... small size3.high filtration accuracy,low initial pressure,high dirt-holding capacity DF PRESSURE FILTER FOR SANDWITH STACKING SERIES The kind of the ... .When the filter element is blocked by contamination and the pressure reaches 0.5Mpa,the indicator will give signals showing the ... small size and it has high filtration accuracy,low initial pressure,and highdirt-holding capacity.Filter ratio β3,5,10,20 ...