Technical FAQs
These technical FAQs answer common questions about Nardi Compressori's high-pressure breathing air compressors (225, 330, and 420 bar), CNG compressors and boosters, medical and dental air systems, industrial compressors and boosters, routine maintenance, and how to select the right model for an application. For company, purchasing, warranty, and general product questions, see our main FAQ page.
High-Pressure Breathing Air
Nardi high-pressure breathing air compressors are available for diving, firefighting and professional use at three standard operating pressures: 225 bar (3250 psi), 330 bar (4800 psi) and 420 bar (6000 psi), depending on the model. Select the pressure and unit based on required flow rate, available power supply, intended use and applicable air-treatment requirements. (Note: We also carry a line of lower pressure oil-free breathing air compressors that are designed for confined space, SAR airline respirators, and oil-free diving hookahs.)
The difference is the maximum fill pressure the unit is engineered to deliver. 225 bar (3250 psi) and 330 bar (4800 psi) cover standard scuba, SCBA and firefighting cylinders, while 420 bar (6000 psi) is reserved for Nardi’s larger, higher-capacity models. Model choice depends on the cylinder pressure rating in use.
A Nardi high-pressure breathing air compressor requires a filtration system sized to the compressor’s flow rate and operating pressure. Each cartridge features a durable, all-aluminum body and is composed of multiple filtration stages: (1) Felt pads to trap larger particulates; (2) Molecular sieve to remove water vapor; (3) Activated carbon to eliminate oil vapors and odors, and (4) Hopcalite (optional) to convert carbon monoxide (CO) into carbon dioxide (CO2). Nardi’s ATL (for Atlantic compressors) and PAC filters (for Pacific compressors) are sized to the compressor size and air demands. Our largest compressors (CX and MX) are equipped with dual PAC3 filters.
Fill time depends on the compressor’s air-delivery rate (FAD), the cylinder’s water capacity (volume), target fill pressure, and residual cylinder air. As a reference, Nardi’s portable Pacific E series FAD ranges from 160 to 350 L/min (5.7–12.4 cfm). The Pacific E 35 fills a standard 10-liter cylinder to 200 bar (2900 psi) in about 5 minutes 47 seconds. The Pacific E 16 fills the same cylinder in 12 minutes 30 seconds. If you have specific filling requirements, contact Nardi Compressori for assistance.
Nardi high-pressure breathing air compressors are built to meet DIN EN 12021 and are produced under ISO 9001-certified quality management, with containment fill stations additionally tested to NFPA 1900:2024. Breathing air quality standard CGA G-7.1 Grade E, CSA Z180.1, and AS/NZS 2299.1 are lesser than or equal to DIN EN 12021 air standards.
CNG
Nardi CNG compressors are rated to 350 bar (5000 psig), compressing natural gas from a low-pressure supply (as low as 0.02–0.65 bar inlet, depending on model) up to the pressure required for vehicle refueling or high-pressure storage. The CNG range spans six models by flow rate; selection depends on inlet gas pressure and required flow.
Yes. Nardi CNG compressors can be integrated with cascade storage banks and existing refueling infrastructure. Optional accessories include a 270 L buffer tank for gas recovery and NGV1 (Europe/Asia) or P36 (U.S.) filling nozzles. Configuration depends on site supply pressure, throughput requirements and the dispensing equipment in place.
Medical/Dental Air
Nardi’s MEDICAL range is certified as Class IIa medical devices and registered with the Italian Ministry of Health, built for the dental and medical industry with epoxy-coated internal tanks, moisture-removing dryers and antibacterial filtration. Certification and configuration vary by model. Please confirm the applicable regional requirement for your installation and let us know your exact specifications.
A medical air compressor is a Class IIa medical device engineered to deliver clean, oil-free air at low pressure (around 8 bar / 116 psi) to medical and dental equipment, while a breathing-air compressor is built to a much higher pressure (up to 420 bar / 6000 psi) and filtered to meet human breathing-air purity standards such as DIN EN 12021. The two are not interchangeable.
Industrial Air
Nardi’s medium-pressure industrial line covers 0 to 80 bar in three bands (10–40, 40–60 and 60–80 bar) across the CM (2- stage compressor), CB (2-stage booster compressor) and BM (1-stage booster) series. A separate high-pressure booster line (BON2) extends to 420 bar (6000 psi) for applications needing higher storage pressure.
An industrial booster raises the pressure of air or gas that has already been partially compressed by a primary compressor or drawn from storage, rather than compressing from atmospheric pressure. Nardi’s BM series, for example, requires a 4–12 bar inlet supply and boosts it up to 40, 60 or 80 bar depending on the model.
Yes. Nardi’s CM, CB and BM series can be integrated into an existing plant air system; CB and CM models accept a lowpressure inlet (as low as 0.05 bar), while BM boosters require an already-compressed 4–12 bar supply. Contact Nardi Compressori or an authorized dealer for a system-specific integration assessment.
Maintenance
Service intervals for a Nardi high-pressure compressor depend on the model, usage hours and operating environment. Nardi’s own maintenance kits are sold at standard intervals of 1,000, 2,000, 4,000 and (for CNG) 6,000 hours. Refer to the compressor’s user manual for which interval applies, or contact us for assistance.
Keeping a Nardi breathing-air compressor within its DIN EN 12021 air-quality specification requires regular filter cartridge replacement (per the model’s ATL or PAC filter rating), condensate drainage and periodic air-quality testing. Replacement intervals depend on usage hours, flow rate, working pressure and ambient temperature.
Compressor Selection
Selecting the right Nardi compressor depends on the gas being compressed, the required final pressure and flow rate (FAD), the available power supply (voltage and frequency), the intended use (diving, firefighting, medical, industrial or CNG) and any applicable air-treatment or certification requirements. For assistance in identifying the correct machine for your application, provide us as many answers possible on our Get a Quote form.
Free air delivery (FAD) is the actual volume of air a compressor delivers at atmospheric conditions after internal losses, while displacement is the theoretical volume swept by the pistons before any losses. FAD is the more accurate figure for sizing a compressor to real air demand, and it’s the rating Nardi itself uses throughout its technical documentation.