Oil-Free Process Gas Compression · Industrial Grade · UK Supply
Oil-Free Lubricated Air Compressors for Industrial Process Applications
Seven specialist models covering flow rates from 9 to 300 Nm³/min and pressures up to 25.00 MPa — engineered without a drop of lubrication oil entering the gas stream, so every cubic metre of compressed air you deliver is genuinely contaminant-free.
4MW-25/40 Oil-Free Process Air Compressor — one of seven models in the range
Across the United Kingdom — from chemical plants in Teesside to food-processing facilities in the West Midlands and pharmaceutical manufacturers along the M4 corridor — the demand for absolutely oil-free compressed air has never been more rigorous. Contamination of just a few parts per million can ruin an entire batch in sterile pharmaceutical production, trigger costly recalls in food packaging, or invalidate calibration in precision analytical instrumentation. Our range of oil-free lubricated process air compressors is built on over two decades of engineering refinement to eliminate that risk entirely, while delivering the pressure ratios and flow rates that heavy industrial processes genuinely require.
Why Oil-Free Compression Matters in UK Process Industries
Standard oil-injected screw or reciprocating compressors rely on lubricant to seal the compression chamber, cool the rotors, and reduce wear. The inevitable consequence is oil carryover into the compressed gas — typically 2 to 5 mg/m³ even after coalescing filtration, with trace aerosols persisting far below what downstream filters can reliably intercept. For process industries in the UK where compressed air makes direct or indirect product contact, this is categorically unacceptable.
Oil-free compressors resolve the problem at source. By using self-lubricating PTFE piston rings, carbon-graphite rider rings, and precision-machined cylinder bores with hard chrome or ceramic coatings, the compression element operates entirely without hydrocarbon lubricant. The result is compressed air certified to ISO 8573-1 Class 0 — zero detectable oil content — giving quality managers, site engineers, and regulatory teams a foundation they can audit and defend.
The Seven-Model Product Range
Each model targets a distinct pressure-and-flow combination. Click any product to enquire directly or scroll to the Technical Specifications section for consolidated parameters.
4MW-25/40 Air Compressor
A four-cylinder W-type oil-free unit delivering 25 Nm³/min at 4.0 MPa — commonly specified for medium-pressure process nitrogen displacement and pilot plant instrument air.
LW-80/2.2 Air Compressor
An L-type twin-cylinder model producing 80 Nm³/min at 0.22 MPa, suited to bulk low-pressure aeration in wastewater treatment and fermentation processes across the UK water industry.
DW-300/1.5 Air Compressor
High-flow D-type compressor rated at 300 Nm³/min and 0.15 MPa. Ideal for large-scale combustion air supply and regeneration gas duties in refinery and petrochemical plants.
4 MW-100/100 Air Compressor
Four-cylinder W-type delivering 100 Nm³/min at 10.0 MPa. A workhorse in high-pressure process applications including PET bottle blowing and gas pipeline pressure maintenance.
DW-18/24-50 Recirculating Raw Material Compressor
A closed-loop D-type unit handling 18 Nm³/min with dual-stage compression between 2.4 and 5.0 MPa — engineered for recirculating rare or hazardous process gases without atmospheric venting.
6 MW-150/50 Raw Material Air Compressor
Six-cylinder M-type machine rated at 150 Nm³/min and 5.0 MPa, designed for bulk raw material conveying where contamination from lubricant must be absolutely zero — common in polymer and specialty chemicals production.
LW-9/8.7-29 Air Booster Compressor
The LW-9/8.7-29 sits at the specialist end of the range — an L-type booster that takes compressed air already at 0.87 MPa and elevates it to 2.9 MPa at a flow of 9 Nm³/min. This configuration is particularly valued in UK aerospace test facilities, medical gas boosting systems, and carbon dioxide recovery loops where the inlet gas is already partially pressurised. Because the unit operates entirely without oil, the boosted gas remains ISO 8573-1 Class 0 compliant throughout the pressure increase — no post-boost oil filtration required, which reduces both capital expenditure and ongoing maintenance cost.
Technical Specifications
Parameters below are consolidated general-range values applicable across all seven models. For the exact datasheet of a specific model — including stage pressures, cooling water flow, and motor configuration — please contact us by email.
| Parameter | Range / Value | Notes |
|---|---|---|
| Single-Unit Displacement | 1 – 500 Nm³/min | Model-dependent; contact for specific unit rating |
| Compression Medium | Air (oil-free) | ISO 8573-1 Class 0 — zero oil carryover |
| Discharge Pressure | 0.1 – 25.00 MPa | Up to 250 bar; multi-stage configurations available |
| Motor Power | 5.5 – 10,000 kW | IE3 / IE4 efficiency class motors supplied as standard |
| Piston Force | 1.5 – 150 T | Heavy-duty forged crankshaft and crosshead assembly |
| Frame Types | M, D, P, L, Z | Selection based on flow, pressure ratio, and site footprint |
| Lubrication System | Oil-free (PTFE / carbon rings) | Crankcase oil does not contact the gas stream |
| Cooling Method | Water-cooled (standard) / air-cooled (optional) | Inter- and after-cooler included on all multi-stage models |
| Valve Type | Ring plate / strip plate | Stainless steel; replaceable without removing cylinder head |
For model-specific parameters — bore diameter, stroke, rotational speed, number of stages, and cooling water temperature range — email our technical team. We respond within one UK business day.
How Oil-Free Reciprocating Compression Works
01
Intake Stroke
The piston descends, drawing ambient or pre-compressed gas through the suction valve. PTFE rider rings guide the piston without metal-to-bore contact, eliminating the need for cylinder lubricant entirely.
02
Compression Stroke
As the piston rises, carbon-graphite piston rings provide the primary gas seal. The rings are self-lubricating — their graphite content transfers a micro-thin film onto the bore surface, maintaining low friction without any liquid lubricant.
03
Discharge & Intercooling
Compressed gas exits through the discharge valve into the intercooler. Water-cooled tube-and-shell heat exchangers reduce the gas temperature before the next compression stage, improving volumetric efficiency and protecting downstream equipment.
04
Distance Piece Isolation
A double-acting distance piece physically separates the oil-lubricated crankcase from the oil-free compression chamber. Any trace lubricant that migrates along the piston rod is captured in the distance piece drain before it could ever reach the process gas.
Key Advantages for UK Process Operators
Zero Oil Contamination
Meets ISO 8573-1 Class 0 from the cylinder — no downstream coalescing filters required to achieve oil-free certification, reducing system complexity and pressure drop.
Wide Pressure Range
0.1 to 25.00 MPa in a single product family — uncommon in the market. One trusted supplier covers your low-pressure aeration duty and your high-pressure gas cylinder filling application.
Lower Lifetime Maintenance
No oil changes, no separator element replacements, no coalescer cartridges. PTFE piston rings and carbon rider rings are inexpensive and can be changed during scheduled planned maintenance windows without specialised tooling.
Regulatory Compliance
Compliant with UK PSSR 2000, PED 2014/68/EU (retained in GB law post-Brexit), and ATEX where specified. Documentation packages for CE/UKCA marking, pressure vessel certification, and third-party inspection are available on request.
High Mechanical Efficiency
Crosshead-guided piston design minimises side loading, extending cylinder bore life and reducing friction losses. Combined with inter-stage cooling, overall isothermal efficiency typically exceeds 75% — competitive with rotary oil-free screw machines at equivalent pressure ratios.
Customisable Configuration
Frame type, number of stages, cylinder material, sealing arrangement, and motor specification can all be adapted to your site conditions. Our engineering team works directly with your process and mechanical engineers from initial enquiry through factory acceptance testing.
Where These Compressors Are Used Across the UK
Oil-free process air compressors from this range serve a broad spectrum of UK industries. In pharmaceutical manufacturing — concentrated in areas such as East Anglia, the Thames Valley, and Scotland’s life sciences corridor — the machines supply sterile instrument air and nitrogen generation feed gas where any hydrocarbon contamination would trigger a batch failure and a mandatory investigation under GMP guidelines. The DW-300/1.5 and 6 MW-150/50 models are regularly specified for fermentation aeration in biotech facilities and brewing, where the large flow rates keep operating cost per Nm³ extremely competitive.
In the UK’s growing hydrogen economy and carbon capture projects — notably along the Humber estuary and in the Merseyside industrial cluster — the high-pressure models (4 MW-100/100 and the LW-9/8.7-29 booster) are used to compress process gases in electrolyser balance-of-plant systems and CO₂ recompression loops. Because these processes involve flammable or corrosive gases, the oil-free compression guarantee is not optional — it is a fundamental safety requirement. The ability to supply ATEX-rated configurations makes these units directly deployable on classified hazardous area sites.
Food and beverage processors across Yorkshire, the North West, and the South East rely on the mid-range models for pneumatic conveying of flour, sugar, and granular materials under Category A compressed air standards. Electronics manufacturers in the Cambridge and Thames Valley technology clusters use them for chip die-bonding and precision dispensing lines, where even sub-ppm oil aerosol would destroy ultra-fine adhesive bond quality. Whatever your process, there is a model — or a custom-configured variant — in this range that matches your flow, pressure, and cleanliness requirement precisely.
Related Air Compressor Products
If your application calls for variable-speed energy savings alongside oil-free delivery, explore our permanent magnet VFD screw air compressor range — specifically designed for facilities with fluctuating compressed air demand:
CM55PVF Permanent Magnet Variable Frequency Air Compressor
55 kW PM-VFD screw compressor offering real-time pressure matching and energy savings of up to 35% versus fixed-speed equivalents. Suitable for general process and instrument air duties.
CM75PVF Permanent Magnet Variable Frequency Screw Air Compressor
75 kW variant of the CM-PVF series. Paired with the oil-free process compressors in facilities where different pressure zones require different compression technologies.
Customer Success Stories
Real operators. Real processes. Real results.
Case Study · UK Pharmaceutical Manufacturing
Sterile Instrument Air Upgrade — Contract Development and Manufacturing Organisation, Cambridgeshire
A mid-size CDMO operating multiple GMP suites was failing quarterly oil-in-air audits on their existing oil-injected screw compressors, despite running three stages of coalescing filtration. The cost of failed batches and audit remediation over eighteen months exceeded £280,000. Following a site survey, two units of the 4MW-25/40 model were installed in a dedicated compressor house with a common header, providing N+1 redundancy and sufficient flow for all four manufacturing suites simultaneously. Post-installation audit results: oil content consistently below the instrument measurement threshold — effectively zero. Annual maintenance cost dropped by 62% compared with the previous installation. The site has now operated for 26 months without a single contamination-related batch rejection.
-62% Maintenance Cost
26 Months Zero Contamination Events
“We run the DW-300/1.5 on our fermentation aeration headers. Flow is rock-solid, and we’ve had zero oil alarms in two years of continuous operation. The technical support team understood our process requirements immediately — not a standard compressor sales pitch.”
— Engineering Manager, Large-Scale Bioethanol Plant, Humberside
“The LW-9/8.7-29 booster was specified for our breathing air system upgrade. Installation was straightforward, documentation was complete for PSSR and COSHH, and the machine has met every performance point in the datasheet. Quoted lead time was accurate too — which is rare.”
— Mechanical Engineer, Offshore Platform Services Provider, Aberdeen
“We purchased three 4 MW-100/100 units for our high-pressure air storage system at a new PET preform facility in the West Midlands. Pricing was highly competitive for the specification, and the custom skid arrangement they built around our existing pipework saved us significant civil engineering cost.”
— Projects Director, Specialist Packaging Manufacturer, West Midlands
Factory Capabilities & Custom Engineering
Every compressor in this range is manufactured at our dedicated facility with a full in-house machining centre capable of holding bore tolerances to within 0.005 mm, a precision crankshaft grinding line, and a dedicated balancing bay for rotating assemblies. The factory operates under a documented quality management system with third-party inspection access for Lloyd’s Register, Bureau Veritas, TÜV, and ATEX notified bodies — all standard documentation that UK purchasers and end-users require for capital equipment records.
Our product customisation capability extends well beyond selecting a standard frame type. We regularly deliver: custom cylinder bore and rod seal arrangements for aggressive process gases; ATEX Zone 1 or Zone 2 classified motor and instrumentation packages; skid-mounted packaged units with common base frame, intercoolers, separator vessels, and full control panel; bespoke capacity control systems including step unloaders, suction valve unloaders, and variable-speed drive integration; and materials upgrades for corrosive service including stainless steel cylinders, Hastelloy valves, and PTFE-lined manifolds. If your process has unusual requirements — pressure ratios, gas composition, site altitude, extreme ambient temperature — bring them to us. We will assess feasibility and provide a written technical response, at no charge, within five UK working days.
Frequently Asked Questions
Ready to Specify Your Oil-Free Process Compressor?
Send us your flow rate, pressure requirement, and process gas details. Our application engineers will recommend the right model — or custom-configure one — and provide a full technical and commercial proposal for your UK site.
edit by gzl