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How Does Compressed Air Breathing Apparatus Work?

Compressed air breathing apparatus typically consists of a compressed-air cylinder, a carrying system, a pressure reducer, a lung demand valve and a face mask. The pressure reducer lowers the cylinder pressure to the level required by the lung demand valve, which supplies breathing air on demand as you breathe. Because this air supply is independent of the surrounding atmosphere, approved configurations can be used in contaminated or oxygen-deficient atmospheres, and even where the contaminant is unknown, conditions where filtering devices must not be used at all.


Choosing the Right Configuration

Lightweight configurations suit tasks where low weight and easy handling matter most, while an ergonomically designed carrying system improves wearing comfort during longer assignments. The right configuration depends on your application, the required operating duration, the cylinder selected and your breathing rate. Every set includes a warning device that alerts you once cylinder pressure or the remaining air supply reaches a defined warning level. Some configurations can also include an automatic switch-over valve, which lets you switch between an external air supply and the cylinder itself, though this is not a substitute for the low-pressure warning system. For potentially explosive areas, only equipment with the appropriate approval for that environment may be used.


Why Hire Compressed Air Breathing Apparatus from Dräger

  • Reliable air supply: Built for demanding environments where a dependable, independent air supply is essential.
  • Ready when you need it: Depending on your hire package, maintenance, calibration and repair services can be included or added.
  • Flexible for every project: Hired for exactly the period your equipment is required, whether for a short industrial task or a longer assignment.
  • No long-term investment: The right equipment is selected to match the hazard, atmosphere, operating duration and applicable approvals, so you only pay for what you need.
  • Personal support: If you are unsure which configuration to choose or your requirements change at short notice, our team is on hand to help.


For a lighter alternative where the atmosphere allows it, take a look at our Powered Air-Purifying Respirators or browse the full Respiratory Protection range.

Person trägt Pressluftatmer-Atemschutzgerät und Schutzhelm in Industrielandschaft mit technischen Anlagen und einem blauen Gerät im Hintergrund
Eine Person trägt blauen Schutzanzug, weißen Helm und Pressluftatmer, bedient Ventil an Rohrleitung. Im Hintergrund weitere Person und technisches Gerät.


Duration depends on the cylinder capacity, filling pressure, your breathing rate and your workload. Depending on the configuration and cylinder size you choose, an SCBA typically offers a working duration of around 30 to 75 minutes, plus a reserve of air that must always be kept available for a safe retreat from the hazardous area. These figures are based on defined test conditions and should be used for planning purposes only, since strenuous work and a higher breathing rate will reduce the actual duration.
Some configurations carry ATEX approval and are also certified to EN 137, but approval always depends on the complete configuration, including the apparatus, mask, cylinder and accessories used together. Always check the ATEX marking of the specific configuration you hire and confirm it suits the hazardous area you are entering before use.
Additional cylinders can usually be arranged alongside your hired apparatus, so you are not limited to a single fill for longer or repeated tasks. The required cylinder type, its compatibility with your apparatus and the number of spare cylinders should be agreed with us before the equipment is dispatched.
In most cases, yes. Working with an SCBA in a hazardous area is normally carried out under a proper entry control and standby procedure, with someone monitoring the wearer, cylinder pressure and entry and exit times from outside the area. The exact set-up depends on your risk assessment, site procedures and any training requirements that apply to your task.
Compressed air breathing apparatus approved for entry and work is designed to protect you throughout a planned task in a hazardous atmosphere. An escape device, by contrast, is approved only to provide a limited-duration air supply, typically 10, 15 or 20 minutes, for leaving a hazardous area safely, and must not be used for entry or work unless the specific configuration is separately approved for that purpose.