Sterling SIHI – German Liquid Ring Technology for Industrial Vacuum & Compression Since 1863
Sterling SIHI is a world-leading manufacturer of liquid ring vacuum pumps, liquid ring compressors, dry running vacuum pumps, and side channel blowers for demanding industrial applications. With over 160 years of German engineering excellence since 1863, Sterling SIHI stands for unmatched reliability, robust construction, and proven wet process technology. We are your competent partner for sales, service, and repair of Sterling SIHI equipment in Austria.
🎯 Our Sterling SIHI Product Portfolio:
💧 Liquid Ring Vacuum Pumps – The Industry Standard
Sterling SIHI is globally renowned for its liquid ring vacuum pump technology – the gold standard for industrial vacuum applications involving wet, contaminated, or explosive gases.
⚙️ Liquid Ring Operating Principle:
- Eccentric impeller rotates inside cylindrical housing
- Service liquid (water, oil, or solvent) is thrown outward by centrifugal force
- Liquid ring forms against housing inner wall
- Crescent-shaped working chambers form between impeller vanes and liquid ring
- Chamber volume increases at inlet side – gas is drawn in
- Chamber volume decreases at outlet side – gas is compressed
- Compressed gas exits along with service liquid
- Gas-liquid separation occurs in external separator vessel
- Service liquid recirculates back to pump
✅ Unique Advantages of Liquid Ring Technology:
| 💪 Extremely Robust |
No metal-to-metal contact in compression chamber – virtually wear-free operation |
| 💨 Wet Process Champion |
Handles moist gases, vapors, condensates, and even entrained liquids without problems |
| 🌡️ Isothermal Compression |
Service liquid continuously cools and seals – prevents overheating |
| 🧹 Self-Cleaning Action |
Service liquid continuously washes contaminants out of pump |
| 🔧 Low Maintenance |
Few moving parts, minimal wear, extended service intervals |
| 🔥 Explosion-Safe |
No spark generation, no hot surfaces – suitable for flammable gases (ATEX certified) |
| 🛡️ Contamination Tolerant |
Handles dust, particles, fibers, and dirty gases without damage |
| ♻️ Environmentally Friendly |
Water as service medium – no oil contamination or disposal |
📊 Sterling SIHI Liquid Ring Pump Series:
🔷 LPHY Series – Single-Stage Liquid Ring Pumps
The LPHY series represents Sterling SIHI's proven single-stage liquid ring vacuum pumps for general industrial applications.
| Parameter | Specification |
|---|
| Pumping Speed Range: |
25 - 30,000 m³/h |
| Ultimate Vacuum: |
up to 160 mbar (abs) with water as service liquid |
| Service Liquid: |
Water (standard), oil, glycol, solvents, process liquids |
| Construction: |
Cast iron, ductile iron, or stainless steel |
| Applications: |
General industrial vacuum, moderate vacuum requirements |
✅ LPHY Series Features:
- ✓ Cost-effective single-stage design
- ✓ Robust cast iron or stainless steel construction
- ✓ Wide range of sizes for different capacities
- ✓ Easy maintenance and service access
- ✓ Available in horizontal or vertical orientation
- ✓ Multiple material options for corrosive applications
- ✓ ATEX-certified versions available
🔶 LPHY-H Series – Two-Stage High Vacuum Pumps
The LPHY-H series features two-stage design for applications requiring deeper ultimate vacuum.
| Parameter | Specification |
|---|
| Pumping Speed Range: |
25 - 20,000 m³/h |
| Ultimate Vacuum: |
up to 33 mbar (abs) with water, down to 3 mbar with oil |
| Design: |
Two-stage tandem configuration for deeper vacuum |
| Applications: |
Deep vacuum processes, distillation, drying, evaporation |
✅ LPHY-H Series Features:
- ✓ Deeper ultimate vacuum through two-stage design
- ✓ Higher efficiency at low pressures
- ✓ Optimized for demanding chemical processes
- ✓ Energy-efficient operation
- ✓ Can use water or oil as service liquid
- ✓ Integrated gas-liquid separator
💎 DOLPHIN Series – Compact Modular Vacuum Systems
The DOLPHIN series represents Sterling SIHI's modern, compact liquid ring vacuum packages – complete plug-and-play systems.
| Feature | Description |
|---|
| Configuration: |
Complete system: pump + separator + piping + controls on compact skid |
| Design Philosophy: |
Plug-and-play – ready for immediate operation |
| Footprint: |
Space-saving compact design – up to 50% smaller than traditional systems |
| Versions: |
Single-stage or two-stage configurations available |
✅ DOLPHIN Series Advantages:
- ✓ Complete system – all components pre-assembled and tested
- ✓ Reduced installation time – 70% faster commissioning
- ✓ Space-saving – compact skid-mounted design
- ✓ Optional features – heat exchangers, controls, automation, VFD
- ✓ Various configurations – once-through or recirculating liquid systems
- ✓ Modular design – easy expansion or modification
- ✓ Turnkey solution – minimal on-site work required
🏭 LOTOS Series – Large Industrial Vacuum Pumps
For large-scale industrial applications, Sterling SIHI offers the LOTOS series – heavy-duty liquid ring pumps for demanding continuous operation.
| Parameter | Specification |
|---|
| Pumping Speed Range: |
10,000 - 50,000+ m³/h |
| Construction: |
Heavy-duty cast iron, ductile iron, or full stainless steel (316L) |
| Design: |
Horizontal or vertical split-case design |
| Applications: |
Large-scale chemical plants, petrochemical refineries, power generation |
✅ LOTOS Series Features:
- ✓ Designed for 24/7 continuous operation
- ✓ Very high capacity for large processes
- ✓ Split-case design for easy maintenance
- ✓ Available with heating jackets for solvent applications
- ✓ Advanced mechanical seals for demanding services
- ✓ Custom-engineered for specific applications
Available Sterling SIHI liquid ring pump models and series: LPHY series, LPHY-H series, DOLPHIN series, LOTOS series, single-stage liquid ring pumps, two-stage liquid ring pumps, water ring pumps, industrial vacuum pumps, wet process pumps, ATEX vacuum pumps, chemical resistant pumps, stainless steel vacuum pumps, skid-mounted vacuum systems
💧 Liquid Ring Compressors – For Gas Compression
Sterling SIHI also manufactures liquid ring compressors for gas compression applications requiring isothermal, oil-free compression.
| Parameter | Specification |
|---|
| Flow Rate: |
10 - 10,000 m³/h |
| Discharge Pressure: |
up to 4 bar (g) – higher pressures in multi-stage configurations |
| Applications: |
Biogas compression, landfill gas, process gas, vapor recovery |
| Service Liquid: |
Water (standard), oil, or process-compatible liquids |
✅ Liquid Ring Compressor Advantages:
- ✓ Isothermal compression – no overheating, stable temperature
- ✓ Can compress wet gases – handles moisture and condensates
- ✓ Handles contaminated gases – particles washed out by liquid
- ✓ Explosion-safe operation – ideal for flammable gases
- ✓ Corrosion-resistant – suitable for aggressive gases
- ✓ Low maintenance – robust design, minimal wear
Typical Applications: Biogas upgrading, landfill gas recovery, chemical process gas compression, vapor recovery systems, pneumatic conveying
🌀 Dry Running Vacuum Pumps – Oil-Free Solutions
For applications requiring completely oil-free vacuum, Sterling SIHI offers dry running vacuum pump technology.
🔷 Dry Screw Vacuum Pumps
| Parameter | Specification |
|---|
| Pumping Speed: |
100 - 5,000 m³/h |
| Ultimate Vacuum: |
< 0.01 mbar (10⁻² mbar) |
| Technology: |
Twin-screw design, completely oil-free pumping chamber |
| Cooling: |
Water-cooled or air-cooled |
✅ Dry Screw Features:
- ✓ 100% oil-free – no contamination risk
- ✓ Deep ultimate vacuum without backing pump
- ✓ Chemical resistance for aggressive gases
- ✓ Internal compression for energy efficiency
- ✓ Low maintenance requirements
- ✓ Suitable for semiconductor and pharmaceutical applications
🔶 Dry Claw Vacuum Pumps
| Parameter | Specification |
|---|
| Pumping Speed: |
50 - 2,000 m³/h |
| Ultimate Vacuum: |
< 1 mbar (10⁻³ mbar) |
| Technology: |
Claw rotor design |
✅ Dry Claw Features:
- ✓ Oil-free operation
- ✓ Compact design
- ✓ Energy efficient
- ✓ Low noise level
- ✓ Minimal maintenance
- ✓ Good performance at medium vacuum
💨 Side Channel Blowers – Versatile Pressure & Vacuum
Sterling SIHI manufactures side channel blowers (regenerative blowers) for both pressure and vacuum applications.
| Parameter | Specification |
|---|
| Flow Rate: |
10 - 1,500 m³/h |
| Vacuum Capability: |
up to -500 mbar |
| Pressure Capability: |
up to +600 mbar |
| Design: |
Single-stage or multi-stage configurations |
✅ Side Channel Blower Advantages:
- ✓ Oil-free and maintenance-free operation
- ✓ Compact and lightweight construction
- ✓ Can operate for pressure or vacuum
- ✓ Quiet operation (55-65 dB(A))
- ✓ Long service life (> 40,000 hours)
- ✓ Simple installation
- ✓ No consumables required
Applications: Pneumatic conveying, aeration systems, vacuum packaging (light duty), drying processes, material handling, dust collection
🏭 Primary Application Industries:
| Industry | Typical Applications |
|---|
| 🧪 Chemical Industry |
Vacuum distillation, evaporation, crystallization, drying, reactor evacuation, solvent recovery, polymerization, degassing |
| 💊 Pharmaceutical |
Freeze drying (lyophilization), API production, vacuum drying, tablet coating, sterile processing, solvent recovery |
| 🥫 Food & Beverage |
Vacuum packaging, concentration, deaeration, sugar processing, dairy processing, beverage carbonation, drying |
| 📄 Paper & Pulp |
Paper machine dewatering, vacuum rolls, pulp washing, suction boxes, press section vacuum |
| 🏗️ Plastics Processing |
Thermoforming, extrusion degassing, drying, pellet conveying, vacuum calibration |
| ⚡ Power Generation |
Steam turbine vacuum systems, condenser evacuation, deaeration, turbine sealing |
| 🌊 Environmental |
Wastewater treatment, biogas compression, landfill gas handling, vapor recovery, soil remediation |
| ⛽ Petrochemical |
Refinery vacuum systems, gas compression, vapor recovery, crude oil vacuum distillation |
| 🔬 Laboratories |
Rotary evaporators, vacuum ovens, filtration, degassing, general laboratory vacuum |
🔩 Construction Features & Materials:
⚙️ Material Options for Corrosive Applications:
| Component | Material Options | Applications |
|---|
| Housing |
Cast iron (standard), Ductile iron, Stainless steel 316L, Special alloys |
Standard to highly corrosive |
| Impeller |
Bronze (standard), Stainless steel 316L, Plastic (PP, PVDF), Titanium, Hastelloy |
Depends on chemical compatibility |
| Shaft |
Stainless steel 316, Duplex steel, Titanium, Hastelloy |
Corrosive environments |
| Mechanical Seal |
Carbon/ceramic (standard), Silicon carbide/silicon carbide, Various elastomers (NBR, FPM, EPDM, FFKM) |
Chemical compatibility dependent |
🛡️ Special Design Features:
- ✓ Corrosion-resistant materials – comprehensive material selection for aggressive media
- ✓ ATEX certification – Zone 1 and Zone 2 compliance for explosive atmospheres
- ✓ Hygienic design – FDA-compliant materials for food and pharmaceutical
- ✓ CIP/SIP capable – clean-in-place and steam-in-place for sterile applications
- ✓ Multiple seal options – single, double, tandem, quench seals available
- ✓ Various drive options – direct drive, belt drive, VFD (variable frequency drive)
- ✓ Split-case design – easy maintenance access on larger models
- ✓ Heating jackets – for solvent applications requiring elevated temperatures
💧 Service Liquid Options & Selection:
Sterling SIHI liquid ring pumps can operate with various service liquids depending on application requirements:
| Service Liquid | Advantages | Ultimate Vacuum | Applications |
|---|
| 💧 Water |
Cost-effective, readily available, excellent cooling, environmentally friendly |
33-160 mbar (abs) |
Most standard applications, general industry |
| 🛢️ Mineral Oil |
Deeper vacuum, higher operating temps (up to 100°C), better sealing at low pressure |
3-10 mbar (abs) |
Deep vacuum applications, solvent recovery, chemical processes |
| 🧊 Glycol Solutions |
Freeze protection, outdoor installation, operation below 0°C |
50-160 mbar (abs) |
Cold climate applications, outdoor installations |
| 🧪 Process Solvents |
Closed-loop systems, solvent recovery, process integration |
Varies |
Solvent recovery, chemical processes with specific solvents |
| 🧴 Synthetic Oils |
Very low vapor pressure, high chemical resistance, high temp stability |
< 3 mbar (abs) |
Demanding chemical applications, high temperature processes |
💡 Service Liquid Selection Guidelines:
- ✓ Water – first choice for most applications (economical, effective)
- ✓ Oil – when deeper vacuum (< 33 mbar) required
- ✓ Glycol – for outdoor or cold environment installations
- ✓ Process solvent – for closed-loop solvent recovery systems
- ✓ Consider service liquid temperature effects on vacuum level
- ✓ Chemical compatibility with pumped gases essential
🔧 Our Comprehensive Service for Sterling SIHI:
| 🛒 Sales & Supply |
Complete Sterling SIHI product range – pumps, compressors, blowers, complete turnkey systems |
| 🎯 Engineering & Design |
System design, pump sizing, application engineering, process optimization, material selection |
| ♻️ Complete Overhaul |
Full reconditioning to factory standards: impeller replacement/refurbishment, seal renewal, bearing replacement, housing repair, testing |
| ⚙️ Expert Repair |
Impeller balancing, mechanical seal replacement, bearing renewal, shaft repair, housing welding/machining, performance restoration |
| 📦 Spare Parts Stock |
Original Sterling SIHI parts inventory: impellers, mechanical seals, bearings, shafts, gaskets, O-rings |
| 🚗 On-Site Service |
Installation, commissioning, alignment, maintenance, troubleshooting, emergency service at your facility |
| 🔍 Performance Testing |
Pumping speed measurement, ultimate vacuum testing, efficiency analysis, vibration analysis |
| 🎓 Training Programs |
Operator training, maintenance training, troubleshooting workshops, best practices |
| 📊 Preventive Maintenance |
Scheduled maintenance programs, condition monitoring, predictive maintenance |
🌟 Why Choose Sterling SIHI?
| 🇩🇪 Since 1863 |
Over 160 years of German engineering excellence and innovation |
| 🏆 Technology Leader |
World-leading manufacturer of liquid ring vacuum and compression technology |
| 💪 Legendary Robustness |
Proven in the most demanding industrial applications worldwide |
| 🌊 Wet Process Specialist |
Unmatched capability for handling moist, contaminated, and explosive gases |
| 🛡️ Explosion-Safe |
ATEX-certified pumps for hazardous atmospheres – intrinsically safe operation |
| 🔧 Low Maintenance |
Long service intervals, minimal wear, extended pump life (20-40+ years) |
| 🌍 Global Presence |
Worldwide service network, local support in Austria |
| 📐 Custom Engineering |
Tailored systems and materials for specific process requirements |
💡 Technology Selection Guide:
✅ Choose Liquid Ring Pumps When:
- Wet or humid gases need to be handled
- Process contains condensable vapors
- Gases are contaminated with dust, particles, or fibers
- Explosive or flammable atmospheres present (ATEX required)
- Chemical resistance to aggressive gases required
- Robust, low-maintenance operation essential
- Vacuum requirement: 30-160 mbar sufficient (single-stage) or 3-33 mbar (two-stage)
- 24/7 continuous operation needed
✅ Choose Liquid Ring Compressors When:
- Isothermal compression needed (prevents overheating)
- Compressing wet or saturated gases
- Biogas or landfill gas compression
- Explosion-safe compression required
- Handling contaminated gases
- Low discharge pressure (< 4 bar) acceptable
✅ Choose Dry Screw/Claw Pumps When:
- Oil-free vacuum absolutely required
- Deeper vacuum (< 1 mbar) needed
- Clean, dry gases (or minimal condensables)
- Pharmaceutical or semiconductor applications
- No service liquid disposal desired
- Process requires completely dry vacuum
✅ Choose Side Channel Blowers When:
- Moderate vacuum (< 500 mbar) or pressure (< 600 mbar) needed
- Oil-free and maintenance-free operation desired
- Compact size and light weight important
- Quiet operation required
- Pneumatic conveying or aeration applications
- Simple, reliable solution preferred
🔧 Maintenance & Service Life:
📅 Typical Maintenance Schedule for Liquid Ring Pumps:
| Task | Interval | Description |
|---|
| Visual Inspection |
Weekly |
Check for leaks, unusual noises, vibrations, service liquid level |
| Service Liquid Quality |
Monthly |
Check liquid clarity, temperature, chemical composition |
| Separator Drain |
Monthly |
Drain accumulated solids from separator vessel |
| Mechanical Seal Inspection |
6-12 months |
Check for leakage, wear, flush system operation |
| Bearing Inspection |
12 months |
Check bearing temperature, listen for noise, verify lubrication |
| Impeller Inspection |
2-3 years |
Check for erosion, corrosion, balance (if vibration increases) |
| Mechanical Seal Replacement |
2-5 years |
Replace seals based on operating conditions and leakage |
| Complete Overhaul |
5-10 years |
Full disassembly, part replacement, reassembly, testing |
⏱️ Expected Service Life:
- ✓ Impeller: 10-20+ years (virtually wear-free due to liquid ring principle)
- ✓ Mechanical seals: 2-5 years typical (depends on service conditions)
- ✓ Bearings: 5-10 years with proper lubrication and alignment
- ✓ Housing: 20-40+ years (cast iron/stainless steel construction)
- ✓ Overall pump life: 25-40+ years with proper maintenance and periodic overhaul
📈 Sterling SIHI Innovations & Technology:
- ✓ DOLPHIN compact systems – plug-and-play modular vacuum packages
- ✓ Energy-efficient designs – optimized hydraulics for reduced power consumption
- ✓ Smart monitoring systems – condition monitoring and predictive maintenance
- ✓ Modular construction – easy adaptation to changing process requirements
- ✓ Advanced materials – extended service life in corrosive applications
- ✓ VFD integration – variable speed operation for energy savings and
