Renting or buying a second hand compressor safely

Compressors are high-performance devices. Just as the complex human body, a compressor can also have its little aches and pains from time to time. Proper maintenance can help prevent this.
Maintenance is crucial for the quality of a used compressor. This article covers what you should take heed of and which parts you need to check when you rent or buy a used compressor.

The All-round Check

If malfunctions are being repaired without delay and a compressor gets regular maintenance and service inspections, you are on the safe side. Therefore, you should request to see/get the service log before you rent or buy a used compressor. Otherwise there is no guarantee for the safety and full functionality of the compressor. IDE seek to set an example and rent and sell second-hand compressors only after a complete overhaul and with warranty coverage for used machines.
Being an internationally acting manufacturer we sometimes also sell showroom models. Typically, they were only used so little that they are as good as new and cannot be compared to a really “used” one. These compressors are particularly recommendable as we grant the full warranty for new machines.

When acquiring a second hand compressor make sure to check the following:

General Inspection

  1. Check intake air filters for black discoloration due to contaminants or oiling. If necessary intake air filters can be replaced quite easily.
  2. Compressors are usually driven by one or more V-belts. Like those in a car they must not be brittle or have cracks.
  3. Like in a car, too: don’t forget the oil. Do check the oil level and the date of the last oil change. If the oil change dates back longer than one year it must be changed (please use only oils that are approved for use with breathing-air). Your compressor will reward you for it with a longer service life.
    Do request to get a new dryer cartridge upon delivery and install it before first putting the compressor into operation.

Testing Safety Systems

The big red button. Its color already shows that pressing this button will have major consequences. Hoping that the emergency-stop switch must never be used for an immediate shutdown of the compressor, its function as a safety device must be tested during an inspection. When pressing the emergency-stop the compressor must shut down within a few seconds!

Safety valves, as parts of the safety system, must be tested, too.
Start the compressor and have the pressure rise until the safety valve opens at the desired pressure. If a malfunction exists, the compressor must not be put into operation.
Repeat the same procedure for the discharge pressure switch.
Important! Also check filling hoses for external damage. If they are damaged or older than five years they must be replaced.
Finally make a leak test for all ducts, connections and drain valves to be sure that the compressor will work safely.

For more information about maintenance and care for your compressor please refer to its operator’s and service manuals.