Description
LW-20/8 Nitrogen Compressor – Mid-Capacity Oil-Free N2 Booster for Continuous Industrial Operations
Delivering 20 m³/min at 0.80 MPa discharge pressure, the LW-20/8 is a two-stage, two-row oil-free piston nitrogen compressor engineered for medium-scale cryogenic air separation, VPSA nitrogen booster stations, and industrial pipeline distribution. Zero lubricant contamination, 24/7 continuous-duty rated, and built for demanding industrial environments.
Gambaran Keseluruhan Produk
The LW-20/8 nitrogen compressor occupies a strategic position in our oil-free piston compressor lineup, bridging the gap between compact entry-level units and large-scale industrial boosters. With a rated capacity of 20 m³/min and a discharge pressure of 0.80 MPa, this model serves as the backbone of medium-scale nitrogen distribution systems across cryogenic air separation, petrochemical inerting, and food processing industries.
What sets the LW-20/8 apart from conventional alternatives is its fully oil-free compression pathway. The piston rings and rider bands are precision-machined from self-lubricating PTFE composite materials that operate without hydrocarbon lubricants, ensuring the nitrogen stream remains completely free of oil contamination. This native oil-free characteristic is essential for applications demanding ISO 8573-1 Class 0 certification, including food-grade nitrogen blanketing, pharmaceutical process inerting, and electronics manufacturing atmosphere control.
The compressor employs a two-stage, two-row (二列二级) architecture that thermodynamically optimizes the pressure ratio across two cylinders. Each stage is independently cooled via a dedicated intercooler, maintaining discharge temperatures within safe operating limits even during sustained 24/7 operation. The robust cast-iron frame and dynamically balanced forged steel crankshaft are engineered for a minimum service life of 15 years under standard maintenance protocols.
Technical Specifications – LW-20/8
| Parameter | Value | Unit |
|---|---|---|
| Model | LW-20/8 | – |
| Corak | Two-stage, Two-row (二列二级) | – |
| Kapasiti | 20 | m³/min |
| Tekanan Pelepasan | 0.80 | MPa |
| Compressor Size (L × W × H) | 2732 × 1550 × 2432 | mm |
| Berat | 3.00 | t |
| Kuasa | 132 | kW |
| Voltan | 380 | V |
| Medium Gas | Nitrogen (N₂) | – |
| Lubrication | Bebas minyak | – |
* All specifications are rated at standard reference conditions (ISO 1217, Annex C). Actual performance may vary based on site altitude, ambient temperature, and inlet conditions.
Key Features & Engineering Advantages
1. Oil-Free PTFE Composite Sealing System
The LW-20/8 utilizes an advanced self-lubricating piston ring and rider band assembly manufactured from high-density PTFE composites reinforced with glass fiber and bronze particulates. This material system achieves a coefficient of friction below 0.08 without any external hydrocarbon lubrication, completely eliminating the risk of oil vapor carryover into the nitrogen product stream. For regulated industries, this delivers ISO 8573-1 Class 0 compliance natively—without the capital expense, maintenance burden, or energy penalty of downstream oil-removal filtration systems.
2. Two-Stage Thermodynamic Optimization
The two-stage compression arrangement splits the overall pressure ratio between a low-pressure cylinder and a high-pressure cylinder, reducing the mean effective temperature per stage and improving volumetric efficiency. An integrated shell-and-tube intercooler removes the heat of compression between stages, maintaining discharge temperatures below 155°C even at maximum continuous load. This thermal management strategy extends valve plate service life by approximately 35% compared to single-stage designs operating at equivalent pressure ratios, while also preventing thermal degradation of the PTFE sealing elements.
3. Heavy-Duty Frame with Inherent Force Balance
The compressor block is cast from GG25 gray cast iron (equivalent to ASTM A48 Class 30B) with integral cooling water passages. The two-row opposed-cylinder configuration provides natural first-order force cancellation, reducing unbalanced inertia forces transmitted to the foundation by over 80% versus single-row designs. This mechanical advantage permits installation on a lighter concrete inertia block (minimum 5 tonnes versus 8+ tonnes for single-row equivalents), reducing civil engineering costs and simplifying retrofit installations in existing compressor houses or machinery rooms.
4. Standard 380V Industrial Motor Drive
The LW-20/8 is driven by a 132 kW, 380V, 50Hz three-phase induction motor conforming to IEC 60034-1 IE3 efficiency class. The standard low-voltage configuration integrates directly into existing 380V industrial distribution panels without requiring medium-voltage switchgear, step-down transformers, or specialized electrical infrastructure. This simplifies both capital expenditure and commissioning timelines, making the LW-20/8 an attractive upgrade path for facilities transitioning from bottled nitrogen or membrane generators to on-site compressed nitrogen supply.
Application Scenarios
Medium-Scale Cryogenic Air Separation Plants
In cryogenic ASU facilities producing 500–1,500 Nm³/h of gaseous nitrogen, the LW-20/8 serves as the primary nitrogen booster between the cold box and the distribution header. Its 20 m³/min capacity matches the output of medium-scale ASUs, while the 0.80 MPa discharge pressure is optimized for pipeline distribution to downstream consumers such as chemical reactors, steel mill ladle inerting systems, and LNG facility purge gas networks. The oil-free design is particularly critical in ASU backup scenarios where nitrogen purity cannot be compromised during primary system maintenance or cold box upsets.
VPSA Nitrogen Booster Stations
Vacuum Pressure Swing Adsorption (VPSA) nitrogen generators produce gaseous nitrogen at near-atmospheric pressure (0.05–0.10 MPa). The LW-20/8 nitrogen booster compresses this low-pressure product to 0.80 MPa for distribution to point-of-use applications. The oil-free compression path is essential in VPSA service because any hydrocarbon contamination would poison the carbon molecular sieve adsorbent, permanently degrading the generator’s separation efficiency and necessitating costly adsorbent replacement. The 20 m³/min capacity supports medium-scale VPSA installations serving multiple industrial consumers through a centralized nitrogen header.
Petrochemical Tank Farm Blanketing & Inerting
Refinery tank farms and petrochemical storage facilities require substantial volumes of nitrogen for tank blanketing, inerting, and gas padding to prevent explosive vapor formation and maintain product quality. The LW-20/8’s continuous-duty rating and 0.80 MPa discharge pressure make it capable of serving multiple storage tanks simultaneously through a centralized nitrogen distribution header. The pressure head is sufficient to overcome tank pressure relief valve settings and maintain positive pressure during product withdrawal cycles, even in facilities with elevated tank geometries or long distribution pipelines.
Food Processing & Modified Atmosphere Packaging
Large-scale food processing facilities utilize nitrogen for modified atmosphere packaging (MAP), controlled atmosphere storage, and nitrogen sparging to extend product shelf life and maintain freshness. The LW-20/8’s 20 m³/min capacity can simultaneously supply multiple high-speed packaging lines, nitrogen-flush tunnels, and storage vaults. The oil-free certification ensures compliance with FDA 21 CFR 173.310 and EU Regulation 231/2012 for food-contact nitrogen, eliminating the risk of off-flavors, rancidity, or product discoloration that can occur with lubricated compressor alternatives.
Material & Construction
Every component of the LW-20/8 is selected for nitrogen service compatibility, corrosion resistance, and long-term mechanical durability:
| Component | Bahan | Specification |
|---|---|---|
| Cylinder Block | Gray Cast Iron | GG25 / HT250, integral cooling water jackets |
| Crankshaft | Forged Alloy Steel | 42CrMo4, Q&T, ISO 1940 G2.5 balanced |
| Piston Rings | PTFE-Glass-Bronze Composite | Self-lubricating, wear rate <0.05 mm/1000h |
| Rider Bands | PTFE Composite | Piston guidance, prevent cylinder wall contact |
| Valve Plates | Stainless Steel | SS316, concentric ring spring-loaded design |
| Connecting Rods | Forged Steel with Babbitt Bearings | Precision-machined, oil-lubricated big end |
| Intercooler | Carbon Steel Shell / SS304 Tubes | ASME VIII Div.1, 1.5× hydrostatic test |
| Aftercooler | Carbon Steel Shell / SS304 Tubes | Finned tube design, 32°C cooling water rated |
All pressure-bearing components are designed and fabricated in accordance with ASME BPVC Section VIII Division 1 or Chinese GB 150 standards. Weld joints undergo 100% radiographic inspection (RT) per ASME Section V, Article 2, and each completed pressure vessel is subjected to a hydrostatic pressure test at 1.5 times the maximum allowable working pressure (MAWP) for a minimum hold time of 30 minutes.
Installation & Maintenance Guidelines
Foundation & Mounting Requirements
The LW-20/8 has a dry weight of 3.00 tonnes and a center of gravity approximately 820 mm above the baseplate. Thanks to the two-row opposed-cylinder design, unbalanced forces are minimal, permitting installation on a reinforced concrete inertia block of 5–6 tonnes. The block should be mounted on elastomeric vibration isolators (natural frequency 6–8 Hz) to prevent vibration transmission to adjacent structures. Minimum clearance requirements: 1.2 m on the non-drive side for valve access, 1.0 m on the drive side for motor maintenance, and 1.8 m overhead for crane access during major overhauls.
Cooling Water System Specifications
Cooling water flow requirement is approximately 22 m³/h at an inlet temperature not exceeding 32°C. The water distribution circuit supplies the cylinder jackets, intercooler, and aftercooler in parallel. Water quality specifications: pH 6.5–8.5, total dissolved solids < 500 mg/L, chloride content < 50 mg/L (to prevent SS304 tube corrosion), and suspended solids < 30 mg/L. For sites with marginal water quality, a closed-loop cooling tower with side-stream filtration and chemical treatment is strongly recommended to prevent scale formation and tube fouling.
Preventive Maintenance Schedule
| Interval | Service Item | Action Required |
|---|---|---|
| Daily | Operational Inspection | Check vibration levels, abnormal noise, cooling water flow, discharge temperature |
| 250 hours | Valve Plate Inspection | Remove and inspect suction/discharge valves for carbon deposits or cracking |
| 1,000 hours | Piston Ring Measurement | Measure ring groove clearance; replace rings if clearance exceeds 0.25 mm |
| 4,000 hours | Intermediate Overhaul | Replace all piston rings, rider bands, and valve plate assemblies |
| 8,000 hours | Major Overhaul | Inspect crankshaft journals, measure bearing clearances, replace main bearings if >0.08 mm |
The oil-free design of the LW-20/8 significantly reduces maintenance complexity compared to lubricated alternatives. There are no oil changes to schedule, no oil samples to analyze, no filter elements to replace, and no oil separator cartridges to monitor. The only recurring wear items are the PTFE piston rings and rider bands, which typically achieve 4,000–6,000 hours of service life under clean nitrogen conditions.
Compliance & Safety Certifications
The LW-20/8 nitrogen compressor is designed, manufactured, and tested to meet the following international standards and regulatory frameworks:
ASME BPVC Section VIII Div.1, GB 150-2011, PED 2014/68/EU Module A
IEC 60034-1 (IE3 efficiency), IEC 60204-1, ISO 12100 (Machinery Safety)
ISO 8573-1 Class 0 (Oil Content), independently tested by TÜV Rheinland
ISO 9001:2015 (Quality Management), ISO 14001:2015 (Environmental Management)
Nitrogen is classified as a simple asphyxiant gas. All LW-20/8 installations must incorporate continuous oxygen deficiency monitoring in the compressor room and adjacent areas. Ventilation systems must be designed to maintain ambient oxygen concentrations above 19.5% volume per OSHA 29 CFR 1910.146. Emergency shutdown interlocks should activate at 19.5% O₂ (alarm) and trigger automatic compressor isolation at 18.0% O₂ (hard shutdown). Personnel entry procedures must include portable oxygen monitors and buddy-system protocols.
Performance & Efficiency Analysis
The LW-20/8 achieves a specific power consumption of approximately 6.60 kW per m³/min of nitrogen delivered at 0.80 MPa discharge pressure. This efficiency metric positions the unit competitively within the 15–30 m³/min oil-free piston compressor segment. For comparison, typical oil-lubricated screw compressors operating at equivalent pressure ratios consume 7.0–7.8 kW/m³/min, while older single-stage piston designs may exceed 8.5 kW/m³/min.
Over a standard 8,000-hour annual operating schedule, the LW-20/8’s efficiency advantage yields approximately 64,000–160,000 kWh of annual energy savings compared to less efficient alternatives. At an average industrial electricity tariff of $0.08/kWh, this translates to $5,120–$12,800 in direct operating cost reduction per year. When combined with the elimination of oil-related consumables (lubricating oil, filter elements, separator cartridges, waste oil disposal), the total cost of ownership for nitrogen compression is reduced by an estimated 20–30% over a 10-year operational life.
The absence of oil in the compression path also eliminates the energy penalty associated with downstream oil-removal equipment. A typical oil-lubricated compressor of this size requires coalescing filters, activated carbon adsorbers, and oil monitoring instrumentation that collectively consume 3–5% of the compressor’s power output. The LW-20/8’s oil-free design removes this parasitic load entirely, improving overall system efficiency.
Customization & OEM Capabilities
We offer comprehensive customization options to adapt the LW-20/8 to specific site conditions, integration requirements, and end-user specifications:
- Skid-Mounted Turnkey Packages: The compressor, motor, intercooler, aftercooler, instrumentation, and control panel are pre-assembled on a structural steel skid with integrated lifting lugs and anchor bolt templates. This approach reduces field installation time by approximately 60% and minimizes commissioning risks.
- Hazardous Area Configurations: ATEX Zone 2 and IECEx compliant motor and electrical enclosures are available for installations in petrochemical facilities where explosive atmospheres may occasionally be present. Gas detection and automatic ventilation interlocks can be integrated into the control system.
- Advanced Process Control: Optional Siemens S7-1200 or Allen-Bradley CompactLogix PLC with 10-inch HMI touchscreen, remote monitoring via Modbus TCP/IP or OPC-UA, and seamless DCS/SCADA integration. Automatic load/unload control and variable speed drive (VFD) compatibility optimize part-load efficiency.
- Environmental Protection: C5-M marine-grade coating systems for coastal or offshore installations; tropicalized electrical components for ambient temperatures up to 55°C; and IP54-rated acoustic enclosures that reduce noise emission from 85 dB(A) to 72 dB(A) at 1 meter.
- OEM & Private Label: Custom paint colors, branded nameplates, and documentation packages are available for system integrators and gas equipment distributors. Technical manuals, spare parts lists, and maintenance procedures can be supplied in local languages.
Custom configurations are available from MOQ 1 unit. Engineering review and proposal generation typically require 5–7 business days. Prototype delivery schedules range from 12–14 weeks; repeat orders are delivered in 8–10 weeks from order confirmation.
Case Study: Food Packaging Nitrogen Supply Upgrade
Client: A major snack food manufacturer in Thailand
Challenge: The manufacturer was relying on liquid nitrogen vaporization for their modified atmosphere packaging (MAP) lines. Rising liquid nitrogen prices, delivery scheduling conflicts, and vaporizer maintenance issues were causing production delays. Additionally, the existing lubricated nitrogen booster (competitor brand) was introducing trace oil contamination that caused off-flavors in sensitive product lines, resulting in customer complaints and product recalls.
Solution: We supplied an LW-20/8 oil-free nitrogen compressor paired with a medium-scale VPSA nitrogen generator (99.9% purity, 25 m³/min) on a common skid. The LW-20/8 boosts the VPSA product from 0.08 MPa to 0.80 MPa for distribution to six high-speed packaging lines. The skid was designed to fit within the existing utility room, eliminating the need for building expansion.
Quantified Results After 24 Months:
- Nitrogen supply cost: Reduced by 48% versus liquid nitrogen purchase and delivery
- Oil contamination in nitrogen: Eliminated completely (ISO 8573-1 Class 0 achieved)
- Product recall incidents: Zero since commissioning (previously 2–3 per year)
- Maintenance expenditure: Decreased by 35% due to elimination of oil changes, filter replacements, and separator overhauls
- Production downtime: Reduced by 60% (no more liquid nitrogen delivery scheduling conflicts)
- Payback period: 2.1 years based on gas cost savings and avoided recall costs
“The LW-20/8 compressor has completely transformed our nitrogen supply. We no longer worry about liquid nitrogen deliveries, our product quality issues have disappeared, and our maintenance team spends far less time on compressor upkeep. The investment paid for itself in just over two years.” — Plant Engineering Manager
FAQ & Selection Guide
Related Products & Solutions
LW Series Large-Capacity Nitrogen Compressors
High-flow oil-free piston compressors (30–130 m³/min) for large-scale cryogenic ASU backup, VPSA boosting, and industrial pipeline distribution. Discharge pressures from 0.30 to 0.80 MPa.
DW Series High-Pressure Nitrogen Compressors
Medium to high-pressure oil-free compressors (0.40–2.00 MPa) for nitrogen injection, pipeline boosting, and chemical synthesis applications. Capacities from 2 to 130 m³/min.
ZW Series Compact Oil-Free Compressors
Compact oil-free compressors (2–10 m³/min) for small-scale VPSA boosting, laboratory nitrogen supply, and electronics manufacturing inerting. Discharge pressures up to 0.80 MPa.
For a comprehensive overview of our industrial nitrogen compressor portfolio, including oil-free oxygen compressors, hydrogen compressors, carbon dioxide compressors, and custom-engineered specialty gas solutions, please contact our application engineering team or browse our online product catalog.
Ready to Optimize Your Nitrogen Compression System?
Our application engineers are standing by to evaluate your nitrogen flow requirements, suction conditions, discharge pressure targets, and integration constraints. We provide complimentary technical proposals, foundation layout drawings, piping and instrumentation diagrams (P&IDs), and detailed total cost of ownership (TCO) analyses within 48 hours of receiving your inquiry.
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