stainless steel check valve Material:304,316L,321,304L,316 size:DN25-150 &1"-6" Sanitary flange check valveMaterial:304,316L,321,304L,316Flux domination of pipeline:DN25-150 &1"-6"Mirror finished Ra≤0.8μm,Inner surface:mechanical polished,electrical polished Ra≤0.2μmOuter surface:polished or matte surface