Why do I need a safety valve for the water heater

Buying your first electric boiler -a landmark event. It can not be forgotten, if only because it is necessary to understand for the first time what is needed for the safety valve for the water heater, the power cord, and also how the entire system is connected and installed.
Subsequently, no questions, as a rule, arethere is, therefore, when replacing the boiler for a new reading, the accompanying instructions are often missed. Today we will talk about what is needed for the safety valve for the water heater and what will happen if you "forget" to install it.

The laws of physics

Every person from childhood knows that whenheating objects expand, increasing in volume. The value depends on the material of the object, the temperature and the environmental conditions - such are the laws of physics. And water is no exception. If there is an increase in volume in a hermetically sealed space, then it is quite possible to damage the borders mechanically - they will simply be torn. The safety valve for the water heater, which is necessarily included in the boiler installation kit, serves to protect the tank walls from damage.
If it is missing, then it is needed separatelypurchase and install. To understand the operation principle of the safety valve of the water heater, let's mentally collect the model of the tank and connect it to the system.

Experiment

The boiler is fed with two pipes: cold water supply and recoil already heated. While the cranes on the outgoing line are closed, the volume of the tank will be filled with cold water, which will begin to be heated by the TEN to the set temperature. It is necessary to open the faucet as a hot liquid rushes from the tank, squeezed out by the cold portions coming from the system. However, there are several points that do not allow the boiler to be operated with this switch-on. Firstly, since the whole mass of cold water (in the tank and the pipe) is not divided in any way, the heater will always work, trying to heat up the entire available volume. Secondly, if for some reason the water disappears in the feed pipe or the pressure drops significantly (it is not uncommon in domestic systems), the stored and heated liquid from the tank will flow back by gravity back to the supply pipeline. To prevent this from happening, a check valve is installed on the connection pipe. The spring-loaded plate passes water only in one direction, mechanically separating the two media - the simplest but incredibly effective solution. Why do I need a safety valve for the water heater? Complicating the problem mentally, adding to the design of a conventional check valve installed on the feed. In this case, the heating will take place without loss, and the disappearance of water in the supply line does not threaten.

But what happens if the heating value isis exposed not on 20-30 degrees, and on 60-80, as often happens? In accordance with the known law of physics, water will begin to expand, and since all the valves are closed, the internal pressure will increase. If the walls of the tank are of poor quality, they will be locally damaged (burst). And if the tank material is selected correctly, the following occurs: pressure and temperature increase, but no boiling of water occurs, since at high pressure the point is displaced. As a result, it turns out that water can be in the boiler with a temperature of over 100 degrees. But someone opens a water tap. The pressure drops sharply, the boiling point returns to the usual 100 degrees, there is an avalanche-like release of steam, which sharply increases pressure and the tank breaks. If you can avoid injuries, then this can be considered luck.

Safety valve for water heater "Ariston"

To prevent such accidents,safety valves. They are arranged in such a way that when a certain value of the internal pressure is exceeded, an automatic discharge of a part of the water (usually several milliliters) occurs. The scheme of these elements is the same, so there is no difference whether they are installed on the boiler "Ariston", "Termex" or others. Inside there are two spring-loaded plates: one of them serves as a simple check valve on the supply, and the other keeps the water in the tank until , until the pressure exceeds some boundary.