Air trap

The invention relates to air traps , particularly for chromatography systems, chromatography systems using such air traps and methods of using such chromatography systems, in which the air trap comprises a liquid inlet pipe , a liquid outlet pipe , a substantially cylindrical reservoir between the inlet and outlet pipes , and an air outlet opening, the air outlet opening being openable and closable by means of a valve, wherein the liquid inlet and outlet pipes connect to the reservoir substantially tangentially to the reservoir wall , the inlet pipe at a distance above the outlet pipe , arranged such that during use incoming liquid at a the maximum permitted flow rate travels a spiral path from the inlet pipe to the outlet pipe .