Insulating materials for pipes. Heat production and consumption Thermal insulation of heating network pipelines

Thermal insulation of heating network pipelines is considered mandatory. This also applies to water supply and sewerage. After all, substances or liquids passing through pipes sometimes freeze in the cold season or gradually lose the energy they carry. Various methods help prevent this. This article will tell you about some of them.

Ways to solve the problem

You can protect networks from changes in external temperature and other influences as follows:

1. Make heating using heating cables. The devices are mounted on top of household pipelines, or are inserted inside the collector. Such devices operate from the mains.

Note! If constant heating is necessary, self-regulating wires are used, which turn off and on automatically, preventing overheating of the structures.

1. Lay communications below the ground freezing level. As a result, they have minimal contact with sources of cold.
2. Use closed underground trays. The air space here is relatively isolated, so the air around the pipelines cools slowly and prevents their contents from freezing.
3. Create a thermal insulation circuit from porous materials. This method of protection is used most often. With such insulation, a buffer zone is created that prevents the loss of heat from hot liquids and protects them from freezing.

Heating a pipe with a heating cable

This article will discuss the latter method of protecting communications.

Regulatory regulation

Thermal insulation of equipment and pipelines is based on SNiP 2.04.14-88. It contains information on materials and methods of their use, and outlines the requirements for protective circuits.

• Regardless of the temperature of the media, it is necessary to insulate any system.
• To create a thermal insulation layer, ready-made and prefabricated structures are equally used.
• Metal parts of networks must be protected from corrosion.
• It is advisable to use a multi-layer circuit design. It consists of insulation, vapor barrier and a protective layer of dense polymer, non-woven fabric or metal. Sometimes a reinforcing contour is installed, which prevents porous materials from creasing and prevents pipe deformation.

The document contains formulas by which the thickness of each layer of a multilayer structure is calculated.

On a note! Most of the requirements for thermal insulation of pipelines apply to high-power transmission networks. However, when installing household water supply and sewerage systems on your own, it is worth reading the document and taking its recommendations into account when designing and installing.

According to SNiP, thermal insulation is mandatory

Analysis of insulating materials

Polymer insulation

When choosing materials to protect pipelines from heat loss, foamed polymers are the first choice. With their assortment, you can choose insulation that will help solve the problem.

At the top of the list are the following insulation compounds:

• Polyethylene foam. The material is characterized by low density, porosity and low mechanical strength. Cylinders with a cut are made from it, which can be installed even by non-professionals. The disadvantage of pipe insulation is considered to be rapid wear and poor heat resistance.

Note! The diameter of the cylinders must match the diameter of the manifold. In this case, after installing the covers, they cannot be removed spontaneously.

• Expanded polystyrene. The insulation is characterized by low elasticity and significant strength. It is produced in the form of segments resembling a “shell”. The parts are connected using locks with tongues and grooves, as a result of which “cold bridges” are eliminated and additional fasteners can be dispensed with.
• Polyurethane foam. It is used for pre-installed thermal insulation, although it can also be used in everyday life. Available in the form of a foam or “shell”, consisting of two or four segments. The spraying method provides reliable hermetic thermal insulation of communications with a complex configuration.

Important! To protect polyurethane foam from destruction by ultraviolet radiation, it is coated with paint or non-woven fabric with good permeability.

Tubular polyethylene insulation

Fibrous materials

Insulation based mineral wool or its derivatives are no less (and sometimes more) popular than polymeric materials.

Fiber insulation insulation has the following advantages:

• low thermal conductivity coefficient;
• resistance to acids, oils, alkalis and other external factors (heating, cooling);
• the ability to maintain a given shape without the help of an additional frame;
• moderate cost.

Note! When installing thermal insulation of equipment and pipelines using such materials, make sure that the fiber is not compressed and is not exposed to moisture.

Mineral wool cylinders covered with foil

Housings made of polymer and mineral wool insulation sometimes covered with steel or aluminum foil. This heat shield reduces heat dissipation and reflects infrared radiation.

Multilayer structures

Insulation using the “pipe-in-pipe” method is done using an already installed heat-protective casing. The installer’s task in this case is to correctly connect the parts into a single structure. The final result looks like this:

• The base is in the form of a metal or polymer pipe. It is considered the supporting element of the entire device.
• Thermal insulation layer made of foamed polyurethane (PPU). It is applied using pouring technology, when a special formwork is filled with molten mass.
• Protective cover. Made from galvanized steel or polyethylene pipes. The first are intended for laying networks in open space, and the second - in the ground using channelless technology.
• In addition, copper conductors are often placed in polyurethane foam insulation, intended for remote monitoring of the condition of the pipeline, including the integrity of the thermal insulation.

Pipes that arrive at the installation site already assembled are connected by welding. To assemble heat-protective circuits, special heat-shrinkable cuffs or overhead couplings made of mineral wool, covered with a layer of foil, are used.

Multi-layer construction with galvanized steel outer shell

Installing thermal insulation on your own

The technology for thermal insulation of equipment and pipelines depends on whether the collector is laid outside or installed in the ground.

Insulation of underground networks

Work on installation and thermal protection of buried household networks is carried out in the following order:

1. Place sewer trays at the bottom of the trench.
2. Lay the pipes and carefully seal the connections.
3. Place heat-insulating casings on them and wrap the structure with vapor-proof fiberglass. For fixation, use special polymer clamps.
4. Close the tray with a lid and fill it with soil. Place the sand-clay mixture in the gap between the tray and the trench and compact it thoroughly.
5. If there is no tray, the pipes are laid on compacted soil, sprinkled with a sand-gravel mixture.

Insulation of pipes laid in a tray

Thermal protection of external pipeline

According to SNiP, thermal insulation of pipelines located on the surface of the earth is carried out as follows:

1. Clean all parts from rust.
2. Treat the pipes with an anti-corrosion compound.
3. Install a polymer “shell” or wrap the pipe with rolled mineral wool insulation.

On a note! You can cover the structure with a layer of polyurethane foam or apply several layers of insulating paint.

1. Wrap the pipe as in the previous version. In addition to fiberglass, foil film with polymer reinforcement is also used.
2. Secure the structure with steel or plastic clamps.

Compliance with the requirements for thermal insulation of pipelines is the guarantee that you will do it correctly. This means that the temperature hot water will be preserved along the route from the boiler room to the house, and the cold one will not freeze even in severe frosts.

Video instruction: pipeline insulation process

If you follow the standard execution scheme installation work and use the right materials, your plumbing and sewer system will function smoothly. Good luck!

When carrying out work on equipment and installation of pipelines, it is necessary to comply with SNiP standards. What is SNiP? These are building codes and rules for organizing construction production, compliance with standards, technical specifications and departmental regulations.

Basic norms and rules for thermal insulation

Heating networks are one of the main elements of centralized heating supply. You should strictly adhere to the rules and regulations when drawing up a pipeline thermal insulation project. Subject to compliance with SNiP, thermal insulation of pipelines will be carried out efficiently without violating standards. Thermal insulation of pipelines SNiP is provided for linear sections of pipelines, heating networks, compensators and pipe supports. Insulation of pipelines in residential buildings and industrial buildings requires strict compliance with design standards and fire safety systems.

The quality of materials must comply with SNiP, thermal insulation of pipelines should be aimed at reducing heat loss.

The main tasks of thermal insulation, features of the choice of materials

The main purpose of thermal insulation is to reduce heat loss in heating systems or hot water pipelines. The main function of insulation is aimed at preventing condensation. Condensation can form both on the surface of the pipe and in the insulating layer. In addition, according to safety standards, the insulation of pipelines must ensure a certain temperature on the insulation surface, and in case of stagnation of water, protect against freezing and icing in winter period.

Insulation of pipelines also increases the service life of pipes.

According to SNiP standards, thermal insulation of pipelines is used both for centralized heating and reduces heat loss from intra-house heating networks. What to consider when choosing thermal insulation:

• Pipe diameter. It depends on what type of insulator will be used. Pipes can be cylindrical, half-cylinders or soft mats in rolls. Insulation of small diameter pipes is mainly carried out using cylinders and half-cylinders.
• Coolant temperature.
• Conditions in which the pipes will be operated.

Types of insulation

Let's consider the most popular and frequently used materials for thermal insulation:

1. Fiberglass. Glass fiber materials are often used for above-ground piping because they have long term operation. Fiberglass has a low application temperature and is characterized by low density. High-quality fiberglass has high vibration, chemical and biological resistance.
2. Mineral wool. Insulation of pipelines with mineral wool is a very effective heat insulator. This insulating material is used in different conditions. Unlike fiberglass, which has a low application temperature (up to 180ºC), mineral wool can withstand temperatures up to 650ºC. At the same time, its heat-insulating and mechanical properties are preserved. Mineral wool does not lose its shape and is highly resistant to chemicals and acid. This material is non-toxic and has a low degree of moisture absorption.

In turn, mineral wool comes in two forms: stone and glass.

Insulation of pipelines using mineral wool is used mainly in residential buildings, public and domestic premises, as well as to protect surfaces that are subject to heating.

1. Polyurethane foam has a wide range of applications, but is quite expensive material. According to SNiP standards, thermal insulation of pipelines is environmentally friendly and does not affect human health. Polyurethane foam is resistant to external factors, non-toxic and quite durable.
2. Expanded polystyrene. In some areas of industry, foam plastic is an indispensable material, as it has low thermal conductivity and moisture absorption and a long service life. Expanded polystyrene is difficult to ignite and is an excellent sound insulator.
3. In addition to the above materials, pipeline insulation can be carried out using other less well-known, but no less practical insulation materials, such as foam glass and penoizol. These materials are durable, safe and are close relatives of polystyrene foam.

Thermal insulating paint can also provide protection against corrosion and high thermal insulation of pipes.

This is a relatively new material, the main advantage of which is that it penetrates into hard-to-reach places and is able to withstand high temperature changes.

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Features of thermal insulation of pipelines for heating networks: standards, materials, technology

When laying pipelines prerequisite is to perform work on thermal insulation of networks. This applies to all pipelines - not only water supply, but also sewerage systems. The need for this is due to the fact that in winter the water passing through the pipes can freeze. And if coolant circulates through the communications, this leads to a decrease in its temperature. To minimize heat loss, when laying pipelines they resort to installing a heat-insulating layer. What materials and methods can be used for thermal insulation of networks - this will be discussed in this article.

Thermal insulation of pipelines: ways to solve the problem

Effective protection for pipeline systems from environmental factors, mainly from outside air temperature, can be achieved by taking the following measures:

Since the last method is most often used, it makes sense to talk about it in more detail.

Standards for thermal insulation of pipelines

Requirements for thermal insulation of equipment pipelines are formulated in SNiP. IN regulatory documents contains detailed information about materials, which can be used for thermal insulation of pipelines, and in addition methods of work. In addition, the regulatory documents indicate standards for thermal insulation circuits, which are often used to insulate pipelines.

• regardless of the temperature of the coolant, any pipeline system must be insulated;
• Both ready-made and prefabricated structures can be used to create a thermal insulation layer;
• Corrosion protection must be provided for metal parts of pipelines.

It is desirable to use a multilayer circuit design when insulating pipelines. It must include the following layers:

• insulation;
• vapor barrier;
• protection made of dense polymer, non-woven fabric or metal.

In some cases, reinforcement can be built that eliminates the collapse of materials and, in addition, prevents pipe deformation.

Let us note that most of the requirements contained in the regulatory documents relate to the insulation of high-power main pipelines. But even in the case of installing household systems, it would be useful to familiarize yourself with them and take them into account when installing water supply and sewerage systems on your own.

Materials for thermal insulation of pipelines

Currently, the market offers a large selection of materials that can be used for pipeline insulation. Each of them has its own advantages and disadvantages, and in addition, application features. For the right choice heat insulator needs to know all this.

Polymer insulation

When the task is to create an effective thermal insulation system for pipelines, attention is most often paid to foam-based polymers. A large assortment allows you to choose suitable material, thanks to which it is possible to provide effective protection from the external environment and eliminate heat loss.

If we talk in more detail about polymer materials, the following can be distinguished from those available on the market.

Polyethylene foam.

The main characteristic of the material is low density. In addition, it is porous and has high mechanical strength. This insulation is used for the manufacture of cylinders with a cut. Their installation can be carried out even by people far from the field of thermal insulation of pipelines. However, this material has one drawback: structures made of polyethylene foam wear out quickly and, in addition, have poor heat resistance.

If polyethylene foam cylinders are chosen for thermal insulation of pipelines, then special attention must be paid to their diameter. It must match the diameter of the collector. Taking this rule into account when choosing an insulation design, it is possible to exclude spontaneous removal of polyethylene foam casings.

Expanded polystyrene.

The main feature of this material is elasticity. It is also characterized by high strength indicators. Protective products for thermal insulation of pipelines made from this material are produced in the form of segments that resemble a shell in appearance. Special locks are used to connect parts. They have tongues and grooves, which ensure quick installation of these products. The use of polystyrene foam shells with technical locks eliminates the occurrence of “cold bridges” after installation. In addition, during installation there is no need to use additional fasteners.

Polyurethane foam.

This material is used mainly for pre-installed thermal insulation of heating network pipelines. However, it can also be used to insulate household pipeline systems. This material is available in the form of foam or shell, which consists of two or four segments. Spray insulation provides reliable thermal insulation with a high degree of tightness. The use of such insulation is most suitable for communication systems with a complex configuration.

When using polyurethane foam in the form of foam for thermal insulation of pipelines of heating networks, you need to know that it is destroyed under the influence of ultraviolet rays. Therefore, in order for the insulating layer to last a long time, it is necessary to ensure its protection. To do this, apply a layer of paint on top of the foam or lay a non-woven fabric with good permeability.

Fibrous materials

Insulation materials of this type are mainly represented by mineral wool and its varieties. Currently, they are most popular among consumers as insulation. Materials of this type are also in high demand, like polymer materials.

Thermal insulation made using fiber insulation has certain advantages. These include the following:

• low thermal conductivity coefficient;
• resistance of the thermal insulation material to aggressive substances such as acids, alkalis, oil;
• the material is able to maintain a given shape without an additional frame;
• the cost of insulation is quite reasonable and affordable for most consumers.

Please note that during work on thermal insulation of pipelines with such materials, it is necessary to prevent compression of the fiber when laying the insulation. It is also important to ensure that the material is protected from moisture.

Products made from polymer and mineral wool insulation for thermal insulation in some cases can be covered with aluminum or steel foil. The use of such screens reduces heat dissipation.

Multilayer structures for pipeline protection

Often, to insulate pipelines, thermal insulation is installed using the “pipe-in-pipe” method. When using this scheme, a heat-protective casing is installed. The main task of the specialists installing such a circuit is to correctly connect all the parts into a single structure.

Upon completion of the work, the result is a design that looks like this:

• the basis of the heat-protective circuit is a pipe made of metal or polymer material. It is the supporting element of the entire device;
• The thermal insulation layers of the structure are made of foamed polyurethane foam. The material is applied using pouring technology; the molten mass is filled into a specially created formwork;
• protective casing. Pipes made of galvanized steel or polyethylene are used for its manufacture. The first ones are used for laying networks in open space. The latter are used in cases where pipeline systems are laid in the ground using ductless technology. In addition, often when creating this type of protective casing, copper conductors are placed in polyurethane foam-based insulation, the main purpose of which is to remotely monitor the condition of the pipeline, including the integrity of the thermal insulation layer;
• If the pipes arrive at the installation site in assembled form, then the welding method is used to connect them. Specialists use special heat-shrinkable cuffs to assemble the heat-protective circuit. Or, overhead couplings made from mineral wool, which are covered with a layer of foil, can be used.

Do-it-yourself thermal insulation of pipelines

There are a number of factors on which the technology for creating a thermal insulation layer on pipelines may depend. One of the most important is how the collector is laid - outside or in the ground.

Insulation of underground networks

To solve the problem of ensuring thermal protection of buried communications, insulation work is carried out in the following order:

Thermal insulation of external pipeline

In accordance with existing standards, pipelines located on the surface of the earth are thermally insulated as follows:

• insulation work begins with all parts being cleaned of rust;
• Next, the pipes are treated with an anti-corrosion compound. After this, they proceed to installing a polymer shell, followed by wrapping the pipes with rolled mineral wool insulation;
• Please note that a layer of polyurethane foam can be used to cover the structure, or the structure can be covered with several layers of heat-insulating paint;
• The next step is to wrap the pipe as in the previous option.

Along with fiberglass, other materials can be used, for example, foil film with polymer reinforcement. When this work is completed, the structures are secured using steel or plastic clamps.

Thermal insulation of pipelines is an important task that must be carried out when laying communications. There are many materials and technologies for its implementation. Having chosen the appropriate method of thermal insulation, you must adhere to the work technology. In this case, heat loss will be minimal, and in addition, the pipeline structure will be protected from various factors, which will have a positive effect on their service life.

kotel.guru

Today, thermal insulation of pipelines is necessary both to reduce heat losses of the corresponding systems and to lower the temperature of communications for their safe use. In addition, without it it is difficult to ensure normal operation of networks in winter, since the likelihood of freezing and failure of pipes is quite high and also dangerous.

According to existing standards, as well as rules for the safe operation of steam and hot water supply pipes, for pipeline elements with a wall temperature of more than 55 degrees and at the same time they are located in accessible places, it is recommended to use additional thermal insulation in such a way as to reduce their heating. In view of this, when calculating the thickness of the protective coating laid in a room, heat flux density standards are taken as a basis. In some cases, the temperature of the outer part of the insulation itself is also taken into account.

How to calculate insulation?

The choice of the required insulation is carried out on the basis of mathematical calculations, from which it is clear which material is better to take, its thickness, composition and other characteristics. If everything is done correctly, then it is quite possible to significantly reduce heat losses, as well as make the operation of systems reliable and absolutely safe.

Figure No. 1. Thermal insulation of pipes with foam plastic

What to pay attention to during calculations:

• - difference in ambient temperatures where communications are used;
• - the temperature of the surface that is supposed to be insulated;
• - possible loads on the pipes;
• - mechanical impacts from external influences, be it pressure, vibration, etc.;
• - the value of the thermal conductivity coefficient of the insulation used;
• - impact and corresponding magnitude from transport and soil;
• - the ability of the insulator to resist various types of deformation.

It should be noted that SNiP 41-03-2003 is considered the main document on the basis of which materials for insulation and their thickness are selected, according to specific operating conditions. The same SNiP states that for networks in which the operating temperature of the pipes is less than 12 degrees, it is necessary to additionally lay a vapor barrier when treating the surface.

Thermal insulation of pipes can be calculated in two ways, and each option can be called reliable and convenient for specific conditions. We are talking about an engineering (formula) and online version.

In the first case, the actual thickness of the optimal insulating layer is determined by a technical and economic calculation, in which the main parameter is temperature resistance. The corresponding value should be within 0.86ºC m²/W in the case of pipes with a diameter of up to 25mm, and at least 1.22ºC m²/W - from 25mm and above. SNiP provides special formulas by which the total temperature resistance of the insulating composition of cylindrical pipes is calculated.

Please note that if you have any doubts about the correctness of the calculation, it is better to seek help and advice from specialists who will carry out the work reliably and efficiently, especially since the prices for their services are quite reasonable. Otherwise, a situation may arise where the scope of certain actions may be more costly in terms of money than doing everything from scratch.

When performing the work yourself, you should also understand that all calculations of the thickness of pipe insulation are made under certain operating conditions, which take into account the materials themselves, temperature changes, and humidity.

The second method is implemented through online calculators, of which there are countless today. Such an assistant is usually free, simple and convenient. Often it also takes into account all the norms and requirements of SNiP, according to which professionals perform calculations. All calculations are carried out quite quickly and accurately. Figuring out how to use the calculator will be easy.

Initially, the required task is selected:

• 1. Preventing liquid freezing of utility pipelines.
• 2. Ensuring a constant operating temperature of protective insulation.
• 3. Insulation of communications of water heating networks of two-pipe underground channel gaskets.
• 4. Protection of the pipeline from the formation of condensation on the insulator.

Then you need to enter the main parameters by which the calculation is carried out:

• 1. Pipe outer diameter.
• 2. Preferred insulation component.
• 3. The time during which water crystallizes in an inert state.
• 4. Temperature indicator of the surface to be insulated.
• 5. Coolant temperature value.
• 6. Type of coating used (metal or non-metal).

After entering all the data, the calculation result appears, which can be used as a basis for subsequent construction and selection of materials.

Figure No. 2. Thermal insulation of central heating pipes

The right choice of insulation

The main reason for freezing of pipes is the low circulation rate of working fluids in them. A negative factor is the freezing process, which can lead to irreversible and catastrophic consequences. This is why thermal insulation of networks is extremely necessary.

Particular attention should be paid to this aspect in pipelines that operate periodically, be it water supply from a well or a country house. water heating. In order not to have to restore working systems in the future, it is still better to carry out their timely thermal insulation.

Until recently, insulation work was carried out using a single technology, with fiberglass used as a protective element. Currently, we offer a huge selection of all kinds of heat insulators designed for a specific type of pipe, having different specifications and composition.

Due to their intended use, it would be wrong to compare materials and say that one is better than the other. For this reason, below we will reveal the insulators that exist today.

According to the component representation option:

• - sheet;
• - roll;
• - filling
• - casing;
• - combined.

By area of ​​use:

• - for water drainage and sewerage;
• - for steam, heating, hot and cold water supply networks;
• - for ventilation pipelines and freezing units.

Any thermal insulation is characterized by its resistance to fire and its thermal conductivity.

• 1. Shell. Its advantage is ease of installation, optimal characteristics and high quality workmanship. It has low thermal conductivity, fire resistance, and a minimal level of moisture absorption. Suitable for protecting heating networks and water supply systems.

Figure No. 3. Shell pipe insulation

• 2. Mineral wool. It is usually supplied in rolls and is used for processing pipes whose coolant has a very high temperature. This option is only advisable for small processing areas, since mineral wool is quite an expensive material. Its installation is carried out by winding communications and fixing them in a given position with stainless steel wire or twine. Additionally, it is recommended to carry out waterproofing, since cotton wool easily absorbs moisture.

Figure No. 4. Insulation mineral wool cylinder

• 3. Expanded polystyrene. The design of thermal insulation of this type is more like two halves, or a shell, through which the pipeline is insulated. The option can safely be called high-quality and convenient in terms of installation. Due to minimal moisture absorption and low thermal conductivity, high fire resistance, minimal thickness, polystyrene foam is excellent for protecting heating and water supply networks.

Figure No. 5. Foam insulation

• 4. Penoizol. Thermal insulation has similar parameters to polystyrene foam, although with a significant difference in installation. Application is carried out using an appropriate sprayer, since the material is in a liquid state. After complete drying, the entire treated surface of the pipe acquires a dense and durable hermetic structure that reliably maintains the temperature of the coolant. A significant advantage is that there is no need to use additional fasteners to secure the material. The only downside is that it is expensive.

Figure No. 6. Insulation of pipes with foam insulation

• 5. Penofol with foil base. An innovative product that is becoming more popular every day. It consists of polyethylene foam and aluminum foil. The two-layer design allows both maintaining the temperature of the networks and heating the space, since the foil is able to reflect and accumulate heat. We especially pay attention to the low combustion ability, high environmental data, ability to withstand high humidity and significant temperature changes.

Figure No. 7. Pipe insulated with foil penofol

• 6. Foamed polyethylene. Thermal insulation of this type is very common, and it is often found on water mains. A special feature is the ease of installation, for which it is enough to cut the required size of the material and wrap it around the production line, fixing it with tape. Foamed polyethylene is often supplied in the form of a wrap for a pipe of a certain diameter with a technological cut, which is put on the desired section of the system.

Figure No. 8. Foamed polyethylene

It is important to know that when insulating pipelines, all insulation materials, except penoizol, require the additional use of waterproofing and adhesive tape for fixation.

From all of the above, it is clear that there are quite a lot of options for processing pipes, and the choice is very large. Experts advise paying attention to the conditions in which each material will be used, its characteristics and installation method. Naturally, competent thermal insulation calculations also play an important role, which will allow you to be confident in the work done.

Video No. 1. Thermal insulation of pipes. Installation example

Methods of thermal insulation of pipelines

SNiP specifications and many professionals recommend following the following options for protecting trunk lines:

• 1. Air insulation. Typically, communication systems running in the ground are protected by thermal insulation of a certain thickness. However, the factor that the freezing of the ground goes from the top to the bottom is often not taken into account, while the heat flow from the pipes tends to the top. Since the pipeline is protected on all sides by a component of minimal thickness, the rising heat is also insulated. In this case, it is more rational to install insulation over the upper part of the line, so that a thermal layer is formed.
• 2. Use of insulation and heating element. Great as an alternative to traditional options. In this case, the point is taken into account that the protection of lines is seasonal, and laying them in the ground is not rational for financial reasons, as is the use of a large thickness of insulator. According to SNiP rules and manufacturers' instructions, the cable can be located both inside and outside the pipes.
• 3. Laying a pipe in a pipe. Here, in polypropylene pipes additionally separate pipes are installed. The peculiarity of the method is that it is possible to warm up the systems almost always, including using the principle of suction of warm air masses. In addition, if necessary, an emergency hose can easily be laid in the existing gap.

Conclusion

Summarizing all of the above, we can say that there are a lot of important points and nuances for processing and protecting the pipeline. In any situation, it is always better to start by calculating the required insulation, choosing its type, thickness and cost. The option of its installation also plays an important role, since the most problematic conditions will require additional significant cash injections into the construction of the necessary systems.

A perfect approach to the selection of thermal insulation can ultimately lead to minimal costs and a reduction in the complexity of the work performed. High-quality selection of the required insulating components will effectively maintain the temperature of the coolant in the pipes, as well as significantly increase their service life.

Video No. 2. Universal thermal insulation for pipes

In order to reduce heat loss and protect above-ground pipelines from freezing, the project provides for the laying of pipelines in thermal insulation with electrical heating. For insulation volumes, see clause 6.6.2, table 19.

Thermal insulation design was carried out in accordance with SP 61.13330.2012 (updated edition of SNiP 41-03-2003) “Thermal insulation of equipment and pipelines”. The project uses insulating materials that are characterized as non-flammable according to SNiP 21-01-97*.

Pipelines are insulated after they have been tested and all defects found have been eliminated.

The design, material, thickness of thermal insulation and cover layer are given below (Table 21).

Thermal insulation design of above-ground pipelines

Diameter	Thermal insulation material	Pokrovny	Fastening integumentary	Coloring surfaces pipeline before applying the thermal insulation layer
22,32,57,108	Heat-insulating cylinders made of mineral wool on synthetic binder grade 150 GOST 23208-2003	GOST 14918-80*	Bandage made from cold-rolled low-carbon steel tape OM-0.5x20 Bandage buckles TU 36.16.22-64-92
				Enamel KO-811
	thickness – 60 mm	thickness - 0.5 mm		GOST 23122-78*
				(three layers)
159,219,273	Thermal insulation mats	Galvanized steel grade OTSB-PN-NO GOST 19904-90/ON-KR-2 GOST 14918-80*
	on-line piercing
	mineral wool
	brand 125
	GOST 21880-2011
	thickness – 80 mm	thickness – 0.5 mm

Thermal insulation of underground pipelines is made of thermal insulating half-cylinders made of extruded polystyrene foam. Waterproofing is carried out with protective wrap Polylen-OB according to TU 2245-004-01297859-99. The design of thermal insulation is shown below (Table 22).

Thermal insulation design of underground pipelines

Pipe diameter, mm	Thermal insulation material	Anti-corrosion insulation before applying a thermal insulation layer	Cover layer
	Semi-cylinders "Penoplex 45"	Primer NK-50	Protective wrap "Polylen-OB" TU 2245-004-01297859-66
	TU 5767-001-01297858-02 (or equivalent)	TU 5775-001-0129-7859*-95
89, 108	thickness – 50 mm	Film "Polylen 40-LI-63"
	Segments "Penoplex 45" TU 5767-001-01297858-02 (or equivalent)	TU 2245-003-01297859-99
		Protective wrap
	thickness – 50 mm	"Polylen-OB"
		TU 2245-004-01297859-66

Fittings, flange connections, and pipeline parts are thermally insulated with the same materials as the pipelines. Removable thermal insulation structures are provided for fittings, flange connections, as well as in places for measuring and checking the condition of pipelines.

Anti-corrosion insulation of pipelines

The project provides for external anti-corrosion protection of steel process pipelines.

Non-thermally insulated overhead pipelines (T11, T21 – diethylene glycol pipeline) should be coated with PF-115 enamel GOST 6465-76* in two layers over primer GF-0119 GOST 23343-78* in one layer.

Pipelines laid in thermal insulation with electrical heating are coated with KO-811 enamel in accordance with GOST 23122-78* (three layers).

To protect underground pipelines from corrosion, cover the outer surface of the pipes with anti-corrosion insulation in accordance with the requirements of GOST R 51164-98 and RD 39-132-94, the insulation thickness is at least 2 mm.

To protect pipelines and connecting parts from soil corrosion during underground installation, a reinforced protective film coating is adopted, and ECP products are also used.

During the transition from above-ground to underground installation, insulating flange connections are installed, providing electrical isolation of a cathodically protected object from a cathodically unprotected one and can significantly reduce the risk of corrosion caused by the influence of stray currents.

The project provides for the following design of the film insulating coating:

• primer “NK-50” according to TU 5775-001-01297859-95;
• film “Polylen 40-LI-63” according to TU 2245-003-01297859-99 in two layers;
• protective wrapper “Polylen-0B” according to TU 2245-004-0127859-99 in one layer.

When transitioning pipelines from underground to above-ground installations, it is necessary to overlap the protective coatings with an overlap of at least 0.5 m in both directions.

Application of insulation must be carried out on a previously prepared surface. The preparation of parts and pipelines before applying anti-corrosion coatings should be carried out according to scheme No. 2 of Table 3 or according to Table B.1 (Appendix B) of GOST 9.402-2004. In the absence of grease and marking paints, degreasing before mechanical processing is not performed. Mechanical cleaning of the surface from oxides is carried out in accordance with Table 9 of GOST 9.402-2004 up to degree 2.

Monitoring of corrosion rates must be carried out in conjunction with operational monitoring of pipelines and equipment using non-destructive methods (inspection of pipelines, technical examination of equipment).

It is necessary to take into account not only design features equipment and pipelines, when selecting the appropriate type of insulating material, but also other factors. This is required by SNiP for thermal insulation of equipment and pipelines.

Let's consider the factors influencing the choice of insulating materials.

1. The intended purpose of the insulating materials themselves.
2. Spatial orientation.
3. Possible atmospheric influences.

We will consider below in this article what requirements apply to thermal insulation of pipelines and equipment.

What function does protection perform?

One of the purposes of thermal insulation of equipment and pipelines is to reduce heat flow values ​​inside structures. The materials are covered with protective coatings, which guarantee complete safety of the layer under any operating conditions.

Much attention is paid to thermal insulation issues in various areas of industry and energy. In structures and equipment in these industries, thermal insulation becomes one of the most important components.

The result is not only a reduction in heat losses during interactions with the environment. But also expanding opportunities to maintain optimal thermal conditions.

Thermal insulation of pipelines and its essence

The calculation for thermal insulation is artificially adapted to all operating conditions characteristic of a particular pipeline or equipment. The conditions themselves are formed with the participation of:

1. Building materials to prepare for the changing seasons.
2. Humidity, which accelerates heat transfer.

Professional companies provide performers with engineering data for future construction. Which specific requirements have the greatest impact on the selection of suitable insulation coatings?

• Thermal conductivity.
• Soundproofing.
• Ability to absorb or repel water.
• Vapor permeability level.
• Non-flammability.
• Density.
• Compressibility.

About the thickness of pipeline and equipment insulation

It is imperative to rely on standards to determine the permissible thickness for each specific equipment. In them, manufacturers write about what density is maintained in the heat flow. SNiPs provide algorithms for solving various formulas along with the formulas themselves.

To identify the minimum thickness of pipelines in a given case, a limit is determined based on the permissible loss values ​​in certain sections.

Polyurethane insulation

Pipelines with this type of insulation are used when it is necessary to lay a structure above the ground, of a ductless type. During production, we try to introduce as many new technologies as possible.

Only materials of the highest quality are allowed into the process. They are tested in large quantities in advance; according to the joint venture, the thermal insulation of equipment and pipelines does not allow defects.

The use of polyurethane foam reduces heat losses. And provides durability for the thermal insulation material itself. The composition of polyurethane foam includes environmentally friendly components. This is Izolan-345, as well as Voratek CD-100. Compared to mineral wool, the thermal insulation characteristics of polyurethane foam are much higher.

PPM and APB insulation

For more than thirty years, so-called polyfoam insulation has been used in pipelines. The main type in this case is polymer concrete. Its characteristics can be described as follows:

• Inclusion in group G1 during flammability tests in accordance with current GOSTs.
• Operating temperature allowing to maintain 150 degrees.
• The presence of an integral type structure, which combines the functions of a waterproofing coating along with a layer of heat insulation.

Until recently, some regional manufacturers were producing reinforced foam concrete insulation. This material has a very low density. The thermal conductivity, on the contrary, is pleasantly surprising.

APB has the following set of advantages:

1. Durability.
2. Waterproof coating with high vapor permeability.
3. The equipment is not subject to corrosion.
4. The ability of the pipeline to withstand high temperatures.
5. Fire resistance.

Such pipes are good because they can be used for coolant at almost any temperature. This applies to networks not only with water, but also with steam. The type of gasket does not matter.

It is even possible to combine it with underground channelless and channel varieties. But products with PPU thermal insulation are still considered a more technological solution.

About the thermal conductivity coefficient

While the equipment is in operation, humidification becomes possible - this is what most affects the calculated thermal conductivity coefficient.

Special rules exist for adopting a coefficient that assumes an increase in the thermal conductivity of insulating coatings. They are based on GOSTs and SNiPs, but other factors cannot be avoided:

• soil moisture according to SP.
• The variety that includes thermal insulation material.

The coefficient is equal to one if we are talking about pipes with PPU insulation, sheathed in high-density polyethylene. It does not matter what the moisture level is in the soil where the equipment is installed. The coefficient will be different for equipment and pipes with APB insulation, which have an integral structure. And allowing for the possibility that the insulating layer may dry out.

1. 1.1 – coefficient level for structures located in soils with a large amount of water, according to SP.
2. 1.05 – for soils where the amount of water is not so large.

For practical calculations, special engineering techniques are used. They usually take into account resistance to external influences from the environment. A two-pipe installation involves taking into account the mutual thermal influence of each element on the others.

One of the determining factors when choosing the appropriate thickness is the cost factor. And these indicators can be determined individually for each specific region.

There are other parameters that matter. Like the calculated coolant temperature. It is also important at what level the temperature in the environment is.

What other rules must be followed?

The production of equipment and pipes along with thermal insulation is carried out not only by Russian, but also by foreign manufacturers.

Some technological pipe rolling lines are capable of producing a total volume of up to three kilometers of rolled pipe in one day (with a pipe length of up to 12 meters). The diameter of the products is in the range of 57-1020 millimeters. The protective wrapper can be made of polyethylene or metal.

But there are still certain shortcomings that cannot be eliminated at the production stage. They were identified by experts through repeated practical tests.

1. During transportation of metal-coated pipes, deformations may occur in the insulating coating.
2. Polyurethane insulation peels off from the pipe, which is subjected to heat treatment.
3. The protective structure is detached from the outer or inner layers of the pipe.

The main problem is the ability of metal pipelines to expand. Temperature heating leads to the fact that the quality characteristics deteriorate. Therefore, protection against such types of influence becomes an important factor.

The stability and stability of the thermal insulation of an object is most influenced by the length of the pipe itself. It does not matter what media it is used to transmit. The longer the length, the higher the likelihood that the layer will simply collapse.

Therefore, this parameter must be selected as carefully as possible. The experts themselves have developed optimal pipe lengths and diameters that will allow the structure to be preserved regardless of the operating conditions in which it is located.

They rely only on SNiP, because the thermal insulation of equipment and pipelines is especially demanding in terms of compliance with the rules.

When laying pipelines, a prerequisite is to perform work on thermal insulation of the networks. This applies to all pipelines - not only water supply, but also sewerage systems. The need for this is due to the fact that in winter the water passing through the pipes can freeze. And if coolant circulates through the communications, this leads to a decrease in its temperature. To minimize heat loss, when laying pipelines they resort to installing a heat-insulating layer. What materials and methods can be used for thermal insulation of networks - this will be discussed in this article.

Thermal insulation of pipelines: ways to solve the problem

Effective protection for pipeline systems from environmental factors, mainly from outside air temperature, can be achieved by taking the following measures:

Since the last method is most often used, it makes sense to talk about it in more detail.

Standards for thermal insulation of pipelines

Requirements for thermal insulation of equipment pipelines are formulated in SNiP. Regulatory documents contain detailed information about materials which can be used for thermal insulation of pipelines, and in addition methods of work. In addition, in regulatory documents standards for thermal insulation contours are indicated, which are often used to insulate pipelines.

• regardless of the temperature of the coolant, any pipeline system must be insulated;
• Both ready-made and prefabricated structures can be used to create a thermal insulation layer;
• Corrosion protection must be provided for metal parts of pipelines.

It is desirable to use a multilayer circuit design when insulating pipelines. It must include the following layers:

• insulation;
• vapor barrier;
• protection made of dense polymer, non-woven fabric or metal.

In some cases reinforcement can be built, which eliminates the collapse of materials, and in addition prevents pipe deformation.

Let us note that most of the requirements contained in the regulatory documents relate to the insulation of high-power main pipelines. But even in the case of installing household systems, it would be useful to familiarize yourself with them and take them into account when installing water supply and sewerage systems on your own.

Materials for thermal insulation of pipelines

Currently, the market offers a large selection of materials that can be used for pipeline insulation. Each of them has its own advantages and disadvantages, and in addition, application features. To choose the right heat insulator, you need to know all this.

Polymer insulation

When the task is to create an effective thermal insulation system for pipelines, attention is most often paid to foam-based polymers. A large assortment allows you to choose the right material, thanks to which can provide effective protection from the external environment and eliminate heat loss.

If we talk in more detail about polymer materials, the following can be distinguished from those available on the market.

Polyethylene foam.

The main characteristic of the material is low density. In addition, it is porous and has high mechanical strength. This insulation is used for the manufacture of cylinders with a cut. Their installation can be carried out even by people far from the field of thermal insulation of pipelines. However, this material has one drawback: structures made of polyethylene foam, wear out quickly and in addition to this they have poor heat resistance.

If polyethylene foam cylinders are chosen for thermal insulation of pipelines, then special attention must be paid to their diameter. It must match the diameter of the collector. Taking this rule into account when choosing an insulation design, it is possible to exclude spontaneous removal of polyethylene foam casings.

Expanded polystyrene.

The main feature of this material is elasticity. It is also characterized by high strength indicators. Protective products for thermal insulation of pipelines made from this material are produced in the form of segments that resemble a shell in appearance. Special locks are used to connect parts. They have tongues and grooves, which ensure quick installation of these products. The use of polystyrene foam shells with technical locks eliminates the occurrence of “cold bridges” after installation. In addition, during installation there is no need to use additional fasteners.

Polyurethane foam.

This material is used mainly for pre-installed thermal insulation of heating network pipelines. However, it can also be used to insulate household pipeline systems. This the material is available in the form of foam or shell, which consists of two or four segments. Spray insulation provides reliable thermal insulation with a high degree of tightness. The use of such insulation is most suitable for communication systems with a complex configuration.

When using polyurethane foam in the form of foam for thermal insulation of pipelines of heating networks, you need to know that it is destroyed under the influence of ultraviolet rays. Therefore, in order for the insulating layer to last a long time, it is necessary to ensure its protection. To do this, apply a layer of paint on top of the foam or lay a non-woven fabric with good permeability.

Fibrous materials

Insulation materials of this type are mainly represented by mineral wool and its varieties. At present They are the most popular among consumers as insulation. Materials of this type are also in high demand, like polymer materials.

Thermal insulation made using fiber insulation has certain advantages. These include the following:

• low thermal conductivity coefficient;
• resistance of the thermal insulation material to aggressive substances such as acids, alkalis, oil;
• the material is able to maintain a given shape without an additional frame;
• the cost of insulation is quite reasonable and affordable for most consumers.

Please note that during work on thermal insulation of pipelines with such materials fiber compression must be avoided when laying insulation. It is also important to ensure that the material is protected from moisture.

Products made from polymer and mineral wool insulation for thermal insulation in some cases can be covered with aluminum or steel foil. The use of such screens reduces heat dissipation.

Multilayer structures for pipeline protection

Often, to insulate pipelines, thermal insulation is installed using the “pipe-in-pipe” method. When using this scheme, a heat-protective casing is installed. The main task of the specialists installing such a circuit is to correctly connect all the parts into a single structure.

Upon completion of the work, the result is a design that looks like this:

• the basis of the heat-protective circuit is a pipe made of metal or polymer material. It is the supporting element of the entire device;
• The thermal insulation layers of the structure are made of foamed polyurethane foam. The material is applied using pouring technology; the molten mass is filled into a specially created formwork;
• protective casing. Pipes made of galvanized steel or polyethylene are used for its manufacture. The first ones are used for laying networks in open space. The latter are used in cases where pipeline systems are laid in the ground using ductless technology. In addition, often when creating this type of protective casing, insulation based on polyurethane foam copper conductors are laid, the main purpose of which is remote monitoring of the condition of the pipeline, including the integrity of the thermal insulation layer;
• If the pipes arrive at the installation site in assembled form, then the welding method is used to connect them. Specialists use special heat-shrinkable cuffs to assemble the heat-protective circuit. Or overhead couplings can be used, made on the basis of mineral wool, which are covered with a layer of foil.

Do-it-yourself thermal insulation of pipelines

There are a number of factors on which the technology for creating a thermal insulation layer on pipelines may depend. One of the most important is how the collector is laid - outside or in the ground.

Insulation of underground networks

To solve the problem of ensuring thermal protection of buried communications, insulation work is carried out in the following order:

Thermal insulation of external pipeline

In accordance with existing standards, pipelines located on the surface of the earth are thermally insulated as follows:

• insulation work begins with all parts being cleaned of rust;
• Next, the pipes are treated with an anti-corrosion compound. After that proceed to installing a polymer shell followed by wrapping the pipes with rolled mineral wool insulation;
• Please note that a layer of polyurethane foam can be used to cover the structure, or the structure can be covered with several layers of heat-insulating paint;
• The next step is to wrap the pipe as in the previous option.

Along with fiberglass, other materials can be used, for example, foil film with polymer reinforcement. When this work is completed, the structures are secured using steel or plastic clamps.

Thermal insulation of pipelines is an important task that must be carried out when laying communications. There are many materials and technologies for its implementation. Having chosen the appropriate method of thermal insulation, you must adhere to the work technology. In this case heat loss will be minimal, and in addition, the pipeline structure will be protected from various factors, which will have a positive effect on their service life.