Lug-Style Butterfly Valve Type 243 FO

  Datasheet (PDF)

The Georg Fischer SYGEF Standard Type 243 lug-style butterfly valve delivers dependable, automated fluid isolation and flow management across demanding chemical processing and high-purity distribution environments. Engineered by Georg Fischer for clean and aggressive media handling, the valve integrates an inert polyvinylidene fluoride (PVDF) disc with premium FKM fluorocarbon elastomer seals to provide outstanding chemical resistance against concentrated acids, oxidizers, and industrial solvents across operating temperatures from -20 degrees to 140 degrees Celsius. The valve body is constructed from an outer 30% glass-fibre reinforced polypropylene housing (PP-GF30) equipped with factory-embedded grade 316 stainless steel threaded lug inserts, ensuring exceptional torsional rigidity and allowing reliable installation as both an intermediate valve and a terminal dead-end shut-off valve. Valve actuation is powered by a high-performance pneumatic actuator utilizing a fail-safe to open (FO) operating mechanism with a factory-calibrated 90-degree rotary stroke. In the event of pilot air supply pressure depletion, heavy-duty internal spring assemblies automatically force the disc into the fully open position, safeguarding critical process circuits that require unrestricted passage during system failures. Configured without manual override for tamper-proof automated reliability, the valve features an overall face-to-face length according to EN 558 and ISO 5752 standards, facilitating smooth installation between metric pipe flanges. The actuator housing is also prepared for optional valve-integrated position feedback modules with electric limit switches, allowing accurate real-time position reporting for supervisory control systems in semiconductor manufacturing, chemical dosing stations, and pharmaceutical water treatment facilities.