Fisher FS1805-18 Back Pressure Relief Valve 1805 Series

Fisher FS1805-18 Cast Iron 1" NPT Back Pressure Relief Valve, 1805 Series, is a back pressure relief valve with a cast iron body and 1" NPT threaded connections. It regulates system pressure by maintaining downstream back pressure and venting excess pressure to prevent overpressure conditions in piping networks. As part of the Fisher 1805 Series, the FS1805-18 provides a standard industrial solution where a robust cast iron construction and 1" pipe fittings are required. This valve is identified by the part number FS1805-18 and belongs to the 1805 family, which covers similar back pressure relief products from Fisher. Key specifications verified here are material: cast iron; connection size: 1" NPT; product line: 1805 Series; model: FS1805-18. Typical applications include process piping and mechanical systems in industries that use back pressure control to stabilize downstream pressure and protect equipment from fluctuations.