Control valve functions
Control valves are used in the piping of the heating system
According to the generally accepted classification, a control valve for heating refers to the elements of shut-off valves included in the piping of the system. Its main purpose is to open and close the channel for the coolant to pass directly through the batteries. Modern requirements for the arrangement of the piping prescribe the mandatory equipping of heating systems with locking elements of various types.
Their presence makes it possible to shut off the movement of the coolant in an accident and perform troubleshooting operations without removing the liquid from the pipes. In addition, by limiting the volume of the circulating medium, it is possible to maintain a comfortable temperature distribution in a private house or apartment.
Regardless of the type of heating system, the ability to control heat flows allows you to reduce fluid consumption and balance the pressure distribution in it. In addition, adjusting elements are used in special devices responsible for maintaining a fixed temperature level.
Types of control valves and their parameters
The types of special valves for controlling the supply of heat to the radiator include:
- regulators made in the form of valve mechanisms with thermal heads, setting a fixed temperature;
- ball valves;
- special balancing valves, manually operated and installed in private houses - with their help it is possible to evenly heat the interior of the house;
- bleed air valves - Mayevsky's manual mechanisms and more advanced automatic air vents.
Ball
With thermal head
Mayevsky crane
Balancing
The list is supplemented by sample valve regulators used for flushing batteries and draining water. The same class also includes a check valve, which prevents the movement of the coolant in the opposite direction in networks with forced circulation.
The indicators characterizing the operation of any type of shut-off valves include:
- standard sizes of devices by which they are matched to specific types of radiators;
- pressure maintained in operating modes;
- limiting temperature of the carrier;
- product throughput.
For the correct choice of a shut-off valve, it will be necessary to take into account all parameters in aggregate.
The principle of operation of the differential pressure regulator
Currently, membrane-type regulators are mainly used. Inside such a device is a chamber with a centrally installed diaphragm, which is connected to the valve plug. Due to its displacement to either side, the position of the shutter changes, as a result of which the amount of water masses flowing through the regulator decreases or increases. The impact on the membrane is carried out by means of two impulse lines, through which signals coming from the supply pipe and "return" are received. The spring reactive to different pressure values is compressed, thus acting on the diaphragm in a certain position.
Danfoss ASV-PV, DN25.
The principle of operation of heating taps
The use of shut-off valves in the heating system
It is more convenient to consider the principle of operation of the crane using the example of a ball valve. To control it, it is enough to turn the lamb by hand. The essence of such a mechanism is as follows:
- When the crane handle is mechanically turned, the impulse is transmitted to the shut-off element, made in the form of a ball with a hole in the middle.
- Due to the smooth rotation, an obstacle appears or disappears in the path of the fluid flow.
- It either completely blocks the existing passage, or opens it for the free passage of the coolant.
It is not possible to regulate the volumes of liquid entering the batteries using a ball valve.
A valve that allows you to do this is noticeably different in its principle of operation from a spherical analogue. Its internal structure allows it to smoothly close the passage opening in a few turns. Immediately after changing the balancing, the valve position is fixed so as not to accidentally violate the device settings. As a rule, such taps are installed on the radiator outlet pipe.
The assortment of valve products includes samples with extended functionality, which allow for additional possibilities for regulating the coolant flow.
Installation and adjustment of valves
A balancing valve is installed to regulate the coolant flows on the way to the boiler
When installing non-adjustable ball valves, simple schemes are used that allow them to be freely placed on polypropylene outlets from the riser even before they enter the batteries. Due to the simplicity of the design, the installation of these products is possible on our own. Such shut-off valves do not need additional adjustment.
It is much more difficult to mount valve devices at the outlet of heating batteries, where flow volume adjustment is required. Instead of a ball valve, in this case, a control valve is installed for heating, the installation of which will require the help of specialists. You can do this on your own only after carefully studying the installation instructions.
Depending on the layout of the devices and the distribution of heating pipes, it is possible to select a special angular valve suitable for radiators with a decorative coating. When choosing a product, attention is paid to the value of the limiting pressure, usually indicated on the body or in the product passport. With a small error, it should correspond to the pressure developed in the heating network of a multi-storey residential building.
It is advisable to adhere to the following recommendations:
- For installation on radiators, you should select high-quality taps made of thick-walled brass, forming a connection with a union nut - American. Its presence will allow, if necessary, to quickly disconnect the emergency line without unnecessary rotational operations.
- On a single-pipe riser, a bypass will need to be installed, installed with a slight offset from the main pipe.
The issue of installing a balancing type valve, which requires special adjusting operations, is even more difficult to solve. In this situation, you cannot do without the help of specialists.
Selection options
With the help of a tap, the consumer can regulate the water flow. By reducing it, the owner lowers the temperature in the room and vice versa. If little heat energy is supplied, then no valve is able to increase its amount.
The taps differ in the mechanism for regulating the flow of water in the radiators. The consumer chooses the option that seems to him the most convenient.
Manufacturers use a variety of materials, from the most durable to the most corrosive. If the buyer is determined that the cranes will last more than one year, it is worth purchasing products made of durable metal.
Views
By the type of regulation, there are:
- mechanical cone models;
- semiautomatic devices;
- automatic machines.
Mechanical conical
Mechanical models.
Owners of such models cannot set the desired number of degrees. There is no temperature scale. This is the easiest and cheapest option.
The thermal sensor is a siphon into which gas is injected or liquid is poured:
- gas options react faster to temperature changes;
- variants with a liquid act more precisely on the coolant.
Adjustment is made by turning the knob. Expanding from heating, the contents of the siphon, having reached a predetermined value, does not allow the coolant to penetrate into the radiator. After manual adjustment, water supply and interruption of water supply occurs automatically.
Note: you need to be prepared for the fact that the rubber gasket is subject to wear.
Semiautomatic device
Semi-automatic model.
The desired parameters are set manually. The thermosensitive element causes the stem to change position if the thermal fluid has reached the specified temperature.
The main difference from mechanical models is the presence of designations indicating how many degrees are in the room, and the level set to the thermostat. The presence of these designations does not affect the regulation process itself, but it is easier to control the operation of the system with them.
Machine
With automatic control valves, you can adjust the response of the equipment to the temperature of the air in the room or the heat carrier in the radiator. The temperature sensor signals the controller, the servos move the stem.
Note: the system can be configured and monitored remotely.
Thermostats are also sold with a valve locking mechanism. Another option is a valve with a cone. Such models guarantee smooth adjustment.
The ability to place thermocouples outside the case increases the accuracy of temperature measurement, because they are not affected by the proximity of the radiator and convection flows.
Straight and angular devices are distinguished by shape. The choice depends on the type of radiators, pipe routing scheme.
Materials (edit)
Brass model.
Control valves for the heating system "work" in difficult conditions:
- exposure to hot water;
- powerful hydraulic shocks.
What material can withstand such an aggressive environment? For systems made of steel and metal-plastic pipes, experts definitely give first place to brass. She is not afraid of corrosion. To make the device more durable, it is additionally covered with a metal protective shell. But here, too, not everything is so simple.
Sellers are too tempted to sell silumin products instead of high-quality brass valves. It is almost impossible to visually distinguish them.
Attention! Counterfeiting is dangerous! In a year, rust and corrosion will thoroughly spoil the body, and the very first water hammer will blow the thinned product to pieces.
Another consequence of buying a fake: after a short operation, the crane will fall off the base. Hot water burns in this case cannot be avoided.
The characteristics of steel and bronze are excellent for making cranes, but the cost of such products will be higher.
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The owners of polypropylene cranes are satisfied with the purchase. Their main trump cards:
- flexibility;
- ease;
- simple connection;
- Ease of use;
- long term of work.
Heating system type
How to choose a control valve for heating? The heating system prompts the solution.
Central system: the quality of the coolant leaves much to be desired, steel and brass ball products can withstand an aggressive environment. Adjustment models become clogged and fail quickly.
Autonomous system: products with thermal heads cope with the energy saving in an autonomous heating system. Factors that reduce efficiency: direct sunlight, furniture in the immediate vicinity.
Tip: when going shopping, do not forget to arm yourself with the parameters of the heating system.For example, if the working pressure of the valve does not correspond to the figures recorded in the project documentation, it will not be possible to save on heating.
Price range
Danfoss is a popular crane manufacturer.
You can contrive and find a part worth a couple of hundred rubles, and, for example, a Danfoss control valve for heating will cost a couple of thousand rubles. The first ones will not last long, for obvious reasons. In order not to run to the store soon and not to eliminate the consequences of the accident, it is better to immediately pay attention to more serious options. Danfoss, Itap brands offer elite products.
Somewhere in the middle between these extremes, there are many models that are suitable in terms of price-quality ratio for each specific heating system and its operating conditions. Quite good reviews about Chinese and Turkish products.
Do not forget when choosing control valves for heating radiators: price is not always a guarantee of quality. But the deliberately low cost suggests that repairs due to a crane that broke down at the most inopportune moment is a much more expensive thing than buying high-quality shut-off and control valves.
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