Ntau yam kev xaiv metallurgic - tso tawm cov vanes ntawm sab nraub qaum thiab pem hauv ntej (ntawm cov impellers kaw) txo qis kev rov ua haujlwm hauv lub twj tso kua mis, thiab pab tiv thaiv kev sib tsoo - xaiv cov castings ncaj los yog semi-Francis vanes (los ntawm 2 mus rau 8 vanes ntawm qee qhov ntau thiab tsawg) muab wider hydraulic xaiv nyob rau hauv ib qhov ntau thiab tsawg.