Check valve PVDF type 561

  Datasheet (PDF)

The Georg Fischer SYGEF Standard check valve type 561 provides reliable backflow prevention for high-purity water circuits and aggressive chemical distribution systems. Manufactured from unpigmented polyvinylidene fluoride (PVDF) and fitted with premium FKM seals, the valve covers nominal pipe diameters from d16 up to d110 mm (DN10 to DN100) with a pressure rating of PN16. Operating without a mechanical spring, the valve relies on fluid dynamics, gravitational force, and downstream backpressure to achieve positive, leak-tight shut-off, initiating dependable sealing at a minimum water column of 2 meters. The internal geometry features a flow-optimized, double-guided return cone that maintains exact axial alignment throughout the stroke, eliminating flutter and delivering vibration-free operation even during high flow velocities and rapid medium displacement. Built with a true union body architecture, the component matches the compact face-to-face installation length of the Georg Fischer type 546 ball valve series, allowing for seamless radial installation, effortless replacement, and fast servicing without straining adjacent pipe runs. Metric fusion sockets enable homogenous jointing via socket fusion, guaranteeing high joint integrity and smooth flow transitions without dead zones. The PVDF construction withstands aggressive media including concentrated acids, salts, fuels, and chemical oxidizers across a broad operating temperature range from -20 degrees C to 140 degrees C. Additionally, the assembly is suitable for rigorous cleaning and sanitisation methods using ozone, hot water, steam, and chemical disinfectants, making it an essential, low-maintenance backflow solution for semiconductor manufacturing, chemical processing, and pharmaceutical purified water systems.