SYGEF Standard check valve type 561 PVDF

  Datasheet (PDF)

The Georg Fischer SYGEF Standard check valve type 561 is an unplasticised polyvinylidene fluoride (PVDF) non-return valve engineered for dependable backflow prevention in demanding chemical distribution networks, high-purity fluid circuits, and aggressive industrial process systems. Manufactured from high-grade thermoplastic PVDF, the valve body provides exceptional chemical resistance against aggressive acids, halogens, and sanitising agents across an operating temperature range extending from -20 degrees to 140 degrees Celsius. Operating entirely without a metallic spring, the internal mechanism utilizes medium backpressure and gravitational return acting upon a flow-optimized, double-guided return cone to achieve bubble-tight shutoff at a minimum water column of 2 meters. This non-metallic, spring-free cone design prevents process fluid contamination from degrading springs, eliminates mechanical binding, and ensures smooth, vibration-free hydrodynamic behavior even under high flow velocity conditions. Featuring a compact installation length identical to the brand's type 546 ball valve platform, the assembly is equipped with metric butt fusion spigots compatible with infrared IR-Plus and conventional thermoplastic welding techniques. The double union design with robust union nuts facilitates rapid radial assembly and disassembly for maintenance without disrupting neighboring line infrastructure, while integrated FKM elastomer seals provide reliable sealing integrity. Designed specifically for vertical installation in industrial piping systems, this non-return solution delivers maximum process reliability, excellent flow coefficient performance, and outstanding resistance to harsh chemical environments.