Note of Caution
This quiz should not substitute for reading the type-specific operation manual of the compressor you use. High-pressure breathing air compressors are expensive, specialized pumps that can compress air to 200 or 300 bar. They also run on special oil that is non-toxic if vaporized into the breathing air, and they feature dedicated filtration systems to remove impurities and moisture. In contrast, ordinary compressors only pump up to about 20 bar, run on standard industrial oil that is dangerous to inhale, and lack appropriate breathing air filtration systems.
Recognizing High-Pressure Breathing Air Compressors
To distinguish a breathing air compressor from a regular one, look for the following features:
Three Piston-Shaped Stages: A breathing air compressor typically uses three stages. The largest stage pumps from atmospheric pressure to an intermediate pressure, and the smallest (third) stage compresses the air up to 230 to 300 bar, depending on the model.
Filter Towers: Breathing air compressors are equipped with prominent filter towers.
Lack of Large Air Tanks: Regular low-pressure compressors are easily identified by their large reservoir air tanks, which high-pressure compressors generally do not have.
Things That Can Go Wrong with a Compressor
Oil Mix-Up
High pressure compressors setups often involve two distinct oils:
1. Pump Oil: The pumping unit requires a specialized synthetic or organic oil safe for human lungs if minor vaporization occurs. This is expensive and typically only available at specialized diving or safety equipment suppliers.
2. Engine Oil: If driven by gas or diesel engine, the engine itself requires standard motor oil, which is widely available.
A dangerous mistake sometimes occurs when an operator runs out of pump oil and tops off the pumping unit with regular engine oil. Inhaling vaporized petroleum-based motor oil is extremely hazardous—it can cause lung pain, severe coughing, allergic reactions, and long-term carcinogenic effects. If the wrong oil is used, the system must be completely drained, flushed/rinsed once with the correct pump oil, drained again, and then refilled with fresh pump oil.
Exploding Air Tanks
Faulty or out-of-test cylinders can rupture violently. Always check if the tank you are about to fill is within its required hydrostatic test date. Building a concrete barrier or basin for tanks to get filled in can add to safety in case one day one of those tanks' bursts. Also, a standing tank falling is at risk of exploding. If there is no safe place to keep scuba tanks standing, then lay them down. In this video for some reason, the tank valve came off and the tank turned into a rocket. Videos like this can help us decide where and how to store our tanks.
Expired Filters
Filtration media must be replaced after a specified number of operating hours. Overusing expired filter cartridges increases the risk of toxic moisture, oil mist, or carbon monoxide reaching the breathing air. Always log operating hours to ensure filter changes happen on schedule.
Filling Hose Rupture
The filling hose can come off and start whipping. Don't go near. Try to stop the engine from a distance. With an electric engine, you can switch off the main power. With a 4-stroke engine, you could preventively tie a stopping line that can get pulled from a distance. Or you can try to stop it with a broomstick so you won't break your fingers.
Hair Entanglement in Fan Belts
Loose hair caught in a rotating belt or pulley will pull your head directly into moving parts. If caught, pull back immediately with force. To prevent this entirely, always tie back long hair and wear a hat or hairnet while operating machinery.
Electrocution
Electrical compressors present a risk of severe shock.
1. Wear thick rubber-soled shoes while operating the machine.
2. Keep the surrounding floor dry.
3. Ensure proper electrical grounding and functional circuit breakers.
Fire and Explosion
Fuel-powered engines carry a risk of fire:
1. Never smoke or allow open flames near the equipment.
2. Never refuel a running engine. Allow it to cool down first.
3. Store fuel containers in a cool, well-ventilated area away from direct sunlight.
Breathing Air Contamination from Exhaust Gases
If compressors are not well ventilated, they could suck up their own exhaust gases and cause carbon monoxide poisoning to the user. Install a hose on the inlet to draw incoming air further away from its own exhaust. Turn the compressor with the inlet at the upwind side of the compressor.
Hearing lossHigh-pressure compressors produce high decibel levels. Prolonged exposure causes irreversible hearing damage. Always wear proper hearing protection (earplugs or earmuffs).
Oxygen-Induced Explosion
Gas blending is a specialized discipline requiring separate certification. If you suspect a cylinder contains enriched oxygen or pure oxygen, bleed it completely before connecting it to a standard air compressor. IF high-pressure pure oxygen backflows into a warm, greased compressor block, a catastrophic explosion can occur. Certified gas blenders ensure compressor delivery pressure exceeds
to 200 bar, before opening cylinder valves to prevent backflow.
Example Checklist: Before Running a Compressor:
- Read and understand the operating manual.
- Verify that the tank to be filled is within its hydrostatic test date.
- Ensure the tank does not contain pure oxygen or high-oxygen nitrox mixtures.
- Check the engine oil level (if gas/diesel powered).
- Check the pump block oil level and oil clarity.
- Check the logbook for upcoming required oil and filter changes.
- Start the compressor.
- Verify that the compressor is properly building pressure.
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Connect the fill whip to the tank and open the tank valve.
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Monitor the fill process; once complete, verify that the auto-shutoff or overpressure relief valve functions correctly.
- Switch the compressor off.
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Bleed the residual pressure and condensation from the filter towers.
- Disconnect the fill hose from the tank.
Troubleshooting & Common Issues
Common Problems
- Clogged Carburetors: Leaving fuel in the carburetor during long storage periods causes fuel degradation, clogging jet nozzles and disrupting engine operation.
- Incorrect Phase/Power: Industrial electric compressors often require three-phase power, whereas residential connections typically provide single-phase power.
- Undersized Extension Cords: Using undersized extension cords causes voltage drops, leading to motor overheating or failure to reach full operating speed.
Reasons for Low Performance - Spray soapy water onto fittings and joints using a spray bottle to pinpoint bubbling leaks.
- Check if the throttle is fully engaged on combustion engines, or verify that the voltage supply meets the motor's operational requirements on electric models.
