Description
The Z-series nitrogen compressor — manufactured under the ZW model designation — is a two-column, two-stage reciprocating unit designed for low-to-medium flow nitrogen compression where a compact footprint, standard 380 V power supply, and low machine weight are the deciding factors. Capacities run from 0.7 m³/min (ZW-0.7/6) to 20 m³/min (ZW-20/10 and ZW-20/22), with discharge pressures ranging from 0.60 MPa to 1.20 MPa depending on the frame selected.
Weight starts at 0.38 t for the smallest ZW-2/7 frame — light enough to install on a standard reinforced floor slab without any special foundation engineering — and reaches 5.00 t for the ZW-20 frames. All models use oil-free cylinder packing; the crankcase runs on circulating oil, but there is no path for lubricant to enter the gas stream.
Z-Series ZW Nitrogen Compressor for Lab and Small Plant: Frame Design and What It Means for Your Operation
The “Z” classification denotes 两列 (two-column) framing — the same opposed-piston layout used in the larger L-series — but ZW frames are engineered for a tighter swept volume range that keeps motor sizes between 11 kW and 160 kW. That power band puts every Z-series model solidly within standard low-voltage (380 V / 50 Hz) electrical infrastructure, which is the primary reason this series gets specified by smaller industrial facilities, pilot plants, research institutes, and laboratories where a medium-voltage transformer room is not available or not economically justifiable.
Key mechanical characteristics shared across all ZW frames:
- Compression arrangement: Two-stage (二列二级) throughout the range. Inter-stage cooling reduces discharge temperature at the second stage and extends valve and ring life compared to a theoretical single-stage machine handling the same pressure ratio.
- Cooling: Water-cooled on all frames. The ZW-2/7 is the exception — at 0.38 t and 18.5 kW it is one of the smallest water-cooled reciprocating nitrogen compressors in the product family. Confirm a cooling water supply is available before specifying even the smallest ZW unit.
- Gas cylinders: Cast iron cylinders with PTFE-composite dry-running piston rings. No oil mist in the N₂ discharge. Rod packing is also oil-free — carbon-filled PTFE rings on stainless-steel piston rods.
- Drive: Direct-coupled, foot-mounted induction motor, 380 V / 50 Hz standard. Motor power ranges from 11 kW (ZW-0.7/6) to 160 kW (ZW-20/10). All frames compatible with standard DOL or star-delta starting; variable-frequency drive (VFD) option available on request for flow modulation without unloaders.
- Skid mounting: All ZW frames are delivered on a welded-steel common base skid. The motor, compressor, inter-stage cooler, separator, and instrument panel are pre-assembled and pre-piped. Site connection points are limited to: cooling water in/out, N₂ inlet, N₂ outlet, condensate drain, and power.
Z-Series Nitrogen Compressor Full Specification Table — Compact Oil-Free N₂ Compressor 0.7–20 m³/min 380 V
Model numbers follow the convention ZW-[Capacity]/[Pressure × 10]. ZW-4.8/8 delivers 4.8 m³/min at 0.80 MPa; ZW-20/10 delivers 20 m³/min at 1.00 MPa. All capacities at atmospheric inlet (0.101 MPa, 20°C).
| Model | Pattern | Capacity (m³/min) | Discharge Pressure (MPa) | Dimensions L×W×H (mm) | Weight (t) | Power (kW) | Voltage (V) |
|---|---|---|---|---|---|---|---|
| LOW-PRESSURE GROUP — 0.60–0.80 MPa Discharge | |||||||
| ZW-0.7/6 | Two-col, Two-stage | 0.7 | 0.60 | 1550×1320×1637 | 0.80 | 11 | 380 |
| ZW-2/7 | Two-col, Two-stage | 2 | 0.70 | 720×763×1475 | 0.38 | 18.5 | 380 |
| ZW-4.8/8 | Two-col, Two-stage | 4.8 | 0.80 | 2250×1296×2350 | 2.00 | 37 | 380 |
| ZW-5.3/8 | Two-col, Two-stage | 5.3 | 0.80 | 2250×1865×2350 | 2.00 | 45 | 380 |
| MEDIUM-PRESSURE GROUP — 1.00–1.20 MPa Discharge | |||||||
| ZW-20/10 | Two-col, Two-stage | 20 | 1.00 | 2764×2000×2600 | 5.00 | 160 | 380 |
| ZW-17.2/12 | Two-col, Two-stage | 17.2 | 1.20 | 2764×2000×2600 | 5.00 | 160 | 380 |
| HIGH-PRESSURE GROUP — 1.50 MPa Discharge | |||||||
| ZW-3/15 | Two-col, Two-stage | 3 | 1.50 | 2250×1865×2350 | 2.00 | 37 | 380 |
| ZW-4.5/15 | Two-col, Two-stage | 4.5 | 1.50 | 2250×1865×2350 | 2.00 | 45 | 380 |
| ZW-6/15 | Two-col, Two-stage | 6 | 1.50 | 2280×950×2170 | 1.80 | 65 | 380 |
| ZW-14/15 | Two-col, Two-stage | 14 | 1.50 | 2764×2000×3277 | 5.00 | 160 | 380 |
| HIGH-PRESSURE / SPECIAL GROUP — 3.0 MPa Discharge (Modular / Skid-Mounted) | |||||||
| ZW-4/30 (Modular) | Two-col, Three-stage | 4 | 3.00 | 1920×1900×2825 | 4.00 | 55 | 380 |
| ZW-13/30 (Modular) | Two-col, Three-stage | 13 | 3.00 | 2764×2000×3277 | 6.00 | 160 | 380 |
* ZW-4/30 and ZW-13/30 are skid-integrated modular (一机组化) units — compressor, motor, coolers, separators, and instrumentation are assembled on a single base frame and tested as a package before shipment. All other ZW frames are also skid-mounted but may require field assembly of peripheral piping. Dimensions are nominal; certified drawings at order confirmation.
Where the Compact Two-Stage N₂ Compressor ZW Gets the Job Done: Applications by Industry
Electronics & PCB Manufacturing
Wave soldering machines, reflow ovens, and selective soldering systems consume 0.5–6 m³/min of nitrogen at 0.6–0.8 MPa. The ZW-0.7/6 through ZW-5.3/8 map directly to this demand range. Because these machines are installed inside production buildings, the compact footprint (the ZW-2/7 at 720×763 mm base) and 380 V supply are non-negotiable — neither a large reciprocating frame nor a medium-voltage motor is acceptable in a PCB shop.
Pharmaceutical Packaging & API Synthesis
Nitrogen blanketing of tablet coating drums, N₂ purge before filling operations, and reactor charging in API batch synthesis all operate at 0.6–1.5 MPa. ZW-3/15 through ZW-6/15 cover the flow rates typical for a mid-size pharmaceutical plant without over-sizing the compressor into the LW range, which would require MV infrastructure.
Food Packaging Modified Atmosphere (MAP)
Meat, dairy, and snack food MAP lines use nitrogen as the inert filler gas at pressures of 0.6–0.8 MPa and moderate flow rates. The ZW-4.8/8 and ZW-5.3/8 are sized for medium-to-large MAP operations, and the oil-free cylinder design eliminates any risk of compressor oil contaminating the N₂ stream that contacts food packaging.
Laser Cutting Assist Gas
Fiber laser cutting of stainless steel and aluminum uses nitrogen as the assist gas at cutting-head pressures of 1.0–2.0 MPa, with machine consumption of 4–20 m³/min depending on the nozzle size and cutting speed. ZW-20/10 at 20 m³/min / 1.00 MPa is the standard specification for a 6–12 kW fiber laser with a high-pressure assist gas manifold.
Pilot Plant & R&D Nitrogen Supply
Research institutes, university engineering labs, and chemical pilot plants need a reliable, cleanly compressed N₂ source at pressures up to 1.5 MPa and small flow rates. The ZW-3/15 (37 kW, 380 V, 2.00 t) is the most common selection — it delivers 3 m³/min at 1.5 MPa from a wall socket with no foundation beyond a level concrete floor.
High-Pressure N₂ Cylinder Filling (3.0 MPa)
The modular ZW-4/30 and ZW-13/30 frames reach 3.0 MPa — the filling pressure for standard 40 L nitrogen cylinders (150 bar working pressure). These package units include the full compression train in a single factory-tested skid, which shortens site commissioning to a single day in most cases.
Two-Stage Nitrogen Compressor Comparison: Z-Series vs L-Series vs D-Series — Which Frame Fits Your Requirement
All three series use the same oil-free cylinder technology and share common spare parts families. The selection comes down to scale and site infrastructure:
| Parameter | Z-Series (ZW) | L-Series (LW) | D-Series (DW) |
|---|---|---|---|
| Capacity range | 0.7–20 m³/min | 7–102 m³/min | 43–150 m³/min |
| Pressure range | 0.60–3.0 MPa | 0.20–3.0 MPa | 0.32–3.20 MPa |
| Motor power | 11–160 kW | 45–350 kW | 500–850 kW |
| Supply voltage | 380 V — all models | 380 V (most) / 6–10 kV (large) | 6 kV / 10 kV — all models |
| Machine weight | 0.38–6.00 t | 1.8–6.6 t | 13–19 t |
| Foundation requirement | Standard slab (small frames: none) | Standard reinforced slab | Dedicated isolated foundation |
| Best fit | Labs, small plants, electronics mfg, laser cutting | Mid-size ASU, chemical, pharma | Large ASU, petrochemical |
Ordering, Lead Time, and Site Commissioning for the ZW Small Nitrogen Compressor
ZW-series frames are built to order. Standard production lead time:
- Small frames (ZW-0.7/6 to ZW-5.3/8): 45–60 days from technically approved order and advance payment. Base castings and cylinder blanks for these frames are held in stock, which shortens the critical path.
- Medium frames (ZW-14/15, ZW-17.2/12, ZW-20/10): 60–90 days. Motor lead time is typically the constraint; confirm power rating and voltage with us at inquiry stage to allow early motor procurement.
- Modular package units (ZW-4/30, ZW-13/30): 75–90 days including factory assembly, pressure testing to 1.5× design pressure, and run-in test on nitrogen gas before shipment.
For the modular units, site work is minimal: level the skid, connect utilities (cooling water, inlet/outlet piping, power), check rotation direction, and commission. Expect half a day for a two-person mechanical crew on the ZW-4/30, and one full day for ZW-13/30.
We supply an operations and maintenance manual, a recommended spare parts list for 2-year operation, and P&ID drawings with every unit. Remote video commissioning support is standard; on-site commissioning supervision is available at additional cost and subject to engineer availability.
Get a Quote for Your ZW Nitrogen Compressor
Share your required flow (m³/min), outlet pressure (MPa), N₂ source (PSA / cryogenic / cylinder), and available power supply. We’ll confirm the correct ZW frame and return a formal quotation within 2 business days.
