When you install a closed-type expansion tank, it should be based on?

The correct answer is based on the capacity of the boiler. When installing a closed-type expansion tank, it is essential to size it according to the boiler's capacity because the expansion tank must accommodate the expansion of water within the boiler system as it heats. As water is heated, it expands and requires sufficient space to prevent excessive pressure buildup within the system.

A correctly sized expansion tank ensures that it can absorb the additional volume of water without causing pressure issues that could lead to system failures. If the expansion tank is too small, it won't be able to handle the volume increase, which could lead to over-pressurization, potentially damaging components or causing leakages.

Other factors, such as the dimensions of the boiler room, the weight of the water in the system, and the length of the piping, do play a role in the overall system design and installation but are not the primary considerations for sizing the expansion tank. Instead, these factors might influence the placement or other logistical considerations, but the primary determinant for sizing the expansion tank remains the boiler's capacity.