Low-Pressure Oxygen Compressor
2 to 8 bar  ·  0.7 to 150 m³/min

Primary-stage reciprocating compressors for air separation unit oxygen output and PSA plant distribution. The widest capacity range in our product line — 21 models spanning 11 kW to 1,200 kW, covering everything from a single laboratory circuit to a large integrated steelworks ASU.

The First Stage — From Source to Pipeline

The D series is not a booster. It is the primary compression stage — the machine that takes oxygen directly from atmospheric pressure at the outlet of an air separation unit (ASU), PSA generator or liquid oxygen vaporiser, and raises it to the first working pressure of your oxygen distribution system: typically 2 to 8 bar (0.20–0.80 MPa).

This is the broadest product range in our catalogue — 21 models spanning from the ZW-0.7/6 (0.7 m³/min, 11 kW, 0.80 kg table-top scale) to the DW-150/4 (150 m³/min, 650 kW, 19 tonnes for a major integrated industrial complex). Every application that moves oxygen from a production source into a pipeline or process system starts here.

If your downstream process needs higher pressure — 10 bar for a PSA distribution header, 15 bar for laser cutting, or 30 bar for a steelmaking oxygen pipeline — the D series feeds into our C series (10–16 bar) or B series (30 bar) booster in a two-stage system.

From 0.38 Tonnes to 26 Tonnes — One Platform

The D series spans a greater capacity range than any other product family in industrial oxygen compression. At one end, the ZW-2/7 weighs 0.38 tonnes and occupies a floor area smaller than a standard workbench — practical for a single-room laboratory or small clinic. At the other, the DW-150/4 delivers 150 m³/min at 19 tonnes — sized for a major air separation plant serving an integrated steelworks.

The engineering approach is consistent across the entire range: horizontal balanced opposed crankshaft, 1 or 2 compression stages, inter-stage cooling where applicable, and the same family of safety interlocks. This means the maintenance philosophy and spare parts logic are transferable regardless of machine size.

Cryogenic ASUs produce oxygen at low pressure — typically 0.1–0.4 MPa — which must be compressed before distribution. Large ASUs often require multiple compressors in parallel. The DW-150/4 (150 m³/min) and 4MW-135/1.7~8 (135 m³/min with pre-pressurised inlet) are sized for the largest industrial ASU applications. Smaller LW models serve medium-scale units.

PSA generators produce oxygen at 0.3–0.6 MPa — already slightly pressurised, but often requiring further compression to reach medical pipeline pressure (typically 4–6 bar) or industrial header pressure (6–8 bar). Medium LW models (LW-13/5, LW-20/6, LW-42/6) are the most common match for PSA system output across hospital, industrial gas and aquaculture applications.

High-density recirculating aquaculture systems (RAS) and intensive fish farms rely on continuous dissolved oxygen supplementation. On-site PSA generation paired with a D series compressor eliminates cylinder delivery costs and supply interruption risk. Small ZW and LW models (0.7–20 m³/min) are scaled for individual fish farm tanks and RAS circuits. The 6 bar (0.60 MPa) pressure range directly feeds underwater diffusers.

Where the target outlet pressure is above 8 bar, the D series acts as the first compression stage, raising oxygen from atmospheric to 6–8 bar, which then feeds a C series (10–16 bar) or B series (30 bar) booster. This staged approach keeps each machine at an efficient per-stage compression ratio rather than asking a single machine to cover the entire pressure range in one step.

One Supplier for the Complete Oxygen Compression Chain

Ever Power manufactures the full chain of reciprocating oxygen compressors — primary low-pressure (D series, 2–8 bar), medium-pressure boosters (C series, 10–16 bar), high-pressure boosters (B series, 30 bar) and cylinder filling machines (A series, 150–165 bar). A single supplier for every stage simplifies project coordination, spare parts management and technical support across the lifetime of your oxygen system.

All models are designed to API 618, manufactured in an ISO 9001 certified facility, and CE marked for European markets. Every machine is factory pressure-tested and performance-verified before shipment. We can provide a full documentation package for EPC and engineering contractor procurement.

Non-standard configurations — unusual inlet conditions, non-standard outlet pressure, ATEX rating, outdoor installation, VFD, or complete skid-mounted packages — are handled as routine orders. We build to your process requirements, not only to our standard catalogue.