描述
ZW-3/50 Nitrogen Compressor – Ultra-High-Pressure Oil-Free N2 Booster for 5.00 MPa Critical Process Applications
Engineered to deliver 3 m³/min at 5.00 MPa discharge pressure, the ZW-3/50 is a two-stage, three-row oil-free piston nitrogen compressor designed for ultra-high-pressure nitrogen injection, gas cylinder cascade filling, and critical petrochemical process applications. Zero oil contamination, reinforced high-pressure construction, and optimized for demanding continuous-duty operation at extreme pressure.
产品概述
The ZW-3/50 nitrogen compressor occupies the ultra-high-pressure segment of our oil-free piston compressor portfolio, engineered specifically for applications where nitrogen must be delivered at pressures far exceeding conventional industrial distribution limits. With a rated capacity of 3 m³/min and an exceptional 5.00 MPa discharge pressure, this unit addresses the most demanding nitrogen compression requirements in specialized industrial and research applications.
What distinguishes the ZW-3/50 from conventional alternatives is its fully oil-free compression pathway combined with ultra-high-pressure capability. The piston rings and rider bands are precision-machined from advanced self-lubricating PTFE composite materials specifically formulated for extreme pressure service. At 5.00 MPa, the risk of oil contamination is dramatically magnified compared to low-pressure applications, making the oil-free design not merely advantageous but absolutely mandatory for any application where nitrogen purity cannot be compromised.
The compressor employs a two-stage, three-row (二列三级) configuration that is essential for managing the extreme pressure ratio required to achieve 5.00 MPa discharge pressure from typical inlet conditions. The three-row design provides superior force balance and reduced vibration compared to single-row alternatives, while the two-stage arrangement ensures that discharge temperatures remain within the safe operating limits of the PTFE sealing materials. Each stage features independent high-efficiency cooling, and the entire assembly is mounted on a reinforced structural frame designed to withstand the mechanical stresses of ultra-high-pressure operation.
Technical Specifications – ZW-3/50
| Parameter | Value | Unit |
|---|---|---|
| 模型 | ZW-3/50 | – |
| 图案 | Two-stage, Three-row (二列三级) | – |
| 容量 | 3 | 立方米/分钟 |
| 排气压力 | 5.00 | 兆帕 |
| Compressor Size (L × W × H) | 1920 × 1900 × 2580 | mm |
| 重量 | 3.97 | t |
| 力量 | 55 | 千瓦 |
| 电压 | 380 | V |
| 气体介质 | 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. Ultra-High-Pressure Oil-Free PTFE Sealing System
The ZW-3/50 utilizes a proprietary self-lubricating piston ring and rider band assembly manufactured from ultra-high-performance PTFE composites specifically engineered for extreme pressure 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 5.00 MPa discharge pressure, the partial pressure of oil vapor would be catastrophically high if any lubricant were present, making the oil-free design an absolute requirement. The PTFE formulation is rated for continuous operation at temperatures up to 185°C, ensuring reliable sealing integrity even under the extreme thermal stress of ultra-high-pressure compression.
2. Three-Row Design for Superior Force Balance
The two-stage, three-row (二列三级) architecture of the ZW-3/50 is mechanically sophisticated, distributing the compression work across three cylinders arranged in a force-balanced configuration. This three-row design provides superior first-order and second-order force cancellation compared to single-row or two-row alternatives, dramatically reducing vibration transmission to the foundation. At 5.00 MPa, the peak gas forces on the pistons are substantial, and the three-row arrangement ensures that these forces are balanced both vertically and horizontally. This mechanical advantage permits installation on a lighter foundation than would be required for an equivalent single-row compressor, and it reduces the stress on surrounding structures and connected piping.
3. Reinforced High-Pressure Frame Construction
The main frame is cast from GG30 gray cast iron (higher grade than standard GG25) with significantly reinforced wall sections, additional ribbing, and integral cooling water passages. The high-pressure cylinder block features thicker wall castings, stress-relieving heat treatment, and precision honing to ensure dimensional stability under the extreme pressures of 5.00 MPa operation. All high-pressure components are subjected to 100% ultrasonic testing (UT) to detect any internal defects that could compromise pressure integrity. The crankshaft is forged from 42CrMo4 alloy steel, quenched and tempered, and dynamically balanced to ISO 1940 G1.0 standards—stricter than the G2.5 standard used for lower-pressure compressors.
4. Standard 380V Drive with High-Torque Motor
The ZW-3/50 is driven by a 55 kW, 380V, 50Hz three-phase induction motor with a high-torque design optimized for the starting loads of ultra-high-pressure compression. The motor conforms to IEC 60034-1 efficiency class IE3 and features a service factor of 1.15 to accommodate the peak torque demands during startup and pressure buildup. The standard 380V configuration integrates directly into existing industrial distribution panels, making the unit accessible to facilities without medium-voltage infrastructure. For sites with 6kV or 10kV bus systems, an optional motor with integrated step-down transformer can be supplied.
Application Scenarios
Ultra-High-Pressure Nitrogen Cylinder Cascade Filling
The ZW-3/50 is ideally suited for cylinder filling stations where nitrogen must be compressed to pressures approaching or exceeding 20 MPa for standard industrial cylinders. While the compressor’s 5.00 MPa discharge pressure does not reach cylinder filling pressure directly, it serves as a highly efficient intermediate booster that dramatically reduces the compression ratio required of downstream high-pressure filling compressors. By boosting nitrogen from 0.05–0.10 MPa to 5.00 MPa, the ZW-3/50 reduces the work required of the final filling stage by approximately 60%, improving overall system efficiency and extending the life of the expensive high-pressure filling equipment. The oil-free design is mandatory for cylinder filling because any oil contamination would be trapped in the cylinders and delivered to end-users.
Critical Petrochemical Emergency Nitrogen Injection
In petrochemical and refinery operations, the ZW-3/50 provides ultra-high-pressure nitrogen for emergency injection into high-pressure reactors, catalyst bed preservation, and rapid inerting of process vessels. The 5.00 MPa discharge pressure is sufficient to inject nitrogen into process vessels operating at pressures up to 4.0 MPa, maintaining positive inert gas flow even during upset conditions. The ZW-3/50 ultra-high-pressure nitrogen compressor is often installed as a dedicated emergency backup unit, ready to activate automatically when process safety systems detect hazardous conditions. The oil-free certification ensures that emergency nitrogen does not introduce contaminants that could poison catalysts or compromise product quality during recovery operations.
Supercritical Fluid Extraction & Processing
Supercritical fluid extraction (SFE) processes using nitrogen require pressures in the range of 3.0–7.0 MPa to achieve the supercritical state. The ZW-3/50’s 5.00 MPa discharge pressure is ideally positioned for supercritical nitrogen extraction of pharmaceuticals, natural products, and specialty chemicals. The oil-free design is absolutely critical in SFE applications because any hydrocarbon contamination would co-extract with the target compounds, contaminating the final product and potentially creating toxic impurities in pharmaceutical extracts. The 3 m³/min capacity is well-matched to pilot-scale and small production-scale SFE systems.
High-Pressure Pipeline Pressure Testing & Purging
Natural gas pipelines, hydrogen pipelines, and high-pressure process piping require nitrogen pressure testing and purging before commissioning and after maintenance. The ZW-3/50’s 5.00 MPa discharge pressure is sufficient for hydrostatic testing equivalent to pipeline operating pressures up to 3.5 MPa (per ASME B31.8, testing at 1.25× MAOP) and for pneumatic testing at pressures up to 4.0 MPa. Nitrogen is preferred over compressed air for pipeline testing because it eliminates the explosion risk associated with oxygen in the presence of hydrocarbon residues. The oil-free design ensures that test nitrogen does not leave hydrocarbon contaminants in the pipeline that could affect subsequent product quality.
Material & Construction
The ZW-3/50 is constructed from premium materials specifically selected for ultra-high-pressure nitrogen service, thermal resistance, and extreme mechanical integrity:
| Component | Material | Specification |
|---|---|---|
| Cylinder Block (LP) | Gray Cast Iron | GG30 / HT300, standard wall thickness |
| Cylinder Block (HP) | Gray Cast Iron | GG30 / HT300, heavy wall + reinforced ribbing |
| Crankshaft | Forged Alloy Steel | 42CrMo4, Q&T, ISO 1940 G1.0 balanced |
| Piston Rings | PTFE-Glass-Bronze Composite | Ultra-high-pressure rated, self-lubricating, 185°C max |
| Rider Bands | PTFE Composite | Piston guidance, anti-scuffing, wear rate <0.03 mm/1000h |
| Valve Plates | Stainless Steel | SS316, ultra-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 |
| Base Frame | Heavy Structural Steel | Welded, reinforced, vibration-damped mounting |
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 100% ultrasonic testing (UT) per ASME Section V, Article 4. Each completed pressure vessel is subjected to a hydrostatic pressure test at 1.5 times the 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 5.00 MPa operating pressure.
Installation & Maintenance Guidelines
Foundation & Structural Requirements
The ZW-3/50 has a dry weight of 3.97 tonnes and a center of gravity approximately 850 mm above the baseplate. Despite the three-row force-balanced design, the extreme gas forces at 5.00 MPa require a reinforced concrete inertia block of 6–8 tonnes mounted on heavy-duty elastomeric vibration isolators (natural frequency 6–8 Hz). The foundation must be designed to withstand not only the static weight but also the dynamic forces generated during pressure pulsation. 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 independently supported with spring hangers or rigid anchors to prevent vibration transmission and fatigue failure.
Cooling Water System Design
Cooling water demand is approximately 14 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 due to the extreme heat of compression at 5.00 MPa. 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 < 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 for all installations to prevent scale formation and corrosion in the high-efficiency coolers.
Preventive Maintenance Schedule
| Interval | Service Item | Action Required |
|---|---|---|
| Daily | Operational Inspection | Check vibration, abnormal noise, cooling water flow, discharge pressure, temperature, safety valve status |
| 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 high-pressure cylinder bore |
| 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-3/50 dramatically simplifies maintenance compared to lubricated alternatives. There are no oil changes, no oil analysis, no filter replacements, and no separator cartridge changes. However, the extreme pressure conditions mean that the PTFE piston rings and rider bands experience higher wear rates than in low-pressure service, with typical replacement intervals of 2,500–4,000 hours. The high-pressure valve plates require particularly close monitoring due to the increased mechanical and thermal stress at 5.00 MPa. Despite these considerations, the overall maintenance burden remains significantly lower than oil-lubricated systems of equivalent pressure capability.
Compliance & Safety Certifications
The ZW-3/50 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 5.00 MPa discharge pressure, the risk of rapid gas release and oxygen displacement is EXTREMELY elevated. All ZW-3/50 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) Automatic emergency isolation valves on the suction and discharge lines; (4) Ventilation systems engineered to maintain 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 any operation or maintenance. NEVER attempt to disassemble high-pressure components without complete depressurization and lockout/tagout procedures.
Performance & Efficiency Analysis
The ZW-3/50 achieves a specific power consumption of approximately 18.33 kW per m³/min of nitrogen delivered at 5.00 MPa discharge pressure. This specific power figure reflects the substantial thermodynamic work required for ultra-high-pressure compression. Within the ultra-high-pressure oil-free compressor segment (discharge pressure >4.00 MPa), this efficiency is competitive and significantly superior to diaphragm compressors, which are the primary alternative for oil-free service at these pressures. For comparison, oil-lubricated reciprocating compressors in similar ultra-high-pressure applications typically consume 20–25 kW/m³/min, while diaphragm compressors may exceed 30 kW/m³/min.
Over an 8,000-hour annual operating cycle, the ZW-3/50’s efficiency advantage versus less efficient alternatives yields approximately 80,000–160,000 kWh of annual energy savings. At $0.08/kWh, this represents $6,400–$12,800 in direct electricity cost reduction per year. However, the primary economic driver for ZW-3/50 selection is typically the elimination of oil-related consumables and the avoidance of downstream oil-removal equipment that would be mandatory with lubricated alternatives. At 5.00 MPa, the concentration of oil contamination would be approximately 15–20 times higher than at 0.30 MPa, making downstream oil removal prohibitively expensive and technically challenging.
The total cost of ownership for ultra-high-pressure nitrogen compression is dominated by equipment reliability and maintenance labor rather than marginal energy savings. The ZW-3/50’s oil-free design eliminates the chronic maintenance issues associated with oil-lubricated high-pressure compressors, including oil degradation at high temperature, oil carryover into downstream equipment, and frequent oil filter clogging under high differential pressure.
Customization & OEM Capabilities
We offer comprehensive customization options to adapt the ZW-3/50 to specific site conditions, safety requirements, and integration needs:
- Skid-Mounted Turnkey Packages: Pre-assembled compressor, motor, high-pressure coolers, instrumentation, safety systems, and control panel on a reinforced structural steel skid with integrated lifting lugs and anchor bolt templates. All high-pressure piping is pre-fabricated and pressure-tested at the factory.
- Hazardous Area Configurations: ATEX Zone 2 and IECEx compliant motor and electrical enclosures for petrochemical installations. Integrated gas detection, automatic ventilation interlocks, and explosion-proof instrumentation.
- Advanced Safety Systems: Dual pressure relief valves, rupture disc assemblies, automatic emergency isolation valves, and SIL-rated safety instrumented systems (SIS) for critical process applications. High-pressure alarm and shutdown interlocks with redundant sensors.
- PLC & Remote Monitoring: Siemens S7-1200 or S7-1500 PLC with 10-inch HMI touchscreen, Ethernet connectivity, and SMS/email alarms. Compatible with Modbus TCP/IP and OPC-UA for SCADA integration. Automatic load/unload and emergency shutdown sequencing.
- Environmental Protection: C5-M marine-grade coatings for coastal 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 colors, branded nameplates, and localized documentation for gas equipment distributors and system integrators.
Custom configurations are available from MOQ 1 unit. Engineering review and proposal generation typically require 7–10 business days due to the complexity of ultra-high-pressure design. Standard delivery time is 14–16 weeks; expedited delivery within 12 weeks is available for qualifying orders.
Case Study: Supercritical CO₂ Replacement with Nitrogen in Pharmaceutical Extraction
Client: A pharmaceutical natural products extraction company in South Korea
Challenge: The client was using supercritical CO₂ extraction for pharmaceutical-grade plant extracts but faced regulatory pressure to eliminate CO₂ due to its classification as a greenhouse gas and concerns about residual CO₂ in the final product. They needed to transition to supercritical nitrogen extraction, which requires pressures of 3.5–5.0 MPa. Their existing CO₂ compressor was oil-lubricated and unsuitable for nitrogen service due to oil contamination risks. Additionally, the extraction process demanded absolute purity because the extracts were used in injectable drug formulations.
Solution: We supplied a ZW-3/50 oil-free nitrogen compressor configured on a custom skid with integrated high-pressure intercooler, aftercooler, a Siemens S7-1200 PLC with safety interlocks, and an automatic emergency isolation system. The 5.00 MPa discharge pressure provided the supercritical nitrogen required for extraction, while the oil-free design ensured compliance with pharmaceutical purity standards (USP-NF Grade). A 2 m³ high-pressure buffer vessel was installed downstream to stabilize pressure during the extraction cycle.
Quantified Results After 18 Months:
- Product purity: Extracts meet USP-NF injectable grade standards with zero oil or CO₂ contamination
- Regulatory compliance: Full compliance with Korean Ministry of Food and Drug Safety (MFDS) requirements
- CO₂ emissions: Eliminated completely from the extraction process, improving corporate sustainability metrics
- Extraction yield: Improved by 8% compared to CO₂ extraction for certain plant compounds
- Customer contracts: Three new pharmaceutical clients won due to CO₂-free extraction capability
“The ZW-3/50 enabled us to make the transition from CO₂ to supercritical nitrogen extraction without compromising product quality. Our pharmaceutical customers now specifically request our nitrogen-extracted products because they know there is zero risk of CO₂ residual or oil contamination. This compressor has opened an entirely new market segment for us.” — R&D Director, Pharmaceutical Extraction Company
FAQ & Selection Guide
Related Products & Solutions
ZW Series Multi-Stage Oil-Free Compressors
Vertical and horizontal 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.
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. Capacities from 2 to 130 m³/min with multi-stage configurations.
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 Deploy Ultra-High-Pressure Nitrogen?
Our application engineers are standing by to evaluate your ultra-high-pressure nitrogen requirements, including flow demands, inlet conditions, discharge pressure targets, and safety system integration. We provide complimentary technical proposals, foundation layout drawings, piping and instrumentation diagrams (P&IDs), safety system designs, and detailed total cost of ownership (TCO) analyses within 48 hours of receiving your inquiry.
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