Abstract: A device, such as a sink trap, for the discharging of waste fluid or the like to a sewer connection. The device comprises a fluid inlet means and fluid outlet means. The fluid inlet means conveys the waste fluid to an inner one of several concentrically arranged, vertically overlapping water seals which cooperate to define a plurality of concentrically disposed chambers forming a tortuous path for waste fluid from the inlet means to the outlet means which connects to the outwardmost of the chambers.