Bullard Free-Air pumps offer a low-cost means of supplying clean, breathable air to respirator wearers working in contaminated environments up to 300 feet away from the pump. Bullard Free-Air Pumps are oil-less, so they do not produce carbon monoxide, oil vapor or oil mist. Ideal for both general purpose and hazardous duty use. The convenient air-driven ADP20 Free-Air pump is an ideal alternate ambient air source for supplied-air respirator users. The ADP20 Free-Air pump does NOT create Graded breathing air. The ADP20 is the best choice for users working in locations without an electrical power source (but compressed air is available). Alternatively, the ADP20 is also ideal for potentially explosive work environments that would require a costly, explosion-proof electrical motor. Expensive carbon monoxide alarms may not be required since the industrial compressor air is not directly used by the worker. The pump inlet filter must be located at a source that will supply a minimum of Grade D breathable air, at all times, which is transferred to the worker through the air driven compressor on the ADP 20. Industrial compressed air at a minimum volume of 85 cfm at 95 psig (2400 lpm at 6.6bar) is used to power the ADP 20 pump. The powerful ADP20 pump is not only versatile but allows the use of a Bullard personal air cooling device to provide additional worker comfort and productivity. The pump provides 24 cfm of air operating at 5 psig (680 lpm at 0.35bar). Maximum pressure output is 20 psig (1.4 bar). Used without a personal air cooling device, the ADP20 pump can supply a continuous flow of air for up to three (3) workers wearing supplied-air full face mask type respirators or up to two (2) workers wearing supplied-air hood or helmet style respirators. For enhanced worker comfort, the ADP20 can supply air to one worker using the Bullard Trinitron 2000 Series personal air cooling device in conjunction with a Bullard hood or helmet series respirator. The Trinitron can lower the temperature of the air supplied to the respirator hood by as much as 20 deg F (11°C) resulting in a more comfortable and productive worker.