When compressed air expands, it gets cold, sometimes to below -30˚F, freezing any moisture in the air supply and stalling the pump. Pumps also stall when a "balanced" air valve centers itself with equal air pressure on both sides. Another problem common to diaphragm pumps is poor efficiency due to underperforming seals and valves.

Engineers at Ingersoll Rand, Montvale, N.J. (Ingersollrand.com), have come up with the ARO Expert Series of diaphragm pumps that does away with these problems through innovative design. To eliminate icing, designers added a device that diverts cold, wet exhaust air from the major air valve and into an expansion chamber.

Balanced valves eventually center, stalling pumps and forcing operators to hit them with a hammer to kickstart operations. Valves can also have metal-to-metal lappedfit seals that let air leak past, decreasing efficiency. ARO valves are intentionally unbalanced with a larger diameter on one end, making the valve always biased toward one side. And positive seals eliminate leaks. These and other energy conserving features will save plants more than $600/yr/pump, according to Ingersoll Rand.