Cast Iron Check Valve with 2" Cast Iron Slip x Slip UnionsThis cast iron check valve prevents backflow of water and sewer gas and reduces motor and pump noise from the plumbing system. Easy to install valve slips over ABS, PVC, steel, or copper piping and can be installed on a vertical or horizontal line. Cast iron slip x slip unions include stainless steel clamps for low pressure systems. Features an extra wide hinge to reduce hinge stress, a neoprene gasket and flapper with stainless steel backing plates