Rolair VT409004 Check Valve

Rolair VT409004 is the OEM check valve used in Rolair VT20TB and VT25BIG portable air compressors. The part is listed in the VT25BIG owner’s manual as Check Valve VT409004 in the compressor’s parts list and is shown in the VT20TB schematic as the dedicated check valve in the air‑delivery circuit, confirming its role within these models. The one‑way valve prevents reverse flow from the tank back toward the pump, helping maintain steady outlet pressure and protecting downstream components such as the reed valve and other elements in the air‑path during cycling. As a genuine Rolair replacement part, VT409004 is designed to integrate with the same connections and fittings used in the VT20TB and VT25BIG units, ensuring compatibility with Rolair’s OEM check‑valve line.