A gas pressure regulator (1) for regulating the flow of gas from a gas supply to a receptacle, includes: a regulator body (2) including a gas inlet (5), a gas outlet (6) and a gas passageway (7) extending between said inlet and said outlet, a first casing part (3) coupled to the regulator body (2), and a first diaphragm (9) interposed between said regulator body (2) and said first casing part (3) capable of restricting the flow of gas through one point along said gas passageway, and a second casing part (4) coupled to the regulator body (2), and a second diaphragm (12) interposed between said regulator body (2) and said second casing part (4) capable of restricting the flow of gas through a second point along said gas passageway. The gas pressure regulator does not include any venting to the external atmosphere, and the regulator body and each casing part is of sufficient strength to withstand the full pressure of gas supply, so that should one diaphragm fail, the regulator can continue to function without releasing gas to the atmosphere. The gas passageway also includes a restricted region (16) which restricts flow through the regulator should the second diaphragm fail. The gas pressure regulator is suitable for use in conjunction with a tank for transporting fish and other aquatic life by air. |