Oil-Free Scroll

Oil-free scroll compressors produce 100% oil-free air, ideal for applications requiring maximum purity.

Oil-Free Design

Unlike screw compressors that require special designs to be oil-free, scroll is inherently suitable for oil-free operation:

    Lubricated Scroll:          Oil-Free Scroll:

    ┌─────────────────┐        ┌─────────────────┐
    │  Scrolls with   │        │  Scrolls with   │
    │  oil film       │        │  PTFE/anodized  │
    │                 │        │  coating        │
    └────────┬────────┘        └────────┬────────┘
             │                          │
    ┌────────┴────────┐        ┌────────┴────────┐
    │  Motor with     │        │  Sealed motor   │
    │  shared         │        │  separate       │
    │  lubrication    │        │  lubrication    │
    └─────────────────┘        └─────────────────┘

Sealing Technologies

Scroll Coatings

Coating	Characteristics	Service Life
PTFE (Teflon)	Low friction coefficient, economical	20,000-40,000 h
Hard anodizing	High hardness, wear resistant	40,000-60,000 h
PEEK	High temperature, chemically inert	30,000-50,000 h
Carbon-graphite	Self-lubricating, high temperature	25,000-45,000 h

Tip Seals

Tip seals are critical for efficiency:

    Section view:

    ┌─────────────────────────────┐
    │        Fixed scroll         │
    │  ═══════════════════════    │
    │         ▓▓▓ ← Tip seal      │
    │  ───────────────────────    │
    │      Orbiting scroll        │
    └─────────────────────────────┘

Tip Seal Material	Application
PTFE	Standard, general use
PEEK	High temperature
Carbon	Long life
Composite	Cost/performance balance

ISO 8573-1 Classification

Certified oil-free scroll compressors meet:

Class	Total Oil	Application
Class 0	User defined	Pharmaceutical, semiconductors
Class 1	≤ 0.01 mg/m³	Food, medical

Advantages Over Other Oil-Free

vs Oil-Free Piston	vs Oil-Free Screw
Lower noise	Lower cost (small capacity)
Less maintenance	More compact
Longer seal life	Less complexity
No valves	No rotor synchronization
Less vibration	Higher reliability

Critical Applications

Medical and Dental

Application	Requirements
Dental air	Class 1-2, dry, quiet
Ventilators	Class 0-1, extreme reliability
Surgical instruments	Class 1, sterile
Nebulizers	Class 1, stable flow

Standards:

• FDA 21 CFR
• ISO 7396-1 (medical gases)
• HTM 02-01 (UK)

Laboratories

Application	Requirements
Gas chromatography	Class 1, ultra dry
Spectroscopy	Class 1, stable
Chemical analysis	Class 1-2, no contaminants
ICP-MS	Class 0-1

Food and Beverage

Application	Requirements
Packaging	Class 1-2, direct contact
Pneumatic conveying	Class 2, high flow
Fermentation	Class 1, sterile
Aseptic filling	Class 0-1

Electronics

Application	Requirements
Clean rooms	Class 1, HEPA filtered
Pick and place	Class 2, stable flow
PCB cleaning	Class 1, dry
Semiconductors	Class 0

Typical Oil-Free Specifications

Parameter	Value
Oil class	0 or 1 (ISO 8573-1)
Discharge temperature	10-20°C above ambient
Dew point (with dryer)	-20 to -40°C
Noise level	52-65 dB(A)
Scroll service life	30,000-60,000 h
Maintenance interval	4,000-8,000 h

Installation Considerations

Environment

Factor	Recommendation
Temperature	5-40°C (41-104°F)
Humidity	30-90% RH
Ventilation	Minimum 1 m³/min per HP
Dust	Filter if excessive

Inlet Filtration

More critical than in lubricated units:

Stage	Efficiency
Pre-filter	10 microns
Main filter	1 micron
HEPA filter (optional)	0.3 microns, 99.97%

Specific Maintenance

Interval	Action
500 h	Visual inspection, filters
2,000 h	Check tip seals
4,000-8,000 h	Replace tip seals
16,000-24,000 h	Scroll inspection
40,000+ h	Complete overhaul

Cost of Ownership

Factor	Oil-Free Scroll	Oil-Free Piston	Oil-Free Screw
Initial cost	$$	$	$$$$
Annual maintenance	$	$$	$$
Energy	$$	$$$	$$
Service life	15-20 years	10-15 years	15-20 years
Noise/Space	Advantage	Disadvantage	Neutral