A magnetic filter 10 includes first and second separation chambers 10, 12. The separation chambers 10, 12 each have an inlet and an outlet, and the separation chambers 10, 12 are joined together such that the inlets of the first and second chambers are adjacent, and the outlets of the first and second chambers are adjacent. An inlet port arrangement 28 connects both inlets to a single inlet pipe, and an outlet port arrangement 30 connects both outlets to a single outlet pipe.