Method and devices for filtering liquid are provided that rely on pressure difference to filter liquid. In one embodiment, a device for filtering liquid includes a feed chamber, a permeate chamber, and a porous membrane that is at least partially hydrophobic and has one or more pores configured to be permeable to vapor. A pressure of a liquid substance in the feed chamber is increased such that vapor of the liquid substance is transported from the feed chamber to the permeate chamber. The resistance of flow in a hydrophilic layer of the membrane can be controlled to make the membrane defect-tolerant. In another embodiment, a second porous membrane is further included and the second porous membrane is spaced apart from the first porous membrane. Various methods for filtering liquid are also provided.