Diaphragm valve DIASTAR 10 Plus PVC-U FC (Fail safe to close)

  Datasheet.pdf

The Georg Fischer DIASTAR 10 Plus is an industrially engineered pneumatic diaphragm valve manufactured from unplasticised polyvinyl chloride (PVC-U), designed for demanding chemical distribution, water treatment, and process automation installations. Operating with a fail safe to close (FC) pneumatic actuator configuration, this valve ensures positive line isolation in the event of pilot air pressure failure. Rated for an operating pressure of up to PN10 (10 bar) on both sides of the diaphragm, the DIASTAR 10 Plus covers metric outer pipe diameters from d20 mm up to d63 mm (DN15 through DN50), connecting seamlessly into metric solvent-cemented industrial piping assemblies.

Engineered to deliver high operational efficiency, the internal flow geometry provides double the flow capacity compared to legacy diaphragm valve designs, substantially minimising pressure loss and reducing overall system pumping energy requirements. Its flow characteristic remains linear across valve stroke travel, making the unit well suited for continuous throttling and automated modulating control. The pneumatic actuator incorporates rotatable air connection ports adjustable at 90 degrees intervals, allowing direct, clean routing of control air tubing within congested plant skids, manifolds, and pipe racks. Maintenance safety is reinforced through factory pre-tensioned internal spring kits that streamline field servicing.

The valve assembly features a central union nut joint linking the pneumatic actuator to the PVC-U valve body. This robust joint eliminates metallic exterior tie-rods, provides high mechanical strength, and exhibits total corrosion resistance in aggressive ambient atmospheres. An integrated mechanical accessory interface allows straightforward retrofitting of position indicators, electrical feedback switches, electro-pneumatic positioners, and direct-mount pilot solenoid valves. Supplied across Europe by BigWeld, an authorised Georg Fischer distributor, the DIASTAR 10 Plus provides reliable shut-off and modulating performance in inorganic acid, alkaline, and saline process environments.