ecoFIT Ventilating and Bleed Valve Type 591

  Datasheet (PDF)

The Georg Fischer ecoFIT Type 591 ventilating and bleed valve is engineered for automatic aeration during pipeline drainage, continuous gas release during pressurized operation, and rapid air discharge during system charging in industrial thermoplastic distribution lines. Built with high-density PE100 long spigots rated at SDR11 and a chemically resilient PVC-U/PE valve body assembly, this PN16-rated valve ensures dependable fluid transport protection across dimensions from d20 mm up to d110 mm (DN15 to DN100). The internal operating mechanism employs a precision-engineered buoyant floater made of solid PP-H (polypropylene homopolymer) that responds dynamically to changes in liquid levels. As liquid enters the valve chamber, the floater rises smoothly to establish a leak-tight seal against the upper sealing seat—offered in either durable EPDM or high-performance FKM elastomeric formulations. When air or entrained process gases accumulate, the fluid level drops, lowering the floater to vent trapped pockets and eliminate flow restrictions, pressure surges, or hydraulic water hammer. Conversely, rapid system emptying drops the floater fully open to admit ambient air, preventing negative pressure vacuum build-up and pipe deformation. The exhaust orifice is capped by an impact-resistant protective cover designed to prevent particulate ingress, constructed from glass-fibre-reinforced polypropylene (PP-GF) for sizes up to DN50 and engineered polyoxymethylene (POM) for sizes DN65 to DN100. Featuring a compact overall face-to-face length and extended spigot ends compatible with heated tool butt welding and electrofusion jointing, the assembly allows rapid inline servicing, straightforward radial dismounting, and total immunity to electrochemical corrosion.