Iron Lungs and Decompression Chambers: Examples of How Pressure Tanks Are Made and Tested

Air pressure is key in many industrial, medical, and manufacturing applications. Air pressure tanks are made for a variety of reasons, including to supply varied air pressure to the production of goods, to process liquids, to hold gases under pressure, and to regulate air and breathing for specific illnesses in humans. There are two examples of air pressure tanks in the medical field (one of which is no longer in use except in rare instances when there is no power and a person's life depends upon it). If you have ever wondered how iron lungs and decompression chambers are made and tested for human use, the following information should answer your questions.

Decompression/Hyperbaric Chambers

Most of these chambers are composed of large steel cylinders and resemble the pressure tanks used for industrial and manufacturing purposes. Some of the hyperbaric chambers used in hospitals have a clear glass tube that encases a single patient and allows doctors and nurses to monitor the progress of the patient without the detrimental effects of opening and closing the chamber to check on the patient. The steel tank versions have several pressure dials and controls on the outside and a portal window into which doctors can peer and talk to the patient.

A decompression chamber or hyperbaric chamber is tested before it ever leaves the factory. Pressure-sensitive materials with an attached meter are placed inside a chamber and then the pressure inside the chamber is turned down and turned up to see if the chamber is effectively holding and containing the expected pressure levels. Faulty chambers are scrapped because they could spell death to a patient.

Iron Lungs

Although "iron lungs" are no longer in use, they too, were made of a large steel tank. The difference here is that iron lungs were "negative pressure" tanks, forcing the air into the patient's lungs before releasing and allowing the air to escape from a patient's lungs. It mimics a person's natural breathing rhythms and was used for patients who could not breathe on their own. The only part of the patient that most doctors could see in many of these tanks was the patient's head, since it had to remain outside the tank to artificially inhale and exhale and expel CO2 outside the tank where it could not build up and potentially poison the patient.

Iron lungs were often tested using an actual patient, since anyone who could breathe on his or her own could disrupt the body's natural ability to breathe. Manufacturers relied heavily on what the machine's pressure dials told them rather than using any other type of pressure measurement device. Thankfully, the machines' gauges were quite accurate.

To learn more about pressure tanks, contact a fabricator like BWS Fabrication Inc.


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