Abstract: A rotary fluid valve has a pivotable disk (36) with through slots (38, 39), the disk blocking outer ends of ports (31, 32) in a neutral disk position. When the disk pivots in first or second directions from the neutral position, one of its slots moves into line with one of the ports. This allows pressured air to flow from the now-uncovered port and through the disk slot, and through an upper chamber (46) lying against the upper face of the disk, to allow air to flow between an external fluid coupling (17 or 18) that is coupled to the port, to another external coupling (19, 20) that is coupled to the upper chamber, as to inflate or deflate a vehicle air bag.