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The RA-N control valve is designed for use in two-pipe pumping systems water heating.
RA-N is equipped with a built-in device for preliminary (mounting) adjustment of its throughput within the following range: K = 0.04–0.73 m3/h - for valves DN=15 mm;
RA-N valves can be combined with all thermostatic elements series RA and RAX, as well as with thermoelectric actuator TWA-A.
To identify RA-N valves, their protective caps are colored red. The protective cap must not be used to block the flow of heat transfer fluid through the heater. To do this, use the handle (code no. 013G3300).
Valve bodies are made of nickel plated pure brass
The technical characteristics of RA-NCX valves in combination with thermostatic elements of the RA and RAX series comply with European standards EN 215-1 and Russian GOST 30815-2002, and the size of the connecting thread - with HD 1215 (BS 6284 1984).
All Danfoss radiator thermostats are manufactured in ISO 9000 (BS 5750) certified factories.
To prevent deposits and corrosion, RA-NCX thermostatic valves should be used in water heating systems where the heat carrier meets the requirements of the Rules technical operation power stations and networks Russian Federation. Otherwise, please contact Danfoss. It is not recommended to use formulations containing petroleum products (mineral oils) to lubricate valve parts.
The low noise characteristics of the valve are especially important for the user. That's why Danfoss valves are equipped with a specially designed flow stabilizer, which makes it possible to operate absolutely silent even at high pressure drops.
"Sticking" - sticking of the valve cone to the seat due to prolonged contact when the valve is closed. For liquid-filled bellows, the closing force is extremely high. When using Danfoss thermostats with gas filling, there is practically no increase in closing force with increasing temperature, since in this case all gas condensate evaporates. This, and the careful selection of valve cone and seat materials made of a special glass-plastic alloy, minimizes sticking.
Danfoss RA valves are optimized to work with gas-filled thermostatic elements and therefore have a stroke increased by 1.5 times from 0.46 mm (for liquid thermocouples) to 0.74 mm.
More stem travel and larger valve bores reduce the likelihood of valve clogging.
In Danfoss RA valves, the capacity setting window is single, with a gradually increasing cross section.
In valves of other manufacturers, the setting window is a set of round holes of different sections. If dirt clogs such a round hole, disassembly is required to clean the valve. Whereas for a Danfoss valve in such a situation, it is enough to turn the setting ring - without disassembling the valve and without using any tool.
For settings Danfoss valves RA under performance radiator does not require special tools.
It is enough to lift and turn the setting ring. The positions of the tuning ring are marked with numbers from 1 to 7, the fully open position is marked with the letter N. So the setting is easy not only to carry out, but also to check.
The RA valve setting ring has 14 precise fixed capacity positions. Many other manufacturers offer a maximum of 6 drills/holes and therefore only 6 possible throughputs.
When replacing the stuffing box, there is no need to turn off the valve and empty the system - the replacement can be done under pressure.
At the end of the last century the lineup radiator valves famous brand Danfoss has replenished with the RTD-G version, adapted to Russian one-pipe heating systems. The result of summarizing the most good options its application was a new modification of the RA-G thermostatic valve, which today the company offers for use all over the world.
An example of a permanent renewal of valves in this series was the appearance on the market since May 2011 of an updated set of equipment for thermal control in a blister pack. It consists of a thermal head type RA2940 with an integrated gas-filled temperature sensor and a direct thermostatic valve RA-G20.
Thermostat valves RA-G are characterized by increased capacity. Temperature control range is from 0°С to 26°С. It is possible to completely shut off the coolant supply.
They differ high strength, which at maximum temperature 120 °C allows to withstand a working pressure of 16 bar. And this means that even with unstable operation of heat supply systems, an exception is guaranteed to create an accident situation.
RA-G valves can be identified by caps gray color, which perform only a protective function and are not intended to limit the movement of the coolant.
In conditions of the same diameter of the connections and the closing section, it is advisable to use a bypass choke type RTD-BR. And when the valve is completely closed, in order to reduce the residual heat transfer of the radiator, it is recommended to install a reverse flow throttle RTD-CB on the return line between it and the closing section. The implementation of these recommendations will ensure that the difference between the coolant flow through the radiator and in the riser is at least 30%.
Connection to pipelines is carried out through a coupling, and to heating devices - using threaded shanks with a union nut.
The indisputable advantage of RA-G valves is the use of modern high-quality technologies for the manufacture of all control components, as well as the use of special materials that eliminate the threat of mechanical wear and corrosion damage
Along with this, they have unique operational capabilities to replace the valve box, seat, cone of the structure on site without stopping the operation of the heating system.
All this makes the RA-G thermostatic valves leaders in providing the most high level energy efficiency among analogues existing in the world market of heat engineering.
Modern heating appliances manufactured by the Danish company Danfoss. RA-G interacts with all thermostatic elements of the RA group installed in modern heating appliances.
The main feature of the device presented in this article is its increased throughput. Its scope is single-pipe water heating systems at home with pump circulation of the heat conductor. The latter must meet the requirements of the "Rules for the technical operation of power plants and thermal networks of the Russian Federation."
The purchaser should be aware that this device should not be used in systems where the heat conductor contains mineral oil impurities.
An important advantage of the device is its oil seal (commodity code - 013G0290), which can be easily replaced from the home heating system at any time. The pressure pin of the stuffing box is made of chrome-plated steel, so that it can not be lubricated throughout the entire life of the device.
The device is supplied with protective caps in gray color. The user should remember that they should never be used to block the flow of a heat carrier. For this purpose, the device has a special locking handle (commodity code - 013G3300).
Video: Radiator Danfoss thermostats RA
Today, Danfoss products are profitable to order via the Internet. Prices in the network are much lower than in the market or in specialized stores. To place an order via the Internet, you need to know the product code. Below we provide a table with codes and some technical parameters products featured in this article.
Code numbers and specifications for RA-G corner vertical version
Device type | Bandwidth | code number | ||||
---|---|---|---|---|---|---|
with thermocouple | without thermocouple | |||||
RA-G 15 | 0.54 | 1.07 | 1.61 | 2.06 | 4.3 | 013G1676 |
RA-G 20 | 0.57 | 1.11 | 1.16 | 2.2 | 5.01 | 013G1678 |
RA-G 25 | 0.59 | 1.27 | 1.77 | 2.41 | 5.5 | 013G1680 |
Code numbers and technical data for RA-G for direct execution
Device type | Bandwidth | code number | ||||
---|---|---|---|---|---|---|
with thermocouple | without thermocouple | |||||
RA-G 15 | 0.51 | 0.94 | 1.35 | 1.63 | 2.3 | 013G1675 |
RA-G 20 | 0.54 | 1.07 | 1.61 | 2.06 | 3.81 | 013G1677 |
RA-G 25 | 0.57 | 1.16 | 1.71 | 2.27 | 4.58 | 013G1679 |
The limiting pressure drop across the valve, at which it is capable, for models 013G1676, 013G1675, 013G1678, 013G1677 is 0.2 bar. For models 013G1680 and 013G1679 - 0.16 bar.
The maximum temperature of the coolant, for normal operation of the valve, should not exceed 120 °C.
As a rule, the series of devices presented in this article is intended for installation in single-pipe building heating systems. Due to the small temperature difference in the radiator batteries of such systems, the range of heat transfer control is negligible here.
Changing the flow through the radiator does not affect its heat transfer. Reducing the flow through the radiator by up to 30 percent in relation to the calculated value leads to a decrease in heat transfer by only 10%. Such a decrease will not cause a decrease in the indoor climate, since the heaters have a supply of heat-releasing surface.
When buying and installing RA-G, the buyer should consider several important points:
The RA-G valve consists of the following parts:
The parts that form the basis of the device are made of stainless materials, which allows the device to perfectly resist corrosion and increase its service life.
Thermoregulatory valves with increased throughput type RA-G are mainly used in one-pipe systems. All RA-G valves are compatible with all thermostatic sensors RA series.
RA-G valves are equipped with a gray protective cap. The cap must not be used to cover the controlled medium. For this purpose, a special metal handle (code no. 013G3300) should be used. The pressure pin in the gland is made of chrome steel and does not require lubrication during the life of the valve. The entire gland assembly can be replaced without emptying the system. To prevent deposits and corrosion, RA-G type valves should be used in water heating systems where the coolant meets the requirements of the Rules for the Technical Operation of Power Plants and Heat Networks of the Russian Federation. It is recommended not to use a heat transfer fluid containing mineral oil.
Thermoregulatory valves with increased throughput type RA-G are mainly used in one-pipe systems. All RA-G valves are compatible with all thermostatic sensors of the RA series.
RA-G valves are equipped with a gray protective cap. The cap must not be used to cover the controlled medium. For this purpose, a special metal handle (code no. 013G3300) should be used. The pressure pin in the gland is made of chrome steel and does not require lubrication during the life of the valve. The entire gland assembly can be replaced without emptying the system. To prevent deposits and corrosion, RA-G type valves should be used in water heating systems where the coolant meets the requirements of the Rules for the Technical Operation of Power Plants and Heat Networks of the Russian Federation. It is recommended not to use a heat transfer fluid containing mineral oil.