Union taper seat galvanised malleable cast iron

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The Georg Fischer union taper seat 340 (ISO/EN U11) provides a robust, separable metallic-sealing connection engineered for fluid and gas conveyance in industrial installations, building utility systems, and potable water networks. Manufactured from decarburised annealed whiteheart malleable cast iron type EN-GJMW-400-5 conforming to EN 10242 Design Symbol A, the three-part assembly comprises a figure 380 union bush, a figure 381 union end, and a figure 374 union nut. Sealing is executed through precision-machined conical taper seating faces that achieve an impermeable metal-to-metal compression seal upon tightening the union nut, entirely eliminating the need for flat elastomeric sealing gaskets. Both connecting ports incorporate parallel internal jointing threads Rp in accordance with EN 10226-1 and ISO 7-1 for pressure-tight sealing on the threads, while the coupling nut utilizes parallel fastening threads G according to EN ISO 228-1. The hot-dip galvanised surface provides durable corrosion protection through multi-layer iron-zinc alloy bonding suitable for hygienic drinking water applications, maintaining full freedom from polycyclic aromatic hydrocarbons. The detachable union design facilitates rapid installation, line inspection, and component servicing without twisting or rotating adjoining pipework. Operating parameters accommodate working pressures up to 25 bar across fluid temperatures from -20 degrees Celsius to 120 degrees Celsius and up to 20 bar at 300 degrees Celsius. Integrated hexagonal and octagonal wrench profiles across all constituent piece parts provide positive tool engagement, ensuring uniform torque transmission and dependable mechanical integrity throughout high-pressure piping assemblies.