Prevost ALTO 4 Air Line Lubricator — 3/4" & 1" FNPT

The Prevost ALTO 4 air line lubricator meters oil into the air stream to keep air motors, impact wrenches, grinders and cylinders running longer between rebuilds. ALTO 4 is the large-body size in the Prevost ALTO range, covering 3/4" and 1" FNPT ports at flows well past what the smaller ATU bodies handle. An adjustable needle valve sets the drip rate, and a sight dome on top lets you confirm the feed at a glance without shutting the line down. The modular ALTO 4 body stacks with the matching ALTO 4 filter and regulator to build a full 3/4" or 1" FRL train. Specifications Port sizes: 3/4" FNPT and 1" FNPT Flow rate: 254 CFM (3/4") / 318 CFM (1") at 87 psi, ΔP = 7 psi Oil capacity: Approximately 8 oz Recommended oil: ISO VG32 air tool oil (Prevost LUB 3256) Feed: Adjustable needle valve with sight dome Body: Aluminum alloy with metal bowl guard Series: Prevost ALTO 4 air treatment module Available Variants & SKUs SKU Port Size Flow Rate TL 204 3/4" FNPT 254 CFM at 87 psi (ΔP = 7 psi) TL 205 1" FNPT 318 CFM at 87 psi (ΔP = 7 psi) Flow ratings are taken from the Prevost 2026 US price list. Install the lubricator last in the train, downstream of the filter and regulator, and never upstream of a dryer or a paint circuit.