Description
The D-series nitrogen compressor is a two-stage, two-column reciprocating machine built for continuous-duty nitrogen compression in chemical processing, metallurgy, electronics manufacturing, and pipeline purging. Discharge pressures span 0.20 MPa to 3.20 MPa with flow rates from 43 m³/min up to 117 m³/min depending on the frame selected — making this the standard choice when a facility needs reliable, high-volume N₂ supply without the maintenance overhead of oil-wetted cylinders.
All D-series frames use oil-free cylinder liners. There is no risk of hydrocarbon contamination in the process stream — a requirement that eliminates the D-series from consideration in some oxygen service applications but makes it the correct tool everywhere nitrogen purity matters.
What Makes the D-Series the Right Two-Stage Nitrogen Compressor for High-Volume N₂ Service
The D designation indicates a two-column, multi-stage compression layout — “D” comes from the Chinese classification for 两列 (two-column) frames. In practice this means balanced cylinder loading on both sides of the crankshaft, which reduces frame vibration, extends bearing life, and allows larger swept volumes than a single-column arrangement of comparable footprint.
- Compression stages: Two-stage (二列二级) standard across the product line; four-stage frames (二列四级) available for DW-43/30 through DW-70/30 when outlet pressure reaches 3.0 MPa.
- Cooling: Water-cooled inter-stage and after-coolers. All models require a closed-loop or once-through cooling water supply — verify flow rate and inlet temperature before commissioning.
- Lubrication: Force-feed lubrication to the crankcase; dry-running, oil-free piston rings and packing in the gas cylinders. Nitrogen purity at outlet is not compromised by compressor oil.
- Drive: Direct-coupled electric motor. Standard supply voltage is 6 kV or 10 kV for all frames in this series due to motor power requirements ranging from 500 kW to 850 kW.
- Construction standard: Welded steel base frame; cast iron cylinders with replaceable liners; stainless-steel piston rods standard on nitrogen service.
D-Series Nitrogen Compressor Technical Specifications — Industrial N₂ Compression up to 30 MPa
The table below lists all available D-series frames. Model numbers follow the convention DW-[Capacity]/[Pressure], where capacity is in m³/min and pressure is in bar (×10 = MPa × 10).
| Model | Pattern | Capacity (m³/min) | Discharge Pressure (MPa) | Dimensions L×W×H (mm) | Weight (t) | Power (kW) | Voltage (V) |
|---|---|---|---|---|---|---|---|
| DW-130/3.2 | Two-col, Two-stage | 130 | 0.32 | 5370×3540×2535 | 13.50 | 600 | 6k or 10k |
| DW-105/3.5 | Two-col, Two-stage | 105 | 0.35 | 5840×3590×2928 | 13.50 | 500 | 6k or 10k |
| DW-150/4 | Two-col, Two-stage | 150 | 0.40 | 6000×3640×3000 | 19.00 | 650 | 6k or 10k |
| DW-117/6 | Two-col, Two-stage | 117 | 0.60 | 6030×3590×2660 | 14.00 | 630 | 6k or 10k |
| DW-90/8 | Two-col, Two-stage | 90 | 0.80 | 5440×3518×2620 | 13.00 | 550 | 6k or 10k |
| DW-100/8 | Two-col, Two-stage | 100 | 0.80 | 5456×3518×2535 | 13.00 | 600 | 6k or 10k |
| DW-43/30 | Two-col, Four-stage | 43 | 3.00 | 6585×3595×2095 | 13.00 | 550 | 6k or 10k |
| DW-50/30 | Two-col, Four-stage | 50 | 3.00 | 6585×3595×2095 | 13.00 | 550 | 6k or 10k |
| DW-55/30 | Two-col, Four-stage | 55 | 3.00 | 6585×3595×2095 | 13.00 | 630 | 6k or 10k |
| DW-60/30 | Two-col, Four-stage | 60 | 3.00 | 8500×2440×3020 | 17.00 | 650 | 6k or 10k |
| DW-70/30 | Two-col, Four-stage | 70 | 3.00 | 8500×2440×3020 | 17.00 | 850 | 6k or 10k |
| DW-35/3.2 | Three-col, Four-stage | 35 (inlet 0.045 MPa) | 3.20 | 6645×3225×2330 | 15.00 | 500 | 6k or 10k |
* DW-35/3.2 is configured for sub-atmospheric inlet conditions (inlet pressure 0.045 MPa absolute). Confirm inlet N₂ supply pressure before ordering. All other models assume atmospheric inlet. Dimensions are approximate; certified drawings issued at order confirmation.
Typical Applications: Oil-Free D-Series N₂ Compressor in Chemical and Metallurgical Plants
Air Separation Plant N₂ Boosting
D-series units are installed downstream of cryogenic air separation columns to boost low-pressure product nitrogen (typically 0.03–0.05 MPa) to pipeline distribution pressure (0.6–0.8 MPa). The DW-90/8 and DW-100/8 cover the most common output range in medium-scale ASU operations.
Petrochemical Purging & Blanketing
Refinery and chemical plant vessels require inert N₂ blanketing at pressures between 0.3 MPa and 0.6 MPa. The DW-117/6 and DW-130/3.2 deliver the flow volumes needed for large-diameter storage tanks and reactor vessels without cycling on/off constantly.
High-Pressure N₂ for Pipeline Testing
The four-stage DW-43/30 through DW-70/30 frames reach 3.0 MPa — the standard test pressure for DN100–DN500 natural gas distribution lines. These units are also used for pressure testing in petrochemical piping prior to startup, where introducing hydrocarbons or air is prohibited.
Electronics & Semiconductor Atmosphere Control
Sintering furnaces, wave soldering lines, and MOCVD reactors require a clean, dry nitrogen atmosphere at 0.3–0.8 MPa. Because D-series cylinder packing is oil-free, the N₂ delivered meets the hydrocarbon contamination thresholds specified in most semiconductor process specifications.
How to Select the Right D-Series Industrial Nitrogen Compressor Frame for Your Application
Frame selection starts with two numbers: required outlet pressure and required flow rate. The model number tells you both directly — DW-100/8 delivers 100 m³/min at 0.80 MPa; DW-50/30 delivers 50 m³/min at 3.00 MPa.
Beyond those two parameters, check the following before finalising a frame:
- Inlet conditions: All frames except DW-35/3.2 assume atmospheric inlet (≈0.101 MPa). If your N₂ feed is from a pressure swing adsorption (PSA) unit at 0.12–0.15 MPa, the effective outlet flow will be slightly higher than nameplate — confirm with our engineering team for accurate sizing.
- Motor voltage infrastructure: Every D-series motor draws 500–850 kW and requires 6 kV or 10 kV supply. If your site is only wired for 380 V, this series is not the right fit — look at the Z or LW series for lower-power options.
- Foundation load: Frames range from 13 t (DW-43/30) to 19 t (DW-150/4) excluding the motor. Provide a certified civil drawing of your compressor house before ordering; we’ll confirm dynamic load requirements for foundation design.
- Cooling water supply: Water inlet temperature should not exceed 30°C; flow rate depends on frame size and is specified in the machine data sheet issued at order. Fouling factor design is 0.0002 m²·K/W standard; specify if your cooling water is harder or softer than 200 ppm CaCO₃ equivalent.
- N₂ purity input: D-series compressors do not purify nitrogen — they compress it. Inlet purity is typically ≥99.5% from a cryogenic ASU or ≥99% from a PSA unit. If inlet purity is lower, some oxygen remains in the discharge stream; confirm this is acceptable for your process.
Lead Times, Spare Parts, and After-Sales Support for D-Series High-Pressure N₂ Compressor
Standard production lead time for D-series frames is 90–120 days from receipt of technically approved drawings and advance payment. Rush schedules are sometimes available for two-stage frames (DW-90/8, DW-100/8, DW-117/6) when base castings are in stock; contact us early in your project timeline.
We maintain a recommended spare parts list (RSL) specific to each frame. For a 2-year operating inventory, budget approximately:
- Piston rings and cylinder packing sets (replace at 8,000 operating hours or annually, whichever comes first)
- Valve plates and valve springs for both stages (suction and discharge)
- Main and connecting rod bearing shells
- Shaft seals and inter-stage gas seals
Installation supervision and commissioning support are available. Our service engineers have conducted startups in China, Southeast Asia, the Middle East, and Eastern Europe. Remote diagnostic support is available via video call for routine troubleshooting once a unit is operational.
Need a D-Series Nitrogen Compressor Quote?
Send us your required flow rate (m³/min), outlet pressure (MPa), and site voltage. We’ll confirm frame selection and issue a formal quotation within 2 business days.
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