Heating pipelines today is a common occurrence, especially in winter, when the weather is frosty. To avoid icing both inside and outside the pipes, the use of heat-insulating materials alone is extremely insufficient. This problem can be solved finally using electric heating systems based on a self-regulating resistive cable.
Applications for heating cable
Heating systems protect piping networks from freezing, oil pipelines or pipes for transferring chemicals from clogging. The heating cable for the water supply is used for external and internal channels, which are laid both on the surface of the earth and under it. It solves the following tasks:
- Protects pipes from freezing, prevents the appearance of damage by an ice outgrowth.
- Regulates the temperature regime of transported substances.
- Heats the pipeline to a certain temperature.
In addition, an electric heating cable can be used to insulate floors in residential or industrial premises. It is also needed for snow removal in open areas, heating the land in greenhouses, etc.
The device and principle of operation of the heating cable
This is a flexible heating element that is placed in an insulator. Depending on its purpose, the system can be performed both for dry places and for rooms with high humidity. Its principle of operation is quite simple: the heating cable for the water supply generates heat, which appears when an electric current passes through it. The higher the power consumption, the more heat is generated.
Why do I need a heating cable for pipes?
Above, we described some of its functions. But there are several more tasks that a heating cable for a pipeline successfully solves. The main advantages of the system are described below:
- When using it, ice is completely absent.
- There is no condensate, the presence of which greatly reduces the life of thermal insulation materials.
- Provides uninterrupted transportation of any liquid material through pipes.
- When a heating cable is used, the installation of the pipeline can be done at any depth. It does not depend on the degree of soil freezing.
The main elements of cable heating systems
As a rule, a heating cable for a water supply system consists of:
- launch system, which is located in the control cabinet;
- aluminum tape for mounting and insulation of the heating system;
- materials for thermal insulation of a water supply system;
- temperature level controller;
- directly heating cable.
Types of heating systems
They are different depending on the application. Used in a variety of devices. Depending on the heat dissipation scheme, the systems are divided into mineral-insulated cables, resistive and self-regulating.
Resistive cable
It can be zonal or linear type. The latest cable models are distinguished by the released heat during the passage of electric current through the conductors. These modifications can be single and two-core, and also consist of several linear or spiral parts. A heating resistive cable for a water supply system, the price of which is much lower than a self-regulating one - from an average of 3000 rubles per 4 meters - requires special sensors for its operation that automatically respond to any temperature change. Cutting this cable into pieces of any size is strictly prohibited.
The principle of operation of the zone resistive device is the same as that of the above models, but it has some design differences. The system consists of two parallel insulated conductors conducting current. In their isolation there are small gaps located with a certain step. A thin spiral of high-voltage alloy is superimposed on top of the conductive wire. In places where there is no insulation, the spiral closes to the conductors, and the cable is an a set of resistors that are connected in parallel to conductive wires. The zone heating cable for pipes can be cut into sections of at least 1.5 m in length.
Self-regulating cable
How is he different? By design, the self-regulating heating cable is identical to the device of the zonal system. It also has conductive wires, but they do not have an insulating coating. They are enclosed in a polymer matrix or connected using spiral polymer conductive threads. During heating, the heat-generating polymer increases resistance. When a self-regulating heating cable is installed, its heat release changes along its entire length and depends on the external temperature. With an increase in the degree mode, the polymer resistance increases, respectively, the heat release decreases, and vice versa. This process is the very self-regulation in which neither cable overheating nor burnout occurs. Such a heating element can be divided into pieces from 20 cm to several meters.
Mineral Cables
This is a metal conductor that is insulated with magnesium oxide, that is, an inorganic mineral in a whole shell of copper, an alloy of nickel, stainless or heat-resistant steel. The mineral insulator has a number of valuable qualities - thanks to it, the structure becomes more stable, it provides high dielectric properties in a wide temperature range. Magnesium oxide in the form of a powder is known as the most reliable and efficient insulator having a high coefficient of thermal conductivity.
This pipe heating element is specially designed for places where:
- high temperature prevails;
- need a strong cable structure;
- it is necessary to maintain a high temperature;
- need a long heater life;
- resistance to corrosion is important;
- need high output power.
Water heating cable: installation
It can be carried out in two ways: outside and inside. When a heating cable for gutters is laid inside the pipe, then in case of freezing it will melt the ice much faster than the one located on top. But it will cope with the responsibilities assigned to the heating system in any cases with a 100% guarantee.
External heating can be done in two ways:
- to lay several heating cores in one line;
- just wind the cable around the pipes with a certain step.
When winding around the pipe, the heating area increases, which adversely affects the level of overall system performance. And how to perform outdoor installation? The heating cable for gutters is tightly wound or laid on channels, secured with aluminum tape in several places. Also do not forget to install temperature sensors between the turns of the cable. They are also fastened with aluminum tape. The next step is to wind aluminum tape along the entire length of the heated water supply. Due to this, the element fits snugly to the pipe, in addition, it provides protection against drying out and destruction of the insulation, which will subsequently be laid. The final stage is the isolation of the cable from unwanted heat loss.
At the end of installation, you must correctly connect the system to electrical power. It does not matter what heating cable for the water supply will be installed, the price for it is not the main factor, it is necessary to install a temperature regulator that, with the help of sensors, will monitor the entire heating system. It is he who will turn it on or off automatically, depending on temperature fluctuations. It must be remembered that the resistive element is highly sensitive to various damages. During installation, do not allow cable crossing or overlapping.
The internal installation of the heating cable is burdened with some difficulties.
- It is not easy to insert it inside the pipe. It is advisable that when installing the pipes do not use ready-made rotary devices, cranes, fittings.
- At the design stage, it must be remembered that the internal arrangement of the heating element reduces the diameter of the pipe, so larger equipment must be purchased.
- The presence of an element for heating gradually leads to overgrowth of water deposits and can lead to an earlier failure of the pipe.
- Replacing the heating cable for the water supply underground is almost impossible.
Internal installation is carried out using an additional tee installed in the pipe through which the wire is laid. The location of the heating cable inside the pipe is usually used to ensure the performance of complex assemblies such as pumps or cranes. The use of an internal heating system allows more efficient use of electricity, because in this case only the moving liquid is heated, and not the pipe and its elements.
The use of heating systems for water supply allows at a minimum cost to ensure year-round and uninterrupted operation of the water supply system and other equipment.