The "D" type is a hybrid, utilized both axial and spiral flow patterns. This design is extensively used in partial, vacuum and atmospheric knockback condensers. Most applications have the vapors entering the top of a vertical SHE axially, which exposes the flow to a large condensing surface area. The reduced flow than enters a spiral path that will subcool and separate the vapors/non-condensable, from the liquids. Elanco Inc has developed new advanced design codes for partial condensers that allow these units to smaller. The new codes have made the premier suppliers of low pressure and partial condensers.