In the heating system of any house there is a certain amount of coolant. From the course of physics, since school, everyone knows that when heated, liquids increase in volume, expanding at the same time. This additional volume must be placed somewhere, otherwise the system will be somewhat reminiscent of a pipe bomb. In order to avoid the danger of an explosion, a special expansion tank is used, into which the resulting excess liquid enters.
The size of a suitable expansion tank should be selected individually in each individual case. It will depend on the total amount of coolant in a particular system.
In modern double-circuit boilers, such a capacity is built into the body. It is not immediately noticed by the owners, because it is hidden under a metal case. The volume of the expansion tank for such boilers reaches an average of 12 liters. The producers themselvesknow the approximate size of the room for which the device is designed, so they install their own expansion tank. It has a certain margin of space for an increasing volume of liquid. The expansion tank for heating, built into the wall-mounted boiler, can be increased or replaced with a larger, more capacious model.
Types of appliances
1. Previously, the most common model was an expansion tank of an open-type heating system. Its principle of operation is similar to the action of a pan with a lid or a container with a welded pipe. Excess water flows through it in case of heating, and then, when the coolant cools down, for example, when the boiler is turned off, it goes back into the system. Often in open-type tanks, an overflow is built in - another pipe at the top. Through it, excess coolant is removed (usually into the sewer). Often, owners do without an expansion tank at all, installing an “overflow” at the highest point of the system. At the same time, it is necessary to ensure that a sufficient supply of water remains in the pipes. The disadvantage of this model is the corrosion of the tank and the large evaporation of the coolant upon contact with air. The advantage of this type of tanks is the simplicity of design and low cost of installation.
2. Modern models are equipped with closed tanks. Such an expansion tank for heating consists of two cavities. One of them is designed to circulate the coolant, the second contains air or nitrogen. The cavities are separated by a special membrane, whichstretches with a decrease or increase in the volume of the coolant. At the same time, the pressure in the entire system remains practically unchanged. Such an expansion tank has certain advantages - the coolant does not evaporate, it is not necessary to put such a tank at the highest point of the system. The disadvantages of this design are the high price and large volume, because half a tank is occupied by a gas container.
To calculate the required optimal volume of the expansion tank, multiply the volume of the coolant by 0.08. So, for a system of 100 liters of coolant, you will need an expansion tank for heating of at least 8 liters.
