Determining Length of Autoclave Cycles

As you may already know, autoclaves use heat, water, steam, and pressure to sterilize instruments and materials. And while autoclaves may vary in size and shape, how they sterilize is pretty much the same in any autoclave. An autoclave has different cycles, just like a washing machine has different cycles, and today in our blog, we are going to talk about the length of an autoclave cycle and how that is determined. 

While the principle of how autoclaves work may sound simple, autoclaves are sophisticated machines. And different autoclaves have different cycles. 

For example, a gravity cycle removes air by gravity. As steam is introduced, the steam rises to the top because it is less dense. Air drops to the bottom (from gravity) and is removed as steam fills the container. 

Another autoclave might have a vacuum cycle, in which air is removed by vacuuming it out of the receptacle while steam is injected in. We mention these two cycles simply to show that not all cycles are the same for each autoclave. Air is typically removed faster in a vacuum cycle than a gravity cycle. 

The length of any autoclave cycle is determined by the size of the autoclave, what the autoclave is sterilizing or its contents, temperature, and what the cycle is supposed to be doing. 

To give a few examples, consider this. A giant autoclave that is as big as a room—the type commonly found in hospitals—is going to have a much longer gravity cycle than a countertop autoclave just because there is more air to expel, so it takes longer. 

Using some kind of quick cooling cycle is going to take longer than not using one. A quick cooling cycle might be used if instruments are needed to be used right away after being autoclaved. 

If you are autoclaving liquids, these cycles take longer than autoclaving solids because steam has to be released very slowly so the liquids do not boil over. 

Most autoclaves also have very short “test” cycles, to make sure the autoclave is working optimally. 

Lastly, autoclaves sterilize more quickly at higher temperatures than at lower temperatures. So, a lower temperature cycle will run longer than a higher temperature one if all other things are equal. 

So, to answer the question in the title of this article, determining autoclave cycle length in time is complicated and depends on multiple variables. There is no one answer that would be true for all autoclaves in all situations. 

If you need help choosing, repairing, maintaining, installing, operating, or validating an autoclave, this is our business and area of expertise for many years. Give us a call, in western Canada at (888) 818-4847. We can help with every aspect of autoclaves including choosing the right one for you. 

Alpha Scientific supplies, installs, and services medical equipment in western Canada. If you have any questions about this article or would like to talk to us about medical equipment, please call our toll-free number, (888) 818-4847, or email us at sales@alphascientific.ca.