The wide range is presented at the modern market of radiators of heating to the buyer today: pig-iron radiators, steel, bimetallic, aluminum devices. When choosing radiator the large role is played by the cost and exterior, however key factor are technical characteristics of the device.
Not all radiators are suitable for mounting in the operating communications of long-distance heating. Calculated temperature of the heat carrier in one-pipe system is 105 wasps, pressure is supported at the level of 10 atmospheres, sometimes above. Besides in heating services the hydraulic shocks arising at start-up of pumping equipment and because of poor quality of water are possible. The majority of modern models of radiators place great demands on the heat carrier. In opening systems of heating they, unfortunately, are not provided. Therefore it is necessary to select heating appliance according to system parameters.
Section pig-iron radiators of heating – traditional devices for our country. Their main advantage before the others is the lack of sensitivity to depletions of system. It means that it is possible to drain water from system as much as often, and such radiators will be suitable for use in opening systems. Cast iron has high heat conductivity. Besides, it is corrosion resistant and practically does not give in to destructive influence of the firm particles which are found in the heat carrier.
Lack of pig-iron radiators is the big thermal lag effect at which the response to closing or opening of thermostatic valve will be slow (pig-iron radiators slowly heat up and long cool down). Also cast iron – fragile material, and the radiators executed from it are afraid of hydraulic shocks. Speaking about resistance of cast iron to stable influences, it should be noted that the majority of radiators of this material are suitable for work under pressure of 9-12 atmospheres and the maximum temperature of the heat carrier of 110 wasps.
Aluminum – the strong, hygienic and light material allowing to create reliable radiators. This material, unlike cast iron, combines low thermal inertia with good heat conductivity. Working pressure of aluminum radiators depending on the chosen model varies from 6 to 20 atmospheres. Aluminum radiators make on two technologies: extrusion (pressing) and casting under pressure. Extrusion radiators receive by breakdown of aluminum weight through different calibers. At the same time use aluminum of high purity. The radiators made in such a way are recommended to be mounted in systems where as the heat carrier instead of water there is nonfreezing liquid. It is connected with high requirements of radiators to quality of the heat carrier. Cast batteries make by casting of aluminum in form under pressure. So-called alpax – aluminum alloy with silicon is applied at the same time.
In aluminum radiators hydrogen in use begins to be allocated and accumulate therefore such devices need to be supplied with the air bleeder.
As aluminum is chemically active metal, the radiators made of it are sensitive to the chemical composition of the heat carrier. Its acidity has to be in pH 7-8 limits. Taking into account such features the aluminum products are recommended to be established in houses where the level of acidity of water is under control or with guarantee does not change.
In order to avoid direct contact of chemically active aluminum with steel when embedding radiators in heating services it is recommended to use bronze, brass or pig-iron adapters.
In such radiators the best properties of tube steel and section aluminum radiators are combined. Each section consists of the steel tube which is filled in with aluminum alloy. At temperature differences and improvements of corrosive firmness of radiator are applied to increase in reliability the alloying additives. Bimetallic radiators are durable and strong, maintain pressure to 50 atmospheres. That aluminum did not contact to the heat carrier, in these heating appliances the steel core is established. Thanks to it radiators impose low requirements to the pH parameter and quality of the heat carrier. Thanks to the technical characteristics and construction features the bimetallic radiators have well proved in the market of the heating equipment, they are suitable for installation in structures of any number of storeys.