The IHI AF Series is a staged, pressure-vessel filtration system engineered to convert contaminated plant air into clean, specification-grade compressed air. Using sequential media for bulk water knock-out, coalescing of oil/water aerosols, fine particulate capture, and vapour polishing, the AF Series delivers stable air quality with disciplined pressure drop across flows from 1,200 to 28,080 m³/hr.

The train is configured to the duty: CF removes condensate and coarse load to 25 µm; GP provides general-purpose coalescing to 1 µm with residual oil to 0.6 mg/m³; FF is the high-efficiency coalescer for point-of-use polishing to 0.01 µm with residual oil to 0.01 mg/m³. Where odor or vapour control is required, OO adds activated-carbon polishing to 0.003 mg/m³; where ultra-low liquid-phase oil is specified, IS drives residual oil to 0.001 mg/m³. Dependencies are enforced by design—FF follows GP; OO and IS follow FF—protecting fine media and keeping the carbon bed dry.

Built for plant compliance, AF housings are manufactured to GB-150 as standard (ASME VIII available) in carbon steel or optional stainless, finished in Munsell 5PB4/6.5. The range is rated to 15.6 barg with a 120 °C maximum inlet. Instrumentation is straightforward: a mechanical differential-pressure gauge is fitted on all grades except OO with durable nylon impulse lines; a mechanical float drain is standard across the range; nameplates are 1.5 mm aluminium for durable identification.

Installation and service are practical and predictable—size to actual operating flow and pressure, hold total ΔP inside the energy budget, and change elements on ΔP rather than calendar time. With correct staging, the AF Series supports ISO 8573-1 Class 1 oil applications at the point of use when validated under site conditions, extending element life, protecting downstream equipment, and delivering clean, reliable air for instrumentation, assembly, packaging, and other quality-critical processes.