Breathing Air Compressor SILENT HD 550 ET with 550 l/min
The Coltri Silent HD 550 ET is a powerful, soundproofed high-pressure breathing air compressor from the Heavy Duty series and has been specifically developed for professional filling stations with high air demand. The fully enclosed housing significantly reduces noise emissions and allows operation in environments where low noise levels are required. With a sound pressure level of below approximately 70 dB, the compressor operates exceptionally quietly for its performance class.
With a delivery rate of 550 l/min (33 m³/h), this model is particularly suitable for larger dive centers, respiratory protection workshops, industrial facilities, and central filling stations operating continuously. Four front-mounted high-pressure filling connections allow multiple cylinders to be filled simultaneously, enabling efficient workflow.
The robust 4-stage high-pressure compressor unit with integrated forced lubrication ensures high operational reliability and long service life even under intensive use. In combination with the dual Hyperfilter system, the compressed air is reliably purified and meets breathing air quality standards in accordance with DIN EN 12021.
Thanks to its stable construction, clear control panel, and various safety and monitoring systems, the Silent HD 550 ET is designed for continuous professional operation.
Technical Details
- Gas type: Breathing air according to DIN EN 12021 (Nitrox up to 40% O₂ possible)
- Working pressure: 232 / 300 / 330 bar
- Max. operating pressure: up to 420 bar
- Intake pressure: atmospheric / max. 300 mbar
- Permissible ambient temperature: –10 °C to +40 °C
- Max. installation altitude: 1,500 m
- Maximum inclination: 15°
- Frame: Steel frame, powder-coated (RAL 9005)
- Delivery rate: 550 l/min (33 m³/h)
- Cooling airflow: approx. 4,500 m³/h
- Noise level: approx. 68–70 dB(A)
- Weight: approx. 455 kg
- Dimensions (W × D × H): approx. 93 × 124.5 × 168.5 cm
- Motor type: Three-phase motor
- Motor power: 9 kW (12 HP)
- Operating voltage: 400 V / 50 Hz or 440 V / 60 Hz
- Rated current: approx. 18 A
- Speed: approx. 2,850 RPM
- Protection class: IP55
- 4 compression stages
- Forced lubrication with gear pump
- Stainless steel piping (AISI 316)
- Interstage condensate separators
- Safety valves after each compression stage
Filter System & Air Quality
- Dual Hyperfilter system (2 filters)
- Filter operating pressure: 250 / 330 / 360 bar
- Air purification capacity: approx. 3,050 m³ (at 20 °C / 300 bar)
- Breathing air quality according to DIN EN 12021
Standard Equipment
- Soundproofed enclosure
- 4 high-pressure filling connections (DIN 232 / DIN 300 / INT-YOKE selectable)
- Electronic pressure switch
- Interstage pressure gauges
- Automatic condensate drain system
- High-pressure final separator
- Pressure maintaining / non-return valve
Optional Equipment
- Presec filter monitoring system
- Tornado high-pressure refrigeration dryer
- Multi-gas analysis system (SAM)
- CO SafeGuard
- Remote filling panel
Product safety information
Manufacturer information:
Aerotecnica Coltri
Via dei Colli Storici 177
Desenzano del Garda (BS), Italien, 25015
https://www.coltri.com
