Much of a plant’s air costs can be associated with inappropriate uses of (or artificial demand for) compressed air. This company’s Air Saver Unit (ASU) pneumatic valves (photo) save energy by interrupting the flow of compressed air to blowing end uses at adjustable frequencies. The devices reduce compressed air costs by as much as 40–50% over typical constant-flow applications, according to the manufacturer. Rather than a steady stream of air, an ASU delivers a series of impulses, which offer a significant mechanical advantage. Because the ASU has an opportunity to recover during the “off” period of each on/off cycle, the impulses are delivered with somewhat greater force than a steady stream of air would provide. — Parker Hannifin Corp., Cleveland, Ohio