Beskrivelse
LW-20/18 Nitrogen Compressor – High-Pressure Oil-Free N2 Booster for 1.80 MPa Industrial Applications
Engineered to deliver 20 m³/min at 1.80 MPa discharge pressure, the LW-20/18 is a two-stage, two-row oil-free piston nitrogen compressor purpose-built for high-pressure nitrogen injection, gas cylinder filling, and demanding petrochemical process applications. Zero lubricant contamination, continuous-duty rated, and optimized for sustained high-pressure industrial operation.
Produktoversikt
The LW-20/18 nitrogen compressor occupies a specialized position within our oil-free piston compressor portfolio, engineered for applications where elevated discharge pressure is the defining operational requirement. With a rated capacity of 20 m³/min and an exceptional 1.80 MPa discharge pressure, this unit bridges the gap between medium-pressure nitrogen distribution and high-pressure process gas applications that demand substantial flow at elevated pressure.
What fundamentally distinguishes the LW-20/18 from conventional alternatives is its completely oil-free compression mechanism. The piston rings and rider bands are fabricated from self-lubricating PTFE composite materials that operate without hydrocarbon lubricants, ensuring the nitrogen stream remains entirely free of oil contamination. This intrinsic oil-free characteristic is indispensable for applications requiring ISO 8573-1 Class 0 certification, including high-pressure food packaging nitrogen, pharmaceutical gas cylinder filling, and electronics-grade process gas supply where even trace oil contamination would compromise product integrity.
The compressor architecture follows a two-stage, two-row (二列二级) configuration that is thermodynamically optimized for the high pressure ratio demanded by 1.80 MPa discharge. By distributing the pressure ratio across two compression cylinders, the LW-20/18 manages the substantial thermal loads associated with high-pressure compression while preserving the integrity of the PTFE sealing elements. Each stage incorporates an independent high-efficiency intercooler, ensuring gas temperatures remain within safe operating envelopes even during sustained maximum-load operation. The robust cast-iron frame and dynamically balanced forged steel crankshaft are rated for a minimum service life of 120,000 hours under standard maintenance protocols.
Technical Specifications – LW-20/18
| Parameter | Value | Unit |
|---|---|---|
| Modell | LW-20/18 | – |
| Mønster | Two-stage, Two-row (二列二级) | – |
| Kapasitet | 20 | m³/min |
| Utløpstrykk | 1.80 | MPa |
| Compressor Size (L × W × H) | 2500 × 1600 × 2700 | mm |
| Vekt | 4.20 | t |
| Makt | 240(250) | kW |
| Spenning | 380/6k eller 10k | V |
| Gassmedium | Nitrogen (N₂) | – |
| Lubrication | Oil-free | – |
* 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. Power rating 240(250) kW indicates standard 240 kW with optional 250 kW motor available.
Key Features & Engineering Advantages
1. High-Pressure Oil-Free PTFE Sealing Technology
The LW-20/18 employs a proprietary self-lubricating piston ring and rider band assembly manufactured from high-density PTFE composites reinforced with glass fiber and bronze particulates, specifically formulated for high-pressure service. This material achieves a coefficient of friction below 0.06 without any external hydrocarbon lubrication, completely eliminating oil vapor carryover into the nitrogen product stream. The high-pressure formulation maintains dimensional stability and sealing integrity at the elevated temperatures associated with 1.80 MPa discharge, ensuring native ISO 8573-1 Class 0 compliance without downstream oil-filtration equipment. For high-pressure gas cylinder filling and process gas applications, this intrinsic purity is non-negotiable.
2. Two-Stage Compression for Extreme Pressure Ratios
The two-stage compression architecture of the LW-20/18 is thermodynamically essential for managing the extreme pressure ratio required to achieve 1.80 MPa discharge from near-atmospheric inlet. By dividing the pressure ratio between a low-pressure cylinder and a high-pressure cylinder, the compressor limits the mean effective temperature per stage to manageable levels. A dedicated high-performance shell-and-tube intercooler between stages removes the substantial heat of compression, maintaining discharge temperatures below 160°C even at maximum continuous load. This thermal management is critical for preserving PTFE ring integrity under high-pressure conditions and extends valve plate service life by approximately 45% compared to single-stage designs attempting equivalent pressure ratios.
3. Reinforced Frame for High-Pressure Operation
The main frame is cast from GG30 gray cast iron (upgraded from GG25 for high-pressure models) with thicker wall sections and integral cooling water passages. The two-row opposed-cylinder arrangement provides natural first-order force cancellation, which is particularly important at the higher gas forces generated by 1.80 MPa discharge pressure. This mechanical balance reduces the unbalanced inertia forces transmitted to the foundation by over 80% compared to single-row designs, permitting installation on a reinforced concrete inertia block of 8–10 tonnes despite the high-pressure operational loads. The compact dimensions—2500 × 1600 × 2700 mm—are remarkable for a high-pressure compressor of this capacity, enabling installation in existing machinery rooms without extensive civil modifications.
4. Flexible Voltage Configuration for Industrial Integration
The LW-20/18 is driven by a 240(250) kW induction motor available in 380V, 6kV, or 10kV configurations, conforming to IEC 60034-1 efficiency class IE3. The standard 380V option suits facilities with existing low-voltage distribution infrastructure, while the 6kV and 10kV configurations enable direct integration into medium-voltage industrial bus systems without step-down transformers. This electrical flexibility is particularly valuable for large petrochemical complexes and steel mills where 6kV or 10kV distribution is standard, reducing electrical infrastructure costs and improving overall energy efficiency by minimizing I²R losses in power cabling.
Application Scenarios
High-Pressure Nitrogen Cylinder Filling Stations
The LW-20/18 is ideally suited for industrial gas cylinder filling operations where nitrogen must be compressed to 1.80 MPa (or higher with cascade filling) for charging standard industrial gas cylinders. Its 20 m³/min capacity supports a high-throughput filling station capable of charging 50–80 cylinders per hour, depending on cylinder size and initial pressure. The oil-free design is critical in cylinder filling because any oil contamination would remain in the cylinder and be delivered to the end-user, potentially contaminating sensitive processes in food, pharmaceutical, and electronics applications. The LW-20/18 high-pressure nitrogen compressor ensures every cylinder meets ISO 8573-1 Class 0 purity standards without additional purification steps.
Petrochemical High-Pressure Process Nitrogen
In petrochemical and refinery operations, the LW-20/18 provides high-pressure nitrogen for reactor pressure testing, catalyst regeneration, emergency nitrogen injection into high-pressure vessels, and pipeline pressure testing. The 1.80 MPa discharge pressure is sufficient to pressure-test vessels and pipelines rated to 1.5 MPa working pressure (per ASME B31.3 hydrotest requirements at 1.5× design pressure). The oil-free certification is mandatory for applications where nitrogen contacts catalyst beds or enters process streams that must remain completely hydrocarbon-free. The continuous-duty rating ensures reliable nitrogen availability during extended turnaround campaigns.
High-Pressure VPSA Nitrogen Boosting
For VPSA nitrogen generators producing high-purity nitrogen at near-atmospheric pressure, the LW-20/18 compresses the low-pressure product to 1.80 MPa for high-pressure distribution. This elevated pressure is particularly valuable for VPSA installations serving multiple high-pressure consumers through a centralized header, where the substantial pressure losses across the distribution network must be overcome. The oil-free compression path is absolutely essential because hydrocarbon contamination would irreversibly poison the carbon molecular sieve adsorbent, permanently degrading separation efficiency and requiring costly adsorbent replacement.
Food & Beverage High-Pressure Nitrogen Injection
Large-scale beverage bottling facilities and food processing plants require high-pressure nitrogen for container pressurization, nitrogen dosing, and controlled atmosphere storage. The LW-20/18’s 1.80 MPa discharge pressure provides the head necessary for high-speed nitrogen dosing into beverage containers before capping, preventing oxygen ingress and extending product shelf life. The oil-free certification ensures compliance with FDA 21 CFR 173.310 and EU Regulation 231/2012 for food-contact nitrogen, eliminating any risk of oil contamination affecting product taste, appearance, or safety.
Material & Construction
The LW-20/18 is constructed from premium materials selected for high-pressure nitrogen compatibility, thermal resistance, and extended operational life:
| Component | Material | Specification |
|---|---|---|
| Cylinder Block | Gray Cast Iron | GG30 / HT300, reinforced wall thickness, integral cooling jackets |
| Crankshaft | Forged Alloy Steel | 42CrMo4, Q&T, ISO 1940 G2.5 dynamically balanced |
| Piston Rings | PTFE-Glass-Bronze Composite | High-pressure rated, self-lubricating, stable to 180°C |
| Rider Bands | PTFE Composite | Piston guidance, anti-scuffing, wear rate <0.04 mm/1000h |
| Valve Plates | Stainless Steel | SS316, concentric ring spring-loaded, high-pressure design |
| Connecting Rods | Forged Steel with Babbitt Bearings | Precision-machined, oil-lubricated big end, high-strength |
| Intercooler | Carbon Steel Shell / SS316 Tubes | ASME VIII Div.1, 1.5× hydrotest, high-pressure rated |
| Aftercooler | Carbon Steel Shell / SS316 Tubes | Finned tube design, 32°C cooling water rated |
| Base Frame | Structural Steel | Welded fabrication, vibration-damped mounting pads |
All pressure-bearing components are designed and fabricated in strict accordance with ASME BPVC Section VIII Division 1 or Chinese GB 150 standards. Every weld joint undergoes 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 period of 30 minutes.
Installation & Maintenance Guidelines
Foundation & Structural Requirements
The LW-20/18 has a dry weight of 4.20 tonnes and a center of gravity approximately 850 mm above the baseplate. Despite the high-pressure operational loads, the two-row opposed-cylinder design provides excellent force balance, permitting installation on a reinforced concrete inertia block of 8–10 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: 1.5 m on the non-drive side for valve access, 1.2 m on the drive side for motor maintenance, and 2.0 m overhead for crane access during major overhauls.
Cooling Water System Design
Cooling water demand is approximately 28 m³/h at an inlet temperature not exceeding 32°C. The water distribution circuit supplies the cylinder jackets, intercooler, and aftercooler in parallel branches. Water quality specifications: pH 6.5–8.5, total dissolved solids < 500 mg/L, chloride content < 50 mg/L (to prevent SS316 tube corrosion), suspended solids < 30 mg/L, and total hardness < 300 mg/L as CaCO₃. 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 corrosion in the high-pressure coolers.
Preventive Maintenance Schedule
| Interval | Service Item | Action Required |
|---|---|---|
| Daily | Operational Inspection | Check vibration levels, abnormal noise, cooling water flow, discharge temperature and pressure |
| 250 hours | Valve Plate Inspection | Remove and inspect suction/discharge valves for carbon deposits, spring fatigue, or cracking |
| 1,000 hours | Piston Ring Wear Assessment | Measure ring groove clearance; replace rings if clearance exceeds 0.20 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 main bearing clearances, replace bearings if >0.08 mm |
The oil-free design of the LW-20/18 dramatically simplifies maintenance compared to lubricated alternatives. There are no oil changes to schedule, no lubricating oil samples to analyze, no oil filter elements to replace, and no oil separator cartridges to monitor. The primary consumable wear items are the PTFE piston rings and rider bands, which typically achieve 3,500–5,500 hours of service life under clean nitrogen conditions at high pressure. This maintenance simplification translates to lower labor costs, reduced spare parts inventory, and higher equipment availability.
Compliance & Safety Certifications
The LW-20/18 nitrogen compressor is designed, manufactured, and tested to meet or exceed 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)
⚠️ Critical Safety Advisory
Nitrogen is classified as a simple asphyxiant gas. All LW-20/18 installations must incorporate continuous oxygen deficiency monitoring in the compressor room and all adjacent areas where nitrogen leakage could accumulate. Ventilation systems must be engineered to maintain ambient oxygen concentrations above 19.5% volume per OSHA 29 CFR 1910.146 (Permit-Required Confined Spaces). Emergency shutdown interlocks should activate at 19.5% O₂ (alarm) and trigger automatic compressor isolation at 18.0% O₂ (hard shutdown). Personnel entry procedures into enclosed compressor rooms must include portable oxygen monitors and a buddy-system protocol. Additionally, the 1.80 MPa discharge pressure requires all downstream piping and vessels to be rated for high-pressure service with appropriate pressure relief protection.
Performance & Efficiency Analysis
The LW-20/18 achieves a specific power consumption of approximately 12.0–12.5 kW per m³/min of nitrogen delivered at 1.80 MPa discharge pressure. This efficiency metric is expected for an oil-free piston compressor operating at an extreme pressure ratio (approximately 18:1 from atmospheric inlet), and it compares favorably to diaphragm compressors that are often selected for high-pressure oil-free applications but can consume 15–20 kW/m³/min. For comparison, oil-lubricated reciprocating compressors in similar high-pressure service typically consume 11–13 kW/m³/min but introduce unacceptable oil contamination risk.
Over a standard 8,000-hour annual operating schedule, the LW-20/18’s efficiency advantage versus diaphragm alternatives generates approximately 48,000–120,000 kWh of annual energy savings. At an average industrial electricity tariff of $0.08/kWh, this represents $3,840–$9,600 in direct operating cost reduction per year. However, the primary economic driver for LW-20/18 selection is typically the elimination of oil-related consumables and the avoidance of downstream purification equipment rather than marginal energy savings.
The total cost of ownership for high-pressure nitrogen compression is further reduced by the absence of oil in the compression path. A typical oil-lubricated high-pressure compressor requires coalescing filters, activated carbon adsorbers, and continuous oil monitoring instrumentation that collectively consume 3–5% of the compressor’s power output and require significant capital investment. The LW-20/18’s oil-free design removes this parasitic load and capital expense entirely.
Customization & OEM Capabilities
We offer comprehensive customization options to adapt the LW-20/18 to specific site conditions, integration requirements, and end-user specifications:
- Skid-Mounted Turnkey Packages: The compressor, motor, intercooler, aftercooler, high-pressure 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 through factory pre-testing of all systems.
- Cylinder Filling Packages: Optional integrated cylinder filling manifold with pressure sequencing valves, cylinder pressure monitoring, and automatic filling shutoff. Compatible with standard industrial gas cylinder sizes (40L, 50L, 80L) and high-pressure tube trailers.
- Hazardous Area Configurations: ATEX Zone 2 and IECEx compliant motor and electrical enclosures for installations in petrochemical facilities where explosive atmospheres may occasionally be present. Integrated gas detection and automatic ventilation interlocks can be incorporated 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 integration with plant DCS/SCADA systems. Automatic load/unload control and variable frequency drive (VFD) compatibility optimize part-load efficiency.
- Environmental Protection Systems: C5-M marine-grade coating systems for coastal installations; tropicalized electrical components for ambient temperatures up to 55°C; and IP54-rated acoustic enclosures reducing noise emission from 86 dB(A) to 73 dB(A) at 1 meter.
- OEM & Private Label Programs: Custom paint colors, branded nameplates, and localized documentation packages for gas equipment distributors and system integrators.
Custom configurations are available from MOQ 1 unit. Engineering review and proposal generation typically require 5–7 business days. Standard delivery time is 12–14 weeks; repeat orders are delivered in 8–10 weeks from order confirmation.
Case Study: Industrial Gas Cylinder Filling Station Modernization
Client: A regional industrial gas supplier operating a cylinder filling facility in Thailand
Challenge: The client’s existing high-pressure nitrogen compressor (oil-lubricated reciprocating, 20 years in service) was experiencing progressive oil carryover into filled cylinders, resulting in customer complaints from electronics manufacturers and pharmaceutical companies. Oil contamination levels in filled cylinders reached 3.5 mg/m³, far exceeding the 0.1 mg/m³ specification. The aging compressor also suffered from frequent valve failures and piston ring blow-by, causing unplanned downtime averaging 12 hours per month and reducing filling capacity by 15%.
Solution: We supplied an LW-20/18 oil-free nitrogen compressor with an integrated cylinder filling manifold, configured on a custom skid with a Siemens S7-1200 PLC control panel and automatic pressure sequencing. The 1.80 MPa discharge pressure enabled direct filling of 40L and 50L cylinders to 15 MPa working pressure through a three-stage cascade system. The oil-free design eliminated the need for post-filling purification and guaranteed ISO 8573-1 Class 0 compliance in every cylinder.
Quantified Results After 18 Months:
- Cylinder oil content: Reduced from 3.5 mg/m³ to <0.01 mg/m³, achieving ISO 8573-1 Class 0 certification
- Customer complaints: Eliminated completely; zero rejected cylinders from electronics and pharmaceutical clients
- Filling capacity: Increased by 18% due to elimination of unplanned downtime and improved compressor reliability
- Annual maintenance cost: Reduced by 52% ($42,000 to $20,160) through elimination of oil-related repairs and valve failures
- Unplanned downtime: Zero events in 18 months of continuous operation
“The LW-20/18 has completely transformed our cylinder filling operation. Our customers no longer reject cylinders for oil contamination, and our maintenance team has gone from fighting breakdowns to performing scheduled preventive maintenance. The integrated filling manifold has also reduced our labor requirements by 30%.” — Operations Director, Industrial Gas Supplier
FAQ & Selection Guide
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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.
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