Hermetic bi-flow filter driers, types DMB and DCB are for use in liquid lines on heat pumps. Hermetic bi-flow filter driers have built-in check valves which ensure that refrigerant liquid always €ows through the •lter driers from the outer side of the fillter core towards the center. Thus all dirt particles are retained irrespective of €ow direction. DMB and DCB fillter driers ensure fast and e‚ective adsorption of moisture as well as organic and inorganic acids. When building heat pump systems, the use of bi-flow filters can, depending on the type of system, save up to ten solder connections. This reduces production costs and the number of potential leakage points. Available with flare and solder (Copper and cuplated steel) connections.