Pneumatic Diaphragm Valve PP-H DIASTAR Six FC d25-63 PN6

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The Georg Fischer PROGEF Standard DIASTAR Six FC pneumatic diaphragm valve provides precision process shut-off and throttling control for industrial metric piping systems across sizes d25 to d63 (DN20 to DN50). Manufactured from unpigmented beta-polypropylene homopolymer (beta-PP-H), the valve body features integrated socket fusion spigot ends conforming to EN ISO 16138, with overall face-to-face dimensions according to EN 558.

Designed specifically for aggressive chemicals, industrial effluent and high-purity water treatment, this configuration pairs an EPDM diaphragm with a robust PPGF (glass-fibre reinforced polypropylene) actuator housing. As an authorised Georg Fischer distributor, BigWeld supplies this high-integrity flow control solution to engineering contractors and plant operators throughout Europe.

Actuation is driven by a fail-safe-to-close (FC) pneumatic mechanism using a heavy-duty, preloaded galvanised steel spring pack that ensures immediate, hermetic closure upon loss of pilot air pressure. Operating at a nominal pressure rating of PN6 (6 bar), the DIASTAR Six incorporates an advanced internal flow geometry that delivers up to double the flow capacity of conventional plastic diaphragm valves, drastically lowering operational head loss. The diaphragm construction keeps the actuator mechanism fully isolated from the process medium.

The mechanical construction features an innovative central housing union nut, eliminating exposed metal body bolts and preventing external atmospheric corrosion. An integrated two-colour optical position indicator provides unambiguous local status monitoring, while the pilot air port offers 90 degrees indexing rotation for clean pneumatic tubing routing. Engineered for enduring service in temperature-demanding environments up to 80 degrees Celsius, beta-PP-H offers exceptional chemical resistance to acids, alkalis and salts, backed by long-term hydrostatic strength designed for a 25-year service life at 20 degrees Celsius, while the EPDM diaphragm maintains tight sealing across cyclic duties. BigWeld supplies industrial, irrigation and utility piping systems across Europe, and fabricates and welds thermoplastics where metal fails.