説明
ZW-3.3/70 Nitrogen Compressor – Ultra-High-Pressure Oil-Free N2 Booster for 7.00 MPa Demanding Applications
Engineered to deliver 3.3 m³/min at 7.00 MPa discharge pressure, the ZW-3.3/70 is a two-stage, two-row oil-free piston nitrogen compressor designed for ultra-high-pressure nitrogen injection, gas cylinder filling, and critical petrochemical process applications. Zero oil contamination, heavy-duty construction, and optimized for continuous-duty operation at extreme pressure.
製品概要
The ZW-3.3/70 nitrogen compressor represents the pinnacle of our oil-free piston compressor engineering, purpose-built for applications where ultra-high discharge pressure is the absolute requirement. With a rated capacity of 3.3 m³/min and an exceptional 7.00 MPa discharge pressure, this unit occupies a specialized niche in the industrial gas compression landscape, serving the most demanding nitrogen boosting requirements in heavy industry.
What distinguishes the ZW-3.3/70 from all alternatives is its fully oil-free compression pathway combined with extreme pressure capability. The piston rings and rider bands are fabricated from advanced self-lubricating PTFE composite materials specifically formulated for ultra-high-pressure service. This design ensures the nitrogen stream remains completely uncontaminated by hydrocarbons even at 7.00 MPa, where oil contamination would be most concentrated and most difficult to remove. For operators in oil & gas, aerospace, and critical manufacturing, this native oil-free certification eliminates the need for complex and expensive downstream purification trains.
The compressor architecture employs a two-stage, two-row (二列二级) configuration that is thermodynamically essential for managing the extreme pressure ratio required to achieve 7.00 MPa from typical inlet conditions. Each stage is independently cooled through high-efficiency intercoolers, ensuring gas temperatures remain within safe operating envelopes and preserving the integrity of the PTFE sealing elements under the most severe thermal stress. The reinforced frame construction and heavy-duty crankshaft assembly are engineered for a minimum service life of 100,000 hours under standard maintenance protocols.
Technical Specifications – ZW-3.3/70
| Parameter | Value | Unit |
|---|---|---|
| モデル | ZW-3.3/70 | – |
| パターン | Two-stage, Two-row (二列二级) | – |
| 容量 | 3.3 | m³/分 |
| 吐出圧力 | 7.00 | MPa |
| Compressor Size (L × W × H) | 1920 × 1900 × 2580 | mm |
| 重さ | 3.97 | t |
| 力 | 75 | kW |
| 電圧 | 380 | V |
| ガス媒体 | Nitrogen (N₂) | – |
| Lubrication | オイルフリー | – |
* 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. Ultra-High-Pressure Oil-Free PTFE Sealing Technology
The ZW-3.3/70 employs a proprietary self-lubricating piston ring and rider band assembly manufactured from ultra-high-performance PTFE composites specifically engineered for 7.00 MPa service. These rings are reinforced with high-density glass fiber and bronze particulates to achieve a coefficient of friction below 0.05 without any external hydrocarbon lubrication. At 7.00 MPa discharge pressure, the partial pressure of oil vapor would be approximately 23 times higher than at 0.30 MPa, making oil contamination catastrophic and virtually impossible to remove downstream. The ZW-3.3/70’s native oil-free design delivers ISO 8573-1 Class 0 compliance without any downstream filtration, a feat that is technically impossible for lubricated compressors at this pressure level. The PTFE formulation is rated for continuous operation at temperatures up to 200°C, ensuring sealing integrity under the extreme thermal stress of ultra-high-pressure compression.
2. Two-Stage Compression for Extreme Pressure Ratios
The two-stage compression architecture of the ZW-3.3/70 is not merely preferred but absolutely mandatory for achieving 7.00 MPa from typical inlet pressures of 0.05–0.10 MPa. The overall pressure ratio of approximately 70:1 to 140:1 is split between a low-pressure cylinder and a high-pressure cylinder, with each stage operating at a thermodynamically manageable pressure ratio. A high-capacity shell-and-tube intercooler between stages removes the substantial heat of compression, maintaining discharge temperatures below 170°C and preventing thermal degradation of the PTFE sealing elements. Without staged compression, the theoretical discharge temperature would exceed 350°C, far beyond the safe operating limit of any known sealing material. The two-stage design also improves volumetric efficiency by reducing the re-expansion losses that would plague a single-stage machine at such extreme pressure ratios.
3. Heavy-Duty Reinforced Frame for Ultra-High-Pressure Loads
The main frame is cast from GG25 gray cast iron with substantially reinforced wall sections, additional ribbing, and integral cooling water passages. The high-pressure cylinder features wall thicknesses approximately 40% greater than standard cylinders, with stress-relieving heat treatment after machining. The two-row opposed-cylinder arrangement provides natural first-order force cancellation, which is critical for ultra-high-pressure compressors where the peak gas forces on the pistons can exceed 50 tonnes per cylinder. This mechanical advantage reduces the unbalanced inertia forces transmitted to the foundation by over 80%, permitting installation on a reinforced concrete inertia block of 6–8 tonnes rather than the 12+ tonnes that would be required for a single-row design of equivalent pressure capability.
4. Standard 380V Industrial Motor Drive with High-Torque Design
The ZW-3.3/70 is driven by a 75 kW, 380V, 50Hz three-phase induction motor conforming to IEC 60034-1 efficiency class IE3, with a high-torque design optimized for the starting loads of ultra-high-pressure piston compressors. The standard low-voltage configuration integrates directly into existing 380V industrial distribution panels without requiring medium-voltage infrastructure. The motor is oversized relative to the running power requirement to provide the high starting torque necessary to overcome the initial compression resistance when starting against 7.00 MPa discharge pressure. This electrical simplicity makes the ZW-3.3/70 accessible to a wide range of industrial facilities regardless of their electrical infrastructure scale.
Application Scenarios
Ultra-High-Pressure Nitrogen Cylinder Filling
The ZW-3.3/70 is purpose-built for filling industrial and medical nitrogen cylinders to 15–20 MPa through a staged compression system. While the compressor’s 7.00 MPa discharge pressure does not reach cylinder filling pressure directly, it serves as a highly efficient first-stage booster that dramatically reduces the compression ratio required of the downstream high-pressure filling compressor. By boosting nitrogen from 0.05–0.10 MPa to 7.00 MPa, the ZW-3.3/70 reduces the filling compressor’s required pressure ratio by approximately 60%, improving overall system efficiency and extending the life of the expensive high-pressure stage. The oil-free design is absolutely mandatory for cylinder filling because any oil contamination would be trapped in the cylinders and delivered to end-users, potentially contaminating their processes and violating gas quality standards.
Oil & Gas Well Nitrogen Injection
In upstream oil and gas operations, the ZW-3.3/70 nitrogen booster provides high-pressure nitrogen for enhanced oil recovery (EOR), well stimulation, and gas lift operations. The 7.00 MPa discharge pressure is sufficient to inject nitrogen into reservoir formations at depths up to 2,000 meters, where reservoir pressures typically range from 5–15 MPa. The oil-free design is critical in oilfield applications because any oil contamination in the nitrogen would alter the wettability of the reservoir rock, reducing oil recovery efficiency and potentially causing formation damage. The compact footprint and 3.97-tonne weight allow the unit to be mounted on mobile skids for deployment to remote well sites.
Aerospace Pressure Testing & Component Validation
Aerospace manufacturers and testing facilities require ultra-high-pressure nitrogen for pressure testing of aircraft components, hydraulic system validation, and fuel tank inerting system testing. The ZW-3.3/70’s 7.00 MPa discharge pressure is adequate for hydrostatic and pneumatic testing of fuselage sections, landing gear components, and fuel system hardware. The oil-free certification ensures that test nitrogen meets the stringent cleanliness requirements of aerospace standards (AS9100, NADCAP), where even trace oil contamination could interfere with non-destructive testing or leave residues that affect component performance.
High-Pressure Chemical Synthesis & Process Inerting
In chemical process industries, the ZW-3.3/70 provides ultra-high-pressure nitrogen for high-pressure reactor inerting, catalyst bed preservation, and supercritical fluid extraction processes. The 7.00 MPa discharge pressure is sufficient to maintain inert atmospheres in high-pressure reactors operating at 5–6 MPa, providing a safety margin above the process pressure. The oil-free design is mandatory for chemical synthesis because oil contamination would poison catalysts, contaminate reaction products, and potentially create hazardous conditions in oxygen-sensitive reactions. The 3.3 m³/min capacity can support multiple high-pressure reactors operating in parallel within a single process unit.
Material & Construction
The ZW-3.3/70 is constructed from premium materials selected for ultra-high-pressure nitrogen compatibility, extreme thermal resistance, and maximum structural integrity:
| Component | Material | 仕様 |
|---|---|---|
| Cylinder Block (LP) | Gray Cast Iron | GG25 / HT250, standard wall thickness |
| Cylinder Block (HP) | Gray Cast Iron | GG25 / HT250, reinforced wall + heavy ribbing, stress-relieved |
| Crankshaft | Forged Alloy Steel | 42CrMo4, Q&T, ISO 1940 G2.5 dynamically balanced |
| Piston Rings | Ultra-High-Pressure PTFE Composite | High-density glass fiber + bronze, 200°C rated, 7 MPa certified |
| Rider Bands | PTFE Composite | Piston guidance, anti-scuffing, wear rate <0.03 mm/1000h |
| Valve Plates | ステンレス鋼 | SS316, ultra-high-pressure concentric ring design |
| Connecting Rods | Forged Steel with Babbitt Bearings | Heavy-duty, 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 rated |
| High-Pressure Piping | Seamless Stainless Steel | SS316, ANSI Class 900 flanges, 100% X-ray inspected |
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 and are 100% X-ray inspected to ensure leak-tight integrity at 7.00 MPa operating pressure.
Installation & Maintenance Guidelines
Foundation & Structural Requirements
The ZW-3.3/70 has a dry weight of 3.97 tonnes and a center of gravity approximately 800 mm above the baseplate. A reinforced concrete inertia block of 6–8 tonnes is required for stable operation, mounted on heavy-duty elastomeric vibration isolators (natural frequency 6–8 Hz). The two-row opposed-cylinder design cancels first-order inertial forces, but the ultra-high-pressure gas loads generate substantial frame stresses that require a robust foundation. 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. The high-pressure discharge piping must be properly supported with spring hangers and expansion joints to accommodate thermal expansion and prevent vibration-induced fatigue at 7.00 MPa.
Cooling Water System Design
Cooling water demand is approximately 15 m³/h at an inlet temperature not exceeding 32°C. The water distribution circuit supplies the cylinder jackets and intercooler in parallel, with the intercooler receiving priority flow allocation due to its critical role in thermal management. Given the extreme pressure ratio, the intercooler must remove a substantial quantity of heat between stages to prevent thermal damage to the high-pressure cylinder’s PTFE sealing elements. Water quality specifications: pH 6.5–8.5, total dissolved solids < 500 mg/L, chloride content < 30 mg/L (strict limit for SS316 corrosion protection at high pressure), suspended solids < 20 mg/L, and total hardness < 250 mg/L as CaCO₃. A closed-loop cooling tower with side-stream filtration and chemical treatment is strongly recommended.
Preventive Maintenance Schedule
| Interval | Service Item | Action Required |
|---|---|---|
| Daily | Operational Inspection | Check vibration, abnormal noise, cooling water flow, discharge pressure, temperature, leak detection |
| 200 hours | Valve Plate Inspection | Remove and inspect suction/discharge valves for carbon deposits, spring fatigue, cracking, seat wear |
| 800 hours | Piston Ring Wear Assessment | Measure ring groove clearance; replace rings if clearance exceeds 0.18 mm |
| 2,500 hours | Intermediate Overhaul | Replace all piston rings, rider bands, and valve plate assemblies; inspect cylinder bores |
| 5,000 hours | Major Overhaul | Inspect crankshaft journals, measure main bearing clearances, replace bearings if >0.06 mm; inspect frame |
The oil-free design of the ZW-3.3/70 dramatically simplifies maintenance compared to lubricated alternatives, though the ultra-high-pressure operation demands more frequent inspection than lower-pressure models. There are no oil changes, 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 2,500–4,000 hours of service life under clean nitrogen conditions at 7.00 MPa. The high-pressure valve plates require more frequent inspection due to the extreme mechanical stress, with replacement intervals of 2,000–3,000 hours.
Compliance & Safety Certifications
The ZW-3.3/70 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 7.00 MPa discharge pressure, the stored energy in the compressed gas and the risk of rapid gas release are extreme. All ZW-3.3/70 installations must incorporate: (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) Emergency isolation valves on both suction and discharge that close automatically on alarm; (4) Ventilation systems maintaining ambient oxygen above 19.5% per OSHA 29 CFR 1910.146; (5) Emergency shutdown interlocks activating at 19.5% O₂ (alarm) and triggering hard isolation at 18.0% O₂; (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 corrosion, erosion, and mechanical damage.
Performance & Efficiency Analysis
The ZW-3.3/70 achieves a specific power consumption of approximately 22.73 kW per m³/min of nitrogen delivered at 7.00 MPa discharge pressure. This specific power figure reflects the substantial thermodynamic work required for ultra-high-pressure compression from atmospheric inlet. Within the ultra-high-pressure oil-free compressor segment (discharge pressure >5.00 MPa), this efficiency is highly competitive. For comparison, diaphragm compressors—the primary alternative for oil-free ultra-high-pressure service—typically consume 25–35 kW/m³/min at equivalent pressures, while oil-lubricated reciprocating compressors consume 20–25 kW/m³/min but introduce unacceptable oil contamination.
Over an 8,000-hour annual operating cycle, the ZW-3.3/70’s efficiency advantage versus diaphragm compressors yields approximately 60,000–120,000 kWh of annual energy savings. At $0.08/kWh, this represents $4,800–$9,600 in direct electricity cost reduction per year. However, the primary economic driver for ZW-3.3/70 selection is typically the combination of oil-free certification, higher capacity, and lower capital cost compared to diaphragm alternatives. A diaphragm compressor with equivalent oil-free certification and 3.3 m³/min capacity would cost 4–6 times more than the ZW-3.3/70 and occupy significantly more space.
The total cost of ownership for ultra-high-pressure nitrogen compression is dominated by capital cost, maintenance labor, and equipment availability rather than marginal energy differences. The ZW-3.3/70’s piston design offers superior maintainability compared to diaphragm compressors, with shorter overhaul times and lower spare parts costs. The absence of oil eliminates the need for expensive high-pressure oil-filtration systems that would be mandatory with lubricated alternatives at 7.00 MPa.
Customization & OEM Capabilities
We offer comprehensive customization options to adapt the ZW-3.3/70 to specific site conditions, integration requirements, and end-user specifications:
- Skid-Mounted Turnkey Packages: Pre-assembled compressor, motor, high-pressure coolers, instrumentation, control panel, and safety systems on a structural steel skid with integrated lifting lugs. Factory pre-testing of all high-pressure systems before shipment.
- Mobile Trailer Units: The ZW-3.3/70 can be mounted on a road-legal trailer with integrated diesel generator, closed-loop cooling system, and high-pressure nitrogen storage, creating a fully mobile ultra-high-pressure nitrogen supply unit for oilfield services, pipeline maintenance, and emergency response.
- Hazardous Area Configurations: ATEX Zone 2 and IECEx compliant motor and electrical enclosures for oil & gas installations. Integrated gas detection, automatic ventilation, and emergency isolation interlocks.
- Advanced Process Control: Optional Siemens S7-1200 PLC with HMI touchscreen, high-pressure safety interlocks including automatic unload on overpressure, emergency isolation valves, and remote monitoring via Modbus TCP/IP or OPC-UA.
- Environmental Protection: C5-M marine-grade coatings for offshore installations; tropicalized electrical components for 55°C ambient; IP54-rated acoustic enclosures reducing noise from 85 dB(A) to 72 dB(A) at 1 meter.
- OEM & Private Label: Custom paint schemes, branded nameplates, and localized documentation for gas equipment distributors and system integrators.
Custom configurations are available from MOQ 1 unit. Engineering proposals are typically delivered within 5–7 business days. Standard delivery time is 12–14 weeks; expedited delivery within 10 weeks is available for qualifying orders.
Case Study: Oilfield Nitrogen Injection for Enhanced Recovery
Client: An independent oil & gas operator in the Middle East with mature oil fields requiring enhanced recovery
Challenge: The operator needed to inject nitrogen into reservoir formations at 6–8 MPa to maintain pressure and improve oil recovery in a mature field where natural pressure had declined. The existing solution involved purchasing liquid nitrogen, vaporizing on-site, and boosting with rental compressors—a logistics-intensive approach costing $2.5 million annually with unreliable supply during peak demand periods. The operator required a permanent, oil-free nitrogen compression solution that could operate continuously in a desert environment with ambient temperatures reaching 50°C.
Solution: We supplied a ZW-3.3/70 oil-free nitrogen compressor paired with a small VPSA nitrogen generator (99.5% purity, 5 m³/min) on a common skid. The ZW-3.3/70 boosted the VPSA product from 0.08 MPa to 7.00 MPa for direct injection into the reservoir through existing wellhead connections. The skid was equipped with tropicalized electrical components, C5-M marine-grade coatings, and a closed-loop cooling tower with sand filtration for the desert environment. A Siemens S7-1200 PLC provided remote monitoring and automatic wellhead pressure control.
Quantified Results After 36 Months:
- Nitrogen supply cost: Reduced by 68% versus liquid nitrogen purchase and rental compressors ($2.5M to $800K/year)
- Oil recovery improvement: +12% incremental recovery due to consistent nitrogen injection pressure and purity
- Supply reliability: 99.2% uptime over 36 months, zero production interruptions due to nitrogen shortage
- Oil contamination in injected nitrogen: <0.01 mg/m³, ensuring no formation damage
- Payback period: 2.8 years based on nitrogen cost savings alone; additional revenue from increased oil recovery
“The ZW-3.3/70 has transformed our nitrogen injection program from a logistical nightmare into a reliable production tool. The oil-free design gives us confidence that we’re not damaging our reservoir, and the cost savings have exceeded our projections. We’ve already ordered two additional units for our other fields.” — Reservoir Engineering Manager, Oil & Gas Operator
FAQ & Selection Guide
Related Products & Solutions
DW Series High-Pressure Nitrogen Compressors
Designed for discharge pressures from 0.40 MPa to 2.00 MPa, the DW series covers nitrogen injection, high-pressure pipeline boosting, and chemical synthesis. Capacities from 2 to 130 m³/min.
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.
LW Series Large-Capacity Nitrogen Compressors
High-flow oil-free piston compressors (20–130 m³/min) for cryogenic ASU backup, VPSA boosting, and industrial pipeline distribution. Discharge pressures from 0.30 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 Upgrade 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.
Email: [email protected] | Response within 24 hours
