What counts as high pressure on hire?
Most factory air runs at about 6–8 bar (roughly 90–115 psig), and general construction portables are typically 7 bar (101.5 psig). “High pressure” on a rental enquiry usually means anything above that, and in practice falls into a few bands:
| Band | Pressure (typical) | Common rental uses | Typical machine |
|---|---|---|---|
| Medium-high | 10–14 bar (145–203.1 psig) | Fibre-optic cable blowing, quarry crawler drills, larger blasting set-ups, some process users | Diesel or electric single-stage screw at a higher pressure rating |
| Drilling | 14–24 bar (203.1–348.1 psig) | Borewell and DTH drilling, deep-hole drilling, pipeline drying and pigging support | High-pressure diesel portables, 600–1,500 cfm |
| Special high pressure | 24–30 bar and above (350–435+ psig) | Deep borewells in hard formations, specialist test support, some oilfield and gas-project duties | Special high-pressure units or a compressor feeding a booster |
Our rental fleet covers 2–30 bar, and high-pressure borewell units go up to about 35 bar (507.6 psig) where the duty needs it. Always give pressure in one clear unit and say whether it is gauge (psig, bar(g)) or absolute.
Pressure and flow are one requirement
A compressor’s flow rating applies at its rated pressure. Ask for 20 bar and the same frame of machine delivers less air than it would at 7 bar, because each extra bar takes more work – roughly 7% more power for every additional bar on a screw machine. That is why high-pressure jobs need machines designed for the pressure, not standard units turned up.
Specify the duty as a pair: for example, “900 cfm at a minimum of 17 bar at the drill rig while drilling”. Then add:
- Minimum flowing pressure at the user, not the pressure on a gauge with the valve shut.
- Maximum allowable pressure of the receiving equipment, hoses and fittings.
- Flow pattern: continuous, intermittent, or charging a volume from one pressure to another.
- Temperature and quality limits: is aftercooling, moisture separation or drying needed?
For borewell work, the bands we work to are 200–250 psig (13.8–17.2 bar) at 600–900 cfm, 250–300 psig (17.2–20.7 bar) at 800–1,200 cfm, and 300–400 psig (20.7–27.6 bar) at 1,000–1,500 cfm, with special units up to about 35 bar. Pressure is set by depth, water column and formation; flow is set by the hole and hammer size and the up-hole velocity needed to lift cuttings.
Does the whole system need high pressure?
Often it does not. Raising an entire site to the pressure of its most demanding user wastes energy and stresses every hose, fitting and tool on the line. Consider:
- a dedicated high-pressure machine on its own branch for the one high-pressure user, with standard machines for the rest;
- a booster fed from a lower-pressure supply, where the high-pressure demand is small and steady;
- a receiver to cover short high-pressure peaks, where the average demand is low and there is time to recharge.
The choice depends on simultaneous demand, available space, control stability and running cost. There is no rule that one large high-pressure package is always simpler.
Compressor or booster?
| Question | Dedicated high-pressure compressor | Booster on a lower-pressure feed |
|---|---|---|
| Best fit | Large, continuous high-pressure flow (drilling, pipeline drying) | Smaller high-pressure flow taken from an existing air supply |
| Feed air | Takes atmospheric air | Needs a reliable feed at the right pressure, flow and dryness |
| Failure points | One machine | Feed compressor plus booster – both must run |
| Treatment | After the compressor | Often before and after the booster |
| Typical drive | Diesel portable on most sites | Diesel or electric, depending on site |
A booster’s output depends entirely on its feed. If the feed compressor is undersized or its pressure sags, the booster cannot make up the difference.
Hoses, fittings and the safe boundary
At high pressure, stored energy in hoses and vessels is the main hazard. A hose that whips loose at 20 bar can kill. The temporary system must be rated for the pressure throughout, not just at the compressor.
- Use hoses, couplings, manifolds and valves rated above the maximum compressor discharge pressure, with the rating marked.
- Fit whip checks (safety cables) across every hose joint and secure long runs.
- Keep a pressure relief device in the system set below the lowest-rated component.
- Provide isolation and a safe vent at the user end so the line can be depressurised before any coupling is broken.
- Route hoses away from traffic, sharp edges and hot exhaust; inspect them daily for cuts, bulges and damaged ends.
- Allow for pressure drop: long or undersized hoses waste the pressure you paid for. Size the line for the flow and length.
Pneumatic pressure testing of pipelines or vessels is a separate, high-risk activity. The client’s or project engineer’s approved test procedure governs it, including exclusion zones, test pressures and hold times. We supply the compressed air and support the set-up; we do not set test pressures or sign off tests.
Air quality at high pressure
Compressed air leaves the airend hot and saturated. At high pressure, more water condenses out as the air cools in the hose, and that water can damage hammers, wash out lubricants, or spoil a pipeline drying operation. For high-pressure work:
- an aftercooler and moisture separator are standard on most jobs;
- pipeline drying or instrument-related duties may need a desiccant dryer, typically to −20 °C or −40 °C pressure dew point, rated for the pressure;
- DTH drilling needs rock-drill oil fed into the air for the hammer, which is the opposite of process air – keep the two duties separate;
- oil-free requirements need an oil-free machine or a specification agreed in advance.
Dryers and filters have their own pressure ratings; a standard 16 bar dryer cannot sit on a 24 bar line.
Running high-pressure units in Indian site conditions
High-pressure portables work hard, and summer heat across Telangana and Andhra Pradesh adds to the load. Discharge temperatures rise with pressure ratio and ambient. Keep the canopy clear for cooling air, clean the oil coolers and aftercoolers regularly in dusty conditions, and watch engine and compressor air filters closely. Safety shutdowns – high discharge temperature, low engine oil pressure, high coolant temperature – protect the machine; repeated trips call for investigation, not resets.
On hire we service every 300 running hours, including the oil change, and we can supply operators on shifts for continuous duty. Our team has delivered high-pressure packages for long projects before: for a major natural-gas development at Kakinada, Andhra Pradesh, we supplied and commissioned three compressors rated 1,100 cfm at 300 psig, two rated 1,000 cfm at 275 psig and one rated 750 cfm at 150 psig, with generators, distribution, operators and a technician on site.
Commissioning a high-pressure package
- Confirm the duty and every component’s pressure rating against the drawing or list.
- Position the machine level, with airflow, fuel access and a clear exclusion zone around hoses.
- Connect hoses with whip checks, check relief settings and isolation valves.
- Start, warm up and bring the system up to pressure in stages, checking for leaks at each stage.
- Measure flowing pressure at the user under real load, not static pressure at the machine.
- Record discharge temperature, pressures and hours, and agree the daily check and refuelling routine.
How Reddy Compressors helps
We rent high-pressure diesel portables and electric machines from our own fleet, across 2–30 bar and 50–2,000 cfm, with special high-pressure borewell units up to about 35 bar. As an independent multi-brand business we rent, sell and service ELGi, Atlas Copco, Ingersoll Rand, KAESER, Chicago Pneumatic, Doosan and others, and we can supply brand-new machines for long-term projects.
- We help you set the pressure and flow pair from the application, and check whether a split or booster arrangement is better.
- We supply aftercoolers, separators, dryers and pressure-rated hoses where the duty needs them.
- Our 20-plus service engineers and technicians cover Telangana and Andhra Pradesh; we supply rentals across India with project-based support where feasible.
- Generators for the site can come from Reddy Generators, under the same management.
Office: Srinilayam, 12-13-200, First Floor, Street No. 1, Tarnaka, Secunderabad 500017. Phone +91 99590 60718 or +91 92468 88812; email reddycompressors@gmail.com.
What to send us
- Application (drilling, cable blowing, pipeline drying, process, test support)
- Required flow and minimum flowing pressure at the user (psig or bar)
- Maximum allowable pressure of the receiving equipment
- Air quality needs: aftercooled, dried, oil-free or lubricated for a hammer
- Hose length from machine to user, and site location and access
- Hours per day and hire duration
Frequently asked questions
What pressure compressor do I need for borewell drilling?
It depends on depth, the water column and the formation. As a guide, many borewells are drilled with 200–250 psig (13.8–17.2 bar) at 600–900 cfm, deeper holes with 250–300 psig (17.2–20.7 bar) at 800–1,200 cfm, and deep hard-rock work with 300–400 psig (20.7–27.6 bar) at 1,000–1,500 cfm. Special units reach about 35 bar. Share your rig, hammer size and expected depth and we will match the machine.
Can I rent a 30 bar air compressor?
Yes. Our rental range runs from 2 to 30 bar, and some special high-pressure borewell units go to about 35 bar (507.6 psig). Tell us the flow you need at that pressure, because high-pressure machines deliver less air per unit of engine power than low-pressure ones, and the hose and fittings must also be rated for the pressure.
Why does my high-pressure compressor show full pressure but the tool is weak?
A gauge at the machine with little flow shows static pressure, not what reaches the tool. Long or undersized hoses, restrictive couplings, a clogged separator or a hose kink can take several bar out of the line under flow. Measure pressure at the user while it is working. If it is low, the problem is usually distribution or a flow shortfall rather than the compressor’s pressure setting.
Is a booster cheaper than a high-pressure compressor?
For a small, steady high-pressure demand fed from an existing air supply, a booster can be the more economical arrangement. For large continuous flows such as drilling or pipeline drying, a dedicated high-pressure compressor is usually simpler and more reliable, because a booster depends completely on its feed compressor and adds a second machine that must keep running.
Do you supply high-pressure air for pneumatic pipeline testing?
We supply compressors, dryers and hoses for pipeline drying, pigging and test support. Pneumatic pressure testing stores a large amount of energy and must follow the client’s or project engineer’s approved procedure, including exclusion zones and test pressures. We support the set-up and keep the air supply running; responsibility for the test procedure stays with the engineer in charge.
What hoses are needed for high-pressure compressor hire?
Hoses, couplings and manifolds must all be rated above the compressor’s maximum discharge pressure, with whip checks across every joint and a relief device set below the lowest-rated item. Hose size should suit the flow and length to limit pressure drop. We supply pressure-rated hoses with our high-pressure rentals and agree the layout with your site team.
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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.