Heated sewerage in a private house. Heating of sewer pipes: external and internal. What types of sewer pipes need heating

In regions where the temperature environment can take negative values, pipeline systems designed to work with liquid media (mainly water supply and sewage systems) need additional funds insulation or heating.

One of the options for protection is the installation of the pipeline below the freezing level of the soil. Another option is insulation with thermal insulation materials. There is also alternative way- the use of a special heating cable, which is especially often used by residents of private houses.

The use of a heating cable for heating pipeline systems can be justified in the following situations:

• Large depth of soil freezing. If the ground freezes more than 4-6 meters, installing a pipeline below this level can be a very labor-intensive undertaking.
• Complex types of soils. Rocky rocks in the area where the sewerage is supposed to be laid.

Of course, all these phenomena should be discussed only in relation to regions in which there is a periodic or constant presence of negative temperatures air that can cause damage to the sewer.

It is worth noting that the use of an internal heating cable for sewerage systems is not without some drawbacks.

So, due to the presence of an additional element, it decreases throughput pipeline. Also, the risk of blockages increases and the tightness indicators deteriorate, since it is necessary to additionally mount the tee. For extended sewer systems, this option may be unreasonably expensive.

But for private courtyards, where sewer systems of a sufficiently large cross section and short length are operated, an internal cable is the best fit.

For sewerage systems based on PVC, concrete or asbestos-cement pipes, internal heating of the pipeline may even be the only one available. These materials have very low thermal conductivity, so it is very difficult to effectively heat them from the outside.

Varieties

Industrial enterprises produce several types of heating cable:

The need to heat the sewer pipes and the heating system arises when it is not possible to lay pipes at a depth that would not allow them to freeze even in severe frosts.

As a rule, installation, maintenance and heating sewer pipes even in private construction, in most cases, professionals carry out.

Pipe heating

On the need for heating

Most in a simple way protection of pipes from freezing of liquids in them is the placement sewer system below the ground freezing level. The average depth of soil freezing in winter is considered to be a distance of approximately 1.2-1.4 meters.

However, some sewer areas may still be affected by low winter temperatures, so the heating of sewer pipes is simply necessary.

Types of pipes that need heating

The main types of sewer pipes that need heating include:

• pipes that are intended for arranging outdoor sewerage;
• drain to a local treatment plant or septic tank;
• pipes that are designed to drain the washing water of the cleaning filter;
• pipes that connect the septic tank to drainage fields or a filtration well.

Methods for heating pipes of sewer systems

The methods of heating pipes of sewer systems include:

• heating with a special heating cable;

• arrangement of the sewer system with pipes that are equipped with a system of thermal insulation and heating;

• laying sewer systems at a level below the freezing of the soil.

Heating cable functions

Often, sewer pipes heated by a heating cable allow solving a number of problems. Heating cable:

• prevents the shutdown of the sewer system due to the formation of traffic jams;
• increases movement speed Wastewater during the cold season;
• retains the technological viscosity of liquids that move through the sewer system;
• prevents accumulation of condensate on the surface of sewer pipes.

Heating cable for sewer systems

What is a heating cable?

In most cases, sewer pipes are heated using a heating cable. This is the most reliable and common way.

The heating cable is a flexible heating element. Its base is a heating core for a resistive cable and a polymer matrix. When voltage is applied to the heating element, the cable heats up.

Types of heating cable

There are several types of heating cable for sewer systems:

• Resistive (constant power cable). This type of heating cable has a constant design resistance along the entire length.
  Heats the pipe evenly load-bearing core regardless of the ambient temperature. Such heating cable requires constant monitoring of the amount of heat generated.
• Self-heating (self-regulating) cable. At the heart of this type of cable is a matrix of semiconductors. It is she who changes the conductive properties of the cable, which depend on the ambient temperature.

The use of a self-heating cable does not require the installation of a control system, since this species cable automatically reduces or increases power when the ambient temperature changes.

Features of the heating cable

The most common is the heating of sewer pipes with a self-heating cable. Features of this type of heating cable:

• The power of a self-heating cable is on average 33 W per meter of pipe.
• In a self-heating cable, a special reinforced tape is used adhesive tape with aluminum coating.
• The self-heating cable can be cut into pieces of the required length for installation.
• A cable longer than eighty meters can be plugged directly into an outlet.

At the first start, the current consumption can be exceeded by three to five times. You shouldn't be afraid of this. The peak load on the first sharp heating will average ninety seconds.

Then the value will acquire the declared value.

Heating cable installation method

Heating of the sewer system can be done in two ways:

• Mount the heating cable inside the pipe.
• Lay the heating cable outside the pipe.

In private construction, it is preferable to use the second option for mounting the heating cable.

The most widespread was the second method and sewage. Experts rarely recommend installing a heating cable inside a sewer pipe, since this method is only suitable for pipes of small diameter.

Heating cable installation

AT middle lane In Russia, heated sewer pipes are more of a necessity than a luxury. with a cable?

Installation of the heating cable consists of several stages:

• Carefully read the installation instructions on the packaging of the heating cable.
• Prepare pipes for the upcoming installation. The sewer pipe must be not only dry, but also clean.
• Place heat shrink tubing over the end of the heating cable.

Heat shrink tubing should be larger.

• Peel the end of the cable (about 50 millimeters) from the braid and sheath.
• Separate the wires of the cable and also strip them about 40 millimeters.
• Place a heat shrink tube on each wire of the cable.
• Heat the tube with a building hair dryer.
• Strip the ends about 6 millimeters.
• Place the braid in metal tube and hold.
• Clean the end of the power cable and separate the wires.

The ground wire must be left 80 millimeters long, the rest should be cut to 35 millimeters.

• Connect the wires of the power cable to the heating cable.
• Wire connections should be insulated with tape.
• Connect the metal braid.
• Also insulate the connection points with tape.
• Then the sewer pipe must be sprinkled with soil.

Proper installation of the sewer system eliminates the question of how to warm the sewer pipe. If you are not sure about own forces, in order to avoid problems during operation, you should seek the help of specialists.

Deepening the external sewage system deeper than the freezing level of the soil is a troublesome job, especially if the work is done in winter. Alternative option frost protection - heating cable for sewer pipes. It is worth familiarizing yourself with the features of its styling, do you agree?

From the article we have proposed, you will learn everything about the device for cable heating of a sewer pipeline. We will tell you how the heating cable works and how to choose the right one best option. For independent hosts step by step guide installation and fastening.

The problem of freezing of the sewer pipe is not immediately detected. Unlike plumbing, here the fluid flow has no permanent and does not completely fill the cross section of the pipe.

In addition, sewage entering the sewer system usually has a higher temperature than, for example, water from a well. Therefore, the freezing of drains occurs gradually.

At first, only some small part of the contents of the sewer can freeze, then another layer of frozen sewage appears, etc. Gradually, the entire lumen of the pipe is filled with a dense frozen mass, after which the problem becomes apparent. Faulty plumbing, such as a leaking faucet or cistern, can aggravate the problem.

Small portions of water enter the sewer, quickly cool and freeze. Even correct styling sewer pipes and the presence of a layer of insulation do not always prevent the freezing of drains. Defrosting a frozen sewer is troublesome, in addition, this phenomenon can lead to damage to pipes, some of which will have to be replaced.

Freezing of a sewer pipe can occur gradually, layer by layer, and slightly leaking plumbing only increases the danger of this unpleasant phenomenon.

Therefore, it is recommended to lay the sewer below the level of soil freezing with the obligatory insulation of communications. If in southern regions and in the middle lane, digging a fairly deep trench is usually not a problem, then in the north everything is a little more complicated. In this situation, the use of a special heating or hot cable is more than appropriate.

When using this type of system, the volumes are significantly reduced earthworks, since the depth of the trench can be reduced to an acceptable level without worrying about the freezing of the soil.

How does a heating cable work?

A heating or hot cable is a heating system for pipes laid in the ground. The electrical cable in the insulating sheath is fixed on the pipe and connected to the power supply. The pipe heats up, as a result, the wastewater acquires a consistently high temperature, which reliably protects it from freezing.

There is a cable for external heating of a pipe or internal. The first is laid outside the structure, and the second - inside. It's believed that outdoor installation easier to produce than domestic, so it is more in demand. In addition to the external cable, a heating film is also used.

Heating with a film for sewer systems is not often used. The material has to be wrapped around the entire pipe, which complicates installation, but ensures uniform heating

This material is completely wrapped around the structure, then it is fixed. The film gives a more uniform heating of the pipe than the cable, it has less power, which allows you to somewhat reduce operating costs.

Three types of cable can be used for heating pipes:

• self-regulating;
• resistive;
• zonal.

Self-regulating cable is considered exclusively convenient option, since it can automatically change the heating temperature depending on climatic conditions. Cable resistance decreases if the ground heats up more and increases as the temperature drops.

Self-regulating cable is most in demand in modern conditions, since it is easy to lay, it is more reliable and does not require additional elements for mounting

This change in operating mode reduces the overall power of the system, i.e. allows you to save energy. Moreover, the change in resistance may be different in individual sections of the pipeline. The result is more high quality heating, it will last longer, and there is no need to install thermostats.

A resistive cable does not have such abilities, but differs in comparison with self-regulating systems by a more reasonable price. When installing this type of cable, you will need to install a set of temperature sensors and thermostats to ensure that the operating mode of the system changes when the weather changes.

Resistive cable costs less than self-regulating counterparts. If this option is selected, a suitable power density must be carefully calculated to prevent overheating.

If this requirement is neglected, the risk of overheating of the cable and its breakage increases. The zonal cable also does not have the ability to regulate resistance, but this system does not generate heat along its entire length, but only in certain sections. Such a cable can be cut into separate fragments, which is convenient when installing pipelines of complex configuration.

It is also widely used in the installation metal sewer or for heating containers. It should be noted that the heating of structures buried in the ground is not the only area of ​​\u200b\u200buse of a heating cable. It is also used to heat pipes laid on the surface or in rooms that are not heated.

Sometimes the cable is used only for certain sections of the pipeline, for example, parts that go to the surface. Systems that are mounted inside the pipe are used relatively rarely. Most often they are used if the pipeline is already laid in the ground, and the installation of an external cable would require extensive excavation.

So installing an internal cable will be much cheaper. But such cables are usually recommended to be used only inside small diameter pipes, since their power is low.

It varies between 9-13 W / m, which is usually not enough for large sewer pipes. The length of such a cable, for obvious reasons, should be equal to the length of the pipe. The internal heating cable is made only of a self-regulating type.

How to choose the right cable?

When choosing a suitable hot cable, it is necessary to determine not only its type, but also the right power.

In this case, it is necessary to take into account such parameters as:

• the purpose of the structure (for sewerage and water supply, calculations are performed differently);
• the material from which the sewerage is made;
• pipeline diameter;
• features of the area to be heated;
• characteristic of the used thermal insulation material.

Based on this information, heat losses are calculated for each meter of the structure, the type of cable, its power are selected, and then the appropriate length of the kit is determined. Calculations can be performed using a special formula, according to calculation tables or using an online calculator.

The calculation formula looks like this:

Qtr - heat loss of the pipe (W); - coefficient of thermal conductivity of the heater; Ltr is the length of the heated pipe (m); tin is the temperature of the contents of the pipe (C), tout is minimum temperature environment (C); D- outside diameter communications, taking into account insulation (m); d - outer diameter of communications (m); 1.3 - safety factor

When heat losses are calculated, the length of the system should be calculated. To do this, the resulting value must be divided by the specific power of the cable heating device. The result should be increased, taking into account the heating of additional elements. The power of the cable for sewerage starts from 17 W / m and can exceed 30 W / m.

If we are talking about sewer, then 17 W / m is maximum power. If you use a more productive cable, then there is a high probability of overheating and damage to the pipe. Information about the characteristics of the product can be found in its technical data sheet.

Using the table, choosing the right option is a little easier. To do this, you first need to find out the diameter of the pipe and the thickness of the thermal insulation, as well as the expected difference between the temperature of the air and the contents of the pipeline. The latter indicator can be found using reference data depending on the region.

At the intersection of the corresponding row and column, you can find the value of heat loss per meter of pipe. Then the total length of the cable should be calculated. To do this, the size of the specific heat loss obtained from the table must be multiplied by the length of the pipeline and by a factor of 1.3.

The table allows you to find the size of the specific heat loss of a pipe of a specific diameter, taking into account the thickness of the heat-insulating material and the operating conditions of the pipeline (+)

The result obtained should be divided by the specific power of the cable. Then you need to take into account the influence of additional elements, if any. On specialized sites you can find convenient online calculators. In the appropriate fields, you need to enter the necessary data, for example, pipe diameter, insulation thickness, ambient and working fluid temperature, region, etc.

Such programs usually offer the user additional features, for example, they help to calculate the required diameter of the sewer, the dimensions of the thermal insulation layer, the type of insulation, etc.

Optionally, you can choose the type of laying, find out the appropriate step when installing the heating cable in a spiral, get a list and the number of components that will be needed for laying the system.

When choosing a self-regulating cable, it is important to correctly consider the diameter of the structure on which it will be installed. For example, for pipes with a diameter of 110 mm, it is recommended to take the Lavita GWS30-2 brand or a similar version from another manufacturer. For a 50 mm pipe, the Lavita GWS24-2 cable is suitable, for structures with a diameter of 32 mm - Lavita GWS16-2, etc.

Complicated calculations will not be needed for sewers that are not used often, for example, on summer cottage or in a house that is used only occasionally. In such a situation, they simply take a cable with a power of 17 W / m with a length corresponding to the dimensions of the pipe. A cable of this power can be used both outside and inside the pipe, and it is not necessary to install a gland.

When choosing suitable option heating cable, its performance should be correlated with the calculated data on the likely heat loss of the sewer pipe

For choose cable with special protection from aggressive influence, for example, DVU-13. In some cases, for installation inside, the brand Lavita RGS 30-2CR is used. This is not entirely correct, but a valid solution.

This cable is designed for heating the roof or storm sewer therefore, it is not protected against corrosive substances. It can only be considered as a temporary option, since with prolonged use in inappropriate conditions, the Lavita RGS 30-2CR cable will inevitably break.

Rules for installing cable on pipes

Laying the heating cable is a relatively simple process. It is simply fixed on the surface of the pipe, usually along, in one strip. Some projects provide for spiral installation. In this case, it is necessary to accurately maintain the calculated step between the turns of the spiral so that the pipe warms up evenly.

After the heating cable is fixed to the sewer pipe, it is recommended to lay an additional layer of thermal insulation in order to improve the quality of heating

The intersection of individual sections of the heating cable is unacceptable. The cable, depending on the type, is fixed with heat-resistant adhesive tape or mounting ties. The step between the attachment points must be at least 200 mm. To fix the cable in the mineral sheath, metal fasteners are used: clamping bands or a special bandage.

But most often I still use heat-resistant tape. Fasteners must carry not only high temperatures, but also be resistant to the influence natural factors and chemical substances. Sometimes aluminum tape is used as fastening. But at the attachment points, the thermal power of the cable will increase.

This is not always useful, it can lead to overheating of communications. It is not recommended to use metal fasteners when installing a heating cable enclosed in a polymer insulating sheath. But in some cases, aluminum tape can even improve the situation.

The heating cable on the plastic sewer pipe can be fixed with aluminum tape to increase the heating efficiency and make it more uniform

When laid on polymer pipe metallized tape is placed both under the cable and above it. This raises a little thermal power and also promotes uniform heating of the pipeline. Inside the sewer, a heating cable is used extremely rarely.

Usually it's heated small areas systems not located in the ground, for example, stimulating the movement of runoff, if natural movement is difficult or impossible.

For installation of the internal cable, a clamping and sealing sleeve may be required, coupling, a set of washers, as well as other elements (+)

To install an indoor cable in a pipe that has been laid, you will first need to cut a tee into the system. This will make a hole for inserting the cable into the pipeline.

In addition, a special nipple coupling may be required. Such a solution may somewhat worsen the characteristics of the sewer system, for example, at the installation site of the tee, the pipe clearance will slightly decrease.

This increases the likelihood of debris buildup and blockages. Difficulties with the internal cable are inevitable if the pipeline has several turns, bends, etc. It is not easy to carry out internal work on the installation of a hot cable, and also in a considerable length.

Of course, you should not connect the system to the power supply until the end of installation work. Before covering the cable with insulation, you should carefully check all connections. If you use thermal sensors, it will be easier to determine the time of activation and shutdown of the system.

You can automate the process using a relay. If the power of the cable laid in one line is not enough, you can install it in a spiral or lay two parallel lines. The main thing that separate sections did not intersect, and there was no overheating. To make the heating of the structure more uniform, sometimes the pipe is first wrapped with foil, then a cable is placed on top.

These examples allow you to get an idea of ​​how to properly connect the supply and heating cables, as well as how to insulate them (+)

Temperature sensors are installed after the insulation is installed. From above, it is recommended to apply markings that reflect the position of the heating elements. For the electrical network, you will need a piece of heat-shrinkable pipe. Then about 50 mm of insulation and 10 mm of braid are removed from the edge of the cable.

The separated and stripped ends are protected with pieces of heat shrink tubing of a suitable diameter and heated with a hair dryer. Now you need to strip about 6 mm of the wire, coil it and clamp it in a metal tube. Similar manipulations will have to be done with the power cable.

About 80 mm must be stripped of insulation and sheath and divided into individual wires. The resulting ends are cut to 35 mm, but one wire should be left uncut for grounding. 6 mm wires are also stripped here.

Now the ends of the heating element and power cables are connected in heat shrink tube equipped with a metal sleeve. It is heated and clamped, the contact point is wrapped with thermal tape, and then closed with another protection tube.

With the features of choosing pipes directly for the device autonomous sewerage will acquaint you with the contents of which we advise you to familiarize yourself.

Conclusions and useful video on the topic

In the case when it is not possible to lay the pipe below the freezing level of the soil, it becomes necessary to heat the sewer pipes. In addition, quite often in areas country houses you have to lay communications over the ground. How to lay sewer pipes with heating and will be discussed in this article.

Varieties of pipes to be heated

It may be necessary to heat the following sewer pipes:

• systems external sewerage- to divert wastewater to treatment plants or septic tanks;
• pipes connecting the septic tank to drainage fields or a filtration well;
• for removal of washing waters of cleaning filters.

As a rule, insulation is carried out by wrapping with thermal insulation, providing an air gap and in other ways (in more detail: ""). The latest technologies can offer more convenient ways heating of sewer pipes - with a heating cable, which can be laid both outside and inside the pipe. In addition, there are elements for sale engineering communications who already have a ready-made heating system. We are talking about sandwich pipes and self-heating cables.

External heating systems

Due to the ease of installation and low cost, the film method of heating the sewer pipe with your own hands is considered quite popular. The installation process of such a system is very simple - wrap the pipes with foil and fix it with tape or clamps.

But the cable for heating sewer pipes from the inside and outside is still more popular, and every day the demand for it is growing more and more. This method involves laying the cable along the entire length of the pipeline. After starting the system, it will be fully warmed up to the required temperature.

At the moment, the following heating cables are being manufactured:

• self-adjusting. According to experts, this type of heating cable is the most efficient and practical from an economic point of view. Its peculiarity lies in the mechanism of work. The fact is that such products react to temperature fluctuations in the air. This means that as the ambient temperature rises, the resistance of the cable decreases significantly, therefore, the current strength also weakens, which means that the power also drops. The principle of operation of the device is laid down in the formula P = U × I, where I is the current strength, U is the resistance, and P is the cable power. Such a mechanism can significantly reduce energy costs and make them more reasonable. The heating cable production technology allows you to adjust the power on different sections of the pipeline, which is quite important due to the constant increase in electricity prices.
• resistive. Products of this type are distinguished by resistance stability along the entire length of the laid line. Therefore, the amount of thermal energy released by such a cable is the same on any segment.
• Zonal. In essence, such a cable works similarly to a resistive one, however, the generation of thermal energy occurs in specific zones. Thanks to this device, the zonal heating cable into the sewer pipe can be cut into pieces and distribute the load at your discretion.

By by and large All these cables work in much the same way, the difference lies only in the features of their installation and use.

Resistive cables can vary in their structure:

• Single core cable. As the name implies, it consists of a single core through which current passes. It is also a heating element and is protected by a layer of insulation, a braid of shielding material, as well as an outer sheath. This type of cable is laid in loops so that both ends converge in one place to connect to the network. Please note that for installation inside pipes, a single-core cable is not used. This is due to the fact that if the cable sections overlap each other, it can overheat and burn out.
• two-core cable. In this case, one of the cores, the resistance of which is greater, serves heating element, and the second core only conducts current. Therefore, it is not necessary to bring both ends of the cable to one point; for this purpose, the return core serves.

Please note that you need to choose one or another type of cable based on the expected conditions of its operation.

Internal sewer heating

It is worth noting that the laying of an internal heating cable for sewer pipes has some disadvantages:

• the internal section and throughput of pipes are somewhat reduced;
• the risk of blockages increases;
• the tightness of the finished pipeline is deteriorating due to the need to install a tee;
• for long sewerage systems, the installation of an internal heating cable will be associated with significant financial and labor costs. See also: "".

However, often the owners of houses in the private sector, who equip themselves with a sewerage system with pipes of a sufficiently large cross section, prefer to opt for laying an internal heating cable.

As a rule, such heating is used to service small sections of the pipeline, for example, to protect street pumps from freezing in winter time. According to the principle of operation, internal heating practically does not differ from external heating.

Carrying out interior installation work

Often, internal heating of pipes is the only feasible solution. As a rule, these are sewage disposal systems made of PVC, asbestos-cement or concrete pipes. That is, these are pipes with low thermal conductivity. Because of this property, the pipes are practically impossible to warm up from the outside. The cable is mounted in the pipe either along its entire length, or on the specified segments. In the latter case, often, such a place is the passage of the system through the foundation.

After laying the cable, the risk of blockage during the operation of the system increases due to the negative impact of drains inside the system. To ready system worked as long as possible, cable laying work must be carried out with the utmost responsibility and in compliance with all rules.

At the same time, so that during operation, heated pipes do not become the cause of different kind problems, it is important to follow a certain sequence.

The following stages of work can be distinguished:

• Clean and dry pipes.
• Remove the sheath from the edges of the cable to a distance of about 5 cm.
• Separate the wires and clean them about 4 cm.
• Put heat shrink tubing on the ends of the cable.
• Warm up the tubes with a building hair dryer.
• Now trim the ends 5-6 cm.
• Pass the braid through the metal tube into the pipeline and fix it.
• Clean and separate the feeding ends. Ground wire - 8 cm, and the rest - 3.5 cm, no more.
• Connect the supply wires to the heating cable with electrical tape.
• Connect the metal braid and also insulate it.

If you are working with a sufficiently long piece of pipe, but there is no revision or tee, it is best to cut out part of it and adjust it using an adapter - a compensating pipe. To feed the cable into the sewer pipe, you need to use a nipple coupling. You need to fix this part on the plug, but if there is a revision, then on its cover.

It should be noted that after connecting the self-regulating cable, its power in the first few minutes will be 3-5 times higher than the declared one. But after that, electricity consumption returns to normal.

Without sufficient heating equipment for sewer pipes, problems are likely to arise due to the deterioration of the functioning of the system in cold weather. At the same time, the fact that the heating cable is powered by electricity cannot be used as a counterargument to the relevance of its use. In fact, you can purchase a ready-made kit, where not only the heating cable will already be present, but also thermostats and other control devices. Thanks to such accessories, you can monitor the temperature in the pipes, control the consumption of electricity and not worry about the health of the sewage system in the winter cold.

Sewer pipes need heating, outdoor and drain cleaning pipes, cleaning filter pipes leading to drainage wells. The heating cable is used for storm sewers, for drainage systems. The Avarit catalog contains solutions from European manufacturers and South Korean brands (Heatus, Lavita, Fine and other brands).

Insulate the sewer pipe special cable for heating, to prevent freezing of sewage in the cold season, so that ice plugs do not form inside the system during frost. A thermal cable with a polyolefin sheath is mounted outside the pipe. For installation inside the pipe they produce cable systems protected by a special sheath. The cable for the sewerage of Korean brands has proven itself perfectly in external heating.

External sewer heating with an ungrounded cable manufactured by Lavita, for example, is considered a budget option.

Sometimes the question arises: what type of heating wires function better and last longer. When answering, initial data are required: footage, width and type of sewer pipe that needs protection, climate zone in which the pipeline is laid. Tell the manager if you need a heating cable only for the sewerage of your house or for the general sewerage system of the entire village. In the store "Avarit" they will help you decide on the choice of product for a specific request, calculate the price of a heating cable for sewerage in a particular case. On sale there are accessories for systems of heating of pipes, sensors, thermostats.

We will help you choose a sewer heating cable

Cable power outside the pipe:

Prices and delivery

Sale of cable for sewerage with delivery to the regions of Russia. Pickup points in Moscow, St. Petersburg and Orenburg (online store prices).