Tandem compressor Pro Line B70-2x7.5-900FT, 900 l, 400 V Two B70 pump units, 2 × 7.5 kW on 400 V, air intake 2,420 l/min at 1,300 rpm, 11 bar, horizontal 900 l tank, 105 dB Lwa / 85 dB at 4 m

Product detailed description

2 × B70 · 900 l · 2,420 l/min · 11 bar · 400 V

The biggest piston compressor we carry in the Pro Line range. A displacement of 2,420 l/min from two cast-iron B70 pump units with 7.5 kW motors at 1,300 rpm and a horizontal 900 l tank at 11 bar — that is the B70-2x7.5-900FT; 105 dB Lwa, 85 dB at 4 m. For shift production with several lines, where at the peak both pump units run, for the rest of the day one with 1,210 l/min, and in between the 900 holds a reserve for the whole pipework.

Where the piston compressor ends

Two B70 pump units with 7.5 kW are the ceiling of the piston range: 2,420 l/min, 15 kW in two motors and a 900 l tank on 2,070 × 800 mm of floor. If in production both pump units run only at the peaks and for the rest of the shift one is enough, it is the right machine — the second pump unit is at the same time the standby for service. But once both pump units run all afternoon and the tank never fills up to the cut-out pressure, that operation wants a different principle from pistons with cycles — a screw machine. The timer relay starts the two motors one after the other, so the supply never has to take two motor starts at once.

Equipment and details

What the B70-2x7.5-900FT has from the factory

• two two-stage B70 pump units with cast-iron cylinders and an intercooler, oil-lubricated, each with an oil sight glass; V-belt drive turning them at 1,300 rpm under sheet-metal belt guards
• two three-phase 7.5 kW (10 hp) electric motors, 400 V / 50 Hz, thermal overload protection; the second motor starts after a delay
• air intake 2 × 1,210 = 2,420 l/min, pressure 11 bar, aftercooler on the outlet of each pump unit
• shared pressure switch with a gauge and a timer relay — the pump units cut in according to the air consumption, while one is being serviced the other runs
• horizontal 900 l tank on feet with holes for bolting down, safety valve, condensate valve in the bottom; air outlet through a ball valve into the pipework (regulator, filter and quick couplings at the workstation)
• noise 105 dB Lwa, 85 dB at 4 m
• AirTube QR code on the tank opens service videos; 2-year warranty (extension to 3 years at extra cost), 10 years on the tank against rusting through

Machine details

Where next if the B70-2x7.5-900FT is not the right fit

The smaller tandem with B70 pump units with 5.5 kW on a 500 l tank is the B70-2x5.5-500FT; the same 900 with B60 pump units is the B60-2x5.5-900FT. A draw without pauses for the whole shift is no longer a job for pistons — that is where the next step is a screw compressor; the 15 kW machines across brands are among compressors with 15 kW of motor power. Where to put the machine and how to route the air is described in our article on setting up a compressor in the compressor room.

Values apply to a 50 Hz supply. Air intake is the sum of the air drawn in by both pump units; how much of it reaches the tool depends on the pressure and the tank. Motor power is the sum of both motors. Noise is given as the sound power level Lwa and the sound pressure at 4 m from the machine. The dimensions are those of the machine without packaging. A piston compressor works in cycles (topping up the tank and pausing), not continuously.