How to choose compressed air accessories: couplings and pressure

If you already have a compressor, accessories are chosen in this order: first the coupling, which must be compatible with that of your line, then the pressure the accessory allows, and finally the air consumption, which the compressor must be able to sustain. For inflating and blowing, an inflation gun or blow gun and a hose are enough; for working you need pneumatic tools (screwdrivers, grinders, sanders); to protect the system from water you need a condensate drain at the low point of the receiver and filters.

The types

• Inflation and blow guns: the former have a pressure gauge and are used for tyres and inflatable items, the latter (blow guns) for cleaning dust and swarf off parts, benches and machines.
• Couplings, fittings and adapters: connect tools, hoses and the line. In the collection you will find brass and nickel-plated steel fittings, bayonet couplings with hose tail or for spiral hose, valves and ball valves.
• Hoses and spiral hoses: air hoses and coiled hoses in polyurethane, rubber or PVC, lighter and more flexible or more robust depending on the material.
• Pneumatic tools: impact wrenches, reversible screwdrivers, drills, straight grinders, orbital sanders, needle scalers. Some are sold in sets or kits with accessories.
• Condensate drains: manual or electronic. They remove the water that forms in compressed air.
• Air kits and compact compressors: for those starting from scratch or who want a ready-matched set.

How to choose according to the job

To get started on a small budget, a complete air kit avoids finding out halfway through a job that a coupling does not fit. If you already have tools from one brand, look for adapters and fittings that use the same coupling.

The features to look at

• Coupling type: this is the first thing to check. A fitting or coupling of a different type from yours will not connect, even if the thread looks similar. If in doubt, bring or describe the part you already have.
• Permitted pressure: every accessory has a limit. Set the regulator to the value given for the tool, not to the compressor's maximum.
• Air consumption: tools that work continuously (sanders, grinders) need more air than a blow gun used in bursts. A small compressor may not keep up with them.
• Material: brass and nickel-plated steel for fittings and couplings that are connected many times; aluminium where lightness matters; polyurethane, rubber or PVC for hoses, with differences in flexibility and abrasion resistance.
• Weight: in the collection, accessories range from a few grams for fittings to about 2 kg for the largest tools. For long jobs overhead or in a vertical position, weight matters.
• Power supply of electronic drains: unlike manual ones, they need electricity. Check the voltage and the type of cable and connector in the data sheet.
• Codes: the item code and EAN are used to reorder exactly the same part.

Common mistakes

• Buying a tool without checking that the compressor can sustain its air consumption: the tool works in fits and starts and seems faulty.
• Mixing couplings and fittings of different types, or forcing a coupling that does not engage.
• Setting the pressure to the compressor's maximum instead of the value permitted for the tool.
• Not installing a condensate drain: water gets into the tools and shortens their life.
• Disconnecting a coupling while the line is still under pressure: always release the air first.

Frequently asked questions

Can I use any gun with any compressor?

Only if the coupling is compatible and the compressor pressure can be set to the value permitted for the gun. If the coupling is different, you need an adapter.

What is the condensate drain for?

Compressed air contains vapour that condenses in the receiver and filters. The drain removes the water from the low point, and you should check periodically that it works.

What pressure should I inflate a tyre to?

The one written on the tyre or in the vehicle handbook. With a gun that has a pressure gauge you check the value as you inflate.

Is a pneumatic tool better than a cordless one?

The pneumatic one is light and stands up to continuous work, but it needs a compressor and a line. If you always work in the same place it is a convenient choice; for jobs on the move, a battery is more practical.

You will find the full range in the compressed air accessories collection, for example a 150 mm orbital sander Abac or a impact wrench set Fervi. If you are not sure about couplings and pressures, ask for a quote or advice from the AMES technicians.