Air Compressors

Add the air consumption of each tool in cfm or litres per second, weight it by how much of the time each tool actually runs, and add around thirty percent margin for leaks and future kit. Compare that figure against the machine's free air delivery, not its displacement or motor power. Sellers can confirm the FAD rating on request.

Piston compressors suit intermittent workshop demand and cost least, but need rest time each hour. Screw compressors run at one hundred percent duty and suit production plants. Vane machines sit between the two, quiet and long-lived at steady medium flow. Map your demand pattern over a shift before choosing, not just the peak figure.

Only if the process specifies it. Spray finishing, instrumentation, electronics and breathing air duties typically call for ISO 8573-1 Class 0 or tight oil limits; general workshop and production air does not, because filtration downstream of a lubricated machine handles most requirements. Check your most demanding application's specification before paying the oil-free premium.

Read the hours meter and ask for service records, since the airend on a screw machine and the pump on a piston machine are the costly parts. Run the machine if possible, listen for bearing noise, and look for oil carryover at the outlet. Confirm the motor plate matches your supply before arranging transport.

Small piston and cabinet units commonly run on a 230 V single phase supply, while screw and vane machines above a few kilowatts need 400 V three phase, often with a dedicated breaker sized for the starting current. Ask the seller for the motor plate details so your electrician can prepare the supply before delivery.