2-1/2" Wafer Check Ductile Iron /Stainless Steel 150/300# Dual Disc with Buna Seat Titan CV41DSB2 1 2" Wafer Check Ductile Iron Stainless Steel 150 300# Dual Disc with Buna Seat Titan CV41DSB Minimal Head Loss Quick Closure to Reduce Water Hammer Resilient Soft Seats BUNA N PROPERTIES: most widely used elastomer. good for most petroleum oils and fluids, silicone greases and oils, and cold water. excellent compression set, tear, and abrasion resistance . poor weather resistance and moderate heat resistance . not recommended for severe ozone