RA-N angle valve with lateral connection. Video principle of operation of thermostats Radiator thermostat ra g
Modern heating appliances manufactured by the Danish company Danfoss. RA-G interacts with everyone thermostatic elements RA group installed in modern heating appliances.
general information
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 technical operation power stations and heating networks of the Russian Federation”.
The buyer must 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.
Protective caps included 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
Nomenclature of commodity items
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 design
| 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.
Application in a one-pipe heating system
As a rule, the series of devices presented in this article is designed for installation in single pipe systems building heating. Due to the small temperature difference in radiator batteries 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.
Some installation features
When buying and installing RA-G, the buyer should consider several important points:
- In a single-pipe heating system with thermostats, there must be a closing section between the return and supply pipes to the battery. Its diameter is recommended to be taken 1 standard size below the diameter of the eyeliners.
- The diameter of the valve should be selected according to the diameter of the connections. By observing points 1 and 2, the buyer will be able to create a heat conductor flow through heater only 25-30 percent of the flow in the riser.
- In the event that the diameters of the liner and section are the same, then it is recommended to use, production trademark Danfoss, to ensure the coefficient of coolant flow into the device.
- To reduce the residual heat transfer of the radiator when fully closed valve thermostat, it is advised to install a reverse flow throttle RTD-CB on the return line between the site and the device.
Instrument design
The RA-G valve consists of the following parts:
- valve disc
- sealing ring
- stuffing box
- pin
- valve seat
- spring
- union nut
- connecting nipple
- frame
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 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 heating networks Russian Federation. It is recommended not to use a heat transfer fluid containing mineral oil.
At the end of the last century, the model range of radiator valves of the well-known Danfoss brand was replenished with the RTD-G version, adapted to Russian one-pipe heating systems. The result of summarizing the most successful options for 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 a built-in gas-filled temperature sensor and a direct thermostatic valve RA-G20.
Thermoregulator valves RA-G: main technical and operational characteristics.
The entire range of RA-G thermostatic valves has a nickel-plated body and internal thread. Manufacturers offer models in straight and angular versions with a nominal diameter of 15 to 25 mm. Valves of the RA-G series are designed for single-pipe pumping heating systems with top/bottom filling. They can also be used in two-pipe gravity heating systems. They are compatible with any thermocouples of the RA series.Thermostat valves RA-G are characterized by increased capacity. Control range temperature regime ranges from 0°C to 26°C. It is possible to completely shut off the coolant supply.
They are characterized by high strength, which maximum temperature 120 °C allows you to withstand operating pressure 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 their gray caps, which only perform protective function and are not intended to restrict the movement of the coolant.
Thermostat valve arrangement RA-G.
The latest designs of RA-G thermostatic valves consist of the following components:1. nickel-plated body
2. oil seal
3. O-ring
4. plates
5. saddles
6. Chrome steel push pin
7. return spring
8. stem
9. union nut
10. connecting nipple
Features of the choice of the thermostatic valve RA-G and its connection
When choosing a thermostatic valve of this series for one-pipe heating systems, you should pay attention to the presence of a closing section between the supply and return lines to the radiator. In this case, the diameter of the RA-G valve is selected according to the diameter of the liner, and the diameter of this section is one standard size smaller than the diameter of the liner.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.
What are the advantages of RA-G thermostatic valves?
A recognized advantage is that these are the only valves with such high flow rates. This was achieved by increasing the diameter of the seat, profiling the inner surface, which has an effect on increasing the coefficient of leakage into the radiator, as well as reducing the risk of valve clogging.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.
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.
The RA-N control valves are designed for use in two-pipe pumped water heating systems.
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;
The RA-N valves can be combined with all thermostatic elements of the RA and RAX series as well as with the 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 coolant meets the requirements of the Rules for the Technical Operation of Power Plants and Networks of the Russian Federation. Otherwise, please contact Danfoss. It is not recommended to use formulations containing petroleum products (mineral oils) to lubricate valve parts.
High-tech body
Silent operation
The low noise characteristics of the valve are especially important for the user. That's why Danfoss valves are equipped with a flow stabilizer special design, allowing to work absolutely silently even at the increased differences of pressure.
Least susceptibility to valve sticking
"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.
Valve that won't clog
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.
Easy Maintenance
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 this round hole, requires disassembly 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.
Easy setup
For settings Danfoss valves RA under performance radiator does not require special tools.
It is enough to lift and turn the setting ring. The settings of the tuning ring are marked with numbers from 1 to 7, completely open position marked with the letter N. So the setting is easy not only to carry out, but also to check.
Fine tuning
The RA valve setting ring has 14 precise fixed capacity positions. Many other manufacturers offer no more than 6 drills/holes and therefore only 6 possible values bandwidth.
Stuffing box replacement under pressure
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.
