... satisfy requirements of most ductwork.The former diameter is between 330mm and 1500mm. 2, Small compact helix ovalizer has less requirement of area ... range1,semicircular mould):Ø150,Ø200,Ø250,Ø300,Ø350,Ø400,Ø450mm 2, Height of column mould:100,200,300,400,500m (Moulds ...