ULVAC Dry Screw Pumps – Advanced Oil-Free Technology for Industrial Applications
ULVAC dry screw vacuum pumps represent cutting-edge oil-free vacuum technology for demanding industrial and semiconductor applications. These advanced pumps combine high pumping speeds, deep ultimate vacuum, and excellent chemical resistance in a compact, reliable package. With internal compression and intelligent design, ULVAC dry screw pumps deliver superior performance for the most challenging processes.
🌪️ What are Dry Screw Vacuum Pumps?
Dry screw vacuum pumps are positive displacement pumps with two counter-rotating screw rotors that compress gas without any oil or liquid in the pumping chamber. They represent one of the most advanced dry pump technologies available today.
⚙️ Operating Principle:
- Two screw rotors rotate in opposite directions within a cylindrical housing
- Intermeshing screws trap gas in the spaces between threads
- Gas is transported axially from inlet to outlet along the screw length
- Internal compression occurs as the gas pocket volume decreases
- Compressed gas is discharged at outlet pressure
- Timing gears maintain precise synchronization (rotors don't touch)
✅ Key Advantages of Dry Screw Technology:
| 🛢️ 100% Oil-Free |
No oil contamination of process gas or environment – completely clean vacuum |
| 🧪 Chemical Resistance |
Can handle corrosive gases, acids, solvents – ideal for chemical processes |
| 📈 Internal Compression |
Energy-efficient operation – compression occurs inside pump |
| 🚀 High Pumping Speed |
Excellent performance throughout entire pressure range |
| ⬇️ Deep Ultimate Vacuum |
Can reach < 0.01 Pa (0.0001 mbar) without backing pump |
| 🔧 Low Maintenance |
No oil changes, minimal wear parts, long service intervals |
| 💪 Robust Construction |
Designed for continuous 24/7 industrial operation |
| ♻️ Process Gas Recovery |
Clean exhaust allows gas recovery and recycling |
📊 ULVAC Dry Screw Pump Models:
🔷 NSS Series – Industrial Dry Screw Pumps
The NSS series represents ULVAC's advanced dry screw pump technology for industrial applications.
| Model | Pumping Speed | Ultimate Vacuum | Power |
|---|
| NSS100 |
100 m³/h |
< 0.01 Pa (0.0001 mbar) |
3.7 kW |
| NSS200 |
200 m³/h |
< 0.01 Pa (0.0001 mbar) |
7.5 kW |
| NSS300 |
300 m³/h |
< 0.01 Pa (0.0001 mbar) |
11 kW |
| NSS500 |
500 m³/h |
< 0.01 Pa (0.0001 mbar) |
18.5 kW |
| NSS750 |
750 m³/h |
< 0.01 Pa (0.0001 mbar) |
30 kW |
| NSS1000 |
1,000 m³/h |
< 0.01 Pa (0.0001 mbar) |
37 kW |
| NSS1500 |
1,500 m³/h |
< 0.01 Pa (0.0001 mbar) |
55 kW |
📊 Performance Characteristics:
| Parameter | Specification |
|---|
| Operating Range: |
Atmospheric pressure down to < 0.01 Pa |
| Compression Ratio: |
> 10⁶ for nitrogen |
| Water Vapor Tolerance: |
Can handle condensable vapors with optional gas purge |
| Operating Temperature: |
Rotor temperature: 80-120°C (controllable) |
| Cooling: |
Water-cooled (standard) or air-cooled (optional) |
| Noise Level: |
< 75 dB(A) |
Available ULVAC dry screw pump models: NSS100, NSS200, NSS300, NSS500, NSS750, NSS1000, NSS1500, dry screw pumps, oil-free screw pumps, chemical resistant pumps, industrial dry pumps, high vacuum dry pumps, semiconductor pumps, process pumps, corrosion resistant pumps
🔩 Construction & Design Features:
⚙️ Core Components:
| Component | Material/Design | Features |
|---|
| Screw Rotors |
Precision-machined special steel with coatings |
Hardened surface, corrosion-resistant coatings, dynamically balanced |
| Housing/Cylinder |
Ductile cast iron or stainless steel |
Water-cooled jackets, temperature-controlled, corrosion-resistant |
| Timing Gears |
Hardened alloy steel |
Precision ground, oil-bath lubricated, ensure rotor synchronization |
| Bearings |
Heavy-duty angular contact bearings |
Oil-lubricated, designed for axial and radial loads, long life |
| Shaft Seals |
Multi-stage mechanical face seals |
Prevent oil migration to pumping chamber, gas-purged |
| Inlet Flange |
ISO-KF or ISO-K standard |
Easy connection to vacuum systems |
| Exhaust |
Flanged connection |
Can be connected to scrubber or exhaust system |
🛡️ Special Design Features:
- ✓ Non-contact operation – screw rotors never touch = no wear in pumping chamber
- ✓ Internal compression – reduces power consumption and heating
- ✓ Temperature control system – maintains optimal rotor temperature
- ✓ Gas purge system – prevents oil migration and handles vapors
- ✓ Minimal clearances – 0.05-0.15 mm for optimal performance
- ✓ Corrosion-resistant coatings – for aggressive chemical processes
- ✓ Integrated cooling – water jackets control operating temperature
- ✓ Vibration isolation – reduces noise and vibration transmission
🌡️ Temperature Management System:
One of the key advantages of ULVAC dry screw pumps is the intelligent temperature control system:
| Feature | Function | Benefit |
|---|
| Water Cooling |
Cooling water circulates through housing jackets |
Controls rotor and housing temperature |
| Temperature Monitoring |
Multiple temperature sensors monitor key points |
Prevents overheating, optimizes performance |
| Heating Option |
Can maintain elevated rotor temperature (80-120°C) |
Prevents vapor condensation inside pump |
| Automatic Control |
PID temperature control system |
Maintains optimal operating conditions |
💡 Why Temperature Control Matters:
- → Prevents condensation of water vapor and solvents inside pump
- → Maintains clearances – thermal expansion controlled
- → Protects materials from corrosion by condensed chemicals
- → Optimizes performance at different process conditions
- → Extends service life by preventing corrosive attack
🏭 Primary Applications:
| Industry | Applications |
|---|
| 🔬 Semiconductor Manufacturing |
CVD (Chemical Vapor Deposition), dry etching, ion implantation, PECVD, diffusion furnaces, load locks |
| 📺 Flat Panel Display (FPD) |
LCD production, OLED manufacturing, touch panel coating, large-area CVD |
| ☀️ Solar Cell Production |
Thin film deposition, PECVD for silicon layers, texturing processes |
| 🎨 Vacuum Coating |
PVD coating, sputtering, evaporation, optical coatings, decorative coatings |
| 🧪 Chemical Industry |
Vacuum distillation, solvent recovery, drying processes with corrosive vapors, polymerization reactors |
| 💊 Pharmaceutical |
Freeze drying (lyophilization), API synthesis, vacuum drying, solvent recovery |
| 🔋 Battery Manufacturing |
Lithium-ion battery production, electrode coating, vacuum drying |
| 🔬 Research & Development |
Material science, thin film research, surface modification, plasma processes |
💡 Dry Screw vs. Other Dry Pump Technologies:
| Feature | Dry Screw | Dry Scroll | Dry Roots |
|---|
| Ultimate Vacuum |
< 0.01 Pa ✅ Best |
0.1 - 1 Pa |
0.1 - 1 Pa |
| Internal Compression |
Yes ✅ |
Yes ✅ |
No |
| Chemical Resistance |
Excellent ✅ |
Good |
Good |
| Pumping Speed Range |
100-1,500 m³/h ✅ |
3-40 m³/h |
50-5,000 m³/h |
| Vapor Tolerance |
Excellent (with heating) ✅ |
Limited |
Limited |
| Energy Efficiency |
Very good ✅ |
Excellent |
Good |
| Typical Use |
Semiconductor, chemical |
Laboratory, clean processes |
Large volume, backing pump |
✅ Choose Dry Screw Pumps When:
- Deep vacuum < 0.01 Pa required without backing pump
- Corrosive or aggressive gases present
- Process involves condensable vapors
- Semiconductor or FPD manufacturing
- Clean, oil-free exhaust essential
- Process gas recovery needed
- High chemical resistance critical
- Moderate to high pumping speeds (100-1,500 m³/h)
🎛️ Control & Monitoring Systems:
🖥️ Integrated Control Features:
- ✓ Digital controller – monitors all pump parameters
- ✓ Temperature monitoring – multiple temperature sensors
- ✓ Motor current monitoring – detects overload conditions
- ✓ Vibration sensors – early warning of bearing issues
- ✓ Cooling water flow monitor – ensures adequate cooling
- ✓ Operating hours counter – tracks maintenance intervals
- ✓ Alarm outputs – warning and shutdown signals
- ✓ Remote monitoring – Ethernet/RS485 communication
🛡️ Protection Systems:
- ✓ Over-temperature shutdown
- ✓ Motor overload protection
- ✓ Cooling water failure alarm
- ✓ Excessive vibration detection
- ✓ Phase loss protection
- ✓ Soft start to reduce mechanical stress
♻️ Process Gas Recovery & Environmental Benefits:
One major advantage of dry screw pumps is the clean, uncontaminated exhaust gas:
| 💰 Gas Recovery |
Expensive process gases can be recovered and recycled (e.g., silane, fluorinated gases) |
| 🌍 Environmental Protection |
No oil mist in exhaust – easier exhaust treatment, reduced environmental impact |
| 💧 Scrubber Compatibility |
Clean exhaust is compatible with wet scrubbers for hazardous gas treatment |
| 📊 Process Monitoring |
Exhaust can be monitored without oil interference |
🔧 Maintenance & Service:
📅 Maintenance Schedule:
| Task | Interval | Description |
|---|
| Daily Check |
Daily |
Visual inspection, check controller display, listen for unusual noises |
| Weekly Check |
Weekly |
Check cooling water flow, verify temperature readings, inspect for leaks |
| Monthly Check |
Monthly |
Check gear oil level, inspect shaft seals, verify alarm functions |
| Gear Oil Change |
6-12 months |
Drain and replace timing gear lubricating oil |
| Seal Inspection |
12 months |
Check shaft seals for leakage, measure purge gas consumption |
| Performance Check |
12 months |
Measure ultimate vacuum, check pumping speed curve |
| Major Service |
2-3 years |
Replace shaft seals, check bearings, inspect rotors, measure clearances |
| Complete Overhaul |
5-7 years |
Full disassembly, rotor reconditioning, replace all wear parts, reassemble, test |
🔧 Maintenance Advantages:
- ✓ No oil changes in pumping chamber – major time savings
- ✓ Long service intervals – typically 20,000+ operating hours between major services
- ✓ Minimal consumables – only gear oil and seal purge gas
- ✓ Predictable wear – operating hours tracking enables planned maintenance
- ✓ Modular design – components can be replaced individually
🔧 Common Wear Parts:
- Shaft seals (mechanical face seals)
- Bearings (typically 30,000-50,000 hours life)
- Timing gears (minimal wear with proper lubrication)
- O-rings and gaskets
- Cooling water seals
- Temperature sensors
💰 Total Cost of Ownership (TCO):
📊 Cost Comparison: Dry Screw vs. Oil-Sealed Rotary Vane:
| Factor | Dry Screw Pump | Oil-Sealed Rotary Vane |
|---|
| Initial Cost |
Higher (2-3x) |
Lower |
| Oil Changes |
None (only gear oil) |
Frequent (monthly/quarterly) |
| Oil Disposal |
Minimal |
Significant cost & environmental issue |
| Maintenance Time |
Low – long intervals |
High – frequent service |
| Chemical Resistance |
Excellent – handles corrosives |
Poor – oil degrades quickly |
| Downtime |
Minimal |
More frequent for oil changes |
| Process Contamination |
None – oil-free |
Risk of oil backstreaming |
| 5-Year TCO |
Lower ✅ |
Higher |
💡 ROI Considerations:
- → Higher initial cost typically recovered within 2-3 years
- → Reduced maintenance labor costs
- → Elimination of oil purchase and disposal costs
- → Higher process uptime
- → Better process quality (no oil contamination)
- → Ability to recover expensive process gases
🔧 Our Service for ULVAC Dry Screw Pumps:
| 🛒 Sales |
New ULVAC NSS series dry screw pumps – all models (100-1,500 m³/h) |
| 🎯 Application Engineering |
System design, pump sizing, integration planning |
| ♻️ Complete Overhaul |
Full reconditioning: rotor refinishing, seal replacement, bearing renewal, testing |
| ⚙️ Repair |
Expert repair of all components, clearance adjustment, coating renewal |
| 📦 Spare Parts |
Genuine ULVAC parts: seals, bearings, rotors, controllers |
| 🚗 On-Site Service |
Installation, commissioning, troubleshooting, training |
| 🔍 Performance Testing |
Pumping speed measurement, ultimate vacuum testing, leak detection |
| 📊 Preventive Maintenance |
Scheduled maintenance programs, condition monitoring |
🌟 Why Choose ULVAC Dry Screw Pumps?
| 🇯🇵 Japanese Precision |
ULVAC quality and engineering excellence since 1952 |
| 🔬 Semiconductor Proven |
Trusted by leading semiconductor manufacturers worldwide |
| 🛢️ Completely Oil-Free |
Zero contamination risk – clean process and exhaust |
| 🧪 Superior Chemical Resistance |
Handles the most aggressive chemical processes |
| ⬇️ Deep Vacuum |
< 0.01 Pa without backing pump – industry-leading performance |
| 💰 Low TCO |
Lower total cost of ownership over pump lifetime |
| ♻️ Environmentally Friendly |
No oil disposal, clean exhaust, gas recovery possible |
| 🔧 Long Service Life |
20,000+ hours between major services |
Need an ULVAC Dry Screw Vacuum Pump?
Whether NSS100-300 for medium-capacity applications, NSS500-750 for standard industrial processes, or NSS1000-1500 for high-throughput semiconductor manufacturing – our ULVAC dry screw pump experts are happy to advise you in selecting the optimal pump for your specific process requirements.
We provide complete system solutions including pump, controller, cooling system, exhaust treatment, and full integration into your process equipment.
We also specialize in complete overhaul and repair of existing ULVAC dry screw pumps – restoring them to factory performance specifications with genuine parts, advanced diagnostics, and expert reconditioning.
Japanese high-tech quality since 1952 – professional local service! Contact us today for expert consultation and cutting-edge dry screw vacuum technology.
