Beschreibung
ZW-0.97/7.5~30 Nitrogen Compressor – Compact Variable Inlet Oil-Free N2 Booster for Medium-Pressure Recycle
Engineered to deliver 0.97 m³/min at 3.00 MPa discharge pressure with 0.75 MPa inlet capability, the ZW-0.97/7.5~30 is a two-stage, single-row oil-free piston nitrogen compressor designed for small-scale nitrogen recycle, gas liquefaction booster circuits, and medium-pressure process applications with variable inlet conditions. Zero oil contamination, ultra-compact footprint, and optimized for continuous-duty operation.
Product Overview
The ZW-0.97/7.5~30 nitrogen compressor is a compact yet capable solution within our oil-free piston compressor family, distinguished by its variable inlet pressure capability spanning from 0.75 MPa up to the discharge pressure of 3.00 MPa. With a rated capacity of 0.97 m³/min and a discharge pressure of 3.00 MPa, this unit occupies the entry-level segment of our high-pressure nitrogen compressor portfolio while maintaining the same engineering rigor as our larger models.
What makes the ZW-0.97/7.5~30 unique is its ability to accept inlet nitrogen at pressures up to 0.75 MPa, as indicated by the model designation “7.5~30” (representing inlet pressure range of 0.75 MPa to 3.0 MPa). This variable inlet capability eliminates the need for upstream pressure reduction when feeding from medium-pressure nitrogen headers or process vents, improving overall system efficiency and reducing pressure losses. The compressor can also operate from atmospheric or low-pressure inlet when required, providing exceptional operational flexibility for small-scale installations.
The compressor employs a two-stage, single-row (二列一级) configuration that is optimized for the moderate pressure ratio required when boosting from 0.75 MPa to 3.00 MPa. The single-row design minimizes mechanical complexity and footprint while the two-stage arrangement ensures efficient thermodynamic performance and manageable discharge temperatures. Each stage features independent cooling, preserving the integrity of the PTFE sealing elements even under sustained operation at elevated pressure.
Technical Specifications – ZW-0.97/7.5~30
| Parameter | Value | Unit |
|---|---|---|
| Modell | ZW-0.97/7.5~30 | – |
| Muster | Two-stage, Single-row (二列一级) | – |
| Kapazität | 0.97 (inlet 0.75 MPa) | m³/min |
| Entladedruck | 3.00 | MPa |
| Inlet Pressure Range | 0.75 ~ 3.00 | MPa |
| Compressor Size (L × W × H) | 2035 × 1240 × 2234 | mm |
| Gewicht | 2.60 | t |
| Leistung | 45 | kW |
| Stromspannung | 380 | V |
| Gasmedium | 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. Capacity is specified at 0.75 MPa inlet pressure; actual capacity varies with inlet pressure.
Key Features & Engineering Advantages
1. Variable Inlet Pressure Capability (0.75–3.00 MPa)
The ZW-0.97/7.5~30 is uniquely engineered to accept inlet nitrogen across a broad pressure range from 0.75 MPa up to 3.00 MPa. This variable inlet capability is achieved through a robust valve design and cylinder sizing that accommodates varying suction densities without mechanical distress. When fed from a medium-pressure nitrogen header at 0.75 MPa, the compressor operates at its rated 0.97 m³/min capacity. As inlet pressure increases toward the discharge pressure, the compressor transitions into a pressure-maintaining or recycle mode with progressively reduced power consumption. This flexibility eliminates the need for upstream pressure regulators or throttling valves that would waste energy and create noise, making the ZW-0.97/7.5~30 ideal for nitrogen recycle loops and process systems with variable upstream pressure.
2. Ultra-Compact Footprint for Space-Constrained Installations
At 2035 × 1240 × 2234 mm, the ZW-0.97/7.5~30 occupies less than 2.5 m² of floor space, making it one of the most compact high-pressure oil-free nitrogen compressors available. This dimensional efficiency is achieved through a vertically oriented crankcase design and a single-row cylinder arrangement that minimizes the machine’s longitudinal footprint. At just 2.60 tonnes, the unit can be transported and positioned using standard forklift equipment, eliminating the need for overhead cranes or specialized rigging. This compact form factor is particularly valuable for retrofit installations in existing process plants, containerized systems, and mobile nitrogen supply units where floor space is at a premium.
3. Oil-Free PTFE Composite Sealing for High-Pressure Service
The ZW-0.97/7.5~30 utilizes a proprietary self-lubricating piston ring and rider band assembly manufactured from high-performance PTFE composites reinforced with glass fiber and bronze particulates. This material achieves a coefficient of friction below 0.06 without any external hydrocarbon lubrication, ensuring the nitrogen stream remains completely free of oil contamination. At 3.00 MPa discharge pressure, the partial pressure of any oil vapor would be significantly magnified, making oil-free design absolutely essential for applications requiring high-purity nitrogen. The PTFE formulation is specifically rated for continuous operation at temperatures up to 180°C, ensuring reliable sealing integrity under the thermal stress of high-pressure compression.
4. Standard 380V Drive with Low Power Consumption
The ZW-0.97/7.5~30 is driven by a 45 kW, 380V, 50Hz three-phase induction motor conforming to IEC 60034-1 efficiency class IE3. The modest power requirement of 45 kW makes this unit accessible to virtually any industrial facility with standard 380V distribution, without requiring electrical infrastructure upgrades or medium-voltage switchgear. The low power consumption also translates to lower operating costs and reduced cooling requirements, making the ZW-0.97/7.5~30 an economically attractive option for small to medium nitrogen systems.
Application Scenarios
Small-Scale Nitrogen Recycle & Recovery
In small chemical process plants and gas treatment facilities, the ZW-0.97/7.5~30 serves as a nitrogen recycle compressor that recovers nitrogen from process vents and boosts it back to the required distribution pressure. The variable inlet capability is critical in these applications because the recovered nitrogen may be at any pressure between atmospheric and the process operating pressure. The compressor automatically adapts to the available inlet pressure, maintaining efficient operation across the full range. This recycle capability reduces nitrogen consumption by 30–50% compared to once-through systems, delivering substantial operating cost savings for small-scale operations where every efficiency gain matters.
Gas Liquefaction & Cryogenic Booster Duty
In small-scale nitrogen liquefaction plants and cryogenic systems, the ZW-0.97/7.5~30 nitrogen booster compresses nitrogen from the liquefier vaporizer or storage tank to the pressure required for distribution or further processing. The 3.00 MPa discharge pressure is sufficient for feeding high-pressure nitrogen into cryogenic storage systems, driving nitrogen through heat exchangers, or supplying high-pressure process equipment. The variable inlet capability allows the compressor to accept nitrogen directly from the liquefier at its operating pressure, eliminating intermediate pressure reduction and improving overall plant efficiency.
Pilot Plant & R&D High-Pressure Nitrogen Supply
Research laboratories and pilot-scale chemical plants require high-pressure nitrogen for high-pressure reactor inerting, catalyst testing under pressure, and supercritical fluid experiments. The ZW-0.97/7.5~30’s compact footprint and standard 380V electrical supply make it ideal for installation in laboratory utility rooms or pilot plant buildings. The 3.00 MPa discharge pressure is adequate for most pilot-scale high-pressure applications, while the oil-free certification ensures that nitrogen purity meets the stringent requirements of research-grade experiments and analytical instrumentation. The variable inlet capability is particularly valuable in R&D environments where experimental conditions change frequently.
Medium-Pressure Header Pressure Maintenance
Industrial facilities with medium-pressure nitrogen distribution headers (0.75–1.50 MPa) often require a pressure maintenance compressor to compensate for demand fluctuations and pipeline losses. The ZW-0.97/7.5~30 can accept nitrogen directly from the header at its operating pressure and boost it to 3.00 MPa for high-pressure consumers or back into the header to maintain pressure during peak demand periods. This dual-mode operation provides exceptional operational flexibility and reduces the need for separate compressor units, making it an economically efficient solution for small to medium facilities.
Material & Construction
The ZW-0.97/7.5~30 is constructed from materials selected for high-pressure nitrogen compatibility, thermal resistance, and compact structural integrity:
| Component | Material | Specification |
|---|---|---|
| Cylinder Block (LP) | Gray Cast Iron | GG25 / HT250, standard wall thickness |
| Cylinder Block (HP) | Gray Cast Iron | GG25 / HT250, reinforced wall + ribbing |
| Crankshaft | Forged Alloy Steel | 42CrMo4, Q&T, dynamically balanced |
| Piston Rings | PTFE-Glass-Bronze Composite | High-pressure rated, self-lubricating, 180°C max |
| Rider Bands | PTFE Composite | Piston guidance, anti-scuffing |
| Valve Plates | Stainless Steel | SS316, high-pressure concentric ring design |
| Intercooler | Carbon Steel Shell / SS316 Tubes | ASME VIII Div.1, 1.5× hydrotest |
| Aftercooler | Carbon Steel Shell / SS316 Tubes | High-pressure finned tube, 32°C cooling water |
| High-Pressure Piping | Seamless Stainless Steel | SS316, ANSI Class 600 flanges |
All pressure-bearing components are designed and fabricated in 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 600 flanged connections to ensure leak-tight integrity at 3.00 MPa operating pressure.
Installation & Maintenance Guidelines
Foundation & Spatial Requirements
The ZW-0.97/7.5~30 has a dry weight of 2.60 tonnes and a center of gravity approximately 700 mm above the baseplate. A reinforced concrete pad of 4–5 tonnes is sufficient for stable operation, mounted on elastomeric vibration isolators (natural frequency 8–12 Hz). The single-row design generates moderate unbalanced forces that are easily managed with standard foundation practices. Minimum clearance requirements: 1.0 m on the non-drive side for valve access, 0.8 m on the drive side for motor maintenance, and 1.5 m overhead for crane access. Special attention must be paid to the high-pressure discharge piping, which must be properly supported and anchored to prevent vibration-induced fatigue at 3.00 MPa.
Cooling Water Specifications
Cooling water demand is approximately 8 m³/h at an inlet temperature not exceeding 32°C. The water distribution circuit supplies the cylinder jackets and intercooler in parallel. Given the high pressure ratio, the intercooler is 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 < 50 mg/L (to prevent SS316 tube corrosion), suspended solids < 30 mg/L, and total hardness < 300 mg/L as CaCO₃. A closed-loop cooling tower with side-stream filtration is recommended for sites with marginal water quality.
Preventive Maintenance Schedule
| Interval | Service Item | Action Required |
|---|---|---|
| Daily | Operational Inspection | Check vibration, abnormal noise, cooling water flow, discharge pressure, temperature |
| 250 hours | Valve Plate Inspection | Remove and inspect suction/discharge valves for carbon deposits, spring fatigue, cracking |
| 1,000 hours | Piston Ring Wear Assessment | Measure ring groove clearance; replace rings if clearance exceeds 0.20 mm |
| 3,000 hours | Intermediate Overhaul | Replace all piston rings, rider bands, and valve plate assemblies |
| 6,000 hours | Major Overhaul | Inspect crankshaft journals, measure main bearing clearances, replace bearings if >0.08 mm |
The oil-free design of the ZW-0.97/7.5~30 dramatically simplifies maintenance compared to lubricated alternatives. 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 3,000–5,000 hours of service life under clean nitrogen conditions. The high-pressure valve plates may require more frequent inspection than low-pressure equivalents due to increased mechanical stress, but the overall maintenance burden remains significantly lower than oil-lubricated systems.
Compliance & Safety Certifications
The ZW-0.97/7.5~30 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 risk of rapid gas release and oxygen displacement is significantly elevated. All ZW-0.97/7.5~30 installations must incorporate continuous oxygen deficiency monitoring in the compressor room and adjacent areas. High-pressure discharge piping must be equipped with pressure relief valves rated at 110% of MAWP and rupture discs as secondary protection. Ventilation systems must maintain ambient oxygen above 19.5% per OSHA 29 CFR 1910.146. Emergency shutdown interlocks should activate at 19.5% O₂ (alarm) and trigger automatic isolation at 18.0% O₂ (hard shutdown). Personnel must be trained in high-pressure gas safety protocols before operating or maintaining this equipment.
Performance & Efficiency Analysis
The ZW-0.97/7.5~30 achieves a specific power consumption of approximately 46.39 kW per m³/min of nitrogen at 3.00 MPa discharge pressure from 0.75 MPa inlet. While this specific power appears high in absolute terms, the true efficiency advantage lies in the ability to accept high-pressure inlet without energy-wasting pressure reduction. When compared to systems that throttle 0.75 MPa nitrogen down to atmospheric pressure before re-compressing to 3.00 MPa, the ZW-0.97/7.5~30 saves approximately 45–55% of the compression energy by utilizing the available inlet pressure directly.
Over an 8,000-hour annual operating cycle in a typical nitrogen recycle application, the ZW-0.97/7.5~30’s variable inlet capability yields approximately 80,000–120,000 kWh of energy savings compared to systems requiring upstream pressure reduction. At $0.08/kWh, this represents $6,400–$9,600 in annual electricity cost reduction. When combined with the elimination of oil-related consumables and the avoidance of downstream purification equipment, the total cost of ownership for nitrogen recycle compression is reduced by an estimated 30–40% over a 10-year operational life.
The absence of oil in the compression path is particularly valuable in recycle applications because any oil contamination would accumulate in the closed nitrogen loop, progressively degrading product quality and potentially contaminating process equipment. The ZW-0.97/7.5~30’s native oil-free design ensures that nitrogen purity is maintained indefinitely in recycle service.
Customization & OEM Capabilities
We offer flexible customization options to adapt the ZW-0.97/7.5~30 to specific site conditions and integration requirements:
- Skid-Mounted Packages: Pre-assembled compressor, motor, coolers, instrumentation, and control panel on a structural steel skid with forklift pockets. Reduces field installation to electrical and cooling water connections only.
- Mobile Trailer Units: The ZW-0.97/7.5~30 can be mounted on a road-legal trailer with integrated diesel generator, cooling system, and nitrogen storage, creating a fully mobile nitrogen supply unit for construction sites, pipeline maintenance, and emergency response.
- PLC & Remote Monitoring: Optional Siemens LOGO! or S7-1200 PLC with HMI touchscreen, Ethernet connectivity, and SMS/email alarms. Compatible with Modbus TCP/IP for SCADA integration.
- Acoustic Enclosures: Compact IP54-rated sound enclosure reducing noise from 82 dB(A) to 68 dB(A) at 1 meter, suitable for indoor installations in noise-sensitive environments such as laboratories and office-adjacent machinery rooms.
- 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 3–5 business days. Standard delivery time is 10–12 weeks; expedited delivery within 8 weeks is available for qualifying orders.
Case Study: Pilot Plant Nitrogen Recycle Optimization
Client: A specialty chemical R&D facility in Singapore operating multiple pilot-scale high-pressure reactors
Challenge: The facility was purchasing high-pressure nitrogen cylinders for reactor inerting and purge operations, consuming approximately 200 cylinders per month at a cost of $15,000/month. The spent nitrogen was vented to atmosphere at 0.60–0.90 MPa after passing through the reactors, representing a significant waste of both gas and energy. The facility wanted to recover and recycle this nitrogen but needed a compact compressor capable of accepting variable inlet pressure and boosting it to 2.50 MPa for re-use in the high-pressure reactor feed system.
Solution: We supplied a ZW-0.97/7.5~30 oil-free nitrogen compressor configured on a compact skid with integrated intercooler, aftercooler, and a Siemens LOGO! PLC control panel. The variable inlet capability allowed the compressor to accept nitrogen directly from the reactor vent header at whatever pressure was available (0.60–0.90 MPa), eliminating the need for upstream pressure regulation. A 0.5 m³ surge vessel was installed upstream to dampen pressure fluctuations from the batch reactor cycle.
Quantified Results After 18 Months:
- Nitrogen cylinder purchases: Reduced by 72% (from 200 to 56 cylinders/month), saving $10,800/month
- Nitrogen vent emissions: Reduced by 72%, improving environmental compliance
- Oil contamination in recycled nitrogen: <0.01 mg/m³, ensuring no reactor contamination
- Compressor availability: 97.8% over 18 months, with only scheduled maintenance downtime
- Payback period: 1.4 years based on cylinder cost savings alone
“The ZW-0.97/7.5~30 has transformed our nitrogen supply from a recurring expense into a closed-loop system. We’ve cut our cylinder purchases by nearly three-quarters, and the compact size meant we could install it in our existing utility room without any building modifications. The variable inlet feature was the key that made this project work.” — R&D Operations Manager, Specialty Chemical Facility
FAQ & Selection Guide
Related Products & Solutions
ZW-2.1/8~25 Variable Inlet Nitrogen Compressor
Larger capacity variable inlet oil-free compressor (2.1 m³/min, 2.50 MPa) with 0.80 MPa inlet capability. Ideal for medium-scale nitrogen recycle and gas liquefaction booster applications.
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.
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 Optimize Your Small-Scale Nitrogen Recycle System?
Our application engineers are standing by to evaluate your nitrogen flow requirements, inlet pressure conditions, discharge pressure targets, and integration constraints. We provide complimentary technical proposals, 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
