How to insulate a pipe with cold water: choosing the best method. How to insulate water pipes in a summer cottage? Insulation of a water pipe in a private house

The presence of water in the house, of course, adds comfort and convenience. However, during the cold season, as a result of freezing of the liquid, ruptures of the system often occur, which requires a long and expensive repair. Insulation of water pipes in the country will help to avoid problems.

All the nuances of this process are described below.

Applicable materials

Now in building supermarkets there is a huge selection of materials that are easy to install and reliably protect the water supply from freezing.

Whatever insulation you choose, it must meet the following requirements:

• have low thermal conductivity and retain heat well;
• be durable and well tolerate various adverse effects of the environment;
• repel water (wetting the material, as a rule, reduces its heat-saving properties);
• function under the influence of high temperatures without collapsing and without changing its technical characteristics.

The properties of the most common heaters are presented in the table.

Advice! If you use country houses from block containers as a temporary habitat in the country, you should not neglect the work on warming. Subsequently, after the construction of a capital dwelling, the container can be converted into a bathhouse, where a permanent water supply system will also be needed.

Self-insulation of the water supply

Technologies used

All materials listed in the previous section have similar characteristics. The choice of a particular method depends on the external conditions and the location of the water pipes. It is advisable to take care of insulation even at the project development stage, since some technologies do not require laborious digging of deep trenches.

You can stop at less expensive ways.

There are several of them:

• High fluid pressure. To insulate the water supply in the country, it is necessary to supplement the water supply system with a special riser, where pressure is pumped (its value must be at least 5 atmospheres). The method is suitable when a submersible pump is used for water intake, capable of providing the required characteristics.

• Air . Here, insulation is carried out using the porous materials discussed above (glass wool, polystyrene foam, basalt insulation). In this case, the effect of the so-called "umbrella" is achieved, protecting the water supply from the effects of external cold air. The result is a water pipe laid in a pipe made of heat-insulating material.
• Electricity . The heating of the pipeline is carried out using a special electric cable, which is laid inside or outside the pipe. Its power ranges from 10 to 20 watts per linear meter.

In this case, it is necessary to bury pipes in the soil to a depth of 50 cm (and not 2 meters, as in other cases). The electricity supply can only be turned on in winter, when there is a risk of liquid freezing.

Advice! In the event of a central power failure or a temporary power outage, you will need current to ensure the operation of such a system. A temporary solution to the problem may be to rent a diesel generator for a summer residence, which will keep all consumers working.

Protection with thermal insulation

Consider the process of pipe insulation using fiberglass:

1. The material is wrapped around water pipes and secured with plastic tape.
2. On top of the resulting layer, waterproofing should be arranged, for which roofing material is perfect.

This method is not bad for protecting pipes indoors.

However, its use is impractical outside the house for the following reasons:

• the arrangement of the second layer of roofing material increases the time and cost of insulation;
• backfilling the soil will compress the material, which will lead to a strong deterioration in its thermal insulation properties.
• compacting the soil during backfilling will further reduce the effectiveness of glass wool, which, moreover, can get wet during autumn rains.

For external insulation, it is better to stop at basalt insulation or expanded polystyrene, the installation of which will not take much time.

1. A heater consisting of two halves is put on a pipe of the appropriate diameter.

1. Its components should overlap each other by 100-200 mm. These "overlaps" are fixed with adhesive tape.
2. Corners, turns, ramifications and so on are protected with special "shaped" parts.

Expanded polystyrene and basalt insulation have an extremely low water absorption coefficient (no more than 2%), which prevents them from getting wet during the rainy season. In addition, these materials do not crumple when backfilling water trenches. In addition to insulating the water supply on the street, the method in question is often used to protect pipes passing through unheated rooms in the house.

Heating with wire

Insulation of water pipes with an electric cable is very effective.

The installation process consists of several stages:

1. The spiral pipe should be glued with foil adhesive tape.

1. A special heating cable is wound onto the resulting spiral (it is sold in hardware stores). The step between the turns is 10-15 cm.
2. It is necessary to fix the wire using the same foil tape.

1. After that, the pipe is additionally protected with polystyrene foam or a material of similar properties. Make sure that there are no gaps between the components of the insulation.

1. The last layer is plumbing tape, which is carefully wrapped around the entire pipe. It will also serve as waterproofing.

If all procedures are carried out correctly, when the electricity is turned on, the water in the pipe will not freeze. Most often, such a water supply system is not buried in the ground more than 50 cm from the surface.

Water supply belongs to the category of especially important systems necessary for a comfortable and cozy stay in a private house. The absence of this system always makes life extremely inconvenient, so when designing housing, water supply is always given close attention.

However, laying the pipeline is only half the battle. When operating the water supply system in winter, negative temperatures can seriously damage it, up to a complete loss of performance. To avoid this phenomenon, it is necessary to carry out the insulation of water supply pipes in a private house, which will be discussed in this article.

Requirements for the materials used

The materials used to insulate water supply pipes must have the following characteristics:

• Low thermal conductivity and the maximum possible ability to retain heat;
• Complete resistance to moisture;
• Good resistance to aggressive external factors;
• Long service life;
• Ease of installation;
• Low cost.

Compliance with all the described qualities allows us to say that the selected material is good enough for pipe insulation. However, there are no ideal heaters, so you need to choose depending on the specific operating conditions.

Types of insulation materials

When deciding how to insulate a water pipe in a private house, you can consider a variety of heaters, but the most common and effective are:

1. Glass wool (fiberglass insulation). As practice shows, this insulation material is best suited for protecting metal-plastic pipes. The main advantage of glass wool is its low density, due to which a low weight of the material is achieved - and hence a relatively simple installation. The main disadvantage is high hygroscopicity, so fiberglass insulation must be covered with a layer of waterproofing material. Reliable waterproofing of water supply pipes will help extend their service life.
2. Basalt insulation. This material looks like a shell, having a cylindrical shape. For maximum protection, basalt is covered with roofing material, glassine or a material similar in properties. The most striking quality of basalt insulation is the ease of installation, for which you have to pay in the most literal sense - the price of such a shell is very high.
3. Styrofoam (expanded polystyrene). It is the foam that is most often used for warming water pipes. In addition to high performance, it is valued for the possibility of multiple installation and installation both indoors and outdoors, and even in the thickness of the soil. On the market there are products with additional coating and without it. See also: "".

Special thermal insulation

All materials used to insulate water supply pipes work according to the same principle: the air between the pipeline and the insulation plays the main role, and it is the air that prevents heat from escaping. Given this fact, the selection of heat-insulating material can be carried out depending on the ease of installation and the characteristics of the pipeline.

Good insulation of water pipes in a country house or in a private house can be created using ordinary tow or mineral wool. These materials are hygroscopic, but this does not prevent them from performing a heat-insulating function - after absorbing a certain amount of water, they increase in volume, thereby creating a hermetic protection for pipes. For normal operation, a layer of material 5 cm thick is enough.

True, tow on average lasts about 10 years - and this is a relatively short period. However, if you cover the insulation with oil paint, then it can last about twice as long. In any case, both mineral wool and tow must be additionally covered with waterproofing, which increases the cost of work. The disadvantage of such insulation is the serious labor required to create the system.

Insulation of pipes in the country can be done much easier and cheaper by choosing polyethylene foam as the material, which is one of the best materials used for thermal insulation. Simple installation is ensured by a design called a shell - after installing the heat insulator, it remains only to close the seams with adhesive tape.

In addition to low cost and easy installation, polyethylene foam is distinguished by:

• Excellent resistance to temperature changes;
• Rot resistance;
• High moisture resistance;
• Long service life (from 25 to 50 years).

Pressure and air insulation

More specific methods can be used to prevent freezing of the water supply. The rupture of the pipe occurs due to the ice formed in it, so the main task is to eliminate the cause of the rupture. This can be achieved by keeping water under pressure - in this case, it cannot change the state of aggregation, so ice will not appear in the system.

To create pressure in the water supply system, the following algorithm is used:

1. First of all, it is necessary to check whether the system is able to withstand a pressure of 5 atmospheres. This information is indicated in the documentation attached to the water pipes. In addition, it is imperative to carefully inspect the pipeline for cracks or other defects, due to which it will not be possible to maintain pressure in the system.
2. The immediate start of work is a tie-in into the pipeline of a submersible pump, which will provide pressure in the system. A non-return valve must be installed directly behind the pump.
3. Then it remains only to turn off the tap on the installed receiver and start the pump. When the required pressure in the system is reached, the pump must be turned off.

Another rather unusual way of insulating a water pipe involves using ordinary air as a heat insulator. It is located in the free space between the water supply main and pipes of larger diameter, in which the former are laid. A layer of air will reduce the effect of frost on the pipes.

To increase the efficiency of air insulation, pipes must be deepened into the ground at least a meter, since they are heated by the heat located in the thickness of the earth. To lay such a system at a shallower depth is impractical.

It must be understood that the insulation of water supply pipes due to a layer of air is easiest to equip when laying a new one or replacing an old pipeline. In addition, the cost of such a design is quite high, and installation is very difficult.

Before you insulate the water pipes in the country, you should consider a few tips, following which can slightly simplify the work or make it better:

• It is necessary to deal with the installation of thermal insulation in the warm season - when frost sets in, firstly, it will be too late to insulate pipes, and secondly, repairing pipes and laying insulation in winter is much more difficult;
• Before the onset of cold weather, it is recommended to check the water supply pipes for leaks - the slightest leak can cause a subsequent rupture;
• Warming is necessary for all sections of the pipeline located in the zone of low temperatures (and this is not only the street, but also, for example, unheated basements);
• When laying underground communications, it is imperative to create a diagram of their location;
• When laying the heat-insulating layer, it is impossible to skip individual sections of the pipeline - the insulation must be solid and airtight;
• If there is no possibility of laying water supply pipes to a depth of at least one meter, you should think about using a heating electric cable that provides reliable protection of the system from freezing;
• When heating the water supply with autonomous heating, it is highly undesirable to turn off the boiler;
• If the water supply pipe is heated by an autonomous heating system, then their pipes must be located inside the heat insulator and have a point of contact;
• In winter, pipes for plumbing with insulation often become a target for various rodents, so it is necessary to take care of the protection of the structure in a timely manner (coating the pipes with a solution with broken glass or a metal mesh is quite suitable).

Conclusion

Thermal insulation materials are presented on the market in a wide range, so if necessary, you can choose the best material suitable for specific operating conditions. This is important, since the insulation of a water pipe in a private house is the most important task aimed at maintaining the system in working condition and preventing its damage.

The main requirement that is set for the insulation of water supply pipes on the street is to protect the system from contact with cold. For its installation, both proven polystyrene shells and high-tech methods in the form of a cable with a sensor are used.

To protect the highway outside the premises, it is not necessary to deepen it much. It is enough to do the insulation correctly.

Article content

Which heater to choose?

The operation of the water supply system outside the premises, that is, on the street, is carried out in extreme conditions. Two requirements are set for its insulation: low thermal conductivity and low water absorption.

Being in the ground, the main is simultaneously in contact with cold on the one hand, and heat on the other, so condensate appears on its surface. The material must be resistant to the formation of fungi and mold, pliable to the mount and have the maximum possible service life.

There are the following heaters for water pipes:

• glass wool;
• basalt wool
• expanded polystyrene.

Glass wool used for mounting the heat-insulating layer is produced in rolls. They are characterized by a soft structure, therefore they are widely used for insulating elements of complex configuration: cranes, etc. The material is used for insulation of metal-plastic pipes. Works only with roofing material or fiberglass.

Basalt wool is produced in the form of cylinders. Builders call them. These are ready-made joints 1 m long. They can be easily cut into smaller pieces to insulate small sections. Some types of basalt are produced with an aluminum surface. She designed to protect the material from mechanical damage, so it lasts longer than the others.

Expanded polystyrene, similar to basalt wool, is produced in the form of shells. It is characterized by ease of installation, therefore it has become widespread among private developers. From expanded polystyrene produce insulation with angular turns. Can be used multiple times.

The material meets all the requirements for insulating gaskets, however, it is combustible, therefore it is not used in places with an increased risk of fire.

Ways to insulate water pipes

In addition to the materials mentioned above, there are ways effectively insulating pipes from the cold in places where deep laying of highways is not required. Among them:

1. Heating cable.
2. Insulation of water pipes with air.
3. High pressure insulation.

It is not necessary to wrap the pipe line with heat-insulating material. You can heat the space around it with a heating cable. The power of its work per 1 m of running pipe is 10-20 watts.

The advantage of the cable is that it can only be operated during the winter months. This method allows you to deepen the pipes only 50 cm from the top soil level, compared to 2 m of conventional installation.

The second way is to create a kind of thermal shield in the way of cold air. Warm streams emanate from the lower part of the highway, which are preserved around it, thanks to the umbrella effect. It is mounted in this way: a pipe is placed in a cylindrical insulating material so that in practice a “pipe in pipe” system is obtained.

The third method involves connecting a receiver, into which pressure is pumped. It is effective in the arrangement of submersible pumps water supply, as they are characterized by the optimum pressure for the system - 5 atmospheres. The operation of the pump requires the installation of a check valve, which allows you to pressurize the entire system.

Insulation with basalt and expanded polystyrene

Installation of shells made of basalt and expanded polystyrene is carried out in the same way. It is better to start it from a flange connection. The installation steps are:

1. Select shells whose inner diameter will correspond to the diameter of the pipe.
2. Put their halves on the main sections so that they overlap 10-20 cm wide.
3. Secure with tape.
4. Put on selected or self-made shells on the places of pipe bends.
5. Isolate the street sections of the highway with roofing felt or foil. Segments that are under the soil cover are not exposed to fiberglass materials.
6. Pull the material around the pipe.

If it is necessary to gain access to the "bare pipe", the dismantling of the insulation layer is carried out in the reverse order.

Expanded polystyrene and basalt wool are materials with a low density. Backfilling soil into a trench with laid pipes can cause deformation of the insulation, and, consequently, a decrease in the thermal insulation layer.

To speed up the installation of insulation and make it more efficient, backfilling must be done in layers, carefully tamping each layer.

Ramming will also protect against soil erosion during the autumn rains, which is important when laying water pipes on the surface.

Pipe heating with cable

There are two ways to install a cable in order to heat supply pipes:

• laying the cable inside the pipe;
• cable laying on top of it.

The first method, although effective, has a number of disadvantages, the main among which is the complexity of installation.

If you want to apply this particular method without the help of a specialist, you can not do. The second method is easier to install. Cable laying takes place before installation.

To simplify the process, manufacturers have released ready-made insulation (i.e. a shell, or a cylinder) with a built-in heating cable or a channel for it.

Do-it-yourself pipe insulation with a heating cable (video)

Heating cable installation sequence

Insulation of pipes on the street with a cable occurs according to the following steps:

1. Along the entire length of the pipe, foil-type adhesive tape must be glued. Its application should not be too tight so that the cable is held when wrapped around the pipe.
2. Lay the wire in an adjusted spiral in increments of up to 15 cm.
3. Glue the cable with foil tape, which will fix the heating cable.
4. Cut the insulation lengthwise and fix it around the highway. To prevent the occurrence of cold bridges, it is necessary to check the coincidence of the joints between the cable and the insulation.
5. Wrap the entire pipe tightly with adhesive tape. It not only fastens the insulation elements, but also prevents the penetration of groundwater to it.
6. Insulation of sections of highways above the soil.

Places of the cold water supply line that pass above the soil, additionally insulated with a polyethylene film. It is wrapped around the entire surface of the pipe and covered with a box on top. A heater will be stuffed under it.

The top of the box is additionally insulated with a moisture barrier.

To control the temperature level along the length of the pipeline, control sensors are installed that collect information in manual or automatic mode. When the temperature drops significantly, a voice signal is triggered.

Owners of country or private houses during the cold season regularly face a situation where the water supply freezes. In urban conditions, such a problem does not arise, since housing and communal services specialists independently insulate the water supply system. In other cases, this task falls on the shoulders of homeowners. The article tells about how to insulate a water pipe in the ground.

The need to insulate water pipes

In winter, the soil at a distance of two meters from the surface can freeze up to -20 o C. This can adversely affect the functioning of the water supply. If its insulation is not enough, or it is completely absent, then the liquid inside will simply freeze. And the residents of the house will be left without water for a long time.

Waiting for it to thaw is not an option, because it is constantly required. You can try to warm the pipeline in various ways. But this approach is a partial solution to the problem. It is best to eliminate it in advance. To do this, it is necessary to place the pipeline under the level of soil freezing, and also install additional insulation for it.

Materials used for insulating pipes in the ground

The most popular materials for insulating water pipes are: glass wool, polystyrene foam and basalt. The first of them is distinguished by its cheapness. Glass wool is best suited for insulating plastic and metal-plastic structures, because it provides good thermal insulation at low density.

This method is easy to implement. Glass wool is simply wound around the pipeline, and then fixed with adhesive tape or plastic tape. To increase the degree of thermal insulation, roofing felt and fiberglass can be used. Cotton wool can be bought in slabs or rolls.

For the task at hand, you can also use basalt insulation. This is a cylindrical material made from molten rocks. Among the advantages of this method are ease of installation and a high degree of thermal insulation. It is best to use roofing material or glassine as a cover layer. The main disadvantage of basalt insulation is its high cost.

The most popular material for this task is foam. It is suitable for pipe insulation both outside and inside the house. The material is reusable, so economical. Styrofoam retains its performance for a long time, even when underground. A shell is made from it, in which the shell is wrapped.

This method of thermal insulation does not require special skills, installation is carried out quite quickly. To begin with, half the shell is put on the pipe, leaving a slight offset, everything is fixed on adhesive tape. The offset is usually between 100 and 200 millimeters. Shaped shells are used to insulate pipeline bends.

Material selection

In free sale, you can find a large number of heaters for a water pipe in the ground. Among the entire range, you should choose the highest quality, durable and easy-to-use options.

Criteria for the selection of heat-insulating materials:

• Low thermal conductivity;
• The resistance of the material to all kinds of external influences;
• Water-repellent properties;
• Heat insulator resistance to temperature changes;
• high thermal insulation properties;
• Long service life.

How to insulate and heat with an electric cable

An excellent option for insulating pipes in the ground is to use a cable connected to the power supply with a power of 10 watts. It is wrapped around the pipes, warming it in the winter.

It is necessary to install a temperature control relay on the cable, otherwise it will continue heating the pipeline even when the earth warms, which will lead to additional electricity costs.

Air insulation

The underground water supply system is subject to temperature fluctuations. Cold eventually penetrates deep into the soil. At the same time, the ground remains warmer than the ground above. To install the insulation, the pipe is wrapped entirely. At the same time, the water supply is insulated not only from the cold from above, but also from the heat from below.

Second layer of pipe

There is another option than to insulate water pipes in the ground. This method can be done by hand. This requires a larger diameter pipe. Polypropylene products are best suited. The bottom line is that the water pipe fits into a large one.

You can also use special paint. This is an advanced version of the insulation of the plumbing system. It needs a sprayer to apply. The larger the layer of paint, the higher the thermal insulation properties of the system will be.

The composition easily tolerates temperature changes, giving the pipe anti-corrosion properties. This method of insulation in all respects is better than using expanded polystyrene.

Pressure insulation

There is a way to insulate with high pressure. To implement it, you need to add a receiver to the water supply system. It will gradually increase the pressure. When its value reaches 3 atmospheres, the water will stop freezing. This method of insulating a HDPE pipe is only suitable for durable water pipes that can withstand high pressure.

Water is supplied to an individual house from any source of water supply through an underground pipeline, the probability of which is quite high in winter. It is not always effective and technically possible to immerse a water pipe to a great depth underground; many owners of land plots with autonomous water supply have to solve the problem of how to insulate a water pipe in the ground.

To supply water to the house, no one uses underground metal pipes that are prohibited for laying underground without waterproofing by building codes, the leader in domestic use is a low-pressure polyethylene (HDPE) pipeline with a diameter of 1 to 2 inches. Although polyethylene has a low thermal conductivity compared to steel and is more resistant to freezing due to its elasticity, when laying at shallow depths, it should be insulated with one of the many methods used in the construction industry.

There are several reasons why underground water supply should be insulated, all of them are related to the rules for laying communications and financial savings - it is obtained after the implementation of insulation work. The main reasons for conducting thermal protection of the water supply system:

Methods for warming underground water pipes

There are several ways in which water pipes are insulated, many use them at home or only in the national economy, the main ones are:

• The use of thermal insulation materials. Insulators, which isolate the water supply from contact with the ground, are widely used in all sectors of the national economy and living conditions, they occupy a leading position in terms of efficiency and material costs.
• Electric heating. Electric cable, the sheath of which is heated by the passage of alternating current, is a popular tool for combating pipe freezing in industrial and domestic settings. Modern self-heating cables operate in automatic mode with minimal energy consumption due to an internal device that increases energy consumption when the ambient temperature drops. Electric cables are moisture resistant and can work in water, so they are often laid inside water pipes, and the combination of electric heating with external thermal insulation is the most effective method of dealing with pipe freezing.

• Continuous flow. Moving water does not freeze, so a little regular water use or closed circuit circulation can prevent the pipeline from freezing in winter.
• Air heating. The technology is used in public utilities and the industrial sector, for its implementation, underground water supply is placed in a shell of large diameter pipes, and heated air masses are injected into the space between the shells.

Note: In domestic conditions, an analogue of this method is sometimes used without forcing warm air; for this, the HDPE water supply is placed in a larger-diameter polypropylene PP or polyvinyl chloride PVC pipeline from sewer pipes - the air gap between the pipe surfaces is an excellent thermal insulator.

• Increasing pressure. One popular internet myth is that you can lower the freezing point of water by pressurizing the system. It can really be lowered by 1 ° C when a water flow is injected into the pipeline with a pressure of 132 atm., Which is unbelievable for a domestic water supply system with a maximum pressure threshold of about 5 atm.

Requirements for insulation materials

To insulate a water pipe in the ground, located at a shallow depth, building insulation is most often used, which must meet the following criteria:

• Low thermal conductivity. This is the main condition, the more the material prevents heat transfer between the pipe sheath and the soil, the more efficient its use and, accordingly, financial savings.
• High chemical resistance. The soil contains a large amount of minerals that have a negative effect on the structure of the material placed in the ground, so the insulation should not be rapidly decomposed when placed in the ground.
• Water resistance. There is always moisture in the soil, so the material should not let water through or saturate it with its shell - this sharply reduces its thermal insulation properties.
• Temperature resistance. The thermal insulation material in the underground location must withstand low ambient temperatures in the cold season and high in the summer, as well as their significant differences.

• Biostability. In the earth there is a large amount of organic matter from microbes, bacteria, mold, the material should not be destroyed under their influence, and it should not be absorbed by underground living organisms.
• Rigidity. The material lowered under the earth layer experiences significant loads of the upper soil layer, therefore, it is subject to increased requirements for strength and rigidity. Due to these qualities, a large number of building pipe insulations are not suitable for underground installation.
• High service life. It is desirable that the material lowered into the ground should be changed as little as possible - this will save financial resources and save personal time.

Thermal insulation materials for underground water supply and their features

In the construction industry, a variety of heaters are used, which are produced in rolls or sheets, it is clear that shells that have the shape of their surface are better suited for pipe insulation. Almost all materials used for thermal insulation are produced in the form of pipe shells, some of them have built-in channels for laying an electric heating cable.

Styrofoam

Expanded polystyrene PPS (polystyrene), due to its physical parameters and rigidity, is the most acceptable option for thermal insulation of underground pipelines, its distinctive qualities:

• One of the lowest thermal conductivity coefficients with an average value of about 0.04 W / m ° C.
• High rigidity (depending on the brand) makes the material indispensable when used in an environment with high loads on the shell, its density reaches 50 kg/m 3 .
• Polyfoam does not pass or absorb water, water absorption depends on the density of the material and does not exceed 2% on average.
• Low cost, due to which the foam is available to a wide range of consumers.
• The service life of the foam shell underground reaches 40 years.
• The temperature range for using polystyrene foam lies in the range from -50 to +70 ° С.
• Expanded polystyrene is resistant to the chemical and biological effects of the underground environment, does not decompose under the influence of mold, bacteria, microbes and other microorganisms.
• The foam shell is light in weight and can be easily assembled by one person in a short time without additional assistance.

An analogue of expanded polystyrene is an extruded variety (orange Penoplex), which has higher strength characteristics, density, low water absorption of about 0.2% and thermal conductivity of about 0.3 W / m ° C. Extruded foam plastic is also used to make shells for thermal insulation of pipelines, it costs a little more than regular foam plastic.

polyurethane foam

PPU polyurethane foam is the leader among all heaters in terms of thermal conductivity, due to this quality it is widely used in the manufacture of insulated pipes with a zinc or polymer outer sheath in an industrial way. Shells made of polyurethane foam of various diameters are presented on the construction market, their characteristic features are:

• Higher price compared to foam.
• Thermal conductivity coefficient 0.025 W/m °C.
• Temperature range of use from -160 to +150 °С.
• Polyurethane foam has high rigidity and strength, its density reaches 250 kg/m 3 .
• The material is resistant to chemical and biological effects, impervious to water, its water absorption is 1-2%.

Polyethylene foam

Shells and foamed PPE polyethylene (Penoplex, Energoflex) are widely used for thermal insulation of external pipelines in individual houses, they can be used outdoors to seal open sections of pipes located in a caisson well or entering a house on piles.

Due to low rigidity, polyethylene foam tubes are crushed during underground use without a rigid shell and, due to a decrease in thickness, they significantly lose their heat-insulating qualities, the main parameters of polyethylene foam are:

• Thermal conductivity 0.31 - 0.55 W / m ° C (depending on the brand, the indicator is lower for products made using the crosslinking technology).
• Temperature range -60 - +75 °С.
• Density from 25 to 100 kg/m 3 .
• Polyethylene foam does not pass or absorb moisture, its water absorption coefficient does not exceed 1%.

Mineral wool

Insulation made of glass and basalt wool is widely popular with the consumer because of its affordability and environmental friendliness, which allows their use inside residential premises. Glass wool has low rigidity and is easily crushed, basalt-based material is tougher, but due to the main drawback - high moisture absorption, quartz and basalt shells are not laid underground. Like other soft materials, mineral wool is used to insulate external water supply in caisson wells and supply points to the house.

Mineral wool has the following characteristics:

• Thermal conductivity coefficient 0.033 - 0.05 W / m ° C.
• Water absorption is about 10%.
• Temperature range from -60 to +450 °C for glass wool and -100 - +700 °C for basalt (depending on manufacturing technology).
• Density 30 - 225 kg / m 3.
• Mineral wool is resistant to most chemicals, non-flammable and does not support combustion.
• The cost of mineral wool is 2 times higher than that of expanded polystyrene.

Heat insulating paints

This type of heat insulator is classified as a high-tech product; acrylic-based paint contains perlite, foam glass particles, quartz fibers and microscopic granules containing vacuum inside the shell. Thermal paint is applied to the surface to be treated with a brush or sprayer in several layers up to 4 mm thick, it is mainly used for processing surface pipelines, containers in the national economy; in everyday life, the use of this product is not economically feasible due to its high cost.

In addition, many experts are not sure of the veracity of the information provided by the manufacturer on the thermal conductivity of the paint below air (0.0012 W / m ° K versus 0.022 - 0.025 W / m ° K), and indicate other data in independent calculations - 0, 07 W / (m ° K.) - this is lower than the values ​​\u200b\u200bof any of the typical heat insulators.

Sprayed heat insulators

In industry, spraying of liquid polyurethane or polystyrene on insulated surfaces is often used, while two components are mixed and the composition is applied to the pipe sheath with a spray gun. After spraying, the substance increases in volume and provides reliable thermal insulation of the object without cold bridges with high tightness.

Due to the high cost, the technology is rarely used in everyday life by individual homeowners, but theoretically this installation can be used to coat HDPE pipes if you agree with its owners on the price.

How to insulate water pipes yourself

Before insulating a water pipe in the ground, they choose the appropriate option, taking into account the financial costs of purchasing materials and carrying out work, they often stop at using cheap high-density foam shells. Some homeowners use a sheath of 110 mm sewer pipes, placing a HDPE pipeline in them - air is the best heat insulator.

Recently, the method of heating the outer or inner shell of pipes with a self-regulating electric heating cable has become popular; ready-made systems with fittings for entering the electric cable into the pipeline are being sold in the distribution network. Thus, the highest efficiency of work on heating the water supply is achieved.

PPS insulation with shells

Due to its low price, availability and suitable physical characteristics, a foam shell is the best option for solving the problem than insulating an underground water pipe on the street. Do-it-yourself installation of a shell on a HDPE pipeline does not present any particular difficulties for any owner and is carried out in the following sequence:

• A foam shell is put on the pipeline raised from the trench, snapping the locks and shifting each segment by approximately 1/3 in relation to the opposite element. Elements are fixed on the surface with adhesive tape or plastic ties.
• After fixing the PPS segments, the pipeline is lowered into the trench on a previously prepared sand cushion 150-200 mm thick - this will prevent the heat-insulating shell from being skewed with a possible kink.
• Then the trench is covered with soil raised to the surface, the removed sod is laid out.

Insulation of the water supply system with a self-regulating electric cable

Insulation of an underground water supply system by heating a pipe with an electric cable is one of the effective methods of combating freezing with a shallow location of the water supply line. The heating cable can be used along the entire length of the pipeline or in a separate section, it is also immersed inside the pipe shell or left outside, on the surface of the pipe. The construction market sells electric cables with fittings for entering the pipeline, equipped with sealing rubber glands, the wire itself is short and is usually placed at the outlet of the pressure pipe from the well. In this place, the efficiency of its use is the highest - heated water will flow along the entire line from the well to the house, preventing pipes from freezing. In addition, laying the cable at the junction of the pressure pipeline from the electric pump with the water line is technically easier to implement than in any other more inaccessible place, which is usually absent throughout the entire water supply line.

Pipe insulation, when the water supply is in the ground, and it is necessary to heat it with an electric cable from the outside, is carried out as follows:

• The HDPE pipeline is located on the surface of the earth next to the trench, and the area in the places where the electric cable is laid is cleaned of dirt.
• They wrap the pipe surface at the point of contact with the electric cable with aluminum foil tape - this increases the thermal conductivity of the shell at the point of contact. If the wire is placed in a straight line along the length of the pipe, one or more straight strips of foil tape are glued, with a spiral placement of the cable, the entire pipe is wrapped with tape.
• After laying the heating wire, it is screwed with the same foil tape to the surface of the pipe along the entire length.
• To reduce heat losses, it is imperative to use an outer shell made of PPS foam, PPU polyurethane foam, which is put on top of the heating wire and fixed with adhesive tape or plastic ties.

Tip: If the wire is in a straight line, it is better to purchase a shell with a cut groove on the inner sheath to accommodate the electrical cable.

• After the installation of the heating section, the cable for power supply is screwed to the pipeline along the entire length with electrical tape or tape and the assembled structure is lowered into the trench, after which it is sprinkled with earth.

For the insulation of water pipes for individual water supply, inexpensive foam shells and a self-heating electrical cable are often used, often both methods are combined. Carrying out installation work on the placement of a heat-insulating shell and a heating wire does not cause any particular difficulties and does not require high qualifications; with knowledge of the technology, all actions can be performed in a short time without much labor by one person.