Expansion Tanks image courtesy of Pope Scientific, Inc.
This past summer, my parents had their home’s water heating system replaced out of an attempt to adhere to our neighborhood’s inspiration to “live more green”, one house at a time. As someone who has never paid enough if any attention to the conglomeration of tanks and pipes and tubes that inhabited a good chunk of my parents’ semi-finished basement, I observed with a surprising amount of interest as the big, burly men heaved in the various components. In my feeble attempt to learn (as well as to flirt with a few of the more agreeable-looking workers), I managed to learn a couple of things here and there, one of which was a necessary piece of the puzzle called an expansion tank.
Expansion tanks are small pressure vessels that are used to maintain constant pressure in the the pipes of the water heating systems in residential and commercial buildings and can either being attached and hung from the piping or connected from above the system in a horizontal fashion. They are relatively easy to maintain and are very important towards insuring safety, as such systems have a knack for leaking and/or exploding when not properly observed.
Because expansion tanks often are responsible for holding drinking water, they are usually made from stainless steel, as it is a strong, durable metal known for its impressive sanitizing capabilities. In addition to stainless steel, they also usually include a rubber spacer that is position inside of the tanks; this is called a diaphragm. Furthermore, the walls of the inside of tank must be smooth, as this also contributes to the health standards set on most expansion tanks.
An expansion tank is designed to absorb the excess water pressure in a closed water heating system; because water expands when the temperature is increased, there needs to be enough room available for it to do so, which is where the expansion tank comes in. Water heating systems without expansion tanks run the risk of explosions and/or burst pipes from too much internal pressure.
