Low-speed Pro Line B60-4, B70-5.5 and B79-7.5 compressors — 11 bar, lower speed
B60-4, B70-5.5 and B79-7.5 · low-speed · 11 bar · 270 and 500 lEight belt-driven ABAC compressors with a two-stage pump running at lower speed: the B60 with a 4 kW motor and the B70 with 5.5 kW run at 1,100 rpm instead of the 1,400 and 1,300 of the standard range, the bigger B79 with 7.5 kW at 900 rpm. The low-rpm design means fewer piston strokes per minute and a lower running temperature for the pump; on the B60 and B70 the price is less displacement than the same pump gives with the stronger motor. Displacement of 660, 1,023 or 1,130 l/min, 11 bar, a horizontal 270 or 500 l tank, a three-phase 400 V motor. The CT version travels around the workshop on castors with a handle and a regulator with two quick couplings; the FT stands on feet and connects to the pipework. We service the ABAC brand.
Which low-speed machine — pump, tank and castors
Three choices, in this order: how much air the pump should deliver, how big a reserve the tank should hold, and whether the machine is to travel around the workshop or stand in one place connected to the pipework.
B60-4: 660, B70-5.5: 1,023, or B79-7.5: 1,130 l/min
The code carries the pump and the motor power, and it is the motor power that tells a low-speed machine from a standard one. The B60-4 is the B60 pump with a 4 kW (5.5 hp) motor at 1,100 rpm — it draws in 660 l/min and has 97 dB Lwa, 77 dB at 4 m, which is 5 dB less than the same pump with 5.5 kW at 1,400 rpm. The B70-5.5 is the B70 pump with 5.5 kW (7.5 hp) at 1,100 rpm and 1,023 l/min; the B79-7.5 is the bigger B79 pump with 7.5 kW (10 hp), which runs at only 900 rpm and draws in 1,130 l/min. All of them fill the tank to 11 bar.
A 270 or 500 l tank
The tank does not add displacement, it only extends the time the tools draw air before the motor cuts in. Take 270 l with the B60-4 or B70-5.5 for a workshop with two or three people on the tools; 500 l where several tools run at once or a gun draws air for long stretches — with a low-speed pump and its smaller displacement a bigger reserve makes all the more sense. The B79-7.5 comes only with 500 l on feet.
CT on castors, or FT stationary
The CT has two front swivel castors with brakes, two rear wheels, a tubular handle with a rubber grip, on the tank a pressure regulator with two DN 7.2 quick couplings and two gauges (tank and outlet) — the hoses plug straight into the machine. The FT stands on feet, has a pressure switch with a gauge and a 1/2" ball valve outlet: the regulator, filter and quick couplings belong in the pipework at the workstation. Four machines are CT (B60-4 with 270 and 500 l, B70-5.5 with 270 and 500 l), four FT (B60-4 with 500 l, B70-5.5 with 270 and 500 l, B79-7.5 with 500 l).
Eight machines side by side
| Low-speed Pro Line B60-4, B70-5.5 and B79-7.5 — two-stage belt-driven ABAC compressors, 11 bar | ||||||||
|---|---|---|---|---|---|---|---|---|
| Model | Version | Tank | Pressure | Motor power | Air displacement | Speed | Noise Lwa / at 4 m | Weight |
| B60-4-270CT | on castors | 270 l | 11 bar | 4 kW (5.5 hp) | 660 l/min | 1,100 rpm | 97 / 77 dB | 150 kg |
| B60-4-500CT | on castors | 500 l | 11 bar | 4 kW (5.5 hp) | 660 l/min | 1,100 rpm | 97 / 77 dB | 204 kg |
| B60-4-500FT | stationary | 500 l | 11 bar | 4 kW (5.5 hp) | 660 l/min | 1,100 rpm | 97 / 77 dB | 201 kg |
| B70-5.5-270CT | on castors | 270 l | 11 bar | 5.5 kW (7.5 hp) | 1,023 l/min | 1,100 rpm | 102 / 82 dB | 173 kg |
| B70-5.5-270FT | stationary | 270 l | 11 bar | 5.5 kW (7.5 hp) | 1,023 l/min | 1,100 rpm | 102 / 82 dB | 170 kg |
| B70-5.5-500CT | on castors | 500 l | 11 bar | 5.5 kW (7.5 hp) | 1,023 l/min | 1,100 rpm | 102 / 82 dB | 249 kg |
| B70-5.5-500FT | stationary | 500 l | 11 bar | 5.5 kW (7.5 hp) | 1,023 l/min | 1,100 rpm | 102 / 82 dB | 246 kg |
| B79-7.5-500FT | stationary | 500 l | 11 bar | 7.5 kW (10 hp) | 1,130 l/min | 900 rpm | 102 / 82 dB | 297 kg |
All of them: a two-stage twin-cylinder pump with an intercooler (the B60 and B70 with cast-iron cylinders), oil-lubricated, with an oil sight glass, V-belt drive under a belt guard, an aftercooler on the pump outlet, a three-phase 400 V / 50 Hz electric motor with thermal overload protection, a pressure switch, a horizontal tank with a condensate drain, an AirTube QR code. The CT adds a pressure regulator with two DN 7.2 quick couplings, a second gauge, castors and a handle; the FT has a 1/2" ball valve outlet. Noise: the first figure is the sound power level Lwa, the second the sound pressure at 4 m from the machine. The B60 and B70 pumps with the stronger motor and higher speed, the upright versions, the 15 bar machines, the versions with a dryer and the tandem have their own categories — the links are further down.
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Low-speed B60-4 and B70-5.5, or standard B60-5.5 and B70-7.5 — and when CT, when FT
Both the B60 and the B70 pump come in two versions: the standard one with a stronger motor and higher speed, and the low-speed one with a smaller motor and lower speed. The machine looks the same; what differs is the motor plate, the drive ratio and the figures in the table.
What the low-speed version changes
The B60-4 draws in 660 l/min instead of the 827 l/min of the standard B60-5.5-270CT, but runs at 1,100 rpm instead of 1,400 and has 97 dB Lwa and 77 dB at 4 m instead of 102 and 82. The B70-5.5 draws in 1,023 l/min instead of 1,210 l/min and runs at 1,100 rpm instead of 1,300; the noise of 102 dB Lwa, 82 dB at 4 m, stays the same. Fewer piston strokes per minute mean a lower running temperature and less wear on the pump in a machine that runs for a large part of the day.
When to stay with the standard version
If you need as much air from the pump as it can give — two people sandblasting, a paint shop with long spraying — take the B60-5.5 or B70-7.5 from the category of standard machines, for example the B70-7.5-500FT with 1,210 l/min. The low-speed version is for an operation where the machine runs often and for long periods, but the draw of the tools is not at the limit of the displacement: a tyre shop, an assembly workshop, a body shop.
CT, or FT
The CT on castors has a pressure regulator with two DN 7.2 quick couplings, two gauges, a handle and brakes on the front castors — an all-in-one machine for a workshop where the air is drawn straight from the tank. The FT on feet has a switch with one gauge and a 1/2" ball valve outlet into the pipework; the regulator and filter go at the workstation. We carry the B79-7.5 only as an FT with a 500 l tank — it is a machine for the compressor room.
Lower speed, two stages, cast iron and V-belts — what is inside
Why 1,100 and 900 rpm
The motor drives the pump through V-belts and the size of the pulleys sets the speed. On the low-speed version the reduction is greater: the B60 and B70 pumps run at 1,100 rpm instead of 1,400 and 1,300, the B79 pump at 900 rpm. The pistons do fewer strokes per minute, the pump heats up less and the air goes into the tank cooler. The same pump with a smaller motor draws in less: that is why the B60-4 gives 660 l/min and the B70-5.5 1,023 l/min.
Two stages and an intercooler
Two cylinders work one after the other: the first compresses the intake air to an intermediate pressure, the air passes through the intercooler — a finned tube between the cylinders — and the second, smaller cylinder takes it up to 11 bar. Each stage does only part of the work, and a tank at 11 bar holds more air than a tank of the same size on a single-stage machine at 10 bar.
Cast-iron cylinders and the oil in the pump
On the B60 and B70 pumps the cylinders are cast iron — for long runs under load with tools that draw air for long stretches: sandblasting, sanding, an impact wrench by the lift. The pump is lubricated with oil from the crankcase, with an oil sight glass; you check the level by eye and change the oil and clean the intake filter as per the manual.
Aftercooler on the outlet
The compressed air leaves the second stage through the finned tube of the aftercooler, where it cools down before it enters the tank. The moisture then drops out as condensate in the tank, not in the hose at the tool; on the CT you drain it through the ball valve under the tank, on the FT through a valve. If you need dry air for spraying, put a filter at the workstation or reach for the version with a dryer.
Tank, switch and outlet
A horizontal 270 or 500 l tank at 11 bar. The pressure switch starts and stops the motor according to pressure; the three-phase 400 V motor has thermal overload protection. The CT has a pressure regulator with two DN 7.2 quick couplings and two gauges on the tank, the FT one gauge on the switch and a 1/2" ball valve outlet. The AirTube QR code on the tank opens service videos.
Equipment, operation and maintenance
What you get with every machine
- Two-stage twin-cylinder B60, B70 or B79 pump with an intercooler (the B60 and B70 with cast-iron cylinders), oil-lubricated, with an oil sight glass; V-belt drive geared down to 1,100 or 900 rpm
- Belt guard — moulded plastic on the B60 and B70, wire mesh on the B79
- Aftercooler on the pump outlet
- Three-phase 400 V / 50 Hz electric motor with thermal overload protection, automatic stop/start pressure switch with a gauge
- Horizontal 270 or 500 l tank at 11 bar with a condensate drain
- CT: two front swivel castors with brakes, two rear wheels, a tubular handle with a rubber grip, a pressure regulator with two DN 7.2 quick couplings and a second gauge for the outlet pressure
- FT: feet for a fixed spot, 1/2" ball valve outlet into the pipework
- AirTube QR code on the tank opens service videos
- 2-year warranty, 10 years on the tank against rusting through; extension to 3 years for a 5% surcharge
Three pumps, two tanks, two versions
Machine details
Where the B60-4, B70-5.5 and B79-7.5 work
Tyre shop and garage
Two lifts, an impact wrench, a ratchet, tyre inflation and blowing off: the B60-4-270CT puts 660 l/min into a 270 l tank at 11 bar, wheels between the lifts on its castors and, at 97 dB Lwa and 77 dB at 4 m, shares the lowest noise in the range with the other B60-4s. If you put the machine in the next room and run the air through pipework, take the B60-4-500FT or the B70-5.5-270FT.
Body, assembly and metalwork shops
A grinder, a riveter, an air chisel and blowing off for three to four people over a shift: the B70-5.5-270CT or B70-5.5-500CT hold 11 bar in the tank and the pump at 1,100 rpm keeps topping it up — the 500 evens out even the moments when everybody draws at once. The regulator with two quick couplings on the tank serves two hoses.
Compressor room with pipework
The B70-5.5-500FT and B79-7.5-500FT stand on feet in the compressor room, the air leaves through the ball valve into the pipework and the workstations have regulators with a filter. The B79-7.5 with 1,130 l/min at 900 rpm is a machine for a hall with several draw-off points; where the whole hall draws air without pauses, the piston machine reaches its limit and the screw compressor takes over.
Accessories and service
The DN 7.2 quick coupling on the CT is the same standard as on the hoses, guns and tools across our whole range; with the FT the regulator, filter and quick couplings go into the pipework at the workstation. ABAC belongs to the Atlas Copco group and is one of the brands we repair in our own service workshop; we carry the B60, B70 and B79 pumps and the service kits as separate items.
- pressure regulator with a filter — A regulator with a filter at the workstation for a spray gun — on the FT the only way, on the CT into one of the quick couplings.
- spray guns — HVLP and LVLP guns for the body shop — the B70-5.5-500CT with 1,023 l/min and a 500 l tank at 11 bar keeps up with spraying parts; a paint shop with long spraying reaches for the standard version with full displacement.
- impact wrenches — An impact wrench by the lift — 11 bar in the tank keeps a reserve even at 660 l/min.
- spiral hoses — Hoses with DN 7.2 quick couplings from the machine to the tool — the CT has outlets for two.
- pneumatic tools — Grinders, riveters and chisels — the tools a low-speed machine with 11 bar is bought for.
- B60 compressor pump — Replacement pump for the three B60-4 machines in the table.
- B70 compressor pump — Replacement pump for the four B70-5.5 machines.
- B79 compressor pump — Replacement pump for the B79-7.5-500FT.
- B60-PK1 service kit — Valve plate, gaskets and an intake filter for a major service of the B60; the oil is bought separately.
- B70-PK1 service kit — The same set of parts for the B70 pump.
- ABAC compressor service — Warranty and post-warranty repairs of ABAC machines in our workshop; belt, filter and oil replacement.
Where next if neither the B60-4, the B70-5.5 nor the B79-7.5 is the right fit
The low-speed machines are the B60 and B70 pumps with a smaller motor and the bigger B79 at 900 rpm, all on a horizontal tank in the CT and FT versions. If you want full displacement from the pump, an upright tank, 15 bar, a dryer, two pumps or a machine running next to the workstation, ABAC has sister machines. You will find the whole range, with filters by output, tank and voltage, among all compressors.
- standard B59B, B60 and B70 compressors — The same B60 and B70 pumps with the stronger motor and full displacement of 827 and 1,210 l/min, plus the smaller B59B with 653 l/min and the 90-litre machine at 15 bar.
- two-stage A49B compressors — The smaller two-stage A49B pump with 2.2 to 4 kW motors, 444 to 595 l/min, 90 to 270 l tanks, also on 230 V.
- upright VT compressors — The B59B and B60 pumps on an upright 200 or 270 l tank — where floor space is short.
- B60 and B70 compressors at 15 bar — The B60 and B70 with a 500 l tank at 15 bar for tools that 11 bar is not enough for.
- compressors with a dryer — FT machines with a built-in refrigerant dryer — dry air into the pipework straight from the machine.
- tandem compressors — Two pumps on one tank for an operation where one pump is not enough.
- sound-insulated ABAC Silent compressors — The B59B, B60 and B70 pumps in a sound-insulated cabinet — for running next to the workstation, where lower speed is not enough.
- cast-iron ATMOS Perfect compressors — Cast-iron twin-cylinder ATMOS pumps with an aftercooler, 10 or 12.5 bar, 90 to 500 l tanks.
- screw compressors — For a draw without pauses for the whole hall, where the piston machine reaches its limit.
- two-stage piston compressors — All two-stage machines with filters by output and tank.
- stationary compressors — Machines on feet across brands.
- compressors with a 500 l tank — Five-hundred-litre machines across brands — the tank of five of the eight low-speed machines.
- compressors with a 5.5 kW motor — Machines with 5.5 kW across brands.
Ventilek advises
You do not buy a low-speed machine for the l/min figure, but for how many hours a day it is going to run. If you want the maximum air from the pump, take the standard B60-5.5 or B70-7.5. If you have a workshop where the compressor cuts in from morning till evening, the same pump at 1,100 rpm gives you fewer piston strokes and a cooler run — for a tyre shop I take the B60-4-270CT, for a body shop the B70-5.5-500CT with a regulator and filter at the workstation, for a compressor room with pipework the B79-7.5-500FT. If every decibel next to the bench bothers you, look at the Silent; if you draw air without pauses for the whole hall, at a screw compressor.
Frequently asked questions
- What does “low-speed compressor” mean?
- A piston compressor whose pump runs at a lower speed than is usual for it: the B60 and B70 at 1,100 rpm instead of 1,400 and 1,300, the B79 at 900 rpm. This is achieved with a smaller motor and a different pulley ratio. The pistons do fewer strokes per minute, the pump heats up less and the air goes into the tank cooler; the price is less displacement — 660 instead of 827 l/min on the B60, 1,023 instead of 1,210 l/min on the B70. It is also called a low-rpm compressor.
- How does the B60-4 differ from the B60-5.5, and the B70-5.5 from the B70-7.5?
- Not in the pump — the B60 and B70 are the same cast-iron two-stage pumps in both versions. What differs is the motor (4 instead of 5.5 kW; 5.5 instead of 7.5 kW), the speed (1,100 instead of 1,400 and 1,300 rpm), the displacement (660 instead of 827; 1,023 instead of 1,210 l/min) and on the B60 the noise too (97 dB Lwa and 77 dB at 4 m instead of 102 and 82). We carry the standard versions in the B59B, B60 and B70 category; the link is in the Where next section.
- Does a low-speed compressor make less noise?
- On the B60 it does: the B60-4 has 97 dB Lwa and 77 dB at 4 m, the standard B60-5.5 102 dB Lwa and 82 dB at 4 m. The B70-5.5 and B79-7.5 have 102 dB Lwa and 82 dB at 4 m, the same as the standard B70-7.5 — they are still machines for the workshop or the compressor room, not for next to the bench. If you need fewer decibels next to the workstation, ABAC has the B60 and B70 pumps in a sound-insulated cabinet in the Silent range; if you can, put the FT in the next room and run the air through pipework.
- How much air do the pumps actually deliver?
- The displacement of 660, 1,023 and 1,130 l/min is the amount of air the pump draws in per minute; how much of it reaches the tool depends on the pressure it works at and on the tank. How to work out the consumption of your tools and choose a machine for it is explained in our article on choosing a compressor.
- What does the CT have that the FT does not, and what do I have to buy extra for the FT?
- The CT has two front swivel castors with brakes, two rear wheels, a tubular handle with a rubber grip, a pressure regulator with two DN 7.2 quick couplings, a second gauge for the outlet pressure and a ball valve for the condensate — you plug the hoses straight into the machine. The FT has a switch with a gauge and a 1/2" ball valve outlet; the regulator, filter and quick couplings for it belong in the pipework at the workstation, and the condensate is drained by a valve under the tank. The FT is for a machine that stands in the compressor room and feeds the air through pipes.
- Is a 230 V socket enough?
- No. All eight machines have a three-phase 400 V / 50 Hz motor and there is no single-phase version in the low-speed range; you need a 400 V socket with a breaker rated for the 4, 5.5 or 7.5 kW motor. Two-stage machines for an ordinary 230 V socket come from ABAC in the smaller A49B range with a 2.2 kW motor; three-phase machines of all brands are grouped together among 400 V compressors.
- Which tank size should I choose?
- The tank does not add displacement, it only extends the time the tools draw air before the motor cuts in — and at 11 bar it holds more than the same tank at 10 bar. 270 l is for a workshop with two or three people on the tools, 500 l for where several tools run at once or a gun draws for long stretches; with a low-speed pump and its smaller displacement a bigger tank makes all the more sense. Parameter categories compare machines of all brands by tank volume, for example compressors with a 270 l tank.
- Who is the low-speed range for?
- For a workshop where the compressor cuts in from morning till evening and the draw of the tools is not at the limit of the displacement: a tyre shop with two lifts, a body shop, an assembly or metalwork shop, a compressor room with pipework to several workstations. A paint shop with long spraying and sandblasting by two people are better off with the standard B60-5.5 or B70-7.5 with full displacement. A piston machine works in cycles and needs pauses; for a draw without pauses for the whole hall choose a screw compressor. Machines for workshops and trade operations of all brands with parameter filters are among compressors for professional use.
- What is the B79 and how does it differ from the B70?
- The B79 is a bigger two-stage pump than the B70: with a 7.5 kW (10 hp) motor it runs at only 900 rpm and draws in 1,130 l/min. We carry it in a single machine, the B79-7.5-500FT — stationary, with a 500 l tank at 11 bar, with a wire-mesh belt guard instead of the moulded one. It is a machine for the compressor room, for a hall with several draw-off points; we also carry the separate B79 pump as a spare part.
- Will a low-speed compressor stand up to all-day running?
- The low-speed design is built for more frequent and heavier use than the standard version: fewer piston strokes, a lower running temperature, cooler air in the tank. It is still a piston machine, though, which works in cycles — tops up the tank, switches off, cuts in again when the pressure drops — and needs pauses as per the motor plate. Where the air has to flow without a break for the whole hall, you need a screw compressor.
- What is the warranty and what does maintenance involve?
- Two years on the machine, an extension to three years for a 5% surcharge, and ten years on the tank against rusting through. Maintenance as per the manual: draining the condensate, checking the oil level in the sight glass, changing the oil and cleaning the intake filter, checking the belt tension; for a major service we carry the B60-PK1 and B70-PK1 service kits with a valve plate and gaskets.
- What does the code B60-4-270CT or B79-7.5-500FT mean?
- The pump, the motor power in kW, the tank volume in litres and the version: C is a machine on castors, F a stationary one on feet, T a three-phase 400 V motor. So the B60-4-270CT is the B60 pump with a 4 kW motor on a 270 l tank on castors, the B79-7.5-500FT the B79 pump with 7.5 kW on 500 l on feet. The manufacturer marks the pumps B6000, B7000 and B7900 and the motor in horsepower — on the label of the machine you will find, say, “PRO B6000 270 CT5.5”.
- Low-speed ABAC, or ATMOS Perfect?
- The ATMOS Perfect are cast-iron twin-cylinder pumps at 10 or 12.5 bar from another brand, which we also service in our workshop; the low-speed ABACs are the two-stage B60, B70 and B79 pumps at 11 bar with lower speed and 270 and 500 l tanks. If you are torn between the brands, compare both in the tables; an overview of all the ABAC ranges is in the ABAC PRO Line guide.
- Where do I find the service videos, and who does the servicing?
- On the tank there is an AirTube sticker with a QR code — scanned with a phone, it opens instructional and service videos for the pump. Service, belts, filters and oil are handled by our workshop; the other ranges, from the suitcase models to the screw compressors, are in the ABAC brand guide.
All values apply to a 50 Hz supply. Air displacement is the amount of air the pump draws in; how much of it reaches the tool depends on the pressure and the tank. Noise is given as the sound power level Lwa and the sound pressure at 4 m from the machine. A piston compressor works in cycles (topping up the tank and pausing), not continuously.
