Pneumatic Diaphragm Valve DIASTAR 025 DA PP-H d75-160

  Datasheet (PDF)

The Georg Fischer PROGEF Standard DIASTAR 025 DA pneumatic diaphragm valve is engineered for automated on/off and throttling duty in demanding industrial chemical processing, water treatment, and aggressive fluid distribution systems. Manufactured from high-grade isotactic polypropylene homopolymer (PP-H), this valve provides superior chemical compatibility against inorganic acids, alkalis, and industrial effluents across a wide temperature spectrum. Sized for metric piping networks from outer diameter d75 up to d160 mm (DN65 to DN150), the assembly features factory-fitted metric flanged ends compliant with EN ISO 16138, ensuring rigid, leak-tight integration into standard industrial pipelines.

Actuation is driven by an integrated double-acting (DA) pneumatic actuator, requiring pilot air pressure for both the opening and closing strokes. This pneumatic configuration guarantees positive stroke control, high cycle stability, and predictable response times without dependence on internal mechanical spring return assemblies. The actuator housing is molded from glass-fibre reinforced polypropylene (PP-GF), providing outstanding structural stiffness and external atmospheric corrosion resistance against harsh chemical plant environments. A high-visibility integrated optical position indicator provides continuous local visual confirmation, while premium stainless-steel fasteners resist external environmental attack.

Internal fluid isolation is achieved through interchangeable high-performance diaphragms, available in resilient EPDM or chemically inert PTFE with an EPDM backing core. The optimized weir-style flow geometry minimizes internal pressure drop while preventing particle accumulation and encrustation. Rated for long-term operational integrity of up to 25 years with water at 20 degrees Celsius, this valve assembly reflects the rigorous engineering standards of Georg Fischer. As an authorised Georg Fischer distributor, BigWeld supplies the DIASTAR 025 series complete with full technical documentation for process engineering and plant installation.