Steam Drums KNM has deep understanding on the mechanical and thermodynamics engineering expertise for this product. Steam drums are a regular feature in many boiler systems. The steam drum provides a space for the saturated steam generated in the tubes and for the separation of moisture from the steam. It is a reservoir of water/steam at the top end of the water tubes in the water-tube boiler. Steam drums store the steam generated in the water tubes and act as a phase separator for the steam/water mixture.