Pneumatic Diaphragm Valve DIASTAR Ten PVC-C FO d20-63

  Datasheet (PDF)

The Georg Fischer DIASTAR Ten PVC-C pneumatic diaphragm valve with Fail-Safe-to-Open (FO) actuator controls and isolates flow in automated industrial piping systems. If the control air pressure is lost, the actuator drives the valve to the fully open position, keeping the line flowing and preventing the media from stagnating in critical continuous processes. Integrated metric solvent cement spigots in sizes d20 to d63 allow the valve to be bonded directly into standard metric PVC-C pipe runs. As an authorised Georg Fischer distributor, BigWeld supplies this valve for chemical dosing, industrial water treatment and corrosive process lines.

The body is moulded in post-chlorinated polyvinyl chloride (PVC-C) in agate grey RAL 7038, offering high chemical resistance to aggressive acids, alkalis and salts and handling media temperatures up to 80 degrees Celsius under pressure. The DIASTAR Ten flow geometry delivers double the flow capacity of earlier diaphragm valve generations, which markedly reduces the pressure drop across the line. Face-to-face dimensions follow EN 558, so the valve retrofits into existing pipeline layouts without reworking the pipework. The pneumatic actuator housing is moulded in glass-fibre reinforced polypropylene (PP-GF) and its air connection ports can be rotated by 90 degrees to suit the installation.

A central housing nut replaces the conventional multi-bolt body flange, applying homogeneous compression around the entire diaphragm circumference and securing permanent leak tightness up to the full PN10 rating (10 bar at 20 degrees Celsius) without localised over-tightening. Diaphragms are available in resilient EPDM or in chemical-grade PTFE backed with EPDM; both separate the process medium completely from the actuator mechanism, preventing contamination and corrosion of the drive. The modular architecture allows in-line inspection and diaphragm replacement without cutting or ungluing the cemented spigot ends from the pipeline.