{"id":578,"date":"2026-07-20T07:47:43","date_gmt":"2026-07-20T07:47:43","guid":{"rendered":"https:\/\/n2-compressor.com\/?post_type=product&p=578"},"modified":"2026-07-20T07:47:43","modified_gmt":"2026-07-20T07:47:43","slug":"zw-2-1-825-nitrogen-compressor","status":"publish","type":"product","link":"https:\/\/n2-compressor.com\/de\/produkt\/zw-2-1-825-nitrogen-compressor\/","title":{"rendered":"ZW-2.1\/8~25 Nitrogen Compressor \u2013 Variable Inlet Oil-Free N2 Booster for Wide-Range Industrial Applications"},"content":{"rendered":"
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ZW-2.1\/8~25 Nitrogen Compressor \u2013 Variable Inlet Oil-Free N2 Booster for Wide-Range Industrial Applications<\/h1>\n

Engineered to deliver 2.1 m\u00b3\/min at 2.50 MPa discharge pressure with 0.80 MPa inlet capability, the ZW-2.1\/8~25 is a two-stage, single-row oil-free piston nitrogen compressor designed for nitrogen recycle, gas liquefaction booster duty, and high-pressure process applications with variable inlet conditions. Zero oil contamination, compact footprint, and optimized for continuous-duty operation.<\/p>\n

Angebot anfordern<\/a>
\nView N2 Compressor Series<\/a><\/div>\n

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Product Overview<\/h2>\n

The ZW-2.1\/8~25 nitrogen compressor<\/strong> represents a specialized solution within our oil-free piston compressor portfolio, distinguished by its variable inlet pressure capability<\/strong> ranging from 0.80 MPa up to the discharge pressure of 2.50 MPa. With a rated capacity of 2.1 m\u00b3\/min<\/strong> and a discharge pressure of 2.50 MPa<\/strong>, this unit is purpose-built for nitrogen recycle applications, gas liquefaction booster circuits, and process systems where the inlet nitrogen is already partially compressed.<\/p>\n

What makes the ZW-2.1\/8~25 unique is its ability to accept inlet nitrogen at pressures up to 0.80 MPa, as indicated by the model designation “8~25” (representing inlet pressure range of 0.8 MPa to 2.5 MPa). This variable inlet capability eliminates the need for upstream pressure reduction when feeding from medium-pressure nitrogen headers, improving overall system efficiency and reducing pressure losses. The compressor can also operate as a conventional booster from atmospheric or low-pressure inlet when required, providing exceptional operational flexibility.<\/p>\n

The compressor employs a two-stage, single-row (\u4e8c\u5217\u4e00\u7ea7)<\/strong> configuration that is optimized for the moderate pressure ratio required when boosting from 0.80 MPa to 2.50 MPa. The single-row design simplifies the mechanical architecture 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.<\/p>\n

\"ZW-2.1\/8~25<\/p>\n<\/div>\n

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Technical Specifications \u2013 ZW-2.1\/8~25<\/h2>\n
\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Parameter<\/th>\nValue<\/th>\nUnit<\/th>\n<\/tr>\n<\/thead>\n
Modell<\/td>\nZW-2.1\/8~25<\/td>\n\u2013<\/td>\n<\/tr>\n
Muster<\/td>\nTwo-stage, Single-row (\u4e8c\u5217\u4e00\u7ea7)<\/td>\n\u2013<\/td>\n<\/tr>\n
Kapazit\u00e4t<\/td>\n2.1 (inlet 0.80 MPa)<\/td>\nm\u00b3\/min<\/td>\n<\/tr>\n
Entladedruck<\/td>\n2.50<\/td>\nMPa<\/td>\n<\/tr>\n
Inlet Pressure Range<\/td>\n0.80 ~ 2.50<\/td>\nMPa<\/td>\n<\/tr>\n
Compressor Size (L \u00d7 W \u00d7 H)<\/td>\n1900 \u00d7 1296 \u00d7 2290<\/td>\nmm<\/td>\n<\/tr>\n
Gewicht<\/td>\n2.60<\/td>\nt<\/td>\n<\/tr>\n
Leistung<\/td>\n75<\/td>\nkW<\/td>\n<\/tr>\n
Stromspannung<\/td>\n380<\/td>\nV<\/td>\n<\/tr>\n
Gasmedium<\/td>\nNitrogen (N\u2082)<\/td>\n\u2013<\/td>\n<\/tr>\n
Lubrication<\/td>\nOil-free<\/td>\n\u2013<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

* 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 0.80 MPa inlet pressure; actual capacity varies with inlet pressure.<\/em><\/p>\n<\/div>\n

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Key Features & Engineering Advantages<\/h2>\n

1. Variable Inlet Pressure Capability (0.80\u20132.50 MPa)<\/h3>\n

The ZW-2.1\/8~25 is uniquely engineered to accept inlet nitrogen across a broad pressure range from 0.80 MPa up to 2.50 MPa<\/strong>. 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 0.80 MPa, the compressor operates at its rated 2.1 m\u00b3\/min capacity. When inlet pressure increases toward the discharge pressure, the compressor transitions into a pressure-maintaining or recycle mode with 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-2.1\/8~25 ideal for nitrogen recycle loops and process systems with variable upstream pressure.<\/p>\n

2. Oil-Free PTFE Composite Sealing System<\/h3>\n

The ZW-2.1\/8~25 utilizes a proprietary self-lubricating piston ring and rider band assembly<\/strong> 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 2.50 MPa discharge pressure, the risk of oil vapor carryover is significantly magnified compared to low-pressure applications, making the oil-free design not merely advantageous but fundamentally essential. The PTFE formulation is rated for continuous operation at temperatures up to 180\u00b0C, ensuring reliable sealing integrity under the thermal stress of high-pressure compression.<\/p>\n

3. Compact Single-Row Design for Space Efficiency<\/h3>\n

The two-stage, single-row (\u4e8c\u5217\u4e00\u7ea7)<\/strong> architecture of the ZW-2.1\/8~25 is mechanically simpler than two-row designs, resulting in a more compact footprint and lower weight. At 1900 \u00d7 1296 \u00d7 2290 mm<\/strong> and 2.60 tonnes, the unit occupies less than 2.5 m\u00b2 of floor space and can be transported and positioned using standard forklift equipment. The single-row configuration is well-suited for the moderate flow rate of 2.1 m\u00b3\/min, where the inertial forces are manageable without the complexity of opposed-cylinder arrangements. This dimensional efficiency makes the ZW-2.1\/8~25 particularly attractive for retrofit installations in existing process plants where machinery room space is limited.<\/p>\n

4. Standard 380V Industrial Motor Drive<\/h3>\n

The ZW-2.1\/8~25 is driven by a 75 kW, 380V, 50Hz three-phase induction motor<\/strong> conforming to IEC 60034-1 efficiency class IE3. The standard low-voltage configuration integrates directly into existing 380V industrial distribution panels without requiring medium-voltage switchgear or step-down transformers. This electrical simplicity reduces both capital expenditure and commissioning complexity, making the unit accessible to a wide range of industrial facilities regardless of their electrical infrastructure scale.<\/p>\n

\"ZW-2.1\/8~25<\/p>\n<\/div>\n

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Application Scenarios<\/h2>\n

Nitrogen Recycle & Pressure Boosting Loops<\/h3>\n

In chemical process plants and gas treatment facilities, the ZW-2.1\/8~25 serves as a nitrogen recycle compressor<\/strong> 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\u201350% compared to once-through nitrogen systems, delivering substantial operating cost savings and environmental benefits.<\/p>\n

\"ZW-2.1\/8~25<\/p>\n

Gas Liquefaction Booster Duty<\/h3>\n

In small-scale nitrogen liquefaction plants, the ZW-2.1\/8~25 nitrogen booster<\/a> compresses nitrogen from the liquefier vaporizer or storage tank to the pressure required for distribution or further processing. The 2.50 MPa discharge pressure is sufficient for feeding high-pressure nitrogen into cryogenic storage systems or for driving nitrogen through heat exchangers and process equipment. The variable inlet capability allows the compressor to accept nitrogen directly from the liquefier at its operating pressure, eliminating the need for intermediate pressure reduction and improving overall liquefaction plant efficiency.<\/p>\n

Medium-Pressure Header Pressure Maintenance<\/h3>\n

Industrial facilities with medium-pressure nitrogen distribution headers (0.80\u20131.50 MPa) often require a pressure maintenance compressor<\/strong> to compensate for demand fluctuations and pipeline losses. The ZW-2.1\/8~25 can accept nitrogen directly from the header at its operating pressure and boost it to 2.50 MPa for high-pressure consumers or back into the header to maintain pressure during peak demand periods. This dual-mode operation\u2014acting as both a booster and a pressure maintainer\u2014provides exceptional operational flexibility and reduces the need for separate compressor units.<\/p>\n

\"ZW-2.1\/8~25<\/p>\n

Laboratory & Pilot Plant High-Pressure Nitrogen<\/h3>\n

Research laboratories and pilot-scale chemical plants require high-pressure nitrogen for high-pressure reactor inerting, catalyst testing, and supercritical fluid applications<\/strong>. The ZW-2.1\/8~25’s compact footprint and standard 380V electrical supply make it suitable for installation in laboratory utility rooms or pilot plant buildings. The 2.50 MPa discharge pressure is adequate for most laboratory high-pressure applications, while the oil-free certification ensures that nitrogen purity meets the stringent requirements of research-grade experiments and analytical instrumentation.<\/p>\n<\/div>\n

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Material & Construction<\/h2>\n

The ZW-2.1\/8~25 is constructed from materials selected for high-pressure nitrogen compatibility, thermal resistance, and compact structural integrity:<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Component<\/th>\nMaterial<\/th>\nSpecification<\/th>\n<\/tr>\n<\/thead>\n
Cylinder Block (LP)<\/td>\nGray Cast Iron<\/td>\nGG25 \/ HT250, standard wall thickness<\/td>\n<\/tr>\n
Cylinder Block (HP)<\/td>\nGray Cast Iron<\/td>\nGG25 \/ HT250, reinforced wall + ribbing<\/td>\n<\/tr>\n
Crankshaft<\/td>\nForged Alloy Steel<\/td>\n42CrMo4, Q&T, dynamically balanced<\/td>\n<\/tr>\n
Piston Rings<\/td>\nPTFE-Glass-Bronze Composite<\/td>\nHigh-pressure rated, self-lubricating, 180\u00b0C max<\/td>\n<\/tr>\n
Rider Bands<\/td>\nPTFE Composite<\/td>\nPiston guidance, anti-scuffing<\/td>\n<\/tr>\n
Valve Plates<\/td>\nStainless Steel<\/td>\nSS316, high-pressure concentric ring design<\/td>\n<\/tr>\n
Intercooler<\/td>\nCarbon Steel Shell \/ SS316 Tubes<\/td>\nASME VIII Div.1, 1.5\u00d7 hydrotest<\/td>\n<\/tr>\n
Aftercooler<\/td>\nCarbon Steel Shell \/ SS316 Tubes<\/td>\nHigh-pressure finned tube, 32\u00b0C cooling water<\/td>\n<\/tr>\n
High-Pressure Piping<\/td>\nSeamless Stainless Steel<\/td>\nSS316, ANSI Class 600 flanges<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

All pressure-bearing components are designed and fabricated in accordance with ASME BPVC Section VIII Division 1<\/strong> 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 2.50 MPa operating pressure.<\/p>\n

\"ZW-2.1\/8~25<\/p>\n<\/div>\n

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Installation & Maintenance Guidelines<\/h2>\n

Foundation & Structural Requirements<\/h3>\n

The ZW-2.1\/8~25 has a dry weight of 2.60 tonnes and a center of gravity approximately 750 mm above the baseplate. A reinforced concrete pad of 4\u20135 tonnes<\/strong> is sufficient for stable operation, mounted on elastomeric vibration isolators (natural frequency 8\u201312 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 2.50 MPa.<\/p>\n

Cooling Water System Design<\/h3>\n

Cooling water demand is approximately 10 m\u00b3\/h<\/strong> at an inlet temperature not exceeding 32\u00b0C. 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\u20138.5, 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 CaCO\u2083. A closed-loop cooling tower with side-stream filtration is recommended for sites with marginal water quality.<\/p>\n

Preventive Maintenance Schedule<\/h3>\n
\n\n\n\n\n\n\n\n\n\n
Interval<\/th>\nService Item<\/th>\nAction Required<\/th>\n<\/tr>\n<\/thead>\n
Daily<\/td>\nOperational Inspection<\/td>\nCheck vibration, abnormal noise, cooling water flow, discharge pressure, temperature<\/td>\n<\/tr>\n
250 hours<\/td>\nValve Plate Inspection<\/td>\nRemove and inspect suction\/discharge valves for carbon deposits, spring fatigue, cracking<\/td>\n<\/tr>\n
1,000 hours<\/td>\nPiston Ring Wear Assessment<\/td>\nMeasure ring groove clearance; replace rings if clearance exceeds 0.20 mm<\/td>\n<\/tr>\n
3,000 hours<\/td>\nIntermediate Overhaul<\/td>\nReplace all piston rings, rider bands, and valve plate assemblies<\/td>\n<\/tr>\n
6,000 hours<\/td>\nMajor Overhaul<\/td>\nInspect crankshaft journals, measure main bearing clearances, replace bearings if >0.08 mm<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

The oil-free design of the ZW-2.1\/8~25 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<\/strong>, which typically achieve 3,000\u20135,000 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.<\/p>\n

\"ZW-2.1\/8~25<\/p>\n<\/div>\n

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Compliance & Safety Certifications<\/h2>\n

The ZW-2.1\/8~25 nitrogen compressor is designed, manufactured, and tested to meet or exceed the following international standards and regulatory frameworks:<\/p>\n

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Pressure Equipment<\/strong>
\nASME BPVC Section VIII Div.1, GB 150-2011, PED 2014\/68\/EU Module A<\/span><\/div>\n
Electrical & Machine Safety<\/strong>
\nIEC 60034-1 (IE3 efficiency), IEC 60204-1, ISO 12100 machinery safety<\/span><\/div>\n
Oil-Free Certification<\/strong>
\nISO 8573-1 Class 0 (Oil Content), independently tested by T\u00dcV Rheinland<\/span><\/div>\n
Quality & Environmental<\/strong>
\nISO 9001:2015, ISO 14001:2015<\/span><\/div>\n<\/div>\n
\u26a0\ufe0f Critical Safety Advisory \u2013 High-Pressure Operation<\/strong><\/p>\n

Nitrogen is classified as a simple asphyxiant gas. At 2.50 MPa discharge pressure, the risk of rapid gas release and oxygen displacement is significantly elevated. All ZW-2.1\/8~25 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% O\u2082 (alarm) and trigger automatic isolation at 18.0% O\u2082 (hard shutdown). Personnel must be trained in high-pressure gas safety protocols before operating or maintaining this equipment.<\/p>\n<\/div>\n

\"ZW-2.1\/8~25<\/p>\n<\/div>\n

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Performance & Efficiency Analysis<\/h2>\n

The ZW-2.1\/8~25 achieves a specific power consumption of approximately 35.71 kW per m\u00b3\/min<\/strong> of nitrogen at 2.50 MPa discharge pressure from 0.80 MPa inlet. This specific power figure reflects the thermodynamic reality of high-pressure compression from an already elevated inlet pressure. However, the true efficiency advantage of the ZW-2.1\/8~25 lies in its ability to accept high-pressure inlet without energy-wasting pressure reduction<\/strong>. When compared to systems that throttle 0.80 MPa nitrogen down to atmospheric pressure before re-compressing to 2.50 MPa, the ZW-2.1\/8~25 saves approximately 40\u201350% of the compression energy by utilizing the available inlet pressure directly.<\/p>\n

Over an 8,000-hour annual operating cycle in a typical nitrogen recycle application, the ZW-2.1\/8~25’s variable inlet capability yields approximately 120,000\u2013180,000 kWh of energy savings<\/strong> compared to systems requiring upstream pressure reduction. At $0.08\/kWh, this represents $9,600\u2013$14,400 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<\/a> is reduced by an estimated 30\u201340% over a 10-year operational life.<\/p>\n

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-2.1\/8~25’s native oil-free design ensures that nitrogen purity is maintained indefinitely in recycle service.<\/p>\n<\/div>\n

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Customization & OEM Capabilities<\/h2>\n

We offer flexible customization options to adapt the ZW-2.1\/8~25 to specific site conditions and integration requirements:<\/p>\n