In winter, very low temperatures can be observed. Even when the thermometer drops below 0º, the water in the pipes begins to freeze. If there are open sections of water supply, sewerage, which are not protected from freezing, the functioning of such important life support systems becomes impossible.
To ensure the normal operation of water communications that are located on the street or in unheated premises, special electrical wires are used. How pipes are heated will be discussed later.
Application area
Electric pipe heating allows you to maintain the optimum temperature inside, at which the water does not freeze. Today, various wires are used to create such a system. They can differ significantly externally, functionally. Depending on the type of wire, they can be wrapped around pipes or lead heating wire directly inside.
The presented systems are mounted on various pipelines. It can be household and industrial communications. not only outside buildings, but also inside basements, attics, and other unheated premises. Regardless of the location of communications, electric cables are used for heating. Pipes can lie in the thickness of the earth or pass on the surface.
In addition to heating the water supply, the presented systems are used to ensure the normal functioning of sewers, various tanks, drainage, and fire hydrants.
Functions
Produced through various types of systems. All of them perform identical functions. The cable, regardless of the type and method of installation, maintains the contents inside communications in a liquid state.
Also, the wire prevents the formation of ice plugs, preventing the contents from moving through the system. Water can move freely through the pipes. At the same time, its speed increases. Liquids that move inside the pipes do not form solid fractions. Condensation does not form on the surface of the pipes.
Not always the owners of a private house can be in their country cottage in winter. If they come here periodically, it will be necessary to protect communications from freezing. Otherwise, they will not be able to operate the water supply and sewerage. From low temperatures, ice appears inside the pipes. In some cases, communications may be interrupted. When it warms up, water will seep out of the pipes. Therefore, it is important to install the heating cable correctly.
Varieties
Various systems of electrical wires are used to heat pipes. They can be divided into two large groups. It is resistive and self-regulating heating cable. 
It features a stable temperature, which does not change along the entire length of the wire. This cable consists of a metal core through which current is supplied. It heats the conductor, all the sheaths of the wire. This is a robust system that may differ in insulation class and power. Depending on the characteristics of the outer sheath, the presented cable can be led directly into the pipe or wrapped around communications.
Self-regulating wire consists of two cores, between which there is a polymer matrix of semiconductor material. Electricity travels through the system to a greater extent if the environment gets colder. will be stronger in this case. When the environment warms up, the matrix reduces the supply of electricity through the system. The wire will heat up less.
Resistive Wire Features
metal communications is possible when using a resistive cable system. Such a wire is heated to a certain temperature. To be able to regulate the level of heating, a thermostat must be added to the system.
The resistive wire consists, as mentioned above, of a core and protective sheaths. For this, manufacturers use different materials. Depending on the selected protective sheaths, the cable receives special performance characteristics. If the outer layer is additionally reinforced and made of food-grade plastic, the wire can be installed directly into the water pipe.
However, more often the wire is pulled from the outside of the communications. When using the presented wire, it is important to calculate the required power. Also, the density of laying the turns of the wire plays an important role in creating high-quality heating.
Disadvantages of resistive wire
Today, many manufacturers produce pipe heating cable, which has many characteristics. However, there are certain disadvantages that are inherent in almost all resistive wires.
The presented category of heating systems, as mentioned above, is characterized by the same temperature along the entire length. This means that the system through which the wire is laid must also have the same temperature along its entire length. If this is not the case, in some areas the cable will overheat. This greatly reduces its service life.
It is also forbidden to cross the wire, which greatly complicates its installation on hydrants, cranes. If you lay the turns of the cable close to each other, then overheating of the system is also possible.
Another disadvantage is the need to use a thermostat. This increases the cost of installing heating pipes.
Features of self-regulating wire
self-adjusting pipe heating tape differs in a number of features. This system does not require a thermostat. The built-in matrix itself determines to what temperature the wire needs to be heated at the moment.
Moreover, it should be noted that a self-regulating cable can be cut, unlike a resistive wire. It consists of separate blocks. Therefore, in different parts of the tape, the temperature may not be the same. This does not reduce the life of the wire. If there is an extra piece of tape left, you can simply cut it off. The resistive cable will have to be laid completely.
Depending on the braid, the self-regulating wire can also be led directly into the water pipe. In this case, less cable is required. Its efficiency will be higher, since the water inside the system will be heated directly. In this case, less electricity is used.
Wire cost
Today it is performed using both categories of wires. Despite the fact that the resistive wire has a lot of disadvantages, in comparison with self-regulating varieties, it is installed on various communications of private and industrial facilities. This is due to the lower cost of such a system. The disadvantage of self-regulating wire is its relatively high cost.
However, it should be noted that the total cost of a resistive wire system with a thermostat will be from 1800 rubles. for 1 m of cable. The indicated price includes the cost of the thermostat. It costs about 800-1500 rubles. Without a control system, it will not be possible to install the wire.
Self-regulating wire costs about 500 rubles. per 1 m. If you need to purchase such a system in bulk, the price can be reduced to 250 rubles. for 1 m. In this case, installation will be much cheaper than when buying a resistive wire.
Benefits of self-regulating wire
It has a lot of advantages when compared with resistive systems. Its main feature is the absence of a thermostat. The durability and quality of heating when using a self-regulating wire will be higher.
The system is protected from overheating. It adapts to environmental conditions. In this case, the cable consumes the optimal amount of electricity. Owners of a resistive heating system must independently set the heating level of the wire. In this case, under equal conditions, more electricity will be spent.
Self-regulating wire is easy to install. It can be crossed, providing heating for hydrants and taps. If necessary, the system is cut into sections up to 15 cm long. This allows you to mount exactly as much wire as necessary for a given object. The system is connected to the network using a conventional electrical plug.
System power
Produced with a cable of a certain power. In order for the system to work effectively, it is necessary to take into account how high the thermometer can drop in winter. Also, when choosing the power of the system, it is important to pay attention to the location of the object, its length. The diameter of the pipe affects the choice of wire power. When calculating, be sure to take into account the material from which the pipe is made, as well as the thickness of the insulation above it.
There is a certain formula that experts use to calculate the power of the wire. She looks like this:
M \u003d (2 x 3.14 x Tm x D x (Tzh - Tn) / Dk x (Dt / Dn) x 1.3, where:
- Tm is the thermal conductivity of the insulation. For calculations, the most commonly used indicator is 0.04.
- D is the length of the pipe.
- Tf is the temperature of the liquid in the pipe.
- Tn - the minimum temperature outside.
- Dt is the outer diameter of the pipe together with thermal insulation.
- Dn - outer diameter without thermal insulation.
- Dk - cable length.
To find the Dk indicator, it is necessary to take into account not only the length of the object, but also all plugs, hydrants and other elements of the system.
Calculation example
To find the wire power required for heated pipes, need to make a calculation. For this, a number of system parameters should be taken into account. For example, the owner of a private house has a water pipe that needs to be insulated. Its diameter without thermal insulation is 32 mm. The length of the object is 45 m. At the same time, it is known that in this area the temperature in winter does not fall below -35ºС. It is planned to mount a layer of thermal insulation on the pipe, which will be 25 mm.
To select the optimal system, you need to calculate according to the above formula. It will look like this:
M \u003d 3.14 x 2 x 45 x 0.04 x (5 - (-35)) / 73 (82/32) x 1.3.
Various wires are on sale. Their power varies from 10 to 40 W/m. Depending on the operating conditions, a certain type is selected.
If the wire is mounted outside the pipe, the minimum power for a 32 mm pipe is 15 W/m. With an increase in the size of the cross section of communications, this figure increases. If the pipe has a diameter of 50 mm, the recommended power reaches 24 W / m, and for 150 mm - 40 W / m.
If the wire is installed inside the pipe, low-power systems can be used. For communications with a cross section of up to 80 mm, wires with an indicator of up to 13 W / m are suitable.
Mounting Features
To mount pipe heating, you must purchase a cable of the required power and length. If you plan to install a resistive variety, a thermostat with a remote sensor is purchased without fail. It will control heat.
It is also mandatory to install an RCD in the system. They are mounted in a special control cabinet mounted inside the house. An additional aluminum tape is also purchased for attaching the wire, thermal insulation on the pipe.
Wire installation
Before installing pipe heating, you should carefully read the manufacturer's instructions. The wire can be mounted on a pipe in a spiral or run in a straight line. The choice depends on the characteristics of communications. Using adhesive tape, the cable is fixed to the surface. If you plan to install the wire inside the pipe, you will need to turn off the water supply. At the appropriate point, the cable is inserted into the system.
If necessary, a sensor from the thermostat is installed on the surface of the pipe. It is also fixed with tape. Next, the system is covered with a layer of thermal insulation.
Having considered the features of the selection and installation of pipe heating, you can correctly install an effective system at the required facility.
If the water supply freezes, expect trouble. Icicles formed in pipes can sometimes reach a length of up to several meters. It takes a lot of effort to remove these blockages. If the winters in your area are severe, this problem needs to be addressed in advance. At low temperatures and prolonged frosts, conventional thermal insulation will not help, so you need to look for an additional option. The most effective way in this case is to use a self-regulating heating cable for plumbing that can maintain the desired temperature. It will provide good heating, and also prevent condensation.
Application
Special wires have long been used for heating sewerage and water supply systems. What is a heating cable? This is a conventional cable, the heating of which is controlled by direct regulation of the electrical resistance.
The heating cable for the water supply is used so that at sub-zero temperatures the water does not freeze in the sections of pipes passing along the street. The wire is usually turned on when the outside air temperature drops to 5 ° C, so that when it gets colder, it protects the water supply from freezing. And if you turn on the heating when the temperature is already below zero, it will take some time for the liquid that has had time to freeze to melt. In the meantime, the water will gradually melt, the pressure in the water supply will be low.
Device
The cable for heating pipes consists of cold (electrical), hot (heating) conductors, a temperature limiter and a plug. The conductors are connected to each other by laser soldering.
Since the external insulation of the heating cable is seamless, it is absolutely protected from moisture penetration, from chemical and high temperature influences. The temperature limiter regulates the temperature of the pipe and turns off the power when the temperature rises to 15°C. When cooled down to 5°C, the power is turned on again. This way you save as much energy as possible.
Good to know! Previously, the heating cable was used only for heating industrial pipelines, but now cable heating systems are widely used in the household.
Benefits of using a heating cable for plumbing:
- Reliability. Proper calculation and proper installation of the heating system will prevent the water pipe from freezing during the entire time of its use.
- Versatility. The self-regulating heating cable can be connected to a pipeline located outdoors or underground. The wire can be laid both on the surface of the water supply system and inside it.
- Safety. The heating cable is also used for heating drinking water pipes.
- Profitability. The heating power is regulated independently, depending on the ambient temperature.
- Ease of use. It is put into action very simply: the cable is fixed on the water supply network and then plugged into the outlet.
Kinds
The range of heating wires for plumbing is quite developed. According to the heat release scheme, they are divided into resistive, self-regulating and mineral insulated wires.
Resistive heating cables are zonal and linear. In linear wires, heat is released as a result of the passage of current through the heating core. The cable can be single or double-core, or it can have several cores in a linear or spiral shape. It is unacceptable to cut such a cable arbitrarily.
By its design, self-regulating heating cable is similar to resistive. It also consists of two conductive wires, but without an insulating coating. Heat dissipation along the length of the cable can change: when the ambient temperature rises, the resistance of the polymer increases, and heat dissipation decreases. The self-regulating effect eliminates burnout and overheating of the product. Self-regulating heating cable can be cut into sections from 20 cm to several meters in length.
How to install
Insulation of a water supply system is a difficult task, but urgent. For this purpose, a heating cable is used. The temperature of cable heating can be changed by varying the resistance value of the device. The heating cable can be installed both inside the pipe and outside. In any case, it is selected in such a way that the heat loss of the water supply network does not exceed the amount of heat generated by the system.
The cable can be laid in parallel rows or in a spiral. Fastening is provided by a tightening metal mesh or adhesive tape. For better preservation of heat from the outside, the pipe with the heating cable is wrapped with foil. The task of installing the heating cable is best, of course, handled by specialists.
Selection
The heating wire is selected in accordance with the tasks that the heating system solves. For example, heating cables can be used both for use in private houses, cottages and suburban areas, as well as in communal heating systems - to protect water pipes, drains and sewer systems from freezing. In this case, a small system is needed.
For these purposes, as a rule, a heating cable with a power of 50-60 W / m is suitable. This will be enough to melt the snow and ice. Higher power in this case is irrational.
This is useful to know! The self-regulating heating cable popular today has two main indicators - power at rest and working power. They are indicated on the surface of the cable.
In conclusion, I would like to once again note the importance of installing a heating cable in water supply, sewage and drain systems. By choosing the right wire, you can prevent freezing of the water supply, as well as avoid low water pressure.
A modern cable system for heating sewer and water pipes is the only effective way to protect utilities from freezing.
Both resistive and self-regulating pipe heating cables are effective for heating purposes, with the second option, although more expensive, being in high demand due to its reliable and economical operation.
Pipe wrapped with heating cable
The structure of the heating cable includes:
- The fuel element is a carbon-based polymer matrix that changes its resistance depending on temperature.
- Two conductive copper wires.
- Thermoplastic electrical insulation.
- Standard metal braid (shield).
- Outer polymer shell.
The principle of operation of a self-regulating cable for pipes is to convert electrical energy into heat. When current passes through the semiconductor matrix, it heats up, resulting in an increase in cable resistance and a decrease in power consumption.
At a certain temperature of the heating wire, a balance is reached between the generated heat and the consumed electrical power. In this way, the process of self-regulation is achieved: the same cable releases different amounts of heat energy depending on climatic conditions . At the same time, the heating force in different parts of the pipe may differ.
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Heating wire laying technology
Installation of a self-regulating cable for heating pipes is carried out both outside and inside the pipeline. Works are carried out at temperatures above -5 ° C - at lower temperatures, damage to the polymeric protective layer is possible. If the wire has lost flexibility at low temperatures, it is carefully unwound from the coil, connected to the power supply for several minutes until it regains flexibility. After that, you can start installation work.
Features of internal installation
This method of laying the heating cable is used for pipelines of small diameter - up to 50 mm, which cannot be directly accessed. In this case, the self-regulating wire is pushed inside the pipe for its entire length. For input, a special gland assembly is used, which includes two bushings, two washers and rubber seals.
Heating cable inside a water pipe with a gland assembly
For internal heating of drinking water pipelines, only self-regulating pipe heating cable with a fluorine-containing polymer outer sheath that has passed all food safety tests may be used.
Safety regulations:
- The length of the electric cable must completely match the length of the pipeline.
- It is forbidden to lay a self-regulating wire through the shutoff valves.
- Be sure to mark the installation location of the heating system on the pipe.
- Cable entry must be carried out with great care - the outer sheath must not be damaged.
- During the insertion process, all sharp edges of the fittings must be covered with factory tape.
Features of external mounting
When laying outside, a self-regulating heating cable for heating pipes is placed on the surface of the pipeline in several ways:
- Linear (along the pipe in one line). This method is used for small diameter pipelines;
- Parallel (two or three cables are laid along the pipe). This option is valid for a large pipe diameter or, if high power is required, if the line is located in open areas;
- Spiral (the pipe is “wrapped” with a cable in a spiral). The pitch of the coil depends on the parameters of the cable, the diameter of the pipeline and the required power;
- wavy line . This method is relevant if the standard cable length is not enough for laying in the above ways. The property of self-regulation of the heating cable allows it to be laid with an overlap for heating external shut-off valves.
During external laying, special attention is paid to the joints of the pipeline with valves, flanges, elbows and other elements so that the wire does not interfere with their functioning, and at the same time exclude its mechanical damage (grinding, compression-stretching). The electrical cable is tightly fixed to the pipeline using aluminum tape. After that, the pipe is thermally insulated to reduce heat loss and ensure the efficient functioning of the heating system.
Instructions for using a heating cable for heating pipes regulate the connection to a 220-240 V network only through an RCD.
Manufacturers overview
The market for heating systems for sewer and water pipes is represented by both foreign and domestic manufacturers. The price of a heating cable for pipes depends on its power, footage and country of origin.
1.LLC "Special systems and technologies" - Russian manufacturer, offers a wide range of heating cables under TM Freezstop:
- Self-Regulating Pipe Heating CableFreez stop – for the lowest temperatures, has a heating power of 25 W/m.
- Freezstop Simple Heat – heating section with a built-in bimetallic thermostat that automatically maintains the temperature of the pipeline.
- Freezstop Lite - miniature wire for pipes of small diameter.
- Freezstop Inside – a special cable for indoor installation with gland assembly included. The outer shell is made of a fluoropolymer that is safe for use with potable water.
2. The world's largest manufacturer of cable heating systems can be called DEVI (Denmark) . To protect against freezing of pipelines, a self-regulating Devi-Pipeguard electric cable with a power of 10 to 31 W / m is used. Devi-Pipeheat 10 with food-grade plastic insulation is suitable for internal installation in the plumbing system.
3.FINE Korea Co. . (Korea) offers the SRF series up to 40 W/m, with low power consumption for the protection of vertical and horizontal pipelines.
Technical characteristics of cable heating system
|
Manufacturer |
Series |
Heating cable power, W/m |
Max. operating temperature, °C |
price, rub. for 1m |
| Special Systems and Technologies LLC | Freezstop |
990 rub. per set 1m |
||
| Freezstop Simple Heat |
1390 rub. per set 2m |
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| Freezstop Lite |
It is very difficult to make uninterrupted water supply in a country house. Residents of such real estate very often face freezing of the pipeline in the winter. To avoid this trouble, when arranging the water supply, a cable is installed to heat the water pipe. Such heating systems protect communications from freezing and destruction.
Heating cable application
Laying the pipeline can do without heating the water supply and sewerage with a heating cable, if the water pipes are buried deep enough and good thermal insulation is made.
However, in wetlands and areas close to water bodies, the groundwater level is very high, which often exposes communications to flooding and freezing. If the pipes are not installed deep and a self-regulating heating cable is laid, then the communications will be reliably protected.
There are also critical areas that are more susceptible to low temperatures - areas where water and sewer pipes are introduced into the house. The heating cable for heating pipes can only be installed in these places.
Such heating systems have very useful features. For example, the possibility of zonal application. That is, from a set of elements, you can assemble a small system for heating a water pipe in a single area without connecting a self-heating wire throughout the network. There are mini "warmers" of 20 cm, and maxi "heaters" of 200 meters.
Depending on the type and technical parameters, the heating cable is used to heat the pipeline and drains, tanks for collecting and storing liquids in the winter. The main task of the system is to protect the liquid from freezing, due to heating through an increase in temperature.
Installation of a heating cable is possible both in a pipe in the ground, that is, internal, and on a pipeline in the open air, that is, outside.
Thus, if it is worth choosing to connect a heating cable or not to lay a heating system, then you should definitely take this opportunity and insure your pipeline from freezing.
Design features of the system
The principle of operation is based on the ability of a resistive or self-regulating cable to convert electricity into heat energy. The wiring itself does not transmit energy, as in the case of power counterparts, it only receives it, and then the wires heat the object, transferring heat.
The heating cable for water pipes consists of the following main elements:
- One or more internal conductors with high resistance to electric current, the higher it is, the more heat will be generated.
- A protective sheath made of polymer, together with plastic, insulation in the form of a copper mesh or an aluminum screen is used.
- The outer sheath is made of durable PVC, which protects the inner sheath and core.
Cable for heating a water pipe from different manufacturers differ in alloy, design of protective elements, cost and other parameters.
The most reliable is considered to be a heating wire with a foil screen and with several cores. Solid wire is a cheaper option, suitable for connecting the system in a small area of pipeline, since the solid wire transfers less heat.
To improve the performance, the copper braid is nickel-plated, and the thickness of the outer PVC sheath is also increased. In addition, the outer layer must be resistant to moisture and UV radiation, so that the protection can withstand both contact with water and exposure to direct sunlight.
Types of cable heating
The heating cable for sewerage and water supply can be one of two types: resistive or self-regulating. Each of them has its own scope. So, the first type is more suitable for heating small sections of pipes with a diameter of up to 40 mm, and a self-regulating cable is good for longer sections. Let's consider each type in more detail.
- Resistive has the following principle of operation: current flows through the cores and heats the cable. Large current and high resistance contribute to excellent heat dissipation. There are pieces of resistive wire with a constant coefficient of resistance. During operation, such a cable gives off an equal amount of thermal energy along its entire length.
The wiring with one core is placed in double internal protection and external insulation. The only core acts as a heater, which will be connected according to a scheme resembling a loop: the wire is connected to the mains, then wound around the tube, then returned back.
A closed circuit heating system, as a rule, is used to equip a “warm floor” and heat a roof drain, there is one option for a plumbing system. Do-it-yourself installation of a heating cable for a water supply system is distinguished by the need for double-sided laying of a single-core wire. It is noteworthy that in this case only an external connection is used.
For underground installations, a single-core resistive cable is not suitable, because laying the "loop" takes up too much space, and crossing the wiring will cause overheating.
Wiring with two cores separates their functions: electricity is supplied to one wire, and the second one heats. The connection scheme is also different: there is no need to create a “loop”, and the cable is connected to electricity at one end, and the other is laid along the pipeline.
The main advantages of a resistive cable are its low cost, reliability, ease of installation and long service life (10-15 years). However, there are also disadvantages, among which it is worth highlighting: a fixed length, a high probability of overheating with a close location of the wires, the impossibility of replacing one segment and the power cannot be adjusted.
In order not to connect the heating system every time, a thermostat with a temperature sensor is mounted. When the temperature drops below the set temperature by 2-3 degrees ºС, the thermostat automatically starts the heating device, and as soon as the temperature rises to the set coefficient, the energy is automatically turned off.
- Self-regulating heating cable. This is a universal type of wiring that can be used to heat a roof element, water supply and discharge lines, containers with various liquids. Such a cable is immediately equipped with a system for adjusting the power and intensity of heat energy. When the temperature drops below the control value, the system starts heating.
It differs from the resistive model in the presence of a conductive heating matrix that regulates the heating temperature, but with regards to insulation and protection, there are no special differences.
The principle of operation of a self-regulating device is based on the ability to reduce or increase the current strength, taking into account the resistance indicator. When the resistance rises, the current decreases, resulting in a decrease in power. As a result, the conductor cools down. After the resistance decreases, the current increases and heating starts again.
Self-regulating heating cable for water supply has an important advantage - zoning. The conductor independently manages its “working force”: it warms up the cooling places well and maintains the optimum temperature in those sections where there is no need for strong heating.
The self-regulating heating cable for heating water pipes works constantly, which is very welcome in the winter. But, when the frosts stop, it is not beneficial for it to always work, therefore, to automate the processes of the conductor, it is equipped with a thermostat tied to the street temperature. The thermostat for the heating warm cable will turn off the system itself when the weather is warm enough outside.
Connection methods: inside or outside?
There are two ways to connect the heating cable: outside or inside the pipe. Each option has special types of wires - for outdoor use and for indoor installation, respectively. The recommended connection method is necessarily indicated in the technical specifications for the conductor.
Insulation of pipes from the inside
Heating cable inside the pipe. To start the installation work of the heater inside the water main, it must meet the following important requirements:
- high degree of electrical protection, not lower than IP68;
- protective insulation should not emit harmful substances;
- end seal.
To be able to refuel the conductor inside, a tee is installed at the end of the water supply, and a cable is inserted into one of the branches through the gland.
Keep in mind that the junction box - the place where the transition between the electrical and heating wire occurs - must be outside the gland and pipe, as it is not designed to function in a humid environment.
Tees for mounting heating wiring inside the water supply can be at different angles of outlet - 180 °, 120 °. 90°. With this method of connection, the cable is not fixed at all, it is simply tucked inside.
Outdoor heating pipeline
Installing a heating water cable outside the pipe assumes its tight fit with the entire circuit. Before mounting on a metal pipeline, their surface must be cleaned of rust, welding marks, dust and other dirt that can damage the wire. A cable is laid on the cleaned pipe and fixed with plastic clamps or metallized tape every 25-30 cm.
If up to two threads are pulled, then they are attached at a short distance parallel to each other from below, that is, in the freezing zone itself. If three or more threads are pulled at once, then they must be arranged in such a way that more wires are installed from below, but with a certain distance.
Another option for external connection is spiral. It is necessary to wind the wiring with great care, without sudden movements and many bends. This can be done by gradually unwinding the coupling and at the same time winding the freed wire onto the trunk, or simply fix the cable with sagging, and only then lay it in a spiral and secure it with metallized tape.
If the pipeline is made of plastic, then under the wiring you must first stick a metallized adhesive tape, which will improve the thermal conductivity and increase the heating efficiency. Valves, fittings, tees and other connecting elements require more thorough heating. Therefore, when mounting on each connection, it is better to make several bends, but remember about the radius of the loops.
In this case, it is necessary to additionally insulate the pipeline. Any kind of mineral wool is categorically not suitable for this, since it loses its properties in a humid environment. It is worth abandoning heat insulators that shrink from gravity, if hard insulation is not used from above.
A shell made of expanded polystyrene in the form of fragments with different diameters is the optimal solution that demonstrates high thermal insulation characteristics: it feels good in a humid environment, does not shrink under weight, and reliably protects.
Power and other characteristics of the heating cable
Before buying a heating cable, it is necessary to clarify the length of the line that is planned to be insulated, to what maximum temperature the soil freezes through and other parameters.
So, when choosing a conductor, you should pay attention to the following characteristics:
- is there a protective braid on the wire that will make the conductor more reliable and provide grounding;
- temperature class;
- type of external insulation;
- power.
For a sewer line, an electric cable with a polyolefin insulation is suitable, however, for a water supply system in the ground, it is better to choose an insulator in the form of a fluoroplastic. For outdoor mounting, a fluoropolymer is suitable, protecting the cable from UV radiation and humid environments.
The required power largely depends on the place of residence, since each region has its own indicators of low temperatures. Also, the choice of power is influenced by the cross section of the tubes, the presence of insulation, the method of laying the heater. The wiring consumption is indicated in a special table in the accompanying documentation for the cable, taking into account the power of the device.
Experience shows that with standard thermal insulation of the pipeline with expanded polystyrene shells (30 mm) in the regions of the Central RF, for heating a pipe segment 1 meter long, a power of 10 W / m is enough from the inside, and a cable with a power of at least 17 W / m is required outside. If you live further north, then the power of the heater should increase accordingly.
If the insulation is not sufficient to prevent freezing, a safe temperature must be maintained. They do this using a set of devices discussed in this article. The main functions are performed by a cable for heating. Its correct choice and application will help to solve the problem without unnecessary costs and difficulties.
Read in the article
How to use a special cable for heating a water pipe
Such solutions are used when it is impossible to obtain the desired result with the help of passive protection against the penetration of cold. Usually enough placement at a depth below the freezing level of the soil in a particular area. But the danger of ice plug formation occurs at the point of connection to centralized systems.
This figure shows a diagram of a standard autonomous. Extreme fluctuations in temperature are often recorded in our time. In severe frost, freezing of the soil below the normal level is not ruled out. Particularly dangerous is the area of exit from the ground and the entrance to the building. Here, even the high-quality modern insulation indicated in the drawing may not fulfill its functions.
It is easier to work with a two-core cable, since the electrical contact in it is created in the end part. In some products of this type, only one conductor is intended for heating.
The main advantage of such heaters is their relatively low cost. But there are also disadvantages that the future user should be aware of:
- The resistance cable for heating must be supplemented with a control device. using a special sensor, it detects a decrease in temperature below a certain level, turns the system on and off.
- Heating is carried out along the entire length of the conductor, regardless of the different levels of cooling of the hotel sections. It's not economical.
- A certain resistance is selected that provides the necessary heating at a supply voltage of 220 V. Therefore, an arbitrary change is impossible.
Self-regulating heater
This title is no exaggeration. Engineers have really managed to create products that do not need external control.
The diagram shows the usual elements: copper wires, shielding, high-temperature-resistant fluoroplastic insulation. But here the main useful function is performed by a special matrix. Its conductivity changes as the temperature increases/decreases. At the same time, there is a decrease / increase in heating.
These products are more expensive than resistive counterparts. However, they are much more economical to operate. When applied, the temperature will rise only where it is really needed.
How much does it cost to install a heating cable for a water pipe outside the pipe: project price
To calculate the total costs, consider the following items:
- Purchase of a heater and power cable, thermostat, electrical safety devices.
- Preparation and installation of the product, connection to the power supply.
- Installation of insulation and mechanical protection.
- Purchase of solder and other consumables, tools as needed.
Such a project can be implemented without outside help, if you use the information provided in this article. To speed up - purchase a ready-made kit with a cable for heating a water pipe