A filter assembly for removing material entrained in a fluid stream includes a housing having a head part and a body part, and inlet and outlet ports for the fluid that is to be filtered, in which at least one of the ports is provided in the head part, the head part having a chamber port fluidly connected to the at least one port in the head part, the head and body parts having first formations which enable them to be connected to one another and separated by relative rotation. The assembly includes a filter element for removing material entrained in the fluid stream that can be received in the body part, the filter element and body part having second formations which restrict relative rotation between them, the filter element having a filter port, in which a fluid tight connection can be provided between the filter port and the chamber port by sliding one of them into the other along a first axis. One of the head part and the filter element provides an inclined surface which is inclined relative to the first axis, and the other provides an ejector part which can act against the said inclined surface so as to push the filter element away from the head part as the head part and the body part are separated by relative rotation, so as to free the filter port from the chamber port.