<p>A dual stage coalescer includes a separator in a separator chamber separating gas and liquid by inertial impaction, and a coalescer filter element in a coalescer chamber separating gas and liquid by coalescence. A transfer tube extends between the separator chamber and a downstream subchamber in the coalescer chamber at the downstream face of the coalescer filter element, and supplies pre- separated liquid from the separator chamber through the transfer tube to the noted downstream subchamber as driven by pressure differential between the separator chamber and the downstream subchamber, to eliminate a dedicated housing drain outlet from the separator chamber. The coalescer may provide a crankcase ventilation filter for an internal combustion engine having blowby gas containing an air-oil mixture.</p>
