Piston compressors without tank on frame
Piston compressors without a pressure vessel (so-called tankless) are a special kind of piston compressor with no integrated receiver (pressure vessel) for accumulating compressed air. They are usually a compressor unit mounted on a base frame with a handle, without a large tank – so they deliver the compressed air directly into the system or hose. The absence of a receiver makes them stand out for their low weight and high mobility, which technical staff working in the field especially appreciate. These compressors nevertheless retain the advantages of piston technology: solid output in a smaller design and relatively simple maintenance. (You can read more about the principle and types of compressors in general in the article How to choose and use a compressor correctly.)
A mobile, light and flexible solution for service and installation work
A tankless piston compressor is the ideal choice where easy carrying and rapid deployment matter. The absence of a heavy pressure vessel means significantly lower weight – the unit often weighs considerably less than a comparable model with a 5–6 litre receiver. Service technicians and installation staff who need to move a compressor regularly between different workplaces will appreciate that. A compact frame with a handle or grip makes handling simple and it fits into smaller service vehicles too. For portable applications (small repairs at a customer's premises, installation work on building sites, maintenance work in the field), a tankless compressor provides sufficient pressure immediately after starting, with no need to wait for a tank to pressurise. Another plus is less bother with maintenance – there is no need to drain condensate regularly or check for corrosion inside a tank. In short, for mobile use these compressors are designed to offer maximum flexibility and instant compressed air wherever it is needed.
Advantages of tankless compressors vs. small pressure vessels
Even small portable compressors with a small pressure vessel (usually 1.5–6 litres) can increase the stability of the air supply – the receiver acts as a pressure store. Tankless compressors, by contrast, push air directly into the line, which brings several differences in operation:
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Pressure steadiness and pulsation: With a tankless compressor, slight pressure fluctuations can occur in rhythm with the piston. A small receiver smooths these pulsations partly, so the air supply is steadier. During a burst of demand (blowing off, or a short use of a pneumatic tool) even a small tank provides more stable pressure – the air is drawn from the tank and the compressor cuts in with a delay, once the pressure falls below a certain level. A tankless model, on the other hand, responds immediately: at the slightest drop in pressure it runs at once to supply air, which can lead to more frequent cycling or continuous running during work. That, however, is not a problem in ordinary use – modern piston units are built to maintain the set working pressure in real time even without a receiver. You just have to reckon with continuous operation generating more noise and wear (unlike a compressor with a tank, which switches off occasionally once pressurised).
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Pressure endurance and air reserve: A small pressure vessel provides a short-term reserve of compressed air. That suits staplers, nailers and other pneumatic tools where the air demand is sharp but brief – the receiver supplies the volume needed at once and the compressor then tops it up. A tankless compressor has no reserve at all: it supplies all the air directly, from its current output alone. With sudden large demands the pressure may drop temporarily before the compressor catches up with consumption. In practice this means that a tankless design may not suit longer jobs or tools with higher continuous consumption – in such situations a larger receiver or an entirely different compressor technology (a screw machine, say) is better. For brief and occasional use, though, the absence of a tank is no drawback and in fact simplifies the work: you do not have to watch the tank pressure or wait for it to re-pressurise after a drop.
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Practical use and controls: Tankless machines please with their rapid readiness – you switch on and can blow or inflate straight away, because you do not first have to pressurise a tank. That speeds up quick jobs (on a service call-out you simply connect the compressor and immediately blow out a filter or top up a tyre). Storage and transport are also easier – a compressor without a pressure vessel tends to be smaller and fits even into cramped spaces. Models with small tanks, by contrast, tend to have a more robust construction: the tank often serves as the base or frame, and they sometimes have wheels. They are still portable but a little less compact. Their operation also includes watching the tank pressure – they typically have gauges and a pressure switch that turns the compressor off and on. Tankless units are even simpler to operate (often just a switch and a safety valve), because they work essentially on demand (according to air draw). Fewer components can also mean lower failure rates and simpler servicing.
Summary of advantages and limits: Piston compressors without a receiver offer maximum mobility and simplicity – you carry them easily to the place of work, put them into operation quickly and have no tank to deal with. They are excellent for small installation jobs, service call-outs, mobile workshops and every situation where speed and portability matter. Their output suffices for ordinary activities such as inflating tyres, blowing off, driving moderately demanding pneumatic tools or short jobs with air. Conversely, if you need longer continuous air draw, more stable pressure without fluctuation or you use tools with high consumption (continuous paint spraying, sandblasting and the like), you will be better served by a classic piston compressor with a larger pressure vessel or a screw compressor. It is important to weigh the specific needs of your use – in our main category Compressors you will find a wide range from small mobile units to powerful industrial machines.
Who is a tankless compressor best for, and when?
A piston compressor without a pressure vessel is the best choice above all for users on the move. A service technician, fitter, maintenance worker or DIY enthusiast who often travels to the job will appreciate the low weight and compactness – the compressor is easily loaded into a car and taken wherever it is needed. On site they quickly obtain compressed air for their work, whether that is topping up a tyre, blowing out a pipe, cleaning equipment with compressed air, or driving a nailer during a small joinery installation. The tankless design also makes sense where the workplace changes often or is hard to reach – on scaffolding, in underground spaces, in cramped workshops or during service calls at customers' homes. In these scenarios a portable frame-mounted compressor without a tank is unbeatable thanks to its readiness for action. So if you are looking for a compressor you will carry often and whose primary job is to supply air quickly for short or occasional tasks, a tankless piston compressor is probably the best choice for you. On the other hand, if you know you need stable pressure over a longer period or a larger air reserve, consider a compressor with a pressure vessel (even a small one) or a stronger model. The right choice avoids disappointment and ensures the compressor fully meets the requirements of your project – our advice centre, where we cover the types of compressor and their uses in detail, will help you find your way.
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Black Wind reciprocating compressors; cheap and simple design
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Atmos reciprocating compressors; PERFECT cast iron series
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Walter reciprocating compressors; GK cast iron robust machines
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ABAC reciprocating compressors; Line series
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ABAC piston compressors; Extensive and Expert series
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ABAC reciprocating compressors; Pro Zero oil-free series
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ABAC reciprocating compressors; Pro Silent series
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Super Silent compressors; super quiet oil-free design
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INDUSTRIAL TECH compressors; industrial for continuous operation
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CLR reciprocating compressors; oil-free dental design
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Combustion compressors; petrol and diesel engines
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Screw compressors; for continuous operation
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Pressure vessels; self-contained and equipped
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Compressor accessories; oil-drain-valves
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Reciprocating compressor in case design with storage compartment for hoses and small tools. Oil-free design with an output pressure of 8 bar, a motor power of 1.1 kW and a...
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The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The most powerful unit of the WALTER range: four-cylinder 7.5 kW on a base frame without a pressure vessel, displacement 1 100 l/min at 768 rpm. For central distribution with...
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The only WALTER unit for standard 230 V: a cast-iron twin-cylinder 2.2 kW on a base frame without a tank, displacement 340 l/min. For workshops and mobile assemblies without a...
Three-cylinder cast iron unit 3.0 kW on a base frame, without pressure vessel. Delivery rate 440 l/min at 10 bar and quieter operation with the 3W arrangement – for custom...
Three-cylinder cast iron unit 5.5 kW on a base frame, without pressure vessel. Discharge 740 l/min at 902 rpm – source for central distribution or a second machine in a cascade.
Oil-free compressor with an output pressure of 10 bar for use as an oil-free air source with TÜV certification according to ISO 8573-1 class 0. Stationary version with a motor...
Oil-free compressor with an output pressure of 10 bar for use as an oil-free air source with TÜV certification according to ISO 8573-1 class 0. Stationary version with a motor...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
Highly economical screw compressor with variable speed control by frequency converter. The compressor is equipped with a direct 1:1 lossless drive and a highly efficient IE4...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
Highly economical screw compressor with variable speed control by frequency converter. The compressor is equipped with a direct 1:1 lossless drive and a highly efficient IE4...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
Highly economical screw compressor with variable speed control by frequency converter. The compressor is equipped with a direct 1:1 lossless drive and a highly efficient IE4...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...
The oil-lubricated screw compressor with extreme volumetric performance and liquid-cooled PM motor IE4 has been developed especially with the most efficient compressed air...