Abstract: In one aspect of the invention, a bed structure having a mattress deck panel and side panels, with internal reinforcing bulkheads and single-piece head- and footboards serving as reinforcing bulkheads at the head and foot of the structure. In another aspect of the invention, there is provided a low-cost air bed employing the above structure. In an additional aspect of the invention, there is provided an air bed which incorporates the air supply and control components within the bed structure itself. In a further aspect of the invention, there is provided a low-noise air flow control pinch valve. In yet another aspect of the invention, there is provided a single air bag which simulates multiple air bags through the use of welded internal baffles. In yet an additional aspect of the invention, there is provided a bed siderail which is patient-operable.