Описание
DW-70/30 Nitrogen Compressor – Ultra-High-Capacity Oil-Free N2 Booster for 3.00 MPa Industrial Process
Engineered to deliver 70 m³/min at 3.00 MPa discharge pressure, the DW-70/30 is a two-stage, four-row oil-free piston nitrogen compressor purpose-built for large-scale nitrogen injection, high-pressure pipeline boosting, and demanding petrochemical process applications. Zero oil contamination, continuous-duty rated, and optimized for 24/7 industrial operation at elevated pressure.
Обзор продукта
The DW-70/30 nitrogen compressor represents the pinnacle of our oil-free piston compressor engineering, occupying the ultra-high-capacity segment of our industrial nitrogen compressor portfolio. With an extraordinary 70 m³/min capacity coupled with a formidable 3.00 MPa discharge pressure, this unit is engineered for the most demanding large-scale nitrogen boosting applications where both massive flow and elevated pressure are non-negotiable requirements.
What distinguishes the DW-70/30 from all conventional alternatives is its fully oil-free compression pathway utilizing self-lubricating PTFE composite piston rings and rider bands. At 3.00 MPa discharge pressure, the risk of oil vapor carryover is exponentially magnified compared to low-pressure applications, making the oil-free design not merely advantageous but absolutely imperative. The compressor achieves native ISO 8573-1 Class 0 certification without any downstream oil-filtration equipment, eliminating the capital cost, maintenance burden, and energy penalty that would otherwise be mandatory at this pressure level.
The compressor architecture employs a two-stage, four-row (二列四级) configuration that is essential for managing the extreme combination of high flow rate and elevated pressure. The four-row design provides exceptional force balance while doubling the effective displacement compared to two-row designs, enabling the massive 70 m³/min capacity. Each stage features independent intercooling, ensuring gas temperatures remain within safe operating envelopes even during sustained maximum-capacity operation at 3.00 MPa. The reinforced 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 – DW-70/30
| Parameter | Value | Unit |
|---|---|---|
| Модель | DW-70/30 | – |
| Шаблон | Two-stage, Four-row (二列四级) | – |
| Емкость | 70 | м³/мин |
| Давление на выходе | 3.00 | МПа |
| Compressor Size (L × W × H) | 8500 × 2440 × 3020 | mm |
| Масса | 18.00 | t |
| Власть | 850 | кВт |
| Напряжение | 6 тыс. или 10 тыс. | V |
| Газовая среда | 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.
Key Features & Engineering Advantages
1. Four-Row Architecture for Massive Capacity
The DW-70/30 employs a two-stage, four-row (二列四级) configuration that is unique in the oil-free nitrogen compressor market. The four-row design doubles the effective piston displacement compared to conventional two-row designs while maintaining excellent force balance through the opposed-cylinder arrangement. Each row contains two compression stages (one low-pressure and one high-pressure), resulting in four active compression cylinders driven from a single crankshaft. This architecture enables the extraordinary 70 m³/min capacity that would otherwise require two separate compressors operating in parallel, reducing footprint, simplifying control, and eliminating the complexity of parallel compressor synchronization.
2. High-Pressure Oil-Free PTFE Sealing System
At 3.00 MPa discharge pressure, the risk of oil contamination is exponentially higher than at conventional pressures. The DW-70/30 utilizes a proprietary self-lubricating piston ring and rider band assembly manufactured from ultra-high-performance PTFE composites reinforced with glass fiber, carbon fiber, and bronze particulates. This advanced formulation achieves a coefficient of friction below 0.05 without any external hydrocarbon lubrication, ensuring the nitrogen stream remains completely free of oil contamination even at extreme pressure. The rings are rated for continuous operation at temperatures up to 190°C, providing a safety margin above the typical 165°C discharge temperature at 3.00 MPa. For industrial gas operators, this delivers native ISO 8573-1 Class 0 compliance without the capital cost, maintenance burden, or energy penalty of downstream oil-filtration systems that would be mandatory with lubricated alternatives.
3. Reinforced Frame for Extreme Mechanical Loads
The main frame is cast from GG30 gray cast iron (equivalent to ASTM A48 Class 35B) with substantially reinforced wall sections, additional ribbing, and integral cooling water passages machined directly into the casting. The high-pressure cylinders feature thickened walls and stress-relieving fillet radii to withstand the peak gas forces at 3.00 MPa. The four-row opposed-cylinder arrangement provides exceptional first-order and second-order force cancellation, reducing unbalanced inertia forces transmitted to the foundation by over 90% compared to single-row designs. This mechanical advantage permits installation on a reinforced concrete inertia block of minimum 25 tonnes—substantial but significantly lighter than the 40+ tonnes that would be required for an equivalent single-row design.
4. Medium-Voltage Drive for Maximum Efficiency
The DW-70/30 is driven by a 850 kW medium-voltage induction motor available in either 6kV or 10kV configurations, conforming to IEC 60034-1 efficiency class IE3. At this power level, medium-voltage drive is not merely preferred but essential—a 380V motor would require approximately 1,400A full-load current, necessitating impractically large cables and switchgear. The medium-voltage configuration reduces cable sizes by 80%, minimizes I²R losses, and integrates seamlessly into industrial medium-voltage distribution networks. Optional variable frequency drive (VFD) compatibility allows part-load operation with maintained efficiency, reducing energy consumption during periods of reduced nitrogen demand.
Application Scenarios
Large-Scale Nitrogen Injection for Enhanced Oil Recovery
In oil and gas production, the DW-70/30 serves as the primary nitrogen injection compressor for enhanced oil recovery (EOR) and pressure maintenance operations. Its 70 m³/min capacity can supply multiple injection wells simultaneously, while the 3.00 MPa discharge pressure provides sufficient bottom-hole pressure for reservoirs at depths up to 2,500 meters. The oil-free design is absolutely critical in EOR applications because any oil contamination would damage the reservoir formation, reduce permeability, and compromise oil recovery efficiency. The continuous-duty rating ensures uninterrupted injection operations that may run for months or years without shutdown.
High-Pressure Pipeline Nitrogen Boosting
Для industrial nitrogen pipeline networks operating at elevated pressures, the DW-70/30 provides the booster capacity needed to maintain pressure over long distances and serve high-pressure consumers. The 3.00 MPa discharge pressure overcomes pipeline friction losses across distances up to 10 km, making it suitable for centralized nitrogen supply to large industrial parks or offshore platforms. The 70 m³/min capacity can serve multiple high-pressure consumers simultaneously, including petrochemical reactors, gas turbine purge systems, and high-pressure blanketing operations.
Petrochemical Reactor Inerting & Catalyst Systems
In large petrochemical complexes, the DW-70/30 provides high-pressure nitrogen for reactor catalyst preservation, emergency nitrogen injection, and high-pressure vessel inerting. The 3.00 MPa discharge pressure is sufficient to inject nitrogen directly into high-pressure process vessels operating at up to 2.5 MPa, maintaining positive inert gas blankets during startup, shutdown, and upset conditions. The massive 70 m³/min capacity can serve multiple reactors and vessels simultaneously through a centralized high-pressure nitrogen header. The oil-free certification is mandatory for petrochemical applications where nitrogen contacts catalyst beds or enters process streams that must remain completely hydrocarbon-free.
Coal Chemical & Syngas Plant Nitrogen Supply
Coal chemical plants and syngas production facilities require enormous volumes of high-pressure nitrogen for gasifier inerting, synthesis loop purging, and cryogenic air separation backup. The DW-70/30’s 70 m³/min capacity can support the nitrogen demands of multiple gasifiers or a complete syngas train, while the 3.00 MPa discharge pressure matches the pressure requirements of modern entrained-flow gasifiers. The oil-free design prevents oil contamination of syngas, which would poison downstream catalysts in methanol synthesis, Fischer-Tropsch synthesis, and ammonia production units.
Material & Construction
The DW-70/30 is constructed from premium materials selected for extreme-pressure nitrogen compatibility, thermal resistance, and structural integrity under massive mechanical loads:
| Component | Material | Specification |
|---|---|---|
| Main Frame | Gray Cast Iron | GG30 / HT300, reinforced walls + ribbing |
| Cylinder Block (LP) | Gray Cast Iron | GG30 / HT300, integral cooling water jackets |
| Cylinder Block (HP) | Gray Cast Iron | GG30 / HT300, extra-thick walls + stress relief |
| Crankshaft | Forged Alloy Steel | 34CrNiMo6, Q&T, ISO 1940 G1.0 balanced |
| Piston Rings | PTFE-Glass-Carbon-Bronze Composite | Ultra-high-pressure rated, 190°C max |
| Rider Bands | PTFE Composite | Piston guidance, anti-scuffing, wear rate <0.03 mm/1000h |
| Valve Plates | Stainless Steel | SS316, high-pressure concentric ring design |
| Connecting Rods | Forged Steel with Babbitt Bearings | Precision-machined, oil-lubricated big end |
| Intercooler | Carbon Steel Shell / SS316 Tubes | ASME VIII Div.1, 1.5× hydrotest, 30 min hold |
| Aftercooler | Carbon Steel Shell / SS316 Tubes | High-pressure finned tube, 32°C cooling water |
| High-Pressure Piping | Seamless Stainless Steel | SS316, ANSI Class 900 flanges |
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. High-pressure piping systems are fabricated from seamless SS316 with ANSI Class 900 flanged connections to ensure leak-tight integrity at 3.00 MPa operating pressure.
Installation & Maintenance Guidelines
Foundation & Structural Requirements
The DW-70/30 has a dry weight of 18.00 tonnes and a center of gravity approximately 1,000 mm above the baseplate. Despite the massive size, the four-row opposed-cylinder design provides exceptional force balance, permitting installation on a reinforced concrete inertia block of 25–30 tonnes. The block must be mounted on heavy-duty elastomeric vibration isolators (natural frequency 5–7 Hz) to prevent vibration transmission to adjacent structures and sensitive instrumentation. Foundation design must account for dynamic forces during startup and shutdown, with a safety factor of 2.0 on the static load. Minimum clearance requirements: 2.0 m on all sides for maintenance access, 2.5 m overhead for crane access during major overhauls, and 3.0 m in front of the control panel for operator access.
Cooling Water System Design
Cooling water demand is approximately 80 m³/h at an inlet temperature not exceeding 32°C. The water distribution circuit supplies the cylinder jackets, intercooler, and aftercooler in parallel branches with individual flow control valves. Given the extreme pressure ratio and massive capacity, the intercoolers are particularly critical for thermal management and must receive priority cooling water flow. Water quality specifications: pH 6.5–8.5, total dissolved solids < 500 mg/L, chloride content < 30 mg/L (to prevent SS316 tube corrosion at high temperature), suspended solids < 20 mg/L, and total hardness < 250 mg/L as CaCO₃. A dedicated closed-loop cooling tower with full-stream filtration and automated chemical treatment is strongly recommended for this unit.
Preventive Maintenance Schedule
| Interval | Service Item | Action Required |
|---|---|---|
| Daily | Operational Inspection | Check vibration, abnormal noise, cooling water flow, discharge pressure, temperature, oil levels |
| 250 hours | Valve Plate Inspection | Remove and inspect all suction/discharge valves for carbon deposits, spring fatigue, cracking |
| 1,000 hours | Piston Ring Wear Assessment | Measure ring groove clearance on all cylinders; replace rings if clearance exceeds 0.20 mm |
| 3,000 hours | Intermediate Overhaul | Replace all piston rings, rider bands, and valve plate assemblies across all four rows |
| 6,000 hours | Major Overhaul | Inspect crankshaft journals, measure all main bearing clearances, replace bearings if >0.06 mm |
The oil-free design of the DW-70/30 dramatically simplifies maintenance compared to lubricated alternatives of this scale. There are no oil changes (which would require 500+ liters per change), no oil analysis, no filter replacements, and no separator cartridge changes. The primary consumable wear items are the PTFE piston rings and rider bands, which typically achieve 3,000–5,000 hours of service life under clean nitrogen conditions at high pressure. The four-row design allows for staggered maintenance scheduling, where individual rows can be serviced while the remaining rows continue operation, maximizing equipment availability.
Compliance & Safety Certifications
The DW-70/30 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, ISO 14001:2015
Nitrogen is classified as a simple asphyxiant gas. At 3.00 MPa discharge pressure, the stored energy in the compressed gas and the risk of rapid release are extreme. All DW-70/30 installations must incorporate multiple layers of safety protection: (1) Continuous oxygen deficiency monitoring in the compressor room and all adjacent areas; (2) High-pressure discharge piping equipped with pressure relief valves rated at 110% of MAWP and rupture discs as secondary protection; (3) Automatic isolation valves on suction and discharge that close on emergency shutdown; (4) Ventilation systems designed to maintain ambient oxygen above 19.5% per OSHA 29 CFR 1910.146; (5) Emergency shutdown interlocks at 19.5% O₂ (alarm) and 18.0% O₂ (hard shutdown); (6) Personnel trained in ultra-high-pressure gas safety protocols before operating or maintaining this equipment. All high-pressure piping must be inspected annually for fatigue cracks and corrosion.
Performance & Efficiency Analysis
The DW-70/30 achieves a specific power consumption of approximately 12.14 kW per m³/min of nitrogen delivered at 3.00 MPa discharge pressure. This efficiency metric is exceptional for an oil-free piston compressor operating at extreme pressure and massive capacity, positioning the unit in the top tier of the ultra-high-pressure compressor segment. For comparison, oil-lubricated reciprocating compressors in similar applications typically consume 13.0–15.0 kW/m³/min, while diaphragm compressors (often selected for oil-free high-pressure service) would require multiple units in parallel and consume 18+ kW/m³/min with significantly higher capital cost.
Over a standard 8,000-hour annual operating schedule, the DW-70/30’s efficiency advantage generates approximately 560,000–1,120,000 kWh of annual energy savings compared to less efficient alternatives. At an average industrial electricity tariff of $0.08/kWh, this represents $44,800–$89,600 in direct operating cost reduction per year. When combined with the complete elimination of oil-related consumables (which would be massive at this scale—1,000+ liters of oil annually, plus filters, separators, and disposal costs), the total cost of ownership for ultra-high-pressure nitrogen compression is reduced by an estimated 25–35% over a 10-year operational life.
The absence of oil in the compression path is particularly valuable at 3.00 MPa because oil contamination becomes exponentially more concentrated and more difficult to remove as pressure increases. At this pressure level, downstream oil-filtration systems would require multiple stages of coalescing filters, activated carbon adsorbers, and continuous oil monitoring instrumentation, consuming 5–8% of the compressor’s power output and requiring frequent maintenance. The DW-70/30’s native oil-free design removes this parasitic load and maintenance burden entirely.
Customization & OEM Capabilities
We offer comprehensive customization options to adapt the DW-70/30 to specific site conditions, integration requirements, and end-user specifications:
- Skid-Mounted Turnkey Packages: The compressor, motor, coolers, instrumentation, and control panel are pre-assembled on a massive structural steel skid with integrated lifting lugs and anchor bolt templates. Factory pre-testing of all systems reduces commissioning time by 70% and minimizes field risks.
- Hazardous Area Configurations: ATEX Zone 2 and IECEx compliant motor and electrical enclosures for petrochemical and offshore installations. Integrated gas detection, fire suppression, and automatic ventilation interlocks can be incorporated into the safety system.
- Advanced Process Control: Siemens S7-1500 or Allen-Bradley ControlLogix PLC with 15-inch HMI touchscreen, redundant remote monitoring via Modbus TCP/IP and OPC-UA, and seamless integration with plant DCS/SCADA. Automatic load/unload control, VFD compatibility, and predictive maintenance algorithms optimize availability and reduce unplanned downtime.
- Environmental Protection: C5-M marine-grade coatings for offshore and coastal installations; tropicalized electrical components for 55°C ambient; and IP54-rated acoustic enclosures with active noise cancellation reducing emission from 88 dB(A) to 72 dB(A) at 1 meter.
- OEM & Private Label: Custom paint colors, branded nameplates, and localized documentation packages for major gas equipment distributors and EPC contractors. Technical manuals, spare parts lists, and training programs can be supplied in multiple languages.
Custom configurations are available from MOQ 1 unit. Engineering review and proposal generation typically require 7–10 business days due to the complexity of this unit. Standard delivery time is 16–20 weeks; expedited delivery within 14 weeks is available for qualifying orders with advance scheduling.
Case Study: Offshore Platform Nitrogen Injection System
Client: A major oil and gas operator in the South China Sea
Challenge: The client’s offshore production platform required a massive nitrogen injection system for reservoir pressure maintenance and gas lift operations. The platform had limited deck space, strict weight constraints, and no access to oil-contaminated nitrogen due to reservoir sensitivity. Existing solutions would have required three separate oil-lubricated compressors with extensive downstream purification, occupying 150 m² of deck space and weighing over 45 tonnes.
Solution: We supplied a DW-70/30 oil-free nitrogen compressor on a compact skid with integrated coolers, control system, and C5-M marine-grade coatings. The four-row design achieved the required 70 m³/min in a single machine, reducing footprint to 65 m² and weight to 22 tonnes (including skid). The oil-free design eliminated all downstream purification equipment. The unit was configured for 6kV direct drive with a VFD for part-load optimization during varying reservoir demand.
Quantified Results After 36 Months:
- Deck space utilization: Reduced by 57% versus three-comparator alternative (65 m² vs 150 m²)
- Total skid weight: Reduced by 51% (22 tonnes vs 45 tonnes), critical for offshore platform load limits
- Oil contamination in injected nitrogen: <0.01 mg/m³, protecting reservoir integrity
- Maintenance intervals: Extended by 40% versus oil-lubricated alternatives due to oil-free design
- Energy consumption: Improved by 8.2% versus design estimate due to VFD part-load optimization
- Availability: 99.2% over 36 months, with only scheduled maintenance downtime
“The DW-70/30 was the only compressor that could deliver our required flow and pressure in a single machine while meeting our strict oil-free requirements. The space and weight savings were critical for our offshore platform, and the reliability has been outstanding. We’ve already ordered a second unit for our adjacent platform.” — Offshore Production Manager
FAQ & Selection Guide
Related Products & Solutions
DW Series High-Pressure Nitrogen Compressors
Comprehensive range of oil-free piston compressors (2–130 m³/min) for discharge pressures from 0.40 MPa to 3.00 MPa. Two-stage and four-row configurations for nitrogen injection, pipeline boosting, and chemical synthesis.
ZW Series Multi-Stage Oil-Free Compressors
Vertical, multi-stage oil-free compressors for oxygen, nitrogen, hydrogen, and specialty gases. Discharge pressures up to 9.00 MPa for ultra-high-pressure gas filling and chemical process applications.
MW Series Medium-Pressure Compressors
Medium-pressure oil-free compressors (1.0–4.0 MPa) for nitrogen recycle, gas liquefaction booster duty, and process gas compression in petrochemical and refinery operations.
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 Transform Your Ultra-High-Pressure Nitrogen 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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