The Collaborative International Dictionary
Double-acting \Dou"ble-act`ing\, a. Acting or operating in two directions or with both motions; producing a twofold result; as, a double-acting engine or pump.
Usage examples of "double-acting".
Baking powders that contain no sodium aluminum sulphate, often found in double-acting baking powders.
It wasn't difficult to guess what they were working at, the working platform was liberally stacked with the tools of their trade: an oil engine-driven air compressor with a steel reservoir with outlet valves, a manually-operated, two-cylinder double-acting air pump with two outlets, two helmets with attached corselets, flexible, non-collapsible air tubes with metal couplings, weighted boots, diving dresses, life-cum-telephone lines, lead weights and scuba equipment such as I had myself, with a stack of com.
It wasn't difficult to guess what they were working at, the working platform was liberally stacked with the tools of their trade: an oil engine driven air compressor with a stored reservoir with outlet valves, a manually-operated, two-cylinder double-acting air pump with two outlets, two helmets with attached corselets, flexible, non-collapsible air tubes with metal couplings, weighted boots, diving dresses, life-cum-telephone lines, lead weights and scuba equipment such as I had myself, with a stack of compressed air cylinders at the ready.
All this is not to deny that Watt greatly improved Newcomen's engine (by incorporating a separate steam condenser and a double-acting cylinder), just as Newcomen had greatly improved Savery's.