Description
CM Series Permanent Magnet Variable Frequency Oil-Free Screw Air Compressor
Water-Lubricated, 100% Oil-Free Compressed Air · ISO 8573-1 Class 0 Certified · 7.5 kW – 320 kW
The CM Series permanent magnet variable frequency oil-free screw air compressor is a water-lubricated, single-stage rotary screw compressor engineered to deliver 100% oil-free compressed air at 0 ppm oil content. Built on single-screw compression technology with roots tracing back to 1960, the CM Series has refined the single-screw compression concept into a production-ready industrial platform widely regarded as a cost-effective alternative to Atlas Copco Z-series, Ingersoll Rand Nirvana OF, Kaishan KRSP-W, and Sullair OF oil-free compressors. The CM Series is available in two pressure-range families: the CM standard series (0.8–1.25 MPa / up to 12.5 bar) for general industrial and process applications, and the CM/G mid-pressure series (2.0–4.0 MPa / 20–40 bar) dedicated to PET bottle-blowing and high-pressure pneumatic equipment.
Unlike conventional dry-screw or two-stage oil-free compressors that rely on complex gear trains, inter-stage cooling, and high shaft speeds of 6,000–25,000 RPM, the CM Series single-screw host runs at only 3,000 RPM, using food-grade purified water as the lubricant, coolant, and seal medium. This eliminates gearboxes, reduces bearing count from 15+ to just 7, removes mechanical seals entirely through a patented seal-free design, and achieves isothermal compression — keeping discharge temperatures below 45 °C under all operating conditions.
✔ 3,000 RPM Single-Screw
✔ 0 ppm Oil in Discharge
✔ <45 °C Discharge Temp
✔ PM VFD Standard
✔ No Gearbox · No Seals
✔ IoT Remote Monitoring
Industries served: Pharmaceutical & GMP manufacturing · Food & beverage processing · Electronics & semiconductor fabrication · Chemical & petrochemical plants · Textile & dyeing · Spray painting & surface treatment · PET bottle blowing · Medical oxygen generation · Aerospace & defense
Technical Parameters — CM Series (Standard Pressure 0.8 – 1.25 MPa)
Model designation key: CM = Water-Lubricated Oil-Free · Number = Motor kW · PV = Permanent Magnet VFD · BV = Standard Fixed-Speed · F = Air-Cooled · No F suffix = Water-Cooled. Red-highlighted cells in the original brochure indicate water-cooled specifications.
| Model | Pressure (MPa) | Flow (m³/min) | Power kW / HP | Noise dB(A) | Weight (kg) | Dimensions L×W×H (mm) |
|---|---|---|---|---|---|---|
| CM08PVF | 0.8 / 1.0 / 1.25 | 0.45–1.15 / 0.41–1.02 / — | 7.5 / 10 | 58 | 630 / 500 | 1550×775×1445 / 1350×774×1150 |
| CM11PVF | 0.8 / 1.0 / 1.25 | 0.62–1.55 / 0.53–1.32 / 0.48–1.02 | 11 / 15 | 58 | 650 / 520 | 1550×775×1445 / 1350×774×1150 |
| CM15PVF | 0.8 / 1.0 / 1.25 | 0.96–2.40 / 0.85–2.12 / 0.64–1.61 | 15 / 20 | 63 | 900 / 750 | 1900×1000×1635 / 1680×1000×1335 |
| CM18PVF | 0.8 / 1.0 / 1.25 | 1.24–3.10 / 1.05–2.62 / 0.85–2.13 | 18.5 / 25 | 65 | 970 / 820 | 1900×1000×1635 / 1680×1000×1335 |
| CM22PVF | 0.8 / 1.0 / 1.25 | 1.40–3.50 / 1.25–3.13 / 1.04–2.61 | 22 / 30 | 65 | 1000 / 850 | 1900×1000×1635 / 1680×1000×1335 |
| CM30PVF | 0.8 / 1.0 / 1.25 | 2.00–5.00 / 1.68–4.20 / 1.52–3.18 | 30 / 40 | 66 | 1150 / 1080 | 1950×1050×1780 / 1900×1050×1430 |
| CM37PVF | 0.8 / 1.0 / 1.25 | 2.44–6.10 / 2.09–5.22 / 1.92–4.81 | 37 / 50 | 67 | 1170 / 1100 | 1950×1050×1780 / 1900×1050×1430 |
| CM45PVF | 0.8 / 1.0 / 1.25 | 3.12–7.80 / 2.45–6.13 / 2.26–5.65 | 45 / 60 | 68 | 1930 / 1430 | 3040×1280×1800 / 2200×1350×1530 |
| CM55PVF | 0.8 / 1.0 / 1.25 | 3.84–9.60 / 3.44–8.60 / 2.97–7.42 | 55 / 75 | 70 | 2050 / 1550 | 3040×1280×1800 / 2200×1350×1530 |
| CM75PVF | 0.8 / 1.0 / 1.25 | 5.16–12.90 / 4.57–11.42 / 3.93–9.83 | 75 / 100 | 73 | 2450 / 1790 | 3040×1280×1800 / 2200×1350×1530 |
| CM90PVF | 0.8 / 1.0 / 1.25 | 6.52–16.30 / 5.81–14.52 / 4.92–12.30 | 90 / 125 | 73 | 3900 / 2160 | 3750×1850×2180 / 2500×1400×1580 |
| CM110PVF | 0.8 / 1.0 / 1.25 | 7.76–19.40 / 7.09–17.72 / 6.04–15.10 | 110 / 150 | 78 | 4000 / 2270 | 3750×1850×2180 / 2500×1400×1580 |
| CM132PVF | 0.8 / 1.0 / 1.25 | 8.88–22.21 / 8.15–20.38 / 7.31–18.29 | 132 / 180 | 78 | 4150 / 2350 | 3750×1850×2180 / 2500×1400×1580 |
| CM160PVF | 0.8 / 1.0 / 1.25 | 11.54–28.85 / 9.81–24.52 / 8.87–22.17 | 160 / 220 | 78 | 5300 / 3720 | 4300×2000×2500 / 3100×1700×2090 |
| CM200PV | 0.8 / 1.0 / 1.25 | 14.65–36.63 / 13.10–32.70 / 11.09–27.72 | 200 / 270 | 78 | 3750 | 3100×1700×2090 |
| CM250PV | 0.8 / 1.0 / 1.25 | 17.15–42.88 / 15.60–39.00 / 13.87–34.64 | 250 / 340 | 78 | 3900 | 3100×1700×2090 |
| CM320PV | 0.8 / 1.0 / 1.25 | 23.64–59.10 / 21.40–53.50 / 19.30–48.25 | 320 / 430 | 80 | 4850 | 3600×2800×2000 |
Note: F suffix = Air-cooled model. No F suffix = Water-cooled model. PV = Permanent magnet variable frequency. BF = Standard fixed-speed air-cooled. Flow range shown reflects VFD output range at each pressure setting. Water cooling connection: DN25 – DN100 depending on model size.
CM/G Series Mid-Pressure (20–40 Bar / 2.0–4.0 MPa) — PET Blowing & High-Pressure Applications
| Model | Pressure (MPa) | Flow (m³/min) | Power kW / HP | Noise dB(A) | Weight (kg) |
|---|---|---|---|---|---|
| CM75GPV | 2.0–4.0 | 2.5–6.3 | 37+37 / 50+50 | 70 | 2250 |
| CM110GPV | 2.0–4.0 | 3.3–8.2 | 55+55 / 75+75 | 72 | 2450 |
| CM150GPV | 2.0–4.0 | 5.4–13.5 | 75+75 / 100+100 | 75 | 3100 |
| CM200GPV | 2.0–4.0 | 7.1–17.8 | 90+110 / 120+150 | 75 | 3850 |
| CM242GPV | 2.0–4.0 | 9.6–24.0 | 110+132 / 150+180 | 75 | 3950 |
| CM320GPV | 2.0–4.0 | 12.6–31.5 | 160+160 / 220+220 | 85 | 5100 |
Note: CM/G series uses dual stainless-steel single-screw hosts in series (2-stage). GPV = G-series permanent magnet VFD. All CM/G models are water-cooled. Max pressure 4.0 MPa (40 bar). Air outlet: DN32–DN50.
How It Works: Single-Screw Water-Lubricated Compression Principle
Single-Screw Compression Architecture
The our compression host consists of one central helical screw and two meshing star-wheel (gate rotor) assemblies positioned at 90° to the screw axis. This geometry creates 12 independent compression chambers per revolution, delivering twice the compression frequency of a conventional twin-screw design at the same shaft speed. Because the axial and radial forces acting on the screw cancel each other through the symmetric star-wheel arrangement, bearing loads are dramatically lower, enabling the reduction of total bearing count from 15+ in traditional oil-free machines to just 7.
Water as the Universal Working Medium
Purified water (city water quality or deionised for pharmaceutical use) is injected directly into the compression chamber, where it simultaneously performs three functions: (1) lubrication — creating a hydrodynamic water film between screw and star-wheel faces that eliminates metal-to-metal contact; (2) sealing — filling clearance gaps between rotor and housing to prevent internal leakage without mechanical shaft seals; (3) cooling — absorbing the heat of compression so that discharge air temperature stays below 45 °C regardless of ambient temperature, achieving near-true isothermal compression. After compression, water is separated in the stainless-steel water-gas separator, filtered through the 0.1 µm glass-fibre water filter, and recirculated. Only the air proceeds to the downstream system.
Permanent Magnet Variable Frequency Drive (PM-VFD)
The CM Series motor is a custom-designed IP55-rated rare-earth permanent magnet synchronous motor with SKF bearings built in, achieving motor efficiency 3–5% higher than IE3 induction alternatives at the same power class. The motor is direct-coupled to the screw host — no belts, no gearbox, no speed increasers. The integrated VFD controller modulates motor speed from 40% to 100% output in response to real-time demand, holding system pressure within ±0.1 MPa of the setpoint, eliminating the energy wasted in load/unload cycling. The result: energy costs representing 45% of TCO instead of the typical 80% for fixed-speed machines.
Isothermal Compression & Its Benefits
Because water continuously absorbs heat during compression, the thermodynamic process in the CM Series approximates isothermal compression — theoretically the most energy-efficient compression mode. Compared with conventional adiabatic (dry-screw) oil-free compression, isothermal compression reduces the energy required per cubic metre of compressed air by 15–30% depending on operating pressure and ambient conditions. Additionally, because the discharge temperature is held below 45 °C (versus 200 °C in dry-type oil-free compressors), downstream dryer capacity requirements are minimised, and the water vapour content of the compressed air is lower, further improving drying efficiency.
7 Core Advantages of the CM Series Oil-Free Screw Compressor
100% Oil-Free — ISO 8573-1 Class 0
Water replaces oil entirely. Discharge air contains 0 ppm oil at all times, verified by third-party testing. Fully compliant with ISO 8573-1 Class 0 — the strictest international oil-free classification. No downstream oil coalescing filters needed, eliminating a major maintenance cost and contamination risk point.
Ultra-Low Discharge Temperature (<45 °C)
The main host never exceeds 45 °C during operation, virtually eliminating fire and explosion risk, protecting personnel from burn injuries, and significantly reducing moisture content in the compressed air. This allows downstream refrigerated dryers to work more efficiently and extends dryer life. Ideal for indoor plant rooms where heat rejection is a concern.
Exceptional Energy Savings — Up to 35% vs Fixed-Speed
The permanent magnet VFD (efficiency 97%) combined with direct-drive coupling and isothermal compression reduces electricity consumption by 15–35% versus comparable fixed-speed oil-free compressors. For a 110 kW unit running 8,000 hours/year, this represents potential annual savings of 40,000–90,000 kWh — enough to justify the investment within 2–3 years in most markets.
Minimal Maintenance — Only 2 Consumables
The CM Series has no lubricating oil to change, no oil separators to replace, no gearbox oil to monitor, and no shaft seals to rebuild. Scheduled maintenance requires replacing only two items every 1,000–2,000 hours: (1) air inlet filter element and (2) water filter cartridge. This compresses the annual maintenance cost to a small fraction of that of conventional oil-free or oil-injected alternatives.
Industry-Leading Low Noise — from 58 dB(A)
Running at only 3,000 RPM with no speed-increasing gearbox and direct motor coupling, plus the patented sound-dampening inlet structure and special high-density acoustic foam enclosure, the CM Series achieves 58 dB(A) on small models — 20–50% quieter than reciprocating piston compressors of equivalent output. Units can be installed adjacent to production areas without a dedicated compressor room in many cases, saving construction cost.
Long Service Life — Host Design Life > 25 Years
The stainless-steel single-screw host (patented design) runs with hydrodynamic water film lubrication, absorbing no oil-contaminated deposits. aerospace-grade composite star-wheel material, rigorously QC-tested per aviation inspection standards, resolves the historical wear challenge of gate rotors in water-lubricated designs. With a 100,000-hour+ main host design life and no gearbox to fail, total compressor lifespan substantially exceeds conventional oil-free machines.
Smart IoT Monitoring — Remote Control & Predictive Alerts
All CM Series units ship standard with the integrated IoT monitoring platform: a 10-inch colour touchscreen controller with RS485 interface supports remote start/stop, real-time parameter monitoring, fault pre-warning, and data logging. The cloud platform enables fleet management across multiple compressor stations, supporting DCS integration and edge-computing-based AI energy optimisation for first-tier energy efficiency station solutions.
Key Components & Material Engineering
① Permanent Magnet Motor (IP55 / F-class)
Custom-wound rare-earth PM synchronous motor with built-in SKF bearings. IP55 ingress protection. Class F insulation rating guarantees 7×24-hour continuous operation. Motor efficiency 3–5% above IE3 induction motor class, validated by IEC 60034-30 protocol. Special design options available on request.
② PLC & VFD Control System (RS485 / Modbus)
Advanced advanced Schneider PLC with 10-inch colour HMI. Displays all operating parameters, fault codes, pressure trends, and maintenance counters. Schneider Electric drive system for stable speed control. Supports RS485/Modbus RTU integration with plant SCADA or DCS systems. Remote firmware update via LAN/4G.
③ Patented High-Efficiency Inlet Valve
100% proprietary valve design with minimum pressure point intake mode, maximising compression efficiency and reducing unloading noise. The modular open-cassette housing structure simplifies filter replacement and valve inspection. Enhances air filter service life by reducing turbulence at the inlet face.
④ All-Stainless Water-Gas Separator
Full 304/316 stainless-steel construction with no internal polymer parts. Proprietary streamlined internal baffles accelerate water-air separation at 10 m/s air velocity, settling water to the tank bottom for minimum-pressure valve ejection. Prevents any residual water carryover into the downstream air network.
⑤ All-Stainless Single-Screw Host (Patent ZL201110000872.4)
Full stainless-steel screw and housing assembly manufactured to aerospace-grade dimensional tolerances. The patented seal-free shaft design (no mechanical contact seals) eliminates the primary wear and leak failure mode of conventional compressors. Rotor ultra-high volumetric efficiency at 3,000 RPM. Designed service life exceeds 100,000 hours / 25 years.
⑥ Lubricating Water Filtration System (0.1 µm)
Stainless outer shell housing with proprietary high-density multi-layer glass-fibre filter element achieving filtration to 0.1 µm. Continuously maintains water purity to protect the host bearings and star-wheel surfaces. Clean lubrication water is the primary factor extending main host service intervals. Element replacement: every 1,000–2,000 hours.
⑦ High-Performance All-Stainless Water Cooler
Multi-flow stainless-steel plate heat exchanger with large cooling surface area. Maintains discharge air temperature below 55 °C even at 40 °C ambient. Superior heat transfer performance per unit of cooler footprint. Stainless construction resists scaling and biological fouling, extending cooler service life significantly versus copper or aluminium alternatives in harsh water quality environments.
Star-Wheel (Gate Rotor) — Aerospace Composite Material
The star-wheel is the only polymer-contact component in the compression path. the proprietary aerospace-composite material formulation, combined with precision configuration placement, has definitively resolved the historical wear issue inherent to water-lubricated single-screw designs. Each star-wheel manufactured by our undergoes aviation-standard screening and inspection, ensuring dimensional conformance and long operational life with less than 5% performance degradation over 50,000 hours.
Typical Application Scenarios
💊 Pharmaceutical & Biotech (GMP)
FDA 21 CFR, EU GMP Annex 1, and Chinese GMP standards all mandate oil-free compressed air in direct or indirect product contact applications. The CM Series 0 ppm oil output and ISO Class 0 certification satisfy the most stringent auditor requirements for tablet coating, sterile filling, lyophilisation, and fermenter aeration. Low discharge temperature also prevents product thermal degradation in pneumatic transfer systems.
Recommended models: CM08PVF – CM132PVF (7.5–132 kW)
🍺 Food, Beverage & Dairy
Food-grade compressed air (BCAS/BRC) requires demonstrable oil-free supply. The CM Series eliminates hydrocarbon contamination risk in bottling, filling, cleaning-in-place (CIP) air agitation, yogurt culture aeration, and modified-atmosphere packaging (MAP). Major clients include leading Chinese dairy brands, beverage manufacturers, and edible-oil processing plants.
Recommended models: CM15PVF – CM200PV (15–200 kW)
🔬 Electronics & Semiconductor
Chip wafer fabrication, PCB etching, LED chip packaging, and display panel production all require Class 0 oil-free compressed air. Even trace oil vapour from conventional oil-injected compressors can contaminate clean-room surfaces and degrade photolithography yields. The CM Series delivers reliably oil-free air with no risk of oil carryover even during filter breakthrough events — a critical safety margin unavailable from oil-injected machines with downstream filters.
Recommended models: CM30PVF – CM160PVF (30–160 kW)
⚗️ Chemical & Petrochemical
Many chemical processes require oil-free instrument air and process air where oil contamination would trigger unwanted catalytic reactions or product impurities. The CM Series all-stainless construction also resists corrosion from chemically aggressive ambient air commonly found in chemical plant environments. The near-zero discharge temperature reduces the risk of auto-ignition in flammable-vapour atmospheres.
Recommended models: CM75PVF – CM320PV (75–320 kW)
🎨 Spray Painting & Surface Coating
Automotive, aerospace, and industrial coating operations cannot tolerate oil mist in compressed air supply — oil causes fish-eye defects, adhesion failures, and coating delamination. The CM Series eliminates the need for activated-carbon oil-vapour filters that require regular monitoring and replacement. Lower air temperature also improves atomisation quality and first-pass paint transfer efficiency.
Recommended models: CM22PVF – CM110PVF (22–110 kW)
🍾 PET Bottle Blowing (CM/G 20–40 Bar)
PET blow-moulding machines (ISBM and 2-stage SBM) require high-pressure oil-free air at 20–40 bar. The CM/G dual-stage series delivers up to 4.0 MPa (40 bar) while maintaining 0 ppm oil and discharge temperature below 45 °C, protecting mould surfaces and ensuring food-contact compliance. Compatible with leading ISBM manufacturers’ specifications including Netstal, Sipa, Sidel, and domestic ISBM OEMs.
Recommended models: CM/G series (75–320 kW, 2.0–4.0 MPa)
How to Select the Right CM Series Model — Buyer’s Guide
Follow these five steps to identify the optimal CM Series model for your facility. If you prefer expert guidance, our engineering team can assist with a no-cost compressed air audit and sizing calculation.
Define Required Discharge Pressure (MPa)
Identify the actual working pressure required at the point of use — not the compressor outlet. Add 0.05–0.1 MPa for pipe pressure drop. Standard applications: 0.7–1.0 MPa (general factory); high-pressure applications: 2.0–4.0 MPa (PET blowing, high-pressure cylinders). Select the compressor pressure rating one step above your required working pressure to allow VFD headroom.
Calculate Peak and Average Compressed Air Demand (m³/min)
Sum the free air delivery (FAD) requirements of all pneumatic tools, instruments, and process equipment. Apply a coincidence factor (typically 0.6–0.85 for mixed loads) to estimate simultaneous peak demand. Size the compressor to cover peak demand, then verify that at minimum demand the VFD output does not fall below 40% of rated capacity (minimum efficient speed). If demand variation exceeds 3:1, consider a VFD + fixed-speed pairing.
Confirm Cooling Type — Air-Cooled (F) or Water-Cooled
Air-cooled (F models): Simpler installation, no cooling water system required, suitable for ambient temperatures up to 40 °C. Limited to 37 kW and below (CM37PVF and smaller). Water-cooled (no F suffix): Required for 45 kW+; provides more stable temperature control, particularly in high-ambient environments; requires a cooling water loop (city water, cooling tower, or chiller at 0.3–0.4 MPa, below 32 °C inlet). For pharmaceutical GMP rooms, water-cooled is generally preferred for heat management.
Assess Water Quality for the Lubrication Circuit
The CM Series requires clean water similar to potable tap water quality. Key parameters: total dissolved solids (TDS) < 500 ppm, hardness < 300 ppm as CaCO₃, pH 6.5–8.5, no corrosive ions (chlorides < 50 ppm). For pharmaceutical applications, deionised or reverse-osmosis water is recommended. Hard water areas should consider water softeners upstream of the compressor water circuit to prevent mineral scale on the 0.1 µm filter and cooler. We provide a water quality checklist on request.
Plan the Downstream Air Treatment Train
Even with 100% oil-free air, downstream drying and particulate filtration are required for most applications. Typical configuration: CM Series compressor → air receiver tank (10× FAD in litres minimum) → refrigerated compressed air dryer (pressure dew point ≤+3 °C) → 1 µm coalescing filter + 0.01 µm sterile filter (pharmaceutical) → distribution. Because CM discharge temperature is already low (<45 °C), refrigerated dryer sizing can be smaller than for equivalent dry-screw oil-free compressors. CM/G PET blowing installations also require high-pressure buffer tanks and dedicated blow-moulding machine connections.
CM Series vs. Leading International Brands — Objective Comparison
Important notice: The brand names listed below (Atlas Copco, Ingersoll Rand, Sullair, Kaeser, Kaishan) are the property of their respective owners. the manufacturer does not manufacture, sell, or represent any products under these brand names. Brand model numbers are referenced solely to assist buyers in technical selection and cross-referencing equivalent specifications. No trademark infringement is intended or implied.
| Comparison Item | CM Series | Atlas Copco ZR/ZT | Ingersoll Rand Nirvana OF | Kaeser CS / DSD-T |
|---|---|---|---|---|
| Oil-free certification | ISO 8573-1 Class 0 ✔ | ISO 8573-1 Class 0 ✔ | ISO 8573-1 Class 0 ✔ | ISO 8573-1 Class 0 ✔ |
| Oil-free mechanism | Water-lubricated single-screw | Dry twin-screw (ZT) / Water (ZR) | Dry twin-screw | Dry twin-screw |
| Discharge temperature | < 45 °C (isothermal) | ZT: ~180–200 °C; ZR: ~45 °C | ~180–200 °C | ~180–200 °C |
| Rotor speed | 3,000 RPM | 6,000–25,000 RPM | 6,000–20,000 RPM | 6,000–15,000 RPM |
| Gearbox required | No — direct drive ✔ | Yes (most models) | Yes | Yes |
| Number of bearings | 7 | > 15 | > 15 | > 15 |
| Number of gears | 0 | 5–7 | 5–7 | 5–7 |
| Noise level (37 kW equiv.) | 58–67 dB(A) | ~70–75 dB(A) | ~72–76 dB(A) | ~70–74 dB(A) |
| VFD / PM motor standard? | Yes — standard ✔ | Optional (premium upcharge) | Optional | Optional |
| Maintenance consumables | 2 (air filter + water filter) | 4–6 (air filter, oil-sep, PTFE coating, gearbox oil, etc.) | 4–6 | 4–6 |
| Typical FOB price (110 kW equiv.) | USD 25,000–40,000 | USD 80,000–130,000 | USD 70,000–110,000 | USD 75,000–115,000 |
| IoT remote monitoring | Standard ✔ | Optional (SmartLink) | Optional (IntelliSys) | Optional (Sigma Air Control) |
| Host design life | > 100,000 hours / 25 years | ~80,000–100,000 hours | ~80,000 hours | ~80,000 hours |
Note: Price ranges are indicative market estimates for comparison purposes only and may vary by region, configuration, and purchase volume. We do not guarantee the accuracy of competitor pricing data.
Frequently Asked Questions — CM Series Oil-Free Screw Compressor
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