Flat bottom seat ring integral with the body,inside and outside epoxy resin coating, wedge wholly bonded with ruber, Resilient Seated Gate Valve F4A. Design Standard DIN1171B. Face to Face Dimension DIN558-1 C. Flange DIN 1092-2D. Body/Bonnet/Wedge iron core Ductile Iron QT500-7 E. 2Cr13 Stainless Steel Stem,Stem Nut: HPb59-3 F. The Closing Bolts of A283grC , Steel plated with Zinc G. Inside and ...