As we all know that there are two typical air compressor types – oil air compressor and oil-free air compressor. Oil air compressors use special oil to lubricate main components to reduce fiction and wear, while oil free air compressors adopt non-oil lubricant or non-lubricant designs.

That’s why oil free air compressors that integrated with air dryer and other post-treatment equipment can deliver ultra-dry, contaminant-free to rapidly purge pipelines, cutting restoration times from days to hours while ensuring operational integrity(Pipeline cleaning is a high-stakes operation where downtime costs thousands per minute).

Whether it’s natural gas pipeline inspection, chemical transfer pipes after cleaning, or municipal water mains awaiting recommissioning, residual moisture is a silent saboteur.

Left unchecked, it spawns corrosion that eats through carbon steel, cultivates deadly Legionella biofilms, or even triggers combustion when meeting methane streams. Conventional compressed air that delivered by oil air compressors contains two invisible threats:

Oil aerosols (0.1–5 mg/m³): Even trace lubricant from oil-flooded compressors adheres to pipe walls, reacting with process fluids or attracting particulate buildup.

Water vapor: Compressing untreated compressed air into the pipeline has no difference with pumping water into it. As temperatures drop, moisture lurks in the air condenses right back into the pipes you’re trying to dry.

That’s why pipeline cleaning demand oil free air compressors coupled with desiccant air dryers. This combo delivers ISO 8573-1 Class 0 air – containing less than 0.01 mg/m³ of oil and dew points as frigid as -100°C (-73°C). The result? Zero hydrocarbon contamination, plus air so dry it actively pulls moisture from pipe walls instead of adding to it.

Oil and gas transmission

After pigging debris or inspecting gas pipelines, trapped moisture can freeze into icy plugs at high pressure, blocking flow or worse – contaminated air risks explosive reactions with methane.

Diesel-powered oil free dry air compressors deliver Class 0 compressed air at remote sites, enabling secure and stable gas flow supply.

Chemical processing

Post-cleaning moisture in chemical transfer lines can hydrolyze sensitive compounds (e.g., isocyanates), degrading product quality. Portable oil free air compressors with heatless air dryers achieve -40°C dew points, ensuring pipes stay chemically inert, removing water without chemical reactions.

Municipal water systems

Standing water in cleaned water mains is a breeding ground for deadly bacteria. Cities using oil-free air injection dry pipes 3x faster than natural evaporation – getting clean water flowing again before headlines hit.

Food/beverage processing

Sanitation protocols require pipelines to be “bone-dry” before production restart to prevent microbial growth. Solution: ISO Class 0 air ensures no oil residue contaminates product-contact surfaces.

Forget generic air compressors, drying pipelines demands integrated weaponry:

Air compression stage

A portable air compressor (typically rotary screw compressor) generates high-volume flow (typically 500–2,000 CFM) at pressures up to 10 bar by using coated rotors or scrolls instead of lubricants, which means zero oil sneaking into at the source.

Air drying frontline

Heatless desiccant air dryers (desiccant towers) are moisture assassins. They pack silica gel or activated alumina that traps water vapor, achieving dew points of -40°C or lower. Pro tip: Twin-tower setups allow continuous drying during regeneration cycles.

Filtration safeguard

Coalescing filters (0.01 μm mesh) catch oil aerosols like spiderwebs, while activated carbon beds adsorb vaporized hydrocarbons – especially crucial when drawing air in polluted industrial zones.

Injection

Dry air enters pipelines via access points (valves, pig traps), creating a low-humidity front that evaporates and carries moisture toward exhaust vents. Flow rates are maintained until outlet air humidity matches inlet specs (e.g., ≤ 30% RH).