Diaphragm valve DIASTAR ABS 025 FO DN65-DN100

  Datasheet (PDF)

The Georg Fischer DIASTAR ABS Series 025 FO is a pneumatically actuated diaphragm valve for automated flow control in industrial water treatment, cooling circuits and chemical processing plants. In the Fail-Safe to Open (FO) control mode, an internal spring drives the valve into the fully open position whenever pilot air pressure is lost, preventing hazardous upstream pressure build-up and keeping the process running. The valve covers dimensions d75, d90 and d110 (DN65 to DN100) for reliable unilateral flow regulation in demanding fluid handling duties.

The body is produced in acrylonitrile butadiene styrene (ABS) and the actuator housing in glass-fibre reinforced polypropylene (PP-GF), a combination that delivers high impact resistance and chemical endurance in harsh plant environments. An elastomeric EPDM diaphragm isolates the medium from the internal actuator components. The actuator carries a standard G 1/4" pneumatic port for industrial instrument air supplies, together with an integrated optical position indicator giving immediate visual confirmation of the valve status during operation.

Flow capacity reaches 2700 l/min while maintaining a low pressure drop. The nominal pressure rating is PN10 (10 bar at 20 degrees Celsius) for d75 (DN65) and d90 (DN80), and PN6 (6 bar at 20 degrees Celsius) for d110 (DN100). The integrated metric fixed flanges follow the universal bolt circles of EN 1092, ISO 7005, DIN 2501 and ANSI B16.5, so the valve bolts straight into existing piping manifolds and skid assemblies without adaptor parts.

The Georg Fischer ABS programme is intended for cooling, chilled water, water treatment and marine applications, with pipework jointed by ABS solvent cement and valve seals supplied here in EPDM. As an authorised Georg Fischer distributor, BigWeld supplies genuine DIASTAR Series 025 valves and complete industrial ABS systems throughout Europe, backed by in-house thermoplastic fabrication and welding expertise for process engineers and piping contractors.