Where to install the expansion vessel on hydraulic plants

In this new video on our Tempo Youtube channel we talk about the expansion vessel, which can be found in every thermodynamic plant, thermoregulation unit, cooling or heating system and hydraulic plants, wherever there are fluids circulating.

As the word itself tells, the expansion tank is aimed at compensating the expansion of fluids that, when exposed to temperature variations, are also subjected to volume variations.

Let’s talk in particular about open expansion vessels, and thus meaning expansion vessels exposed to the atmosphere. Well, where the expansion vessel has to be installed? The expansion vessel always has to be installed at the highest point of the plant. That’s because, complying with the communicating vessels principle, all of the fluids within the pipings tend to settle at the same level.

Therefore, if the expansion tank is installed at a lower point compared to the pipings, there will be an overflowing of the fluid due to an excess of the capacity volume. It happens because the fluids circulating in the pipings at higher positions tend to settle at the same level of the spot opened and exposed to the atmosphere.

That’s why, in consequence, the expansion vessel must be installed at the top. On the piping side it will then possible to install some vent valves.


Stay updated on the latest applications of thermal energy management by subscribing our monthly Tempco Newsletter – Solid Temperature.