A filter comprising: a tube extending from a first end to a second end, the first end being tapered, that is the centre of the first end extends longitudinally further than an outer portion of the first end, the tube defining a bore with an internal cross-sectional area, the tube having: an inlet to the tube , the inlet being positioned through the first end of the tube , and the inlet having an inlet cross-sectional area; an outlet from the tube at the second end, the outlet having an outlet cross-sectional area; a plurality of slots in the tube between an outside thereof and the bore, the slots extending generally parallel to the longitudinal direction from the first to the second end; the tube comprising a mounting means suitable for mounting it to a pipeline, the mounting means comprising a threaded outer body; the tube comprising a further mounting means suitable for attaching a nozzle thereto; wherein the inlet cross-sectional area is less than the outlet cross-sectional area, the inlet cross-sectional area is less than the internal cross-sectional area of the bore defined by the tube; wherein the internal cross-sectional area of the bore defined by the tube is the same along at least 75% of its length; and wherein, in use, the fluid flows from a pipeline into the filter through the inlet and the plurality of slots , through the bore of tube , and out of the filter through the outlet into a nozzle. a tube extending from a first end to a second end, the first end being tapered, that is the centre of the first end extends longitudinally further than an outer portion of the first end, the tube defining a bore with an internal cross-sectional area, the tube having: an inlet to the tube , the inlet being positioned through the first end of the tube , and the inlet having an inlet cross-sectional area; an outlet from the tube at the second end, the outlet having an outlet cross-sectional area; a plurality of slots in the tube between an outside thereof and the bore, the slots extending generally parallel to the longitudinal direction from the first to the second end; an inlet to the tube , the inlet being positioned through the first end of the tube , and the inlet having an inlet cross-sectional area; an outlet from the tube at the second end, the outlet having an outlet cross-sectional area; a plurality of slots in the tube between an outside thereof and the bore, the slots extending generally parallel to the longitudinal direction from the first to the second end; the tube comprising a mounting means suitable for mounting it to a pipeline, the mounting means comprising a threaded outer body; the tube comprising a further mounting means suitable for attaching a nozzle thereto; wherein the inlet cross-sectional area is less than the outlet cross-sectional area, the inlet cross-sectional area is less than the internal cross-sectional area of the bore defined by the tube; wherein the internal cross-sectional area of the bore defined by the tube is the same along at least 75% of its length; and wherein, in use, the fluid flows from a pipeline into the filter through the inlet and the plurality of slots , through the bore of tube , and out of the filter through the outlet into a nozzle. <EOS>