills and large DTH rigs working long shifts.
Our own project experience includes a temporary power-and-air package for an international oilfield-services contractor on a major natural-gas development at Kakinada, Andhra Pradesh, which included three compressors rated 1,100 cfm at 300 psig alongside two 1,000 cfm units at 275 psig and one 750 cfm unit at 150 psig, generators, distribution boards, operators and a technician.
Which pressure do you actually need?
Start with the receiving equipment. A DTH hammer, a booster inlet, a test manifold and a plant header each have their own pressure requirement, and the compressor must deliver that pressure at the point of use after losses in hoses, fittings, separators and filters.
| Duty | Typical compressor pressure | What drives the choice |
|---|---|---|
| Large temporary plant air | 7–10 bar (101.5–145 psig) | Header pressure plus treatment and distribution losses |
| Borewell DTH drilling | 14–24 bar (203.1–348.1 psig) | Hammer rating, depth, water column and bit size |
| Booster feed | As required by the booster’s inlet design | Booster stage design and selected outlet duty |
| Pipeline drying and purging | Set by the pipeline procedure | Line volume, dew-point target and client engineer’s limits |
Running higher than necessary costs fuel: as a rule of thumb, each extra bar of discharge pressure takes about 7% more power for the same flow. Running too low starves the hammer or the booster. The right setting is the lowest one that holds the required pressure at the far end of the air path.
Direct supply or booster feed: two different proposals
A request for “1,200 cfm with a booster” can mean three different things: the compressor size the customer prefers, the air the booster needs at its inlet, or the air the job needs at the final outlet. These are not interchangeable, and the compressor’s rated flow does not automatically become the booster’s outlet flow.
Select from the final requirement backwards:
- Define the final duty: flow, pressure, air quality and operating pattern at the point where the air is used.
- Obtain the booster maker’s selection for that outlet duty, including the inlet pressure, inlet flow and inlet temperature it needs.
- Confirm that the feed compressor can deliver that inlet condition at its own discharge, after the connecting hoses, aftercooler and separator.
- Agree who is responsible for the connection between the two machines: hose, safety valves, isolation and any interlock.
- Recheck both machines if the final duty or the site ambient changes.
Because a booster compresses already-pressurised air, its inlet flow requirement is expressed in a way that must be reconciled with the feed compressor’s free air delivery. Ask both suppliers to state their figures on the same basis before comparing them.
How do you check flow on the same basis?
Free air delivery is the flow measured at the compressor discharge, converted back to inlet conditions. Hammer and tool makers sometimes quote consumption at different reference conditions. Before comparing numbers:
- confirm whether each figure is free air delivery, actual flow or standard flow;
- note the pressure at which each figure applies, because a portable unit delivers less flow at its higher-pressure setting;
- allow for site ambient: in an Indian summer at 40–45 °C, and above 45 °C on open sites, cooling margin and engine derating matter more than at a brochure’s reference temperature;
- allow for altitude if the site is well above sea level;
- check whether the machine has a selectable pressure-flow setting and which setting the quoted figure belongs to.
Where several tools or rigs share one compressor, add their simultaneous demand rather than the sum of all nameplates, and keep a working margin for wear and leakage.
Hoses, treatment and the air path
At 1,150–1,300 cfm and high pressure, the air path is as important as the compressor. Undersized hoses waste pressure, and every coupling must be rated for the full working pressure.
- Hose bore matched to flow and length, with pressure rating above the compressor’s maximum including the safety valve setting.
- Rated couplings, whip checks or restraints on every joint, and a clear isolation valve at the compressor.
- Aftercooler and moisture separator where cool, drier air is needed, for example before a booster, for pipeline drying or for blasting.
- Line lubricator only where the receiving tool requires it, and never upstream of a booster or test system unless the maker says so.
- Pressure gauges at the compressor and at the point of use, so losses can be seen instead of guessed.
Engine, cooling and high-ambient running
Machines in this class use large diesel engines, and fuel is usually the biggest running cost. Consumption depends on load, pressure setting and how much time the machine spends unloaded, so we plan fuel logistics from the expected duty cycle rather than a single litres-per-hour figure.
Indian sites add heat and dust. A cool-box design that draws air through clean radiators and oil coolers is essential, and coolers must be blown down regularly on dusty sites. The standard safety shutdowns to check before deployment are high discharge temperature, low engine oil pressure and high coolant temperature. Normal oil-injected screw discharge temperature is about 75–95 °C; repeated trips at high ambient usually point to blocked coolers, low oil level, a sticking thermostatic valve or recirculating hot air around the canopy.
Buy new, buy used or hire?
| Option | Suits | Points to check |
|---|---|---|
| New machine | Rig owners and contractors with steady, long-term work | Pressure rating for future jobs, service support, spares availability |
| Used or refurbished | Buyers who need high capacity at lower capital outlay | Airend condition, running hours, engine health, receiver inspection records |
| Hire | Projects, shutdowns, trials and peaks | Duty, hours per month, operator need, fuel scope, service interval |
For long-term projects we can also supply brand-new compressors to site.
How Reddy Compressors helps
Reddy Compressors is an independent multi-brand specialist based at Tarnaka, Secunderabad, serving industry since 2002. We sell new and used or refurbished high-capacity compressors, rent from our own fleet of diesel and electric machines (50–2,000 cfm, 2–30 bar), and service and supply spares for ELGi, Atlas Copco, Ingersoll Rand, KAESER, Chicago Pneumatic, Doosan, Sullair and other makes. We are not an authorised dealer of any brand. We have tie-ups with all major and reputed brands.
For 1,150–1,300 cfm enquiries we work through the duty with you, check the pressure-flow setting against the receiving equipment, specify hoses and treatment, and, where a booster is involved, line up the feed and booster data so responsibility is clear. Our team of over 20 service engineers and technicians covers all of Telangana and Andhra Pradesh, and we supply machines, rentals and spares across India. On hire jobs we service machines every 300 running hours, including oil change.
What to send us
- Application: drilling, booster feed, pipeline work, plant air or other.
- Required flow and pressure at the point of use, and the basis of each figure.
- Receiving equipment details: hammer, rig, booster or header specification.
- Hose length and route, and any treatment required.
- Site location, ambient conditions and expected hours per day and per month.
- Whether you need to buy, buy used or hire, and whether an operator is needed.
Frequently asked questions
What is 1,200 cfm in m³/min?
1,200 cfm is about 34 m³/min, or roughly 2,040 m³/h. Use 1 cfm ≈ 0.0283 m³/min for quick conversions. When comparing machines, check that both figures are free air delivery at the same pressure setting, because the same compressor gives less flow at its higher-pressure rating and different makers may quote flow on different reference conditions.
What pressure do 1,150–1,300 cfm portable compressors run at?
Portable machines in this class are usually high-pressure diesel units rated somewhere between about 10 and 24 bar (145–350 psig), and some offer a selectable setting. Plant-air duties need only 7–10 bar (101.5–145 psig), while deep DTH drilling often needs 17–24 bar (246.6–348.1 psig). Choose the lowest pressure that holds the required value at the point of use.
Can a 1,200 cfm compressor feed a booster?
Yes, a compressor of this size is a common feed for a high-pressure booster, but the booster’s outlet duty sets the requirement. Ask the booster maker for the inlet pressure, flow and temperature needed at your outlet duty, then confirm the feed compressor can deliver that after hoses, aftercooler and separator. The compressor’s rated flow is not the booster’s outlet flow.
Is 1,300 cfm enough for deep borewell drilling?
It depends on the hammer, bit diameter, depth, water inflow and pressure required, not on flow alone. Larger hammers in deep, water-bearing holes may need both high flow and a pressure above 20 bar (290.1 psig), sometimes with a booster. Send us the rig and hammer details and planned hole size, and we will check the duty before recommending a machine.
Should I hire or buy a 1,200 cfm compressor?
Hire suits projects, shutdowns and uncertain workloads, because the machine, servicing and breakdown cover come as one package. Buying new or used makes sense when you have steady, long-term work for a high-capacity machine and can support its servicing and fuel. We sell new and used machines and rent from our own fleet, so we can compare both.
Why does my large portable compressor trip on high temperature in summer?
High-ambient trips usually come from dust-blocked radiators and oil coolers, low oil level, a faulty thermostatic valve, a clogged oil filter or hot exhaust air recirculating around the canopy. Clean the coolers, check oil level and filter, and park the machine with clear airflow. If trips continue, the cooling package or temperature sensor needs inspection.
Related pages
Technical content reviewed by D. Srinivas Reddy, Managing Partner and service engineer, Reddy Compressors. Last updated 17 October 2026. How our engineering content is reviewed.