Air Compressors
This text is machine translated.
About Compressed Air Compressors
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What was a compressed air compressor
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What was the pressure specification on compressors?
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Tank size: So that the compressor never runs out of air
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What was it about the number of cylinders
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Pay attention to the compressor volume
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Compressors with and without oil
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Further equipment of compressed air compressors
What was a compressed air compressor
Compressors are suitable for almost all compressed air applications in DIY and workshop areas. A compressed air compressor sucks in air from the surrounding area. The air drawn in is compressed in the cylinder. The compressed air flows into the pressure vessel and is stored there. At the outlet it is available for the supply of compressed air tools – from the blow gun to the tire filler and paint sprayer to the screwing, stamping and grinding tools.
Once the compressor has reached its maximum pressure, you can start working. The standard equipment on compressors includes at least one quick coupler to relieve the pressure. Connect the compressed air hose to the coupling. It transports the compressed air to the desired tool.
Piston compressors with a pressure vessel are equipped with an automatic on/off switch for the pump. When the maximum pressure is reached, the motor switches off. As soon as the boiler pressure falls to the starting pressure, the air compressor switches on again.
In addition to the piston compressors used in DIY and semi-professional applications, there are also screw compressors for industrial use. They work according to the rotation principle, do not provide such high pressure and are therefore not so universally usable.
What was the pressure specification on compressors?
There are especially small compressed air compressors, low-cost models for the DIY enthusiast and powerful devices for professional use. The different versions differ mainly in the performance and the operating noise.
The power of a compressed air compressor is not determined by the power of the engine in watts, but by the effective air flow rate in liters per minute (L/min). It indicates how much compressed air the device can provide. The output performance is determined in a standardized process. The output volume corresponds to about 60 to 70 percent of the suction power in L/min, i.e. the quantity that the device pulls and compresses from the environment.
The individual tools have a specific air consumption in L/min. This refers to the amount of compressed air that must flow out of the compressor per minute when using the tool. If the compressor cannot supply the required air quantity (air delivery quantity is less than air consumption), you cannot use the respective tool properly.
With the filling capacity or the filling volume in L/min, the manufacturers indicate how much compressed air the device pumps into the boiler per minute. Because the value depends heavily on the counter pressure that the producers handle differently, the filling capacity is only suitable for a limited comparison of products.
Drain the compressor – that's how it works!
Most compressors have a drain cock on the compressed air tank. It is used to drain the condensation water that accumulates inside the metal container during operation. Regular emptying is useful to prevent the formation of rust in the inside of the boiler. After the pressure has been released, simply turn it on and wait for a moment – done! In order to prevent rust, pay attention to the corrosion-through guarantee offered by some manufacturers.
Tank size: So that the compressor never runs out of air
The maximum pressure in bar indicates how much air in the boiler is compressed. The boiler volume, i.e. the boiler size, is more important. It is expressed in liters and indicates how much compressed air the device can store. More storage capacity means more compressed air reserves and allows for longer work until the engine starts again.
Compressed air tools often require a certain working pressure so that the grinding disc can move quickly enough or the impact driver can tighten or loosen screws correctly. If the boiler pressure falls below the required working pressure, you must pause until the required pressure is restored in the tank and you can continue working.
Some small compressors do not have visible air boilers. Thanks to their compact dimensions and low weight, they are easy to transport and store, for example in the boot. Small compressors are intended as a supplement for the garage. They are mainly used to pump up car and bicycle tires, footballs, air mattresses and makeshift beds. Battery-powered models are suitable for use at home and on the road, such as on the beach for filling a hose boat or for service on bicycle tours.
What was it about the number of cylinders
Low-cost piston compressors generate compressed air with a single-stage cylinder. These models are designed for occasional work. The cylinder is fitted with a piston whose movement compresses the air. Devices with two-stage compressors offer a higher quantity of supply. Models with two-cylinder units for intensive use or for continuous compressed air are characterized by an even higher degree of efficiency.
More expensive compressors have a professionally designed motor and cylinder for continuous use. The robust design ensures reliable compressed air supply even when using pressure-intensive tools and precise painting.
Pay attention to the compressor volume
An important factor to consider when purchasing a compressor is the operating noise. It is expressed in dB – the higher the value, the louder the device is when the engine is running. When performing precision work in the workshop, such as painting, sand blasting or airbrush painting, a loud operating noise may be disturbing. For this purpose, there are particularly sound-reduced compressors with insulated housing design, sound-insulated suction system and low-speed industrial compressor block.
Vibration-absorbing feet provide not only a safe, but also a quiet stand. The rubber buffers reduce the vibrations that occur when the air compressor is started up and reduce the noise. They are especially important when the compressor is close to you at work.
Compressors with and without oil
If you need a service-free engine, choose a compressor that does not require you to add oil. Such air compressors do not require additional lubrication. These models are identified by the addition "oil-free" or "maintenance-free" in the product description. Disadvantage of oil-free compressors: They run hot quickly under load. Oil-free devices are only suitable for air-hungry tools such as chisels, hammers, impact screwdrivers, compressed air ratchets, tackers, nail controllers, drills and grinders.
A long-life oil-lubricated piston compressor is recommended for this operation. You can check the oil level of the pump via a dipstick or - more conveniently - a sight glass and refill or change the oil if necessary. The manual shows which oil is suitable.
Further equipment of compressed air compressors
You can read the tank pressure on the compressor pressure gauge. With some work, the full air pressure would be too much of the good. Then finely metered compressed air is required, for example when blowing out jewelry and other small objects, when using pneumatic jigsaw and carving tools or when using airbrush. For these applications, a pressure reducer on the compressor is practical, allowing you to set the pressure continuously up to the maximum. The regulated working pressure is then displayed on a second pressure gauge. Although some tools such as blow guns also offer pressure control on the trigger, the pressure pre-selection via pressure reducer is more precise. Better compressors often offer an unregulated outlet with maximum pressure in addition to a regulated one. You can use both connections at the same time.
The standard for boiler compressors is a check valve and a safety valve, both of which ensure the safety of the user. Safety exctras are a thermal switch and a starting relief. The thermal overload switch interrupts the power supply in the event of a fault. The start-up relief ensures a load-free and thus reliable starting of the compressor even at low temperatures. An advantage is a start-up relief if you want to use the device frequently in the colder season.
Better models have one or more air filters to clean the intake air – convenient when using the compressor in dusty environments. You should clean or replace the filter regularly.
As the size increases, so does the weight. On average, a compressor with a 24-liter tank already weighs between 20 and 30 kilograms. Models with a volume of 100 liters bring it to around 70 kilograms. If the compressor is not always in the same position, for example a fixed place in the workshop, large wheels and retaining brackets are recommended for easy transport. They provide for mobility and thus more application possibilities. This way you can also push large pressure generators out of the workshop or garage with moderate effort, for example for work around the house or in the garden.
Also be aware of transport considerations: Many compressors can be transported in any position, while some models can only be transported upright.
The right accessories for compressed air compressors
Accessories
Normally, your new compressor comes without accessories. There are also compressor sets, which include a compressed air hose and some basic tools for blowing out and filling tires or balls. Depending on the application, you will need different accessories.
Workplace Safety
Wear eye protection or protective mask for your eyes, depending on the tool you use. A breathing mask is recommended for dust-generating work. In addition, hearing protection is recommended for non-sound-insulated pressure air generators.