5. Grooved Coupling & Fittings 5-1. Size : 1 ~12" 5-2. Applications Fire Extinguishing Pipelines Water supply pipelines 5-3. Materials : Ductile iron castings(ASTM A536) / Stainless steel CF8 & CF8M 5-4. Working Pressure : 20 bar / 35 bar (High-pressure model) 5-5. Features - One-push insertion method that simply pushes in without disassembling the product (Improving workability) Step-by-step sealing effect by uniquely designed gasket that lets it naturally adheres to the pipe surface (No gasket deformation and leakage) Reduced construction time by 4 times compared to basic products Completion of product quality and function verification through Only supplier in Korea who has acquired the UL approval for both of ductile iron and stainless steel materials