997,974. Valves. BOWSER Inc. Jan. 30, 1964 [May 6, 1963], No. 4022/64. Heading F2V. [Also in Division B1] A device for dispersing a contaminant in a liquid flow, e.g. water in a liquid fuel, to produce a uniform dispersion for testing purposes (see Figs. 1 and 3, not shown), comprises a conduit 12 discharging through apertures 70 into a conduit 14; a chamber 78 resiliently biased against the liquid flow 82 uncovers a greater number of apertures as the rate of flow increases in order to provide a substantially constant pressure-drop across the device. Specification 993,479 is referred to.