Molecular sieve 3A, wanda kuma aka sani da molecular sieve KA, tare da buɗaɗɗen kusan 3 angstroms, ana iya amfani dashi don bushewar iskar gas da ruwa da kuma bushewar hydrocarbons.Hakanan ana amfani da shi sosai don bushewar gas mai fashe, ethylene, propylene da iskar gas.
Ka'idar aiki na sieves kwayoyin suna da alaƙa da girman pore na sieves, waɗanda suke 0.3nm/0.4nm/0.5nm bi da bi.Suna iya haɗa ƙwayoyin iskar gas waɗanda diamita na ƙwayoyin cuta ya yi ƙasa da girman pore.Girman girman girman pore, mafi girman ƙarfin talla.Girman pore ya bambanta, kuma abubuwan da ake tacewa da raba su ma daban-daban.A cikin sassauƙan kalmomi, 3a sieve na ƙwayoyin cuta zai iya haɗa ƙwayoyin da ke ƙasa da 0.3nm, 4a sieve na ƙwayoyin cuta, ƙwayoyin da aka tallata su ma dole ne su kasance ƙasa da 0.4nm, kuma 5a sieve na ƙwayoyin cuta iri ɗaya ne.Lokacin da aka yi amfani da shi azaman desiccant, sieve na ƙwayoyin cuta zai iya ɗaukar nauyin 22% na nauyinsa a cikin danshi.