Professional 2-in-1 Air Compressor Regulator & Filter - 140 PSI Aluminum Water/Oil Separator with Gauge (AI303-R1)

Quick Facts 140 PSI / 10 Bar1/4" NPTAluminum body5-micron filterBuilt-in gaugeLe Lematec Best for: Compact air preparation in home garages and small shops. One unit combines pressure regulation, water-oil filtration, and a gauge — replaces three separate components. The Le Lematec AI303-R1 combines a precision pressure regulator and a 5-micron oil-water separator in one compact aluminum housing. Rated to 140 PSI with 1/4" NPT connections and a built-in analog gauge, it delivers clean, regulated air to HVLP spray guns, plasma cutters, impact wrenches, and any pneumatic tool that depends on dry, pressure-stable air. Compatible With Air compressors Any compressor up to 140 PSI with a standard 1/4" NPT outlet Air tools HVLP spray guns, plasma cutters, impact wrenches, ratchets, sanders, nailers Air lines Standard 1/4" NPT air hoses, quick-connect couplers, manifolds Mounting Wall, pipe, or compressor outlet — best installed at the point of use to catch in-line condensate What’s in the Box AI303-R1 filter regulator combo unit Analog pressure gauge (pre-installed) Aluminum filter bowl with 5-micron element Push-button drain valve 1/4" NPT inlet/outlet fittings Mounting bracket User manual Key Features Two-stage air conditioning: 5-micron filter element removes water, oil mist, and particulates; integrated regulator dials in working pressure. Built-in analog gauge: Monitor regulated output PSI at a glance — no separate gauge or tee required. 140 PSI / 10 Bar rated: Handles the output of single- and two-stage compressors typical of home and pro shops. Aluminum construction: Lightweight, corrosion-resistant, and longer-lived than plastic filter bowls. Push-button drain: Quick contaminant removal without tools — empty the bowl in seconds between jobs. 1/4" NPT universal fit: Drops into any standard pneumatic system. Technical Specifications Maximum pressure 140 PSI / 10 Bar Maximum flow 48 SCFM @ 140 PSI Filter element 5-micron, reusable Connection 1/4" NPT (male/female) Housing Aluminum body, polycarbonate bowl Best applications HVLP spray, plasma cutting, general workshop air Common Questions Do I need a separate filter if I have the AI303-R1? No. The AI303-R1 combines filtration and regulation in one unit. The 5-micron element removes water, oil mist, and particulates. For ultra-clean air on spray painting or plasma cutting, add a desiccant dryer downstream — but for typical air tools, this unit is the only conditioning stage you need. What air compressor do I need to drive it? Any compressor with a 1/4" NPT outlet rated up to 140 PSI. The regulator handles up to 48 SCFM at maximum pressure, which exceeds the demand of every common single-tool operation. For high-demand tools (sandblasters, large sanders), mount the unit close to the tool to minimize pressure drop. Can I use this for spray painting? Yes. The AI303-R1 is widely used by auto painters and refinishers. The filter removes moisture and oil that cause fisheye defects, and the gauge lets you dial in the precise PSI your spray gun needs — typically 25–50 PSI at the gun for HVLP. Can I wall-mount it? Yes. The included bracket supports wall or pipe mounting. Mount at the point of use rather than at the compressor — that placement catches the condensate that forms in the air line between compressor and tool. How do I drain the bowl? Push the drain valve at the bottom of the bowl. Collected water and oil discharge in seconds. Drain after each session, or daily if the compressor runs heavily — a full bowl will start passing moisture downstream. When should I choose the AI303-R1 over the AI303-C1 or AI-304? The AI303-R1 is the only unit in this lineup with an integrated pressure regulator and gauge — choose it when you need to dial in a specific PSI at the tool. Pick the AI303-C1 (1/4" NPT, 150 PSI, filter-only) if you already have a separate regulator. Pick the AI-304 (1/4" NPT, 200 PSI, slim inline filter) when you need the highest-pressure, lowest-profile filtration without regulation. Related Guides Complete FRL Unit Guide Inline Air Regulator Buying Guide Air Compressor Accessories Buying Guide Related Products & Categories You might also like AI303-R1 Filter-Regulator 15-piece NPT Fittings Kit DAR01B Digital Air Regulator Browse categories All Air Regulators Air Filters