Katlakivi tekib veest otse soojusülekandepindadele sadestuvatest lisanditest või vees olevatest heljumitest, mis settivad metallile ning muutuvad kõvaks ja kleepuvaks.
Boiler scale is formed from impurities that precipitate directly from the water onto heat transfer surfaces or from suspended solids in the water that settle on the metal and become hard and sticky.
