Prevost ALTO 4 Filter-Regulator — 3/4" & 1" FNPT, 7–145 PSI

The Prevost ALTO 4 filter-regulator combines water separation, particulate filtration and pressure regulation in a single 3/4" or 1" body. It is the high-flow answer to the popular Prevost ATU filter-regulators, which stop at 1/2" — if you have outgrown a 1/2" unit, this is the Prevost part that replaces it. Combining both functions in one module saves you a fitting, a nipple and roughly half the wall space of a stacked filter plus regulator. The relieving diaphragm regulator vents excess downstream pressure when you dial the setting back, the knob locks by pushing down, and a 1/4" gauge port accepts a gauge on either side. Condensate dumps through a manual push-button drain. Specifications Port sizes: 3/4" FNPT and 1" FNPT Flow rate: 150 CFM (3/4") / 177 CFM (1") at 87 psi, ΔP = 14 psi Adjustment range: 7 to 145 psi Regulator type: Relieving diaphragm, lockable knob Gauge port: 1/4" (gauge sold separately) Drain: Manual push-button Body: Aluminum alloy with metal bowl guard Replacement element: Prevost TF C45, 25 micron Series: Prevost ALTO 4 air treatment module Available Variants & SKUs SKU Port Size Flow Rate TM 204 3/4" FNPT 150 CFM at 87 psi (ΔP = 14 psi) TM 205 1" FNPT 177 CFM at 87 psi (ΔP = 14 psi) Flow ratings are taken from the Prevost 2026 US price list. If you need more than 150 CFM on a 3/4" port, step up to the 1" TM 205 and reduce at the outlet, or run a separate ALTO 4 filter and regulator.