... weight,sensitive action. Main parts materials: Valve body, valve cover: ZG230-450, ZGlCr18Ni9Ti Spool, the valve seat: 1Cr18Ni9T, Levin Titanium Alloy Welding ... 60Si2Mn Stem, putting: 2Cr13, 1Cr18Ni9Ti Specification and technical dataDN20253240506580100125150200rated flow coefficient Kvline6.91117.627.54469110176275440690percentage6.31016254063100160250400630actuatordrect action PZMA-4PZMA-5PZMA ...