ZW-4/8 Nitrogen Compressor – Precision Oil-Free N2 Booster for High-Pressure Small-Scale Applications

描述

ZW-4/8 Nitrogen Compressor – Precision Oil-Free N2 Booster for High-Pressure Small-Scale Applications

Delivering 4 m³/min at 0.80 MPa discharge pressure, the ZW-4/8 is a two-stage, two-row oil-free piston nitrogen compressor engineered for high-pressure laboratory supply, precision instrument inerting, and compact industrial nitrogen boosting where elevated pressure and absolute purity are non-negotiable.

ZW-4/8 nitrogen compressor high pressure oil-free precision unit

产品概述

ZW-4/8 nitrogen compressor is a precision-engineered oil-free piston compressor designed for applications where high discharge pressure and compact footprint must coexist. With a rated capacity of 4 m³/min and an elevated discharge pressure of 0.80 MPa, this unit addresses the demanding requirements of high-pressure nitrogen distribution in laboratory complexes, precision manufacturing facilities, and small-scale industrial processes.

Unlike conventional compressors that compromise on either pressure capability or purity, the ZW-4/8 achieves both through a fully oil-free compression mechanism. The piston rings and rider bands are manufactured from advanced self-lubricating PTFE composites that operate without hydrocarbon lubricants, ensuring the nitrogen stream remains completely free of oil contamination. This native oil-free characteristic is essential for applications such as GC-MS carrier gas supply, pharmaceutical sterile processing, and semiconductor wafer handling where even trace oil vapor can compromise product integrity.

two-stage, two-row (二列二级) architecture is specifically optimized for the 0.80 MPa discharge pressure target. By distributing the pressure ratio across two compression stages with inter-stage cooling, the ZW-4/8 maintains discharge temperatures within safe limits while achieving the higher pressure output that single-stage designs cannot reach. The compact dimensions of 2250 × 1296 × 2200 mm and a weight of just 2.00 tonnes make this unit suitable for installation in confined machinery rooms, mobile skids, and containerized nitrogen supply systems.

ZW series nitrogen compressor compact high pressure two stage design

Technical Specifications – ZW-4/8

范围 价值 单元
模型 ZW-4/8
图案 Two-stage, Two-row (二列二级)
容量 4 立方米/分钟
排气压力 0.80 兆帕
压缩机尺寸(长×宽×高) 2250 × 1296 × 2200 毫米
重量 2.00 t
力量 30 千瓦
电压 380 V
气体介质 氮气(N₂)
润滑 无油

* 所有规格均在标准参考条件下(ISO 1217,附录 C)测得。实际性能可能因现场海拔、环境温度和进气条件而异。

主要特性及工程优势

1. High-Pressure Oil-Free Piston Technology

The ZW-4/8 employs a 自润滑活塞环和导向带组件 fabricated from high-density PTFE composites reinforced with glass fiber and bronze particulates. These rings achieve a coefficient of friction below 0.08 without any external lubrication, delivering ISO 8573-1 Class 0 oil content certification in the compressed nitrogen stream. This is particularly critical for high-pressure applications where oil contamination would be amplified by the pressure ratio, making downstream oil removal exponentially more difficult and expensive.

2. Two-Stage Compression for Elevated Pressure Ratios

two-stage, two-row architecture is thermodynamically essential for achieving the 0.80 MPa discharge pressure from typical nitrogen generator outlet pressures of 0.05–0.10 MPa. The first-stage cylinder compresses the nitrogen to an intermediate pressure of approximately 0.25–0.30 MPa, after which an inter-stage cooler removes the heat of compression. The second-stage cylinder then raises the pressure to the final 0.80 MPa target. This staged approach limits the discharge temperature of each stage to below 160°C, preventing thermal degradation of the PTFE sealing elements and maintaining valve plate integrity under the elevated pressure duty.

3. Compact Footprint with High Power Density

At 2250 × 1296 × 2200 mm, the ZW-4/8 occupies less than 3 m² of floor space while delivering 0.80 MPa discharge pressure—a combination that is difficult to achieve with alternative compressor technologies. The compact vertical crankcase design minimizes the longitudinal footprint while providing adequate access for routine maintenance. The 2.00-tonne weight permits transportation and positioning using standard forklift equipment, making the ZW-4/8 suitable for retrofit installations in existing machinery rooms, mobile nitrogen supply skids, and containerized process units.

4. Efficient 380V Motor Drive

The ZW-4/8 is driven by a 30 kW, 380V, 50Hz three-phase induction motor conforming to IEC 60034-1 IE3 efficiency class. The standard low-voltage configuration integrates directly into existing 380V industrial distribution panels without requiring specialized medium-voltage infrastructure. This electrical simplicity is particularly valuable for small-scale facilities, laboratories, and mobile installations where medium-voltage switchgear would be prohibitively expensive. The 30 kW power rating provides an excellent balance between compression capability and electrical demand, keeping operating costs manageable for intermittent-duty applications.

ZW-4/8 nitrogen compressor general assembly compact high pressure design

应用场景

High-Pressure Laboratory Nitrogen Supply

Research laboratories and analytical facilities require high-pressure nitrogen for gas chromatography carrier gas, mass spectrometry nebulizer gas, and inert atmosphere glove box supply. The ZW-4/8’s 0.80 MPa discharge pressure is sufficient to feed high-pressure nitrogen regulators and distribution manifolds serving multiple instruments simultaneously. The oil-free certification ensures that the nitrogen stream meets the stringent purity requirements of analytical instruments without requiring additional purification cartridges or oil-monitoring instrumentation. The 4 m³/min capacity can comfortably support 8–12 GC-MS systems or 4–6 ICP-MS instruments operating in parallel.

ZW-4/8 nitrogen compressor high pressure laboratory supply application

Precision Manufacturing & Semiconductor Inerting

In electronics and semiconductor manufacturing, nitrogen is used for wafer handling inerting, reflow oven atmosphere control, and component storage dry cabinets. The ZW-4/8 high-pressure nitrogen compressor delivers the 0.80 MPa pressure required for precision pressure regulators that maintain sub-atmosphere inert environments in glove boxes and wafer transfer chambers. The oil-free design is absolutely critical in these applications because even nanogram-level oil contamination can cause solder joint defects, conformal coating adhesion failures, and contamination of optical surfaces on precision components.

Pharmaceutical Sterile Processing & Aseptic Filling

Pharmaceutical manufacturing facilities use high-pressure nitrogen for aseptic filling line inerting, vial headspace displacement, and freeze-dryer chamber purging. The ZW-4/8’s 0.80 MPa discharge pressure provides the head necessary to feed nitrogen through HEPA-filtered distribution systems and precision pressure regulators that maintain sterile barrier pressures in isolators and restricted access barrier systems (RABS). The oil-free certification ensures compliance with FDA 21 CFR 211.72 (equipment construction) and EU GMP Annex 1 (sterile medicinal products) without requiring additional oil-removal validation.

ZW-4/8 nitrogen compressor pharmaceutical sterile processing application

Small-Scale VPSA Nitrogen Booster

For compact VPSA nitrogen generators producing 99.5–99.9% purity nitrogen at near-atmospheric pressure, the ZW-4/8 compresses the low-pressure product to 0.80 MPa for high-pressure distribution. The compact footprint allows the compressor to be mounted on the same skid as the VPSA generator, creating an integrated nitrogen supply system that occupies minimal floor space. The oil-free compression path protects the carbon molecular sieve from hydrocarbon poisoning, preserving the generator’s separation efficiency and extending adsorbent life by preventing irreversible contamination.

材料与施工

The ZW-4/8 is constructed from materials selected for high-pressure nitrogen compatibility, corrosion resistance, and long-term mechanical reliability:

成分 材料 规格
Cylinder Block 灰铸铁 GG25 / HT250, integral cooling passages
曲轴 锻造合金钢 42CrMo4, Q&T, ISO 1940 G2.5 balanced
活塞环 PTFE-Glass-Bronze Composite Self-lubricating, oil-free rated
骑手带 聚四氟乙烯复合材料 Piston guidance, anti-scuffing
阀板 不锈钢 SS316, concentric ring spring design
Intercooler Carbon Steel Shell / SS304 Tubes Compact shell-and-tube, 1.5× hydrotest
后冷却器 Carbon Steel Shell / SS304 Tubes Finned tube design, 32°C cooling water
底座框架 Structural Steel Welded, vibration-damped mounting

All pressure-bearing components are designed and fabricated in accordance with ASME BPVC 第 VIII 节第 1 部分 or Chinese GB 150 standards. Weld joints undergo 100% radiographic inspection (RT), and each pressure vessel is subjected to hydrostatic testing at 1.5× the maximum allowable working pressure (MAWP) for a minimum hold time of 30 minutes.

ZW-4/8 nitrogen compressor factory precision machining quality control

安装和维护指南

Foundation & Spatial Requirements

The ZW-4/8 weighs 2.00 tonnes and features a low center of gravity due to its compact vertical design. A reinforced concrete pad of 3–4 tonnes is sufficient for stable operation, mounted on elastomeric vibration isolators (natural frequency 8–12 Hz). The two-row opposed-cylinder arrangement inherently cancels first-order inertial forces, minimizing vibration transmission to sensitive laboratory equipment or precision manufacturing machinery nearby. Required clearances: 1.0 m on the non-drive side for valve maintenance, 0.8 m on the drive side for motor access, and 1.5 m overhead for routine service.

Cooling Water Specifications

冷却水需求量约为 8 m³/h at an inlet temperature not exceeding 32°C. The water distribution circuit feeds the cylinder jackets and intercooler in parallel. Acceptable water quality: pH 6.5–8.5, total hardness < 300 mg/L as CaCO₃, chloride < 50 mg/L, suspended solids < 30 mg/L. For laboratory installations without dedicated cooling water infrastructure, a compact air-cooled aftercooler option is available, eliminating the need for water supply entirely.

预防性维护计划

间隔 服务项目 需要采取的行动
日常的 Visual & Operational Check Inspect for leaks, abnormal noise, cooling water flow
250小时 Valve Plate Inspection Check for carbon deposits, spring fatigue, or plate cracking
1000小时 Piston Ring Wear Assessment Measure groove clearance; replace if > 0.20 mm
4,000 hours Intermediate Service Replace piston rings, rider bands, and valve assemblies
8,000 hours 大修 Inspect crankshaft, measure bearing clearances, replace as needed

The oil-free design of the ZW-4/8 dramatically reduces maintenance complexity compared to lubricated alternatives. There are no oil changes to schedule, no oil samples to analyze, no filter elements to replace, and no oil separator cartridges to monitor. The only consumable wear items are the 聚四氟乙烯活塞环和活塞环带, which typically achieve 4,000–6,000 hours of service under clean nitrogen conditions.

ZW-4/8 nitrogen compressor workshop assembly and quality inspection

合规与安全认证

The ZW-4/8 nitrogen compressor meets or exceeds the following international standards and regulatory requirements:

Pressure Equipment
ASME BPVC 第 VIII 部分第 1 部分、GB 150-2011、PED 2014/68/EU 模块 A
电气与机械安全
IEC 60034-1 (IE3 efficiency), IEC 60204-1, ISO 12100
Oil-Free Certification
ISO 8573-1 Class 0 (Oil Content), TÜV Rheinland independently tested
质量与环境
ISO 9001:2015,ISO 14001:2015

⚠️ Safety Notice

Nitrogen is an odorless, colorless asphyxiant gas. All ZW-4/8 installations must include continuous oxygen monitoring in the compressor room and adjacent areas. Ventilation must maintain ambient oxygen above 19.5% per OSHA 29 CFR 1910.146. Alarm interlocks should trigger at 19.5% O₂ and hard shutdown at 18.0% O₂. Personnel entry into enclosed compressor rooms requires portable oxygen monitors and a buddy system. High-pressure nitrogen systems must be equipped with pressure relief devices rated to ASME BPVC Section VIII requirements.

ZW-4/8 nitrogen compressor ISO certification and compliance documentation

性能与效率分析

The ZW-4/8 achieves a specific power consumption of approximately 7.50 kW per m³/min of nitrogen at 0.80 MPa discharge pressure. While this specific power is higher than our larger LW-series models due to the reduced scale efficiency inherent in small-capacity compressors, it remains competitive within the sub-5 m³/min high-pressure oil-free piston segment. For comparison, oil-lubricated screw compressors in this pressure and size range typically consume 8.0–9.5 kW/m³/min, and diaphragm compressors (often selected for oil-free high-pressure duty) can exceed 12 kW/m³/min.

Over an 8,000-hour annual operating cycle, the ZW-4/8’s efficiency advantage versus less efficient alternatives yields approximately 12,000–32,000 kWh of energy savings per year. At $0.08/kWh, this represents $960–$2,560 in annual electricity cost reduction. However, the primary economic driver for ZW-4/8 selection is typically the elimination of oil-related consumables and downstream purification equipment rather than marginal energy savings.

total cost of ownership for high-pressure nitrogen compression in small-scale applications is dominated by maintenance labor and consumables. The ZW-4/8’s oil-free design eliminates oil changes ($300–600/year), filter replacements ($150–300/year), separator cartridge changes ($400–800/year), and oil analysis ($100–200/year), delivering total consumable savings of $950–$1,900 annually compared to lubricated alternatives. Additionally, the elimination of downstream oil-removal equipment (coalescing filters, activated carbon adsorbers, oil monitors) saves $3,000–$8,000 in capital expenditure.

定制化和OEM能力

We provide flexible customization options to adapt the ZW-4/8 to specific installation constraints and end-user requirements:

  • Skid-Mounted Packages: Pre-assembled compressor, motor, cooler, and control panel on a structural steel skid with forklift pockets and lifting eyes. Reduces field installation to electrical connection and cooling water hookup only.
  • Mobile Trailer Units: The ZW-4/8 can be mounted on a road-legal trailer with integrated diesel generator, cooling system, and nitrogen storage, creating a fully mobile high-pressure nitrogen supply unit for construction sites, pipeline maintenance, and emergency response.
  • Air-Cooled Configuration: Optional air-cooled aftercooler eliminates the need for cooling water supply, making the ZW-4/8 suitable for laboratory installations without plumbing infrastructure or mobile applications where water availability is limited.
  • PLC & Remote Monitoring: Optional Siemens LOGO! or S7-1200 PLC with 7-inch HMI touchscreen, Ethernet connectivity, and SMS/email alarm notifications. Compatible with Modbus TCP/IP for SCADA integration.
  • Acoustic Enclosures: Compact IP54-rated sound enclosure reducing noise from 82 dB(A) to 66 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 packages for gas equipment distributors and system integrators.

可提供自定义配置 最小起订量 1 件. 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.

ZW-4/8 nitrogen compressor custom skid mounted installation site

Case Study: Pharmaceutical Aseptic Filling Line Nitrogen Upgrade

客户: A pharmaceutical manufacturing facility in Thailand specializing in sterile injectable products

挑战: The facility was using a lubricated reciprocating nitrogen compressor to supply high-pressure nitrogen (0.70 MPa) to their aseptic filling lines. Oil contamination in the nitrogen stream was detected at 1.5 mg/m³, exceeding the 0.1 mg/m³ limit specified in their product quality agreement with international buyers. The oil was also causing frequent clogging of the 0.22 μm absolute filters in the nitrogen distribution system, requiring filter replacement every 3 weeks instead of the designed 6-month interval.

解决方案: 我们提供了 ZW-4/8 oil-free nitrogen compressor as a direct replacement, configured on a custom skid with an air-cooled aftercooler (eliminating cooling water requirements), a Siemens LOGO! PLC control panel, and an integrated 0.5 m³ surge vessel. The skid footprint was designed to fit into the existing compressor room without civil modifications. The 0.80 MPa discharge pressure provided a safety margin above the 0.70 MPa required by the filling line regulators.

Results After 24 Months:

  • 氮油含量: Reduced from 1.5 mg/m³ to <0.01 mg/m³, achieving ISO 8573-1 Class 0 certification
  • Absolute filter replacement interval: Extended from 3 weeks to 8 months, saving $18,000/year in filter costs and reducing production downtime
  • Overall maintenance expenditure: Decreased by 45% due to elimination of oil changes, filter replacements, and separator overhauls
  • Product quality complaints: Zero oil-related rejections since commissioning, preserving international buyer contracts
  • 计划外停机: 零事件 in 24 months of continuous operation

“The ZW-4/8 compressor solved our oil contamination problem permanently. Our filter replacement costs dropped by 85%, and we have not had a single quality rejection related to nitrogen purity since installation. The air-cooled option was a bonus—no cooling water meant one less utility to worry about.” — Quality Assurance Manager, Pharmaceutical Manufacturing Facility

ZW-4/8 nitrogen compressor pharmaceutical installation case study site

常见问题解答及选购指南

What is the expected service life of the ZW-4/8?

The ZW-4/8 is engineered for a 最低设计寿命15年 (approximately 120,000 operating hours) in clean nitrogen service. The cast-iron frame and forged steel crankshaft are rated for the full design life. PTFE piston rings and rider bands are the primary wear items, with replacement intervals of 4,000–6,000 hours. Valve plate assemblies typically last 2,500–4,000 hours before requiring refurbishment.

Can the ZW-4/8 operate from a VPSA nitrogen generator with pulsating outlet pressure?

Yes. The ZW-4/8 can accommodate 入口压力变化范围为0.03兆帕至0.12兆帕. For VPSA applications with significant pressure pulsation, we recommend installing a 0.5–1.0 m³ surge vessel upstream of the compressor suction to dampen cyclic fluctuations and protect the valves from hydraulic shock. An optional pulsation dampener can be fitted for severe pulsation conditions.

Is the ZW-4/8 suitable for outdoor installation?

The standard ZW-4/8 is designed for 室内安装 in a ventilated machinery room. For outdoor use, we offer an optional IP54 weatherproof enclosure with space heating (for -20°C climates), solar shields (for 55°C ambient), and forced ventilation. The acoustic enclosure option is recommended for outdoor installations to maintain noise compliance.

How does the ZW-4/8 compare to oil-lubricated alternatives for high-pressure nitrogen compression?

Oil-lubricated screw compressors offer higher capacity density but introduce unacceptable oil contamination risk for pharmaceutical, food-grade, and electronics applications. The ZW-4/8 achieves ISO 8573-1 Class 0 natively without downstream filtration. At high pressure ratios (8:1 to 16:1), piston compressors also demonstrate superior efficiency compared to screw compressors, which are optimized for lower pressure ratios. For a comprehensive TCO comparison, see our 氮气压缩机投资回报率分析.

When should I avoid selecting the ZW-4/8?

The ZW-4/8 is NOT recommended for: (1) Discharge pressures above 1.00 MPa—consider our DW series or ZW multi-stage models for higher pressure requirements; (2) Capacity requirements above 8 m³/min—larger ZW-8/6 or LW-series models offer better scale efficiency; (3) Continuous flow modulation below 45% of rated capacity—piston compressors are less efficient at deep turndown; a dual-unit arrangement or VFD-equipped alternative may be preferable for highly variable demand.

相关产品及解决方案

ZW-8/6 Compact Nitrogen Compressor

Higher capacity (8 m³/min) at 0.60 MPa for small-scale industrial nitrogen boosting, VPSA booster stations, and laboratory supply. Same compact footprint with doubled flow capacity.

Explore ZW-8/6 →

DW系列高压氮气压缩机

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.

探索DW系列 →

LW系列大容量氮气压缩机

适用于低温空分装置备用、VPSA增压和工业管道输送的高流量无油活塞式压缩机(20–130 m³/min)。排气压力为0.30至0.80 MPa。

探索 LW 系列 →

For a complete overview of our 工业氮气压缩机 portfolio, including oil-free oxygen compressors, hydrogen compressors, and specialty gas solutions, please contact our engineering team or browse our online catalog.

Ready to Upgrade Your High-Pressure Nitrogen Supply?

Our application engineers are available to evaluate your nitrogen flow requirements, inlet conditions, discharge pressure targets, and integration constraints. We provide complimentary technical proposals, layout drawings, piping and instrumentation diagrams (P&IDs), and detailed TCO analyses within 48 hours.

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