Malleable iron service external threads

  Datasheet (PDF)

The Georg Fischer malleable iron service union with flat seat and external threads (figure 356) provides an engineered detachable joint specifically designed for the rapid radial mounting and dismounting of inline utility and industrial piping components, including pumps, filters, check valves, regulating equipment, and heat exchangers. Manufactured from premium whiteheart decarburised annealed malleable cast iron grade EN-GJMW-400-5 in accordance with EN 1562 and design symbol A standards, the assembly consists of two figure 371 union ends with taper external jointing threads (R) compliant with EN 10226-1 and ISO 7-1, a central figure 375 flat-seat union bush with parallel external fastening threads (G...B) to EN ISO 228-1, two figure 374 union nuts with internal fastening threads (G), and two pre-packaged 2 mm flat sealing gaskets. The unique operational mechanism allows the central union bush to be retracted radially from the pipeline axis simply by unscrewing both union nuts, creating adequate axial clearance because the bush exceeds the length of standard pipe jointing threads. This innovative configuration replaces the conventional requirement of installing two separate standard unions on either side of equipment, significantly reducing overall laying lengths, installation labor, and the total quantity of threaded connections while requiring wrench access at only one single location. Available in black or hot-dip galvanised finishes executed to EN 10242 standards for superior corrosion protection, this service union operates at maximum permissible pressures up to 25 bar at working temperatures between -20 degrees and 120 degrees Celsius, with the supplied gaskets reliably sealing common industrial media including natural gas, liquid petroleum gas, compressed air, oils, and heating water up to 150 degrees Celsius at 25 bar.