Same Frame. Different Gas. Different Internal Specification.
Both the nitrogen and hydrogen filling compressors are built on the ZW reciprocating platform — the same crankshaft, connecting rods and casing dimensions. The differences are in what touches the gas: piston rings, valve materials, sealing compounds and surface treatments. Selecting the wrong variant for your gas service causes contamination or premature wear.
N₂ Series — Full Parameters
Two pressure options for every flow rate: 150 bar (15.0 MPa) for standard T-type cylinders, and 165 bar (16.5 MPa) where higher fill density or pipeline pressure margin is needed. All models 380V. All dimensions reference values.
| Model | Gas | Flow (m³/min) | Outlet (MPa) | Layout | Motor (kW) | Weight (t) | L × W × H (mm) |
|---|---|---|---|---|---|---|---|
| 150 bar / 15.0 MPa | |||||||
| ZW-1/150 Oil-Free Nitrogen | N₂ | 1 | 15.00 | 2-col / 4-stage | 30 | 4.00 | 2495×1800×2945 |
| ZW-1.67/150 Oil-Free Nitrogen | N₂ | 1.67 | 15.00 | 2-col / 4-stage | 37 | 4.00 | 2495×1800×2945 |
| ZW-1.82/150 Oil-Free Nitrogen | N₂ | 1.82 | 15.00 | 2-col / 4-stage | 37 | 4.00 | 2495×1800×2945 |
| ZW-3/150 Oil-Free Nitrogen | N₂ | 3 | 15.00 | 3-col / 5-stage | 55 | 4.50 | 2575×2064×3407 |
| ZW-3.3/150 Oil-Free Nitrogen | N₂ | 3.3 | 15.00 | 3-col / 5-stage | 55 | 4.80 | 2575×2064×3407 |
| ZW-4.2/150 Oil-Free Nitrogen | N₂ | 4.2 | 15.00 | 3-col / 5-stage | 75 | 5.60 | 2900×2300×3500 |
| ZW-5/165 Oil-Free Nitrogen | N₂ | 5 | 15.00 | 3-col / 5-stage | 90 | 5.60 | 2900×2300×3500 |
| 165 bar / 16.5 MPa | |||||||
| ZW-1/165 Oil-Free Nitrogen | N₂ | 1 | 16.50 | 2-col / 4-stage | 30 | 4.00 | 2495×1800×2945 |
| ZW-1.67/165 Oil-Free Nitrogen | N₂ | 1.67 | 16.50 | 2-col / 4-stage | 37 | 4.00 | 2495×1800×2945 |
| ZW-1.82/165 Oil-Free Nitrogen | N₂ | 1.82 | 16.50 | 2-col / 4-stage | 45 | 4.00 | 2495×1800×2945 |
| ZW-3/165 Oil-Free Nitrogen | N₂ | 3 | 16.50 | 3-col / 5-stage | 55 | 4.50 | 2575×2064×3407 |
| ZW-3.3/165 Oil-Free Nitrogen | N₂ | 3.3 | 16.50 | 3-col / 5-stage | 55 | 4.80 | 2575×2064×3407 |
| ZW-4.2/165 Oil-Free Nitrogen | N₂ | 4.2 | 16.50 | 3-col / 5-stage | 75 | 5.60 | 2900×2300×3500 |
| ZW-5/165 Oil-Free Nitrogen | N₂ | 5 | 16.50 | 3-col / 5-stage | 90 | 5.60 | 2900×2300×3500 |
All dimensions are reference values; confirm with engineering drawings. Voltage: 380V throughout. Oil-free compression zone — PTFE piston rings, no lubricating oil in the compression cylinder.
H₂ Series — Full Parameters
Oil-free compression throughout — PTFE piston rings eliminate oil contamination in the hydrogen gas stream. Primarily 150 bar (15.0 MPa); the ZW-5 variant is also available at 165 bar. Same ZW frame dimensions as the N₂ series.
| Model | Gas | Flow (m³/min) | Outlet (MPa) | Layout | Motor (kW) | Weight (t) | L × W × H (mm) |
|---|---|---|---|---|---|---|---|
| 150 bar & 165 bar / Oil-Free Compression | |||||||
| ZW-1/150 Oil-Free Hydrogen | H₂ | 1 | 15.00 | 2-col / 4-stage | 30 | 4.00 | 2495×1800×2945 |
| ZW-1.34/150 Oil-Free Hydrogen | H₂ | 1.34 | 15.00 | 2-col / 4-stage | 37 | 4.00 | 2495×1800×2945 |
| ZW-1.67/150 Oil-Free Hydrogen | H₂ | 1.67 | 15.00 | 2-col / 4-stage | 37 | 4.00 | 2495×1800×2945 |
| ZW-1.82/150 Oil-Free Hydrogen | H₂ | 1.82 | 15.00 | 2-col / 4-stage | 37 | 4.00 | 2495×1800×2945 |
| ZW-3.3/150 Oil-Free Hydrogen | H₂ | 3.3 | 15.00 | 3-col / 5-stage | 55 | 4.80 | 2575×2064×3407 |
| ZW-4.2/150 Oil-Free Hydrogen | H₂ | 4.2 | 15.00 | 3-col / 5-stage | 75 | 5.60 | 2900×2300×3500 |
| ZW-5/165 Oil-Free Hydrogen | H₂ | 5 | 16.50 | 3-col / 5-stage | 90 | 5.60 | 2900×2300×3500 |
All H₂ models use oil-free compression — PTFE piston rings running dry in the cylinder bore, no lubricating oil in the gas stream. Dimensions are reference values. Voltage 380V. Confirm motor configuration and site requirements when ordering.
Oil-Free Compression — Why It Matters at 150 bar
PTFE Dry-Running Piston Rings
Polytetrafluoroethylene piston rings run dry in the cylinder bore without lubricating oil. This is the fundamental design feature that keeps oil out of the gas stream at all pressure stages.
Gas Purity at Every Stage
Between each compression stage, an inter-stage cooler and separator removes heat and condensed moisture. No oil coalescer is required downstream because there is no oil to remove.
Critical for Hydrogen Purity
Hydrogen used in fuel cells, hydrogenation reactors and precision calibration gas mixtures has strict purity requirements. Oil contamination from a non-oil-free compressor cannot be fully removed by downstream filtration.
Reduced Maintenance Overhead
No oil-change schedules. No oil coalescer element replacements. No oil mist separation system to service. Annual maintenance is limited to piston ring inspection, valve seat check and general mechanical inspection.
Where N₂ and H₂ Filling Compressors Are Used
Gas distributors and industrial gas companies fill standard 40-litre T-type cylinders at 150 bar or 165 bar for supply to welding, food packaging, chemical blanketing and laboratory customers. Typical filling station throughput: 200–1,000 cylinders per day. ZW-3/150 to ZW-5/165 are the standard specification for mid-to-high volume stations.
Factories with on-site PSA nitrogen generators often supplement pipeline supply with a small cylinder filling circuit — allowing cylinder stock to be maintained for maintenance purging, instrument supply and emergency use without relying on external deliveries. ZW-1/150 and ZW-1.67/150 are sized for single-machine PSA output cylinder charging.
By-product hydrogen from chlor-alkali plants, refineries and coke ovens is collected, purified and compressed into cylinders for sale. Hydrogen from water electrolysis systems is similarly compressed and distributed. The oil-free ZW H₂ series maintains gas purity throughout compression, ensuring output meets industrial or research-grade hydrogen cylinder specifications.
Hydrogen storage stations for industrial supply chains use cylinder banks as buffer storage between production and distribution. The ZW H₂ series provides the compression stage from low-pressure hydrogen source (electrolysis output or pipeline) to high-pressure cylinder storage. For applications requiring 35 MPa or 70 MPa (fuel cell vehicle standard), the ZW series operates as a first-stage compressor feeding specialist high-pressure boosters.
Common Questions
Oil-free oxygen filling. ZW series. 60–300 Nm³/h. Medical and industrial service.
ASU primary output. 0.7–150 m³/min. PSA distribution.
Steel mill and industrial pipeline oxygen. 4–100 m³/min.
Tell us your gas type, daily cylinder count and required pressure.
We will recommend the right model and return dimensional drawings and pricing within one business day.
