441,055. Aerating liquids; valves. COWEY, L. E., Archer Works, Kew Gardens, Surrey. April 10, 1934, No. 10832. [Class 14 (i)] [See also Group XXIX] An apparatus for aerating liquids of the liquid-shower type comprises means for showering the liquid at a pressure head which is independent of the pressure of the liquid-supply service, float - operated means for controlling the supply of liquid to the apparatus, and improved combined gaspressure-reducing and gasventing devices controlled by the pressure conditions within the apparatus. The apparatus comprises a closed aerating chamber 1 at the upper end of which is a cistern 7 to which water is supplied by a pump by way of pipes 15<a>, 14, valve casing 15, and inlet 13. The lower end 8 of the cistern is connected by a pipe 9 to a casing 10 for a finely-per. forated screen 11, from which the water is showered down chamber 1 to meet aerating gas introduced at the opening 24<a>. The aerated water collects at the bottom of the chamber, and can be drawn off at 25. The pressure head of the shower is determined by the length of the pipe 9. Inspection windows 60 are provided in the wall of the chamber. In a modification, two showering devices are arranged in series in the chamber. The pump discharges into the the valve casing 15, Fig. 3, by a port 16<a> controlled by a pulsating non- return valve 16. A byepass passage 18 leads from below the valve 16 to the interior of the casing 15 by way of a spring-biassed valve 19 adapted to be opened by a plunger 20d which co-operates with a pivoted lever 22. The arm 22<c> of the latter projects through a sealing diaphragm 23<a> and the opening 24<a> into the path of movement of a float 12 which is guided on a pin 12b at the lower end of the chamber 1. When a certain quantity of aerated water has collected in the chamber 1, the float tilts the lever 22 to open the valve 19. The water discharged by the pump, or a part of it, then returns, by way of the valve 19 and passage 18, from the valve casing 15 to the port 16<a>. The float is perforated at its lower end to prevent damage by excessive pressures. In a modification, Fig. 4, the lever 22 controls, through weighted trip mechanism 75, 73, 72, a catch device 72b adapted to lock the valve 16 in open position when the supply of water to the aerating chamber is to be arrested. The float is then modified to operate the lever 22 positively in both directions. Aerating gas is supplied from a pressure source, such as a carbon dioxide cylinder, by a port 34 with gas filters 39 to a pressure-reducing valve 46, and passes to the aerating cylinder by a pipe 38 and the opening 24<a>. The pressure-reducing valve comprises a ball 46 which is forced to its seat in the fitting 42 by the gas pressure, and is adapted to be opened by a pin 49 carried by a piston member 48 raised by a spring 50. The upper surface of the member 48, which is formed as a packing washer, is engaged by a tubular member 55<a> carried by a gas-tight diaphragm 51 which closes a chamber 27<c> which communicates with the gas-supply pipe 38 by way of bores in the valve fitting 42. The diaphragm 51 is biassed by a spring system 56 acting through a cup member 54. If the pressure in the aerating chamber, and consequently in the chamber 27<c>, falls, the diaphragm 51 is depressed by the springs 56, so that gas passes from the source into the aerating chamber. When the required pressure is re-established, the diaphragm rises, and the valve 46 re-closes. If pressure in the aerating chamber rises too high, the diaphragm 51 rises, and the member 55<a> separates from the packing washer on the member 48. Air and excess gas are then vented through the member 55<a>. The compression of the springs 56 is adjustable by a cap nut 58, in order to vary the pressures at which the valves 46, 55<a> will be actuated. By the arrangement described, the gas-supply valve is water-jacketed by the water passing through the casing 15, preventing freezing of the gas valve and promoting cooling of the water. The valve fitting 42 has a seating 47<a> for the ball 46 to prevent escape of gas from the aerating chamber to the port 34, for example, when attaching a new gas cylinder. Specification 441,109, [Group XXIX], is referred to.