The CMN Oilless Low‑Pressure Screw Compressor series is purpose‑built to deliver ISO 8573‑1 Class 0 oil‑free compressed air in the 0.12 – 0.40 MPa (17 – 58 psi) range. Designed and manufactured under ISO 9001:2015 quality management, every unit undergoes a full‑load factory acceptance test (FAT) and is certified by TÜV Rheinland for true oil‑free performance. With thousands of installations worldwide in pharmaceutical, food, textile and powder conveying applications, CMN’s dry‑screw technology guarantees contaminant‑free air where product purity is non‑negotiable.
Our in‑house application engineers have refined the low‑pressure screw element over two decades of field feedback, resulting in an optimised rotor profile that balances specific power (kW/m³/min) with outstanding durability. The following specification table outlines the standard performance data of the CMN DV series. Detailed performance curves and data sheets for specific operating points are available on request.
1 FAD (Free Air Delivery) measured in accordance with ISO 1217, Annex C, at standard inlet conditions.
2 Exhaust temperature at compressor outlet, ambient 20 °C.
3 Sound pressure level tested per ISO 2151, free‑field conditions at 1 m.
4 Data for specific configurations available upon request. Contact our engineering team for detailed performance curves and dimensional drawings.
Dry screw element with proprietary coating — absolutely no lubricant in the compression chamber. Certified ISO 8573‑1 Class 0 by TÜV Rheinland, ensuring air suitable for direct product contact in food, pharma and electronics.
Patented 4+6 lobe combination reduces internal pressure pulsation and specific energy consumption. Delivers up to 12% better efficiency than conventional designs in the 0.2–0.4 MPa band.
Direct‑coupled permanent magnet motor with variable speed drive (VSD) as standard. Maintains constant pressure while reducing energy consumption by up to 35% compared to fixed‑speed models.
7‑inch colour HMI with real‑time monitoring of pressure, temperature, power and running hours. Built‑in RS‑485/Modbus and optional Ethernet/IP for seamless integration into plant SCADA systems.
Fully enclosed canopy with acoustic insulation achieves noise levels as low as 70 dB(A). Compact layout allows installation close to the point of use, reducing piping losses.
Every compressor undergoes a 4‑hour full‑load run‑in and leak test before shipment. Standard test report included. Ready to install and commission immediately upon delivery.
The CMN oilless compressor uses a two‑stage dry screw element. Ambient air is drawn through a high‑efficiency inlet filter, compressed between two intermeshing rotors without any lubricant, and discharged through an aftercooler. Because the rotors never touch — a precision gear set maintains exact synchronisation — there is no metal‑to‑metal contact and therefore no need for oil in the compression chamber. The result is air that is inherently free of oil aerosols and hydrocarbons.
A permanent magnet motor drives the male rotor directly via a flexible coupling, eliminating transmission losses. The RAYDAFON VSD adjusts motor speed to precisely match air demand, maintaining a stable discharge pressure within ±0.01 MPa. Compression heat is recovered by a water‑cooled (or optional air‑cooled) aftercooler, keeping exhaust temperature below 45 °C (for models where specified) and allowing direct connection to downstream dryers or filters without additional cooling.
Match the compressor to your process pressure. Low‑pressure applications (fermentation, air knives, blow moulding) typically require 0.15–0.4 MPa. The CM DV series covers 0.12–0.40 MPa.
Calculate total air demand (FAD) at the required pressure. Always add 10–15% margin for future expansion and leakage. The CM series spans 5.5 to 30.1 m³/min.
If air contacts food, medicine or sensitive electronics, ISO 8573‑1 Class 0 is mandatory. All CMN DV models are certified Class 0 — no additional filtration for oil.
Air‑cooled models suit well‑ventilated rooms; water‑cooled are ideal for high‑ambient or constrained spaces. Specify cooling type when ordering.
Standard VSD with HMI supports remote start/stop, scheduling and alarm logging. Optional IoT module for predictive maintenance alerts.
All units come with CE declaration, FAT report and material certificates. Pharma/F&B customers should request full validation documentation (IQ/OQ).
Step 1 — Site Preparation: Place compressor on level ground with ≥1 m clearance all around for ventilation. Connect power supply according to nameplate ratings and install a lockable isolator.
Step 2 — Commissioning: Verify correct motor rotation direction (check phase sequence). Fill water‑cooling circuit (if applicable). Turn on the controller and perform a “dry run” for 5 minutes without load.
Step 3 — Start‑Up: Press “Start”. The VSD ramps the motor to minimum speed, then gradually increases to meet set pressure. Monitor discharge pressure and temperature on the HMI.
Step 4 — Normal Operation: Compressor auto‑regulates flow. Check HMI alerts daily. Inspect air intake filter differential pressure every week; replace when indicated.
Step 5 — Shutdown: Press “Stop”. The controller runs an unloaded cooling cycle before shutting down. Isolate power and water (if water‑cooled) for long‑term storage.
Step 6 — Maintenance: Follow the service plan in the manual — typically every 2000 hours or 1 year for air filter, 4000 hours for oil‑lubricated bearings (gearbox, motor). Use only CMN‑approved parts.
CMN provides equivalent or superior performance to premium brands at a competitive factory‑direct price point.
Sterile oil‑free air for aerobic cultures, solvent recovery and tablet coating. Meets FDA/GMP requirements.
Provides stable low‑pressure air for texturing jets, network nozzles and filament entanglement.
Clean, dry air for blow‑moulding beverage bottles, jars and cosmetic containers. Prevents product contamination.
Pneumatic conveying of flour, coffee, cement, chemicals and pharmaceutical powders. No oil contamination risk.
Air knives, sparging, packaging and bottling lines where oil‑free air is a food safety requirement.
Ultra‑clean air for PCB drying, wafer handling and cleanroom pneumatic tools.
We installed a CM75DV for our pharmaceutical fermentation process. The oil‑free certification was mandatory for our GMP compliance, and CMN delivered full IQ/OQ documentation without any extra charge. The machine has been running 24/7 for nearly two years with zero oil carryover detected in our regular air quality tests.
Our texturing plant switched from oil‑flooded compressors to CMN low‑pressure oil‑free units and saw immediate improvement in yarn quality. Oil stains on the filaments were completely eliminated. Energy consumption dropped by 28% thanks to the PM motor and VSD. The remote monitoring feature is very useful for our automated factory.
We use the CM45DV for pneumatic conveying of coffee powder. The compressor is compact, quiet and keeps our conveying lines completely oil‑free. The only reason for not giving 5 stars is that the English manual could be more detailed for the maintenance section. But the support team responded quickly to all my questions via email.
Q1: Is the air truly oil‑free?
Yes. All DV series compressors are certified ISO 8573‑1 Class 0 by TÜV Rheinland. No lubricant enters the compression chamber.
Q2: What is the maintenance interval?
Air filter: 2000 h; inlet valve check: 4000 h; motor/greasable bearings: 4000 h; major overhaul (rotor coating inspection): 16,000 h or 4 years.
Q3: Can I get a custom pressure/flow configuration?
Absolutely. We can tune the VSD setpoints and provide alternative rotor combinations for specialised low‑pressure applications. Contact our application engineers with your requirements.
Q4: Do you offer air‑cooled and water‑cooled models?
Yes. CM45DV and CM55DV are typically air‑cooled; CM75DV and CM110DV are available in both variants. Please specify when requesting a quote.
Q5: What warranty comes with the compressor?
Standard warranty is 24 months from commissioning or 30 months from shipment, whichever occurs first. Extended warranty packages are available.
CMN is a globally recognised manufacturer of oil‑free screw air compressors, specialising in low‑pressure solutions for critical process industries. Headquartered in Asia with regional service centres in Europe, North America and Southeast Asia, CMN combines 20+ years of dry screw design experience with in‑house manufacturing of rotors, gearboxes and controllers. The RAYDAFON permanent magnet motor division provides fully integrated drive trains, eliminating reliance on third‑party motor suppliers and ensuring seamless compatibility between the compressor air end and its drive system.
CMN operates two ISO 9001‑certified factories totalling 45,000 m² of production space. Every compressor is factory‑tested under full‑load conditions and supplied with a traceable test report. The company holds multiple international patents related to dry screw rotor coatings and low‑pressure compression efficiency. With thousands of oilless compressors installed in pharmaceutical, food, textile and electronics plants worldwide, CMN has earned a reputation as a reliable, cost‑effective alternative to traditional European and American brands. Contact CMN today to request a quote, discuss a custom specification, or arrange a factory visit.
CMN’s oilless low‑pressure screw compressors are the preferred choice for pharmaceutical fermentation, chemical fiber texturing, glassware blow moulding, powder transportation and many other applications where pure, contaminant‑free air is essential. For technical consultation and a custom quotation, reach out to our engineering team today.
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