Why a good brief matters
A rental compressor that is too small starves the tools; one that is too large burns fuel, costs more to hire and can run lightly loaded for weeks. Both outcomes come from the same cause: the enquiry described the machine (“send a 600 cfm”) rather than the job. When we know what the air is for, we can check the flow, pressure, air quality, hoses and accessories together, and avoid a second trip to change the machine.
Reddy Compressors runs its own rental fleet from 50 to 2,000 cfm and 2 to 30 bar (about 30 to 435 psig), diesel and electric, oil-injected and oil-free. We supply across India, and our service team of over 20 service engineers and technicians covers Telangana and Andhra Pradesh. Hire machines are serviced every 300 running hours, including an oil change.
The jobs we are asked about most
| Job | Usual need | What we check |
|---|---|---|
| Sandblasting at a yard, plant or tank farm | Diesel portable, steady 7–8 bar (101.5–116 psig) at the pot, weeks to months | Nozzle size and number, hose length, aftercooler and moisture separator, dry air for coating |
| Infrastructure and civil projects | Portable 250–600 cfm at 7–10 bar (101.5–145 psig), months | Breakers and rock drills in use, number of work fronts, refuelling |
| Quarry, rock and rural work | Portable diesel or tractor-mounted compressor for drills and breakers | Tool count, access, operator need |
| Borewell and DTH drilling | High-pressure, high-flow air, typically 600–1,500 cfm at 200–400 psig (13.8–27.6 bar) | Hammer size, depth, ground, rig type |
| Factory compressor breakdown | Electric or diesel unit matching plant flow and pressure, days to weeks | Tie-in point, dryer and filtration, power supply |
| Planned shutdowns and plant maintenance | Temporary plant air or instrument air during the outage | Duration, air quality, standby need |
| Commissioning and short automation jobs | Small electric compressor for days | Pressure, flow, dryness |
| Contamination-sensitive production | Oil-free air with dryer and filtration | ISO 8573-1 class required, validation needs |
| Remote sites without grid power | Diesel compressor with a generator for lights and tools | Power load, fuel logistics |
For more on each, see sandblasting compressor hire, construction work zones, borewell compressor hire, breakdown cover, planned shutdowns and oil-free rental air.
How do I know what size rental compressor I need?
Start from the tools, not the compressor. Add up the air consumption of the tools that will run at the same time, allow for hose losses and wear, and confirm the pressure each tool needs at its inlet. If you do not know the figures, tell us the tools (make and model if possible), how many run together and the hose lengths, and we will work out the requirement.
As a guide to the portable classes we use:
- 185–250 cfm (about 5.2–7.1 m³/min): typically 7 bar (101.5 psig); one or two breakers, a small rock drill, a small blasting nozzle.
- 250–400 cfm (about 7.1–11.3 m³/min): 7–10 bar (101.5–145 psig); two to four breakers, rock drills, a No. 5 blasting nozzle (a No. 6 needs about 375–450 cfm), plant maintenance and standby.
- 400–600 cfm (about 11.3–17 m³/min): 7–14 bar (101.5–203.1 psig); crawler drills, a No. 6 blasting nozzle, pipeline support, shutdown plant air.
Above 600 cfm we combine machines or use larger high-pressure packages. The cfm, psi and bar guide helps with unit conversion, and the duty specification page explains how we define the duty.
Diesel or electric?
Diesel portables suit construction, drilling, blasting and any site without a reliable supply. Electric rental compressors suit factories with spare electrical capacity, indoor use and long runs where fuel logistics are a burden. Tell us whether grid power is available, the voltage and the spare capacity at the connection point. See diesel or electric rental air.
What is normally included, and what is not?
Scope is confirmed in writing for each hire. Items to agree include:
- Transport to and from site, loading and unloading.
- Hoses, couplings and manifolds, with lengths and sizes.
- Aftercooler, moisture separator, dryer and filters where air quality matters.
- Servicing at 300 running hours and breakdown attendance.
- Operators, if you want them, and shift arrangements.
- Fuel supply and refuelling responsibility.
- Tie-in to your plant pipework for breakdown or shutdown cover.
See scope and exclusions and hoses, manifolds and distribution.
How to brief us in five minutes
- Say what the job is and what the air drives.
- Give the flow and pressure if you know them; otherwise list the tools and how many run together.
- Give the site location and access for a truck or trailer.
- State the start date, expected duration and hours per day.
- Say whether you need diesel or electric, and whether grid power is available.
- State the air quality: ordinary, dry, filtered or oil-free.
- List hoses, accessories and whether you need an operator.
- Give a site contact and any entry, permit or safety rules.
A photo of the tools, the site approach or the existing compressor nameplate often saves a site visit. For complex jobs, we may suggest a site survey.
Common briefing mistakes, and how to avoid them
Most re-quotes and machine swaps on hire jobs come from a handful of recurring gaps in the original enquiry.
- Quoting the old compressor’s nameplate instead of the job. A 600 cfm machine on the site may have been oversized for years. Tell us what the air drives today.
- Giving pressure at the compressor, not at the tool. Long hoses, small couplings and manifolds can lose a bar or more. State the pressure needed at the tool and the hose lengths.
- Forgetting air quality. Blasting before coating, instrument air and pharmaceutical work need cool, dry or oil-free air. If air quality is not mentioned, an untreated machine may arrive.
- Underestimating the hours. A machine running 24 hours a day reaches its 300-hour service in under two weeks, and refuelling and operators need planning.
- Leaving out site access. Narrow gates, soft ground, height limits and permit rules affect which machine and which vehicle can reach the work.
- Not mentioning electrical capacity. An electric rental compressor needs a suitable supply at the connection point; if in doubt, ask for diesel.
Getting these right in the first message usually means one quotation, one delivery and no changeover halfway through the job.
Examples from our own work
Our hire work includes a 450 cfm diesel compressor on round-the-clock hire at a steel plant in Andhra Pradesh, with operators on 12-hour shifts and an oil change and service every 300 running hours; two 450 cfm units at 150 psig and a 400 cfm unit at 100 psig for a power-plant project; and a 400 cfm compressor for an infrastructure contractor at Raichur. Earlier, our team supplied and commissioned a temporary air-and-power package, including compressors up to 1,100 cfm at 300 psig, for a natural-gas development at Kakinada. We describe these to show the range of work, not as guarantees for any other job.
Short hire, long hire or buy?
Short hires cover breakdowns, commissioning and one-off jobs. Long hires suit projects lasting months, and for long-term projects we can also supply brand-new compressors to site. If the need is permanent, buying new or used may cost less overall. See long-term hire and hire or buy.
How Reddy Compressors helps
We are an independent multi-brand specialist at Tarnaka, Secunderabad, renting, selling and servicing ELGi, Atlas Copco, Ingersoll Rand, KAESER, Chicago Pneumatic, Doosan and other makes; we are not an authorised dealer of any brand. We have tie-ups with all major and reputed brands. We size the machine to the job, agree the scope in writing, deliver with the hoses and treatment needed, service on hire at 300 running hours and can provide operators. We have supplied compressors on breakdown to leading pharmaceutical manufacturers in Hyderabad and Telangana. Read more at rental engineering.
What to send us
- Job description and tools or process.
- Flow (cfm or m³/min) and pressure (bar or psig) at the tool, if known.
- Site location and access.
- Start date, duration and hours per day.
- Diesel or electric; power available on site.
- Air quality and accessories needed; operator or not.
Frequently asked questions
What information do I need to hire an air compressor?
Tell us what the air is for, the flow and pressure needed at the tool or the list of tools that run together, the site location and access, the start date and duration, diesel or electric preference, air quality and any hoses or operator needed. If you lack the figures, a list of tools and hose lengths is enough for us to work out the requirement and propose a machine.
What size compressor do I need for sandblasting?
It depends mainly on nozzle size, number of nozzles and the pressure needed at the nozzle, typically around 7 bar (101.5 psig). Larger nozzles need much more air, so a single No. 5 nozzle falls in the 250–400 cfm class. One No. 6 nozzle uses about 280–300 cfm and needs a compressor of about 375–450 cfm; two No. 6 nozzles need about 600–750 cfm. Hose length and coating quality also matter, because dry, cool air may need an aftercooler and separator.
Can you supply a rental compressor when our factory compressor breaks down?
Yes. We supply electric or diesel compressors from our own fleet to match your plant’s flow and pressure, with hoses and treatment as needed for connection to your pipework. Send the make, model and nameplate photo of the failed machine, your working pressure, the tie-in point and power availability, so we can propose a suitable unit and plan the connection.
Do you provide operators with rental compressors?
Yes, operators can be provided where the job needs them, for example on round-the-clock hire with shift working. Tell us the hours per day, number of shifts and any site training or permit requirements. Whether operators are included, and who handles refuelling, is confirmed in the written scope for each hire.
How often are rental compressors serviced on hire?
Our hire machines are serviced every 300 running hours, including an oil change. For long or continuous hires we plan these services with the site so that the work fits around production or shift changes. Daily checks such as fuel, oil level, coolant and drain condition remain part of normal operation on site, and we explain them at handover.
Do you rent compressors outside Hyderabad?
Yes. Our service team covers the whole of Telangana and Andhra Pradesh, and we supply rental compressors across India, with project-based site support where feasible. Our projects have included work in Telangana, Andhra Pradesh and Karnataka. Tell us the site location and access so we can plan transport and support.
Related pages
Field guide
The five-minute brief that gets the right rental machine
Most delays in hiring a compressor come from missing information. A short, complete brief lets us size the machine, quote correctly and dispatch the first time. Use the checklist below, even if some answers are “not sure”.
The brief
| Question | Example answer |
|---|---|
| What will the air run? | Two jackhammers and a chipping hammer; or a 150 mm DTH hammer; or a factory line while our compressor is repaired |
| Pressure needed at the tool or process | 7 bar; or “the hammer maker says 17 bar” |
| Air demand | Tool data, nozzle sizes, or the size of the compressor being replaced |
| Air quality | Ordinary site air; dry air for painting; oil-free for a process |
| Site location and access | Town, distance from road, any height or weight limits |
| Power | Diesel needed, or electrical supply available (voltage and capacity) |
| Hose length and connection | 60 m to the blast pot; connect to our 2-inch header |
| Start date, duration and hours per day | From Monday, 3 weeks, two shifts |
| Who refuels and who operates | Our staff, or yours |
Typical rental situations and what we ask
- Compressor breakdown in a factory: make, model and pressure of the failed machine, the connection point, and whether a dryer must be included.
- Planned shutdown: date, duration and what must keep running during the shutdown.
- Borewell or DTH drilling: hole size, depth, hammer and expected water.
- Sandblasting: number and size of nozzles, hose length, and whether air must be dried. See sandblasting compressor hire.
- Construction: tools, how many work at once and how far they are from the compressor.
What happens next
- We confirm the machine size and accessories, and tell you if anything in the brief needs checking.
- You receive a rental proposal with rate, period, delivery and responsibilities.
- The machine is delivered, connected and started, and the handover is recorded.
- During the hire, service support is available; at the end, the machine is collected and checked.
What to send for a quotation
- The brief above, as complete as you can make it.
- Photos of the site access and connection point.
- Nameplate photo of the compressor being replaced, for breakdown hires.
Send it through find my part or the spare parts enquiry, or call +91 99590 60718 or +91 92468 88812.
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.