ABAC Tech ATH 20 bar: two-stage machines for continuous duty
ABAC Tech ATH · 20 bar · two-stageTwenty bar is twice what an ordinary single-stage piston compressor can manage. ABAC Tech ATH gets there in two stages of compression: the larger low-pressure cylinder pre-compresses the air, an intercooler takes the heat out of it and the smaller high-pressure cylinder pushes it up to working pressure. Add an S1 motor at a 100% duty cycle, direct drive without belts and a slow 1,500 rpm. Eleven machines from 1.5 to 15 kW: seven on a base frame for your own installation and four ready-mounted on a horizontal receiver.
Three things that decide the choice
All eleven machines are oil lubricated, two-stage for 20 bar, direct driven and run on a three-phase 400 V supply. They differ in three things.
1. How much air at twenty bar?
What matters is the delivery at 20 bar, not the intake — that is the air which actually reaches your process. The range is 126 to 1,080 l/min. Because the motor may run continuously, work with the average consumption per shift, not with the peak.
2. On a frame, or straight on a receiver?
Seven machines come on a base frame without a vessel — for plants that already have pipework or their own 20 bar pressure vessel; the two strongest (11 and 15 kW) exist in no other form. Four arrive mounted on a horizontal receiver (90 or 270 l) as a complete assembly that only has to be placed and connected.
3. Will your supply take a direct start?
Seven machines carry an X in the code — the motor starts through a star-delta sequence, so the inrush current is gentler. From 4 kW up it is a necessity rather than an extra. Four machines up to 2.2 kW start directly.
How to read the machine code
The code ATH-5.5/20-270FTX has four parts: ATH is the high-pressure range, the first number is the motor input in kilowatts, /20 is the working pressure in bar and the letters at the end define the version.
BT — on a base frame
Seven machines, 71 to 189 kg. Airend and motor on a steel frame, no vessel. The air goes straight into the pipework or into your own pressure vessel — which has to be certified for 20 bar.
FT — on a horizontal receiver
Four machines, 93 to 223 kg. A complete assembly: airend, motor and pressure switch mounted on the vessel, which doubles as the base. Volume 90 or 270 litres.
X — star-delta
Seven machines from 4 kW up. The motor starts in two steps, so the current peak at start-up is markedly lower. Once running, it makes no difference.
Why two stages and not one
Compressing air to twenty bar in a single step cannot be done — the outlet temperature would go beyond what the oil and the valves will take, and efficiency would collapse. ATH therefore uses two cylinders connected in series: the larger low-pressure one draws the air in and pre-compresses it, the intercooler takes the heat out and the smaller high-pressure cylinder pushes it to 20 bar. Cooling between the stages is exactly what makes a two-stage design efficient.
The figures show it: the 1.5 kW airend draws in 204 l/min and still delivers 126 l/min at a full twenty bar, which is 62 % of the intake volume. A single-stage machine of the same size loses almost two thirds even at half that pressure. The rest of the build is the same as in the other ABAC Tech ranges: an oil-lubricated airend with V-arranged cylinders, stainless steel valves, bearings greased for their whole service life, a large fan and a four-pole S1 motor for continuous load.
All eleven machines side by side
ABAC Tech ATH 20 bar compressors — 11 machines, two-stage, S1 100 %, 1.5 to 15 kW, 126 to 1,080 l/min delivered | ||||||||
|---|---|---|---|---|---|---|---|---|
| Model | Receiver | Starting | Input | Intake | Delivery at 20 bar | Lwa / Lwp | Weight | Dimensions |
| ATH-1,5/20-BT | no vessel | direct | 1.5 kW | 204 l/min | 126 l/min | 98 / 78 dB(A) | 71 kg | 686 × 575 × 671 mm |
| ATH-1,5/20-90FT | 90 l | direct | 1.5 kW | 204 l/min | 126 l/min | 98 / 78 dB(A) | 93 kg | 1,000 × 533 × 980 mm |
| ATH-2,2/20-BT | no vessel | direct | 2.2 kW | 252 l/min | 174 l/min | 99 / 79 dB(A) | 73 kg | 686 × 575 × 671 mm |
| ATH-2,2/20-90FT | 90 l | direct | 2.2 kW | 252 l/min | 174 l/min | 99 / 79 dB(A) | 97 kg | 1,000 × 533 × 980 mm |
| ATH-4/20-BTX | no vessel | star-delta | 4 kW | 456 l/min | 300 l/min | 99 / 79 dB(A) | 80 kg | 686 × 575 × 671 mm |
| ATH-5,5/20-BTX | no vessel | star-delta | 5.5 kW | 570 l/min | 402 l/min | 100 / 80 dB(A) | 101 kg | 1,073 × 693 × 761 mm |
| ATH-5,5/20-270FTX | 270 l | star-delta | 5.5 kW | 570 l/min | 402 l/min | 100 / 80 dB(A) | 211 kg | 1,915 × 606 × 1,162 mm |
| ATH-7,5/20-BTX | no vessel | star-delta | 7.5 kW | 780 l/min | 546 l/min | 101 / 81 dB(A) | 121 kg | 1,073 × 693 × 761 mm |
| ATH-7,5/20-270FTX | 270 l | star-delta | 7.5 kW | 780 l/min | 546 l/min | 101 / 81 dB(A) | 223 kg | 1,915 × 606 × 1,162 mm |
| ATH-11/20-BTX | no vessel | star-delta | 11 kW | 1,392 l/min | 906 l/min | 106 / 86 dB(A) | 185 kg | 1,073 × 820 × 840 mm |
| ATH-15/20-BTX | no vessel | star-delta | 15 kW | 1,716 l/min | 1,080 l/min | 106 / 86 dB(A) | 189 kg | 1,118 × 820 × 840 mm |
Delivery is the amount of air the machine actually supplies at a working pressure of 20 bar; intake is the volume drawn in by the low-pressure cylinder. Lwa is the sound power level from the rating plate, Lwp the sound pressure level at a distance of four metres. Dimensions are length × width × height. All values are manufacturer data.
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Noise without window dressing
These machines are loud and there is no point hiding it: the sound power level Lwa is 98 to 106 dB. It is an open industrial machine with no enclosure at all, designed for output and heat removal, not for quiet in the room. It belongs in a plant room, an annex or behind a wall, not next to a workbench.
🔴 Be careful when comparing offers. Catalogues often quote 78 to 86 dB for the same machine — but that is the sound pressure Lwp measured at four metres, roughly 20 dB(A) below the sound power Lwa on the rating plate. Both figures are correct, each simply measures something different. We list both for every machine.
The versions up close
The same two-stage airend arrives either on a base frame or mounted on a horizontal receiver.
What all the machines share
Two-stage compression to 20 bar
The low-pressure cylinder pre-compresses, the intercooler removes the heat and the high-pressure cylinder pushes the air up to working pressure.
S1 motor at 100 % duty
A four-pole motor rated for continuous load. It needs no cooling breaks.
Direct drive without belts
The airend sits directly on the motor. No belt tensioning and no belt replacement.
V-arranged finned cylinders
Heavy finning carries away the heat, of which twenty bar produces more than an ordinary machine.
Stainless steel valves
A stainless valve plate takes high temperatures and the cyclic load of continuous duty.
Bearings greased for life
The crankshaft bearings are not greased at service intervals — they are filled at the factory.
Three-phase 400 V supply
The whole range runs on 400 V / 50 Hz. From 4 kW up with star-delta starting.
Two-year warranty
A two-year warranty applies to every machine in the range.
Ventilek recommends
Twenty bar is only carried by a system built for twenty bar. The compressor is only the beginning. The pipework, fittings, hoses and above all the pressure vessel have to be rated for 20 bar — a ten-bar or even a fifteen-bar vessel simply cannot be connected here. If you do not have a twenty-bar vessel, go straight for the FT version on a receiver, where a certified vessel is part of the package. And if five bar less will do, look at the same range at 15 bar — the same kilowatts buy you noticeably more air there.
Frequently asked questions
- Why do I need a two-stage machine if I want 20 bar?
- Because single-stage compression to twenty bar is not realistically possible: the outlet temperature would exceed what the oil and the valves will take, and efficiency would collapse. Two stages share the work and the air is cooled between them. With ATH the figures show it: 204 l/min of air drawn in against 126 l/min delivered at a full twenty bar, which is 62 % — a single-stage machine has a worse ratio even at lower pressure.
- How much air do I lose against the fifteen-bar version?
- Roughly thirty per cent. A machine of the same 5.5 kW input delivers 552 l/min in the fifteen-bar version and 402 l/min in the twenty-bar one. It holds across the range: higher pressure means a smaller quantity. If your process does not genuinely need twenty bar, the fifteen-bar branch will give you more air for the same kilowatts.
- What exactly does S1 mean and why does it matter?
- S1 is the standard designation of a motor duty type: the machine may run continuously at full output as long as it is cooled. Ordinary workshop compressors have S3, which means that after a certain running time a cooling break has to follow — usually roughly half and half. Leave an S3 machine running non-stop and it will overheat, cutting its life to a fraction.
- What is the difference between the BT and FT versions?
- The machine inside is the same. BT is the airend with motor on a steel base frame without a vessel — the air goes into the pipework or into your own pressure vessel. FT is the same unit mounted on a horizontal receiver (90 or 270 l) that doubles as the base. FT only has to be placed and connected; BT assumes you already have the air reserve.
- Does the whole system have to be certified for 20 bar?
- Yes. The pressure vessel, pipework, hoses and fittings have to be rated for the working pressure and the vessel must have a valid inspection. A 10 or 15 bar vessel cannot be connected to a twenty-bar machine. If you are not sure what your existing set-up will take, the FT version with the manufacturer’s vessel is the safer choice.
- Why does the table show delivery instead of intake?
- Because delivery is the air that actually reaches your process at a working pressure of 20 bar. Intake is the volume drawn in by the low-pressure cylinder — on the ATH-1.5/20 that is 204 l/min against 126 l/min delivered. Delivery decides the choice of machine; we list both so it is clear which is which.
- Is it really that loud?
- Yes. The sound power Lwa is 98 to 106 dB, which is what an open industrial machine without an enclosure sounds like. The figure of 78 to 86 dB that appears for these machines is the sound pressure at four metres — a different quantity, roughly 20 dB(A) lower. If you need a machine for a room where people work, look for a version in a sound-insulated enclosure.
- Can the machine run on 230 V?
- No. Every machine in this category runs on a three-phase 400 V / 50 Hz supply. The seven strongest ones also start through a star-delta sequence, so matching protection is required.
Where to go next
This category is the twenty-bar branch of the ABAC Tech ATH range. The other branches of the industrial range look like this: You will find an overview of every range in the Compressors category.
- ATH at 15 bar — the same two-stage range five bar lower — more air for the same kilowatts
- ATH at 30 bar — the highest pressure of the range — for pressure testing and special processes
- The ten-bar ATL range — when high pressure is not needed — single-stage S1 machines for 10 bar
- All 20 bar compressors — an overview of twenty-bar machines from the whole offer, across all ranges
- ATL on a receiver — complete assemblies for 10 bar — 90 and 270 litres
- How to choose a compressor — from the consumption of your tools through output to the size of the receiver
Performance data are measured to ISO 1217, Annex C, latest edition; noise to ISO 2151. Under the European machinery directive the sound power level Lwa is stated on the machine rating plate, while the sound pressure level Lwp is measured at a distance of four metres and is roughly 20 dB(A) lower. All values are manufacturer data.
Bestsellers
Product sorting
List of products
Eleven kilowatts on a base frame. Two thirds more air than the 7.5 kW machine and a different weight class — 185 kg and five decibels louder.
The strongest machine of the category: fifteen kilowatts and over a thousand litres of air per minute at twenty bar. On a base frame, with star-delta starting.
The smallest complete assembly of the range: a two-stage airend mounted on a horizontal ninety-litre receiver. Place it, connect the supply and the pipework.
The smallest machine of the twenty-bar range on a steel base frame. Twenty bar in two stages, no pressure vessel — the air goes straight into the pipework or into a receiver you...
A complete assembly with a horizontal ninety-litre receiver and a direct start. The strongest machine of the range you can place and connect without dealing with star-delta.
Two point two kilowatts on a base frame. The strongest machine of the range that still starts directly, without star-delta starting.
Four kilowatts on a base frame with star-delta starting. The first machine of the range where the manufacturer softens the current peak at start-up.
Five and a half kilowatts mounted on a horizontal two-hundred-and-seventy-litre receiver. A complete assembly for continuous duty that only has to be placed and connected.
Five and a half kilowatts on a base frame with star-delta starting. The mid-range machine for plants that have their own twenty-bar pressure vessel.
The largest complete assembly of the category: seven and a half kilowatts on a horizontal two-hundred-and-seventy-litre receiver. The highest delivery you will get here on a...
Seven and a half kilowatts on a base frame, star-delta starting, no pressure vessel. Of all the machines in the category it gives back the largest share of the air it draws in.