Description
Two-Column Two-Stage · Oil-Free · 0.70 – 0.80 MPa · Compact Frame
ZW Series Oil-Free Air Compressors
Space-efficient two-stage reciprocating compressors for small-capacity, high-purity air supply. The ZW series covers 1.5 m³/min to 6 m³/min at discharge pressures of 0.70 – 0.80 MPa, with frame weights as low as 0.58 t — suited to workshop, laboratory, and pilot-scale processing environments.
ZW Series — Compact oil-free two-stage reciprocating compressors, 0.70 – 0.80 MPa
ZW Series: Small-Frame Oil-Free Reciprocating Compressors for Precision Air Applications
The ZW series occupies the smallest-capacity segment of the Ever-Power oil-free reciprocating compressor range. With only two catalogued models — the ZW-3/7-A (3 m³/min, 0.70 MPa, 22 kW) and the ZW-6/8-A (6 m³/min, 0.80 MPa, 45 kW) — the ZW line is precisely engineered for applications where flow demand is modest but oil contamination in the compressed air is operationally intolerable.
Both models adopt the same two-column, two-stage reciprocating architecture used throughout the DW and LW families, with PTFE composite piston rings ensuring oil-free compression that meets ISO 8573-1 Class 0 purity at the discharge flange. The ZW-3/7-A, at 0.58 t and a footprint of 720 × 763 × 1274 mm, is among the most compact oil-free reciprocating compressors in the industrial grade — deployable in a standard plant-room bay or even a large workshop without dedicated compressor-room construction.
The ZW-6/8-A at 2.00 t and 2250 × 1296 × 2350 mm doubles the flow output while still fitting within the dimensional constraints of many existing equipment pads. Both units operate from standard 380 V three-phase supply, requiring no medium-voltage infrastructure, which simplifies commissioning for laboratories, pilot lines, and small-batch production environments.
Technical Design Features
Smallest Oil-Free Reciprocating Footprint
The ZW-3/7-A measures only 720 × 763 × 1274 mm and weighs 0.58 t — dimensional data verified from the manufacturer’s published parameter table. This makes it physically installable on a standard 800 mm × 800 mm equipment pad, a constraint frequently encountered in laboratory utilities rooms and pilot-plant skid builds.
380 V LV Supply — No Transformer Required
Both ZW models are rated for standard 380 V three-phase supply. Unlike DW and larger LW units that may require 6 kV or 10 kV medium-voltage connections with associated switchgear, the ZW range connects directly to the most common industrial LV distribution used in China, the EU (400 V nominal, ±10%), and many export markets.
Verified ISO 8573-1 Class 0 Output
PTFE-ring oil-free compression eliminates lubricant carryover into the gas stream. Verified total oil content ≤ 0.01 mg/m³ at rated conditions. This purity level satisfies the requirements of ISO 8573-1 Class 0, applicable to medical device manufacture, microelectronics assembly, analytical instrumentation purge gas, and other precision-air end uses.
Two-Stage Compression at Low Power
Inter-stage cooling in a two-stage configuration reduces the discharge temperature relative to single-stage alternatives and improves volumetric efficiency at 0.70 – 0.80 MPa discharge pressure. The ZW-3/7-A achieves this at just 22 kW — a power level that falls within the service capacity of many facility motor-control centres without panel upgrades.
ZW Series — Technical Specifications
| Model | Pattern | Capacity (m³/min) | Discharge Pressure (MPa) | Compressor Size L×W×H (mm) | Weight (t) | Power (kW) | Voltage (V) |
|---|---|---|---|---|---|---|---|
| ZW-3/7-A | 二列二级 | 3 | 0.70 | 720 × 763 × 1274 | 0.58 | 22 | 380 |
| ZW-1.5/8-A | 二列二级 | 1.5 | 0.80 | 720 × 763 × 1274 | 0.58 | 15 | 380 |
| ZW-6/8-A | 二列二级 | 6 | 0.80 | 2250 × 1296 × 2350 | 2.00 | 45 | 380 |
* Both ZW models operate from standard 380 V three-phase supply. No medium-voltage switchgear required. Custom configurations available on request.
ZW-3/7-A vs ZW-6/8-A: Model Selection Guide
ZW-3/7-A — Select when:
- Air demand is ≤ 3 m³/min continuously
- Installation space is limited to ≤ 1.0 m² floor area
- Available motor supply circuit is ≤ 22 kW at 380 V
- Discharge pressure target is 0.70 MPa
ZW-6/8-A — Select when:
- Flow demand ranges from 3 – 6 m³/min
- Higher discharge pressure of 0.80 MPa is required
- Pilot line is expected to scale; ZW-6/8-A supports future LW replacement
- Installation weight capacity allows 2.0 t equipment load
Application Sectors
The ZW series fits environments where scale, power availability, and precision air purity converge. Documented use sectors include small-scale industrial applications demanding oil-free compressed air for critical processes:
Pneumatic actuators, test bench supply — Class 0 mandatory
GC carrier gas, spectrometer purge lines at 1.5 – 3 m³/min
Reactor sparging, pneumatic valve operation in R&D scale plants
SMD rework stations, conformal coating, optical bonding
Precision tool air where oil contamination destroys surface finish
Frequently Asked Questions
Is the ZW-3/7-A suitable as a laboratory oil-free compressor for analytical instruments?
The ZW-3/7-A delivers 3 m³/min at 0.70 MPa from a 22 kW, 380 V motor in a 0.58 t frame — making it one of the smallest oil-free reciprocating compressors in the heavy-industrial catalogue. Discharge air meets ISO 8573-1 Class 0 for oil content. For analytical instrumentation requiring even lower particle counts, a final coalescing filter and HEPA breather should be specified downstream by the instrument manufacturer’s own air-quality specification.
Can ZW units be installed without a dedicated compressor room?
The ZW-3/7-A and ZW-1.5/8-A share an identical frame (720 × 763 × 1274 mm, 0.58 t), which allows installation within a general workshop or service room provided ambient temperature is maintained within 5 – 40 °C and ventilation is adequate for the 22 kW / 15 kW motor heat rejection. The ZW-6/8-A at 2250 × 1296 × 2350 mm is larger and should have a minimum 1.0 m clearance on all sides for maintenance access to cylinder heads and valve assemblies.
What is the noise level of ZW series compressors?
Specific sound-power data for the ZW series is not included in the published parameter table; measurement conditions and enclosure configuration affect the final value. As reciprocating compressors operating at 0.70 – 0.80 MPa, typical in-class machines without acoustic enclosures measure approximately 72 – 82 dB(A) at 1 m per ISO 2151. Operators placing ZW units in occupied areas should confirm site-specific acoustic requirements and specify a sound-attenuating enclosure if necessary.
Enquire About ZW Series Compact Oil-Free Compressors
Provide your required flow rate, pressure, and site voltage. Our engineers will confirm the appropriate ZW model and supply dimensional drawings within 24 hours.
