Expansion tank

SPECIFICATION

In hot-water heating systems, when the water is being heated from 10 °C to 90 °C its volume expands by %3.55 of its initial volume. In order to absorb this expansion caused by the heat we use expansion tanks. Along with the safety of the system expansion tanks also fulfill the task to prevent pressure increase and provision of necessary water support to the system.

The volume of the expansion vessel to be used in heating system is determined by calculating the volume of the water that is going to expand. The required volume can also be determined through the catalog values provided by the boiler manufacturers.

ADVANTAGES OF CLOSED EXPANSION TANKS

1- Since the heating system will turn into a closed system there will be no contact with air and corrosion will be reduced.

2- Since there is no water loss in closed heating systems due to water evaporation and therefore heat loss will be reduced. Additionally there will be no water loss and this means there will be no water in the system and thus no new calcification. For this reason there will be no heating problems due to calcification and as a result less fuel costs.

3- In a closed system the pressure distribution will be equal and thus the heating of each radiator will be more equal as well.

4- In the closed system water will be heated under pressure and this would increase the efficiency and gain additional fuel savings.

5-Since the vessel would be installed adjacent to the boiler you would save the pipe material leading to the roof, isolation material, space that would be required for the pipes and labor costs. The risk of frost would be avoided. Additionally you would gain roof space etc. and benefit from architectural aesthetics.

CALCULATION OF THE TANK’S PRESET PRESSURE

Please calculate the vertical height (static height) from the radiator on the top floor of the building and the level where the tank is.
Static height (m) / 10 = static pressure (bar)
For example; if the height difference between the radiator on the top floor and the vessel is 25 meters; the pre-set gas pressure on the tank would be calculated as follows;
Static pressure; P static = Static height[m] /10 25 / 10 = 2,5 bar
Pre-set pressure; Ppr = Pstatic + 0,2 bar 2,5 + 0,2 = 2,7 bar
System operating pressure; PF = P0 + 0,3 bar 2,7 + 0,3 = 3 bar.