How Do Steam Boilers Work?

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Ever wonder how hospitals keep surgical equipment sanitary? While it is true that single-use items are common in every operating room, the most common tools are typically made of stainless steel and are sanitized in steam boilers called autoclaves. Autoclaves are also in use in some body-mod shops to handle reusable items like tattoo machines and piercing needles.

How Do Steam Boilers Work?
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How to Sterilize Equipment

To sterilize equipment, the temperature must get to or exceed 270 degrees Fahrenheit (around 132°C). While many heat sources could go up to that temperature, steam is the most common source of sterilization in use within hospitals today. The pressurized autoclave removes all of the air and allows only the steam to permeate the chamber.

The primary reason that steam is used in a pressurized system like an autoclave is that steam causes humidity. This humidity from the water vapors can penetrate microorganisms and kill them much more effectively than other sterilizing methods.

How Does a Boiler Work?

The way that a steam boiler works is a straightforward process that aligns with the natural heating, cooling and condensation process. In most cases, raw water is fed into the boiler from a pipe system. That water is then purified to clean it of any debris.

Next, the water is fed into a de-aerator that removes air. To better understand that concept, think of an aerator that can be used with wine. Aerators add air to a liquid, while the de-aerators pull that air out.

From there, the water is fed into the boiler tank and is heated. Particles and other waste get filtered out by way of piping called the blowdown. Clean steam is captured by a series of pipes and cools to become condensate. That condensate flows back into the de-aerator to be reused in the boiler.

How to Operate a Steam Boiler

Operation of a steam boiler is dependent on the purpose and the manufacturer of that boiler. Before you run any steam boiler system, be sure to read all literature and become comfortable with the workings of the device.

From an operator standpoint, most boilers are simple to use. For an end user, it can be as simple as adding water and hitting a button for smaller, tabletop units. For more complex boilers, such as the ones that provide steam for sterilizers, a program may need to be selected to run certain types of equipment or material through.

Benefits of Steam Heat

There are many benefits to steam heat over other heating methods. First, steam is able to be recycled easily within the boiler itself, meaning that as you run your boiler, it will supplement the water supply from the steam that is collected from the main boiler. Steam also burns very cleanly and will not add extra fumes or chemicals to the air.

Steam boilers are also an excellent way to sanitize water for cooking or drinking. Between the filtering system that feeds water into the boiler and the extra purification that comes from the process of evaporation and condensation, water that has been fully processed through a boiler will be safe for cooking, drinking and bathing.

Steam Boilers for Home Use

Because steam is an extremely cost-effective form of heating, some homes are making a switch from gas or electric heat to steam. Many heated floors, for example, use steam instead of gas due to the risk of fire from an electrical short or gas ignition.

In floors, for example, boiler heaters below the floor heat water that is passed through pipes that line the underside of your floor materials. When that water cools down, it passes back through the boiler in the same way that an autoclave would.


Danielle Smyth is a writer and content marketer from upstate New York. She holds a Master of Science in Publishing from Pace University. She owns her own content marketing agency, Wordsmyth Creative Content Marketing (, and she enjoys writing home and DIY articles and blogs for clients in a variety of related industries. She also runs her own lifestyle blog, Sweet Frivolity (

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