Final answer:
Air line breathing equipment respirators vary across different fields such as firefighting, medicine, and recreational diving, including lightweight breathing systems for firefighters, positive pressure respirators for medical patients with breathing difficulties, and self-contained underwater breathing apparatuses (scuba) for divers.
Step-by-step explanation:
The question pertains to different types of air line breathing equipment respirators used in various settings. One notable example is the breathing apparatus developed with aerospace technology that is used by firefighters. This apparatus includes a lightweight system composed of a face mask, frame, harness, and an air bottle made from an aluminum composite, aimed at protection from smoke inhalation injury.
In the medical field, positive pressure respirators are used to aid patients in breathing. For example, a Continuous Positive Airway Pressure (CPAP) device helps sleep apnea patients by pumping air into their airways to keep them open. Another alternative is the Expatriatory Positive Air Pressure (EPAP) device, which also shows promise for treating sleep apnea. For extreme environments, like BSL-4 laboratories, suits with their own air supply and positive pressure are used to protect against hazardous biological agents.
In recreational diving, scuba divers use compressed air through a self-contained breathing apparatus to breathe underwater, typically involving cylinders containing compressed air and a regulator to control the flow of air.