Thermal insulation of pipelines of various types is one of the priority areas of modern energy saving. Due to the use of high-quality materials with unique characteristics and the best technologies, it is possible to significantly reduce heat losses, as well as protect the pipes themselves and, accordingly, the transported substances from the negative effects of significant temperature changes.
The structure of the substance that is part of the insulation
Thermal insulation of pipes: an important need
High-quality and inexpensive insulation of pipeline systems is a must everywhere, from small country houses to large industrial enterprises, shopping malls, etc.
If thermal insulation is included in the project from the very beginning and it is carried out at the first stages of construction, then significant funds can be saved on the repair and operation of backbone networks.
If we talk about the requirements for insulating materials for pipes, then they depend on the specific types of highways, as well as their operating conditions. In general, the main task of thermal insulation is to protect the insulated surfaces for the longest periods.
Often, all these requirements are met by heat insulating materials from mineral fibers - their characteristics are simply ideal for various types of pipelines.
Insulation of pipelines indoors
It should be noted that in the case of the use of mineral wool insulation for water supply networks, air conditioning and refrigeration equipment, it is possible to effectively protect structures from freezing, corrosion, and condensation.
In addition, high-quality materials will help reduce heat losses in the lines and significantly extend the period of trouble-free operation.
Main characteristics and features
Modern mineral wool thermal insulation is a fibrous material that is obtained by melting mountain silicates, slags, and their mixtures. Depending on the type of feedstock used, insulating mineral wool can be either stone or slag.
In the first case, such rocks as basalt, limestone and diabase are used, while in the second case, slags and wastes of metal production are used.
Heat insulators made in the form of cylinders
Due to the processing of raw materials under high pressure and with a special temperature regime, it is possible to give mineral wool unique characteristics, in particular, in terms of its level of heat and sound insulation, as well as resistance to the negative effects of many factors, the material simply has no equal.
Yes, and in terms of cost, mineral wool is in a fairly affordable range - its price is much lower than that of polymer analogues.
Cylinders made of mineral wool - convenient and practical thermal insulation
High-quality and modern heat-insulating pierced mats made of mineral wool are actively used to insulate pipes of various diameters and lengths. But at the same time, it should be noted that special cylinders made on the basis of mineral wool are more actively used.
These are cylindrical products, often made of basalt using a special winding technology.
An example of the use of basalt fiber insulation for the insulation of external pipelines
Due to the use of cylinders and semi-cylinders, the technology of thermal insulation of pipelines with mineral wool becomes extremely simple, comes down to performing just a few basic steps.
Due to the large selection that offers today domestic market heaters, you can choose the best option for each type of pipe, providing them with the best conditions for operation for a long time.
Advice. Cylindrical mineral wool insulation should be chosen directly for the outer diameter of the pipe. In this case, it will be possible to achieve maximum insulation performance, to exclude the formation of condensation and corrosion under the wool layer.
As a rule, in most cases, all mineral wool mats and cylinders are additionally covered with a layer of aluminum foil, fiberglass, and fiberglass - this helps protect them from damage, fire and other negative factors.
Due to the special packaging in which the products are sold, it is very convenient to store and transport them.
Photo of material with an additional coating of aluminum foil
Benefits of using mineral wool cylinders
A heat-insulating cord made of mineral wool or a full-fledged cylinder made of a unique material is the best option for insulating pipelines of various types.
The use of just such a form of heat insulator has a lot of advantages and advantages, among which are:
- Low thermal conductivity. Inside the cylinder layer of mineral wool contains a large volume of air, which (thanks to the thin and flexible fibers of the material) remains motionless, does not allow heat to pass through;
- Resistant to fire and high temperatures. The instruction for cylinders made of mineral wool says that they are non-combustible, do not melt and do not lose their shape even under the influence of extremely high temperature conditions (from -150C to + 750C);
- Long term trouble-free operation. The use of basalt rocks and slag as feedstock prolongs the service life of mineral wool insulation by almost decades. On average, even the most inexpensive heat insulator can last 50-60 years without losing its performance;
Variety of shapes and sizes of insulation materials
- Durability and reliability. Mineral wool easily withstands even the highest loads and pressures. Cotton wool has closely interwoven fibers, and therefore its density and strength are significantly increased;
- Hydrophobicity. The insulation has an increased resistance to moisture due to the protective layers of foil and fiberglass, due to this it is not afraid of direct water ingress. If necessary, you can additionally process the materials with special water-repellent compounds;
Advice. If it is intended to use the pipeline in conditions of high humidity, then it is best to subject the mineral wool to additional processing. Thus, it will be possible to extend the life of the line, significantly reduce the cost of maintenance and repair.
- Availability. The price of mineral wool heat insulators is in an affordable range, which allows them to be used to insulate even long pipelines;
- Ease of use. Everyone can insulate even large volumes of pipelines with their own hands. The process of thermal insulation is quite simple, it requires the use of only improvised materials;
Mineral wool semi-cylinders
- Environmental friendliness. Cylinders and semi-cylinders made from natural raw materials are absolutely safe for human health and environment. As a result, mineral wool materials can be used to insulate any pipes.
The effectiveness and benefits of using mineral wool pipe insulation
Thermal insulation materials made of mineral wool, made in the form of cylinders, allow achieving high efficiency, providing better operating conditions for highways:
- Heat losses in straight sections of pipelines when using mineral wool will be reduced by almost 3.6 times. Unlike other materials, it loses only 8% of heat, which is very important, especially for hot water systems;
- Reducing the time spent on thermal insulation. It is no longer necessary to wind the pipes with fiberglass and mineral wool mats - the cylinders have an inner diameter similar to the dimensions of the main line;
Simple cutting of material with a knife during installation
- Protective coatings will help prevent damage to the cylinders from the insulation, maintain the level of thermal insulation for a long time. At the same time, the thickness of the insulating layer is not lost throughout the entire service life.
Advice. To simplify the process of covering pipes with mineral wool insulation in the form of cylinders and semi-cylinders, the use of a construction knife will help. Cutting materials with such a tool is much easier, and dimensional accuracy can be maintained.
Thermal insulation materials made on the basis of mineral wool in the form of cylinders are an excellent option for pipes of any type, size and length.
It should be noted that the domestic market is filled with offers from various manufacturers, you can choose the right type of insulation specifically for a particular pipeline with a certain diameter, length and types of transported material.
The use of special coatings for additional protection of heat-insulating materials from the negative effects of mechanical damage and other factors
Mineral wool is a heater with unique characteristics, the best option if it is necessary to protect pipelines of various categories from the negative effects of temperature changes, the negative effects of various factors, ranging from chemicals to mechanical damage.
Due to the convenient form and affordable cost, it is possible to choose the most optimal heat insulators for each specific case, ensuring the performance of a wide range of work without loss of time and finances.
In the presented video in this article you will find additional information on this topic. The process itself is very simple, accessible to everyone, even those who are not prepared for construction work.
Source: pro-uteplenie.ru
Insulation of pipelines with mineral wool
Various materials are used to insulate heating pipes and other communications. One of the most common is polyethylene foam covers (usually gray color). But they can only be used for communications with a small diameter, for example, for polypropylene pipes. If we are talking about central networks, then the thermal insulation of pipelines with mineral wool has no alternatives.
For which pipelines mineral wool is used
Mineral wool can be used in combination with other heaters.
Thermal insulation of pipelines with mineral wool is a set of measures aimed at reducing heat transfer in the following communication systems:
- heating;
- hot water supply;
- water pipes;
- sewerage;
- conditioning.
Mineral wool for pipeline insulation works on the principle of a thermos, when hot remains hot and cold remains cold. In addition to preventing heat transfer, the insulating material transfers the dew point, respectively, condensation does not form on the pipes. Also, all types of mineral wool have high soundproofing and vibration-absorbing characteristics. This aspect is extremely important when insulating air conditioning ducts and air heating houses.
Mineral wool insulation for pipes is used inside unheated premises, in underground and above-ground laying of communications. In the last two cases, particularly thorough insulation is required, since heat losses due to wind, snow, and moisture in the ground increase greatly, especially in cold climatic zones.
Probably the smallest home heaters are fan heaters with ceramic heaters.
Read more about modern heaters for summer cottages in this article.
What materials are used for pipe insulation
Shells with foil for pipe insulation.
Mineral wool is the general name for all fibrous thermal insulation materials, for the production of which various kinds of minerals are used. IN civil engineering only two types of mineral wool for pipes are used:
Glass wool is made from quartz or its derivative (glass). The fibers of this material are long and soft, they do not break, therefore, material of any configuration is suitable for insulating pipes with fiberglass mineral wool. Glass wool is produced in plates, mats, rolls and cylinders. If you do not take into account the cylinders (shells), then the differences are only in the length of the material. The slabs are the shortest, the mats are twice as long, and the rolls are the longest. The size depends on the manufacturer, there is no general standard. Thickness from 50 to 150 mm. Each of the products can be laminated foil.
There is a pattern: with an increase in the density of the heat-insulating material, its thermal conductivity also increases, that is, it works worse as a heater.
Mineral wool for insulating pipes in cylinders consists of two parts - this is a sleeve, the internal section of which is equal to the outer diameter of the communications. Conditional passage of shells varies from 18 to 1024 mm. Insulation thickness from 20 to 80 mm, standard length 1 m. They can also be covered with foil on the outside. General characteristics for all fiberglass insulation:
- thermal conductivity lambda 0.036-0.042 W/m*k;
- high hygroscopicity;
- flammability class NG.
Fiberglass mineral wool for pipelines is much lighter than basalt insulation, respectively, its density is also lower. Basalt wool for pipes is produced only in shells and lamella rolls - this is a set of narrow rectangles (lamellas) glued to the base. Basalt is a volcanic rock, essentially a stone, hence the name of the material. Stone wool is very dense, its fibers are short and inelastic. They break, and because of this, dust is formed. A priori, wrapping communications with an ordinary basalt slab will not work, it will simply break.
Be aware that a home air heater can burn oxygen. Pay attention to the configuration of the heating element.
Here is the principle of operation of a fireplace with a water circuit, which is able to heat a medium-sized house.
Pipeline insulation technique
This state of affairs leads to enormous heat losses.
Thermal insulation of pipes with mineral wool is carried out taking into account the high hygroscopicity of the material, that is, the properties of the insulation to absorb and retain moisture. At the same time, when wet, the insulator loses its qualities, and instead of warming, on the contrary, it accelerates heat loss. Therefore, you need to use waterproofing. In this capacity, roofing material or foil is often used.
The foil on the thermal insulation itself also saves the material from moisture, but the ends remain unprotected, through which water can easily penetrate inside. The method of mounting roll insulation is extremely simple:
- communications are wrapped in mineral wool for pipelines so that each next turn overlaps the previous one by 5 cm;
- insulation is fixed with wire;
- according to the same principle, waterproofing is screwed on and clamped with stainless wire.
If the insulation of pipelines with mineral wool is carried out with foil materials, then the reflective surface is placed outside. Mounting cylinders is even easier. You just need to put the shell on the pipe, like a cover. A special adhesive is applied to the longitudinal section of the heat-insulating cylinder, which is protected by a paper tape. During installation, the tape is removed.
At underground laying of communications any thermal insulation must be protected from mechanical influences, because the weight of the earth is rather big. Therefore, pipes together with thermal insulation are placed in plastic sleeves. Suitable sewer PVC pipes of large diameter. There are also special insulated pipes coated with a polymer layer on sale.
Mineral wool for pipeline insulation is of two types: glass wool and stone (basalt) wool. Any glass wool is used (plates, mats, rolls, with and without foil). It is soft and elastic, it can be wrapped around communications without any problems. Stone wool is inelastic, so only lamella mats can be used. There are also heat-insulating cylinders made of mineral wool - these are sleeves, the conditional passage of which must be equal to the outer diameter of the pipe. Cylinders come in different diameters, thicknesses, with and without foil.
Source: utepleniedoma.com
Pipeline for technological and network purposes
Thermal insulation structures for technological pipelines, heating networks, as well as gas ducts and indoor equipment with application temperatures from -180 °С to +650 °С.
- Energy efficiency - reduction of heat losses through insulation during the estimated service life;
- Operational reliability and durability - to withstand without reducing the heat-shielding properties and destruction of operational temperature, mechanical, chemical and other influences during the estimated service life;
- Safety for the environment and maintenance personnel during operation and disposal (meet the requirements of the technical regulation on fire safety according to FZ-123).
The following products are used to solve this problem:
- Winding cylinders ROCKWOOL 150;
- WIRED MAT mats;
- TEXMAT mats.
Winding cylinders ROCKWOOL 150
Winding cylinders ROCKWOOL 150 hydrophobized on a synthetic binder are hollow products that are made of stone wool based on rocks of the basalt group.
WIRED MAT
It is possible to perform thermal insulation using WIRED MAT mats, which can be used for thermal insulation of pipelines with an outer diameter of 45 mm or more.
For pipelines with an outer diameter of 45 to 216 mm inclusive, a heat-insulating layer is provided:
- Bandages from tape 0.7 x 20 mm when laying mats in one layer with an insulation thickness of 40–100 mm. It is recommended to install at least three bandages per 1 meter of pipeline length (per mat width);
- Rings made of wire with a diameter of 2 mm for the inner layers of two- and three-layer structures with a thickness of 120 mm or more. Installation of three wire rings on 1 meter of length of the pipeline is provided. Bandages from tape 0.7 x 20 are installed along the outer layer in the same way as in a single-layer construction.
For pipelines with an outer diameter of 219 or more, a heat-insulating layer is provided:
- Tape bandages 0.7 x 20 mm and wire hangers 1.2 mm for laying mats in one layer with an insulation thickness of 40–100 mm. It is recommended to install at least three bandages per 1 meter of pipeline length (per mat width);
- Rings made of wire with a diameter of 2 mm for the inner layers of two- and three-layer structures with a thickness of 120 mm or more and pendants. Hangers of the second and third layers are attached to the hanger of the first layer from below. Bandages made of 0.7 x 20 tape are installed on the outer layer in the same way as in a single layer construction.
Hangers are not installed on vertical pipelines. The heat-insulating layer is fastened with bandages and wire rings up to a diameter of 476 mm incl. To prevent slipping of rings and bandages, wire strings with a diameter of 2 mm are used. Unloading devices are installed on vertical pipelines with a step of 3-4 meters in height.
Mats TECH MAT
It is also possible to use TEX MAT stone wool mats, installation is carried out similarly to WIRED MAT mats.
The heat-insulating layer of TEX MAT mats is laid with a seal in thickness:
- Up to 1.35 - with an outer diameter up to 108 mm inclusive;
- 1.2 - with an outer diameter of 133 mm or more, including flat surfaces.
Source: www.rockwool.ru
Insulation of pipes with mineral wool
- Features of thermal insulation
- Advantages and disadvantages
- Warming technology
- Choice of mineral wool
- Installation of a cylindrical heater
- Installation of soft mineral wool
Insulation of pipes with mineral wool is an excellent option for thermal insulation of elements of plumbing systems of any type, size and length. The material protects communications for various purposes from temperature extremes, mechanical damage and exposure to chemicals. Convenient shape and low cost allows you to choose an insulator for a wide range of jobs. We will talk about the technology of pipeline insulation with this fibrous product in our article.
Features of thermal insulation of pipes with mineral wool
Non-insulated heating systems give off up to 50 W at a coolant temperature of 60 degrees, and they can be considered as radiators. According to European standards, the allowable loss should not exceed 6 W of heat per hour. Such requirements can be provided by a mineral fiber-based insulation - basalt wool and glass wool, less often - slag wool. These are fibrous products made from rocks. All free space between the threads is filled with air or neutral gas, which remains stationary and provides good thermal insulation.
Mineral wool for pipes allows you to isolate heating, hot water, plumbing, sewage, air conditioning systems. Products are used on communications in unheated premises, with underground and above-ground arrangement of elements. The advantages of mineral wool are especially noticeable in the last two cases, when strong wind, snow, and moisture in the ground act on the pipes. The insulator functions on the principle of a thermos: hot stays hot, cold stays cold.
Without fail, pipes are insulated in such cases:
- The tilt angle of the system is small.
The samples were buried in the ground less than 0.5 m.
There is an erroneous opinion that only elements located outside the building are insulated. Communications without protection radiate part of the heat into the wall or soil under the floor, so the protection of hidden pipelines in the room is also necessary.
There are two ways to install mineral wool. Classic involves wrapping plumbing equipment in rolls or mats. This option has many disadvantages: the plates do not hold their shape well, the layer thickness is uneven, installation takes a long time.
Mineral wool cylinders are devoid of such disadvantages. Long workpieces of two or more parts allow you to quickly complete the work, the influence of the human factor is reduced to a minimum. The outer metal coating on the shell will protect the material from adverse external influences. Products are placed in a regular place and fixed in various ways.
Very easy to use mineral insulation, covered with metal foil, fiberglass, mesh to protect against mechanical stress, fire, moisture and other negative influences.
Heat insulators are sold in a convenient container, which facilitates their transportation and storage.
Advantages and disadvantages of pipe insulation with mineral wool
To date, the most popular insulation is mineral wool in the form of mats or cylinders.
It is popular due to the following qualities:
- The product has a low level of thermal conductivity.
The samples do not contain impurities harmful to humans, because. made from natural material.
Pipe insulation with mineral wool shifts the dew point from the surface, which helps to avoid premature corrosion of the metal.
After laying the insulation, noise is reduced and the vibration of the structure is reduced. Such qualities are important for air conditioning systems in buildings.
The product prevents freezing of the coolant and subsequent destruction of communications.
It is a durable material, the service life of which exceeds 50 years. Its performance does not change throughout the operation.
Warming with mineral wool does not require special knowledge, the work is done quickly.
Pipelines are well protected from mechanical impact. The fibers of the insulator are closely intertwined, which allows it to withstand heavy loads.
Minvata does not shrink. It can be reused.
It prevents accidental burns from hot heating systems.
The material does not rot, it resists fungus and mold well.
Does not collapse under the action of aggressive media, such as cement.
The product does not burn, has a low flammability.
The insulator has disadvantages that affect its applicability:
- The material can harm the human body, especially glass wool. The fibers cause a strong burning sensation, so cover the respiratory organs, skin and eyes with personal protective equipment. Work in clothes thick fabric, which is thrown away when heavily soiled - a robe contaminated with fiberglass cannot be washed.
Mineral wool pipe insulation technology
Insulation can be installed by one person who does not have experience in such work. Special tools for thermal insulation of pipes with mineral wool are not required, a sharp knife is enough to cut off excess parts. The right choice of material is essential.
Choice of mineral wool
There are many modifications of mineral wool on sale, each of which is designed for use in certain cases. In order not to make a mistake with the choice, we suggest that you familiarize yourself with the following information.
Glass wool is most often used outside residential buildings. This is due to the fact that it is vulnerable to high temperatures. The material is sold in the form of mats, plates, rolls and cylinders. It is soft and elastic, suitable for pipe insulation in any form. There is no general standard for the length of blanks; each manufacturer produces samples at its discretion. Product thickness - 50-150 mm.
Stone wool has a high temperature resistance threshold, which makes it possible to insulate pipes in the residential sector and industrial facilities. It is used to insulate heating systems, plumbing fixtures in basements and living rooms. With its help, pipes are insulated in boiler rooms and other rooms with extreme operating conditions. It has no restrictions on use outside or inside the building. For this task, buy stone wool in the form of shells or lamella rolls, which look like rectangular elements glued on foil. It will not work to wrap the pipe with a single plate - the product has too short a pile, which gives the material rigidity.
Slag wool has poor thermal insulation properties and is purchased only because of the low price. It is forbidden to use it indoors due to the harmful effects on the human body. The material is used in non-responsible places, tk. it loses its properties in a humid environment and at critical temperatures.
Heaters for pipes are made with linings and without them. For thermal insulation in a non-lining way, special stitched mats made in accordance with GOST 21880-94 will be needed. They are sold in rolls wrapped in special paper and are of considerable size. Shellless products are budget materials. They do not resist weathering well, therefore they are mounted in closed spaces, for example, in attics or in tunnels. To protect the room from fibers, it is recommended to cover the finished casing with a film.
Insulation with a lining is made in the form of stitched mats with a protective mesh. Compared to unlined mats, these products have increased strength and flexibility. After wrapping, there are no gaps or cracks left. Heat loss after installation is negligible.
Manufacturers offer rigid samples of a given shape from basalt fiber in the form of cylinders or semi-cylinders for pipe insulation. For ease of installation, they are equipped with grooves. Also for these purposes, small segments of mineral wool can be used. Such a heater does not lose its shape at high temperatures, well protects pipes from mechanical stress.
Cylindrical products are 3.6 times more efficient than roll products. The total heat loss during their use reaches 8% throughout the entire period of operation. Mats and rolls lose their insulating properties every year. In the first year, the losses are 10%, in the second - 30%, and in the third year they exceed 45%. On average, annual losses for thermal insulation with traditional wool are 28%, which is much more than when using cylindrical products.
Fiber shells are produced with a density of 80 kg/m 3 . It is issued from metal coated or without it. The choice of samples is influenced by several factors, the main one being the location of the system. Mineral wool with an aluminum sheath is intended for use outside buildings. To reduce the absorption of moisture, it is strongly compacted and carefully waterproofed from above.
Hydrophobic insulating cylinders are also produced, which are used in damp rooms or in places where condensation occurs, but they are very expensive.
The mineral wool shell for pipes consists of two parts. The inner diameter varies between 18-1024 mm and is selected according to the diameter of the insulated element. Only in this case the effect will be maximum. The thickness of the insulating layer is 20-80 mm, the standard length is 1 m. The mineral wool shell works well in a wide temperature range - from -40 to +74 degrees.
Insulations coated with foil and fiberglass can be used in wet rooms, they are not afraid of direct water ingress. For insurance, the products are additionally impregnated with special hydrophobic substances.
The method of installing a cylindrical insulation
Insulation of pipes with mineral wool is carried out only in dry weather. The work is performed in the following sequence:
- Inspect the surface of the insulated element, make sure that it is intact and dry. Repair leak if necessary. If condensation remains on the surface, the plumbing product will quickly fail.
Treat the surface with an anti-corrosion coating, you can use a primer.
Put the halves of the mineral wool shell on the pipe with an offset of 10-15 mm and secure first temporarily with wire, and then with special foil tape. It is sold at any hardware store. If it is not available, use a simple adhesive tape, but the effectiveness in this case will decrease slightly. The shift of the parts is necessary for the overlap.
Difficult sections of pipelines (corners, turns, styles) are insulated with special curly elements. Wrap the adhesive tape very tightly, make sure that there are no open gaps.
The larger the shell diameter, the more parts it has. A cylinder with a diameter of up to 50 mm has only one cut. To place the slot in place, open the product, install it on the pipe and secure with adhesive tape.
Installation technology of soft mineral wool
Outside the building, the elements of the system can be laid above or below the ground. In the first case, precipitation and wind can negatively affect the insulation, in the second - groundwater with aggressive elements. Let's consider each case separately.
Insulation of above-ground pipes is carried out in the following sequence:
- Examine the surface of the sample and, if necessary, modify it, as in the previous case.
Tape the pipe with foil tape, arranging it in a spiral.
Wrap the insulation tightly, making sure there are no gaps between the joints.
Fix the insulator with sanitary tape. Gaps between the turns of the tape are not allowed. Water can get in and damage the system over time.
If pipes are planned to be buried in the ground, they must be protected from water in any way. Otherwise, an insulator with a low density will begin to collapse.
The order of work is as follows:
- Dig a trench 60 cm wide and 5 cm deeper than the calculated one.
At the bottom of the trench, pour a layer of sand 10-15 cm thick, level and compact.
Collect the pipeline on the surface, insulate it, as in the previous case. Check that the mineral wool and adhesive tape do not hang out. Such treatment will ensure the integrity of the insulator even under the action of loads during spring and autumn soil movements.
To insulate plumbing systems, you can apply multi-layer protection using a heating cable. This will allow you not to dig the system deep.
The work is done as follows:
- Wind the heating wire around the pipe.
Lay glass wool on top in rolls and secure with soft wire.
Connect the wires to the outlet.
Fill the trench with earth.
How to insulate pipes with mineral wool - look at the video:
Thermal insulation of pipelines is a set of measures aimed at preventing the heat exchange of the carrier transported through them with the environment. Thermal insulation of pipelines is used not only in heating systems and hot water supply, but also where technology requires the transportation of substances with a certain temperature, for example, refrigerants.
The meaning of thermal insulation is the use of means that provide thermal resistance to heat transfer of any kind: contact and carried out by means of infrared radiation.
The greatest application, expressed in numbers, is the thermal insulation of pipelines of heating networks. Unlike Europe, centralized system heating dominates throughout the post-Soviet space. Only in Russia alone, the total length of heating networks is more than 260 thousand kilometers.
Much less often, insulation for heating pipes is used in private households with an autonomous heating system. Only in a few northern regions, private houses are connected to the central heating main with heating pipes placed outside.
For some types of boilers, for example, powerful gas or diesel ones, the requirements of the set of rules SP 61.13330.2012 “Thermal insulation of equipment and pipelines” require a separate location from the building - in a boiler room several meters away from the heated object. In their case, the strapping fragment passing through the street necessarily needs to be insulated.
On the street, insulation of heating pipelines is required both for open ground placement and for hidden laying underground. The latter method is channel - a reinforced concrete gutter is first laid in the trench, and pipes are already placed in it. Channelless placement - directly in the ground. The insulating materials used differ not only in thermal conductivity, but also in vapor and water resistance, durability and installation methods.
The need to insulate cold water pipes is not so obvious. However, it cannot be dispensed with in the case when the water supply is laid in an open ground way - the pipes must be protected from freezing and subsequent damage. But inside buildings, it is also necessary to insulate water pipes - to prevent moisture condensation on them.
Glass wool, mineral wool
Proven insulating materials. They meet the requirements of SP 61.13330.2012, SNiP 41-03-2003 and fire safety standards for any installation method. They are fibers with a diameter of 3-15 microns, similar in structure to crystals.
Glass wool is made from waste glass production, mineral wool from silicon-containing slag and silicate metallurgy waste. The differences in their properties are insignificant. They are produced in the form of rolls, stitched mats, plates and pressed cylinders.
It is important to be careful with materials and be able to handle them correctly. Any manipulations should be performed in protective overalls, gloves and a respirator.
Installation
The pipe is wrapped or lined with cotton wool, ensuring a uniform filling density over the entire surface. Then the insulation, without too much pressure, is fixed with a tie wire. The material is hygroscopic and easily gets wet, therefore, the insulation of external pipelines made of mineral or glass wool requires the installation of a vapor barrier layer made of a material with low vapor permeability: roofing felt or polyethylene film.
A cover layer is placed on top of it, which prevents the penetration of precipitation - a casing made of roofing sheet, galvanized iron or sheet aluminum.
Basalt (stone) wool
Thicker than glass wool. The fibers are made from a melt of gabbro-basalt rocks. Absolutely non-combustible, briefly withstands temperatures up to 900 ° C. Not all insulating materials can, like basalt wool, be in long-term contact with surfaces heated to 700 ° C.
The thermal conductivity is comparable to polymers, ranging from 0.032 to 0.048 W/(m K). High performance indicators make it possible to use its thermal insulation properties not only for pipelines, but also for the arrangement of hot chimneys.
Available in several versions:
- like glass wool, rolls;
- in the form of mats (stitched rolls);
- in the form of cylindrical elements with one longitudinal slot;
- in the form of pressed cylinder fragments, the so-called shells.
The last two versions have different modifications, differing in density and the presence of a heat-reflecting film. The slot of the cylinder and the edges of the shells can be made in the form of a spike connection. 
SP 61.13330.2012 contains an indication that the thermal insulation of pipelines must comply with safety and environmental protection requirements. By itself, basalt wool fully complies with this indication.
Manufacturers often resort to tricks: to improve consumer performance - to give it hydrophobicity, greater density, vapor permeability, they use impregnations based on phenol-formaldehyde resins. Therefore, it cannot be called 100% safe for humans. Before using basalt wool in a residential area, it is advisable to study its hygiene certificate.
Installation
Insulation fibers are stronger than those of glass wool, so the ingress of its particles into the body through the lungs or skin is almost impossible. However, when working, it is still recommended to use gloves and a respirator.
The installation of a roll web does not differ from the way in which glass wool heating pipes are insulated. Thermal protection in the form of shells and cylinders is attached to pipes using mounting tape or a wide bandage. Despite some hydrophobicity of basalt wool, pipes insulated with it also require a waterproof vapor-permeable sheath made of polyethylene or roofing felt, and an additional one made of tin or dense aluminum foil.
Foamed polyurethane (polyurethane foam, PPU)
More than doubles heat loss compared to glass wool and mineral wool. Its advantages include: low thermal conductivity, excellent waterproofing properties. The service life declared by the manufacturers is 30 years; Range operating temperature from -40 to +140 °C, maximum withstand for a short time - 150 °C.
The main brands of PPU belong to the combustibility group G4 (highly combustible). When changing the composition with the help of the addition of fire retardants, they are assigned G3 (normally combustible).
Although polyurethane foam is excellent as an insulating material for heating pipes, keep in mind that SP 61.13330.2012 allows the use of such thermal insulation only in single-family residential buildings, and SP 2.13130.2012 limits their height to two floors.
The heat-insulating coating is produced in the form of shells - semicircular segments with tongue-and-groove locks at the ends. Ready-made steel pipes insulated from polyurethane foam with protective sheath made of polyethylene.
Installation
The shells are fixed on the heating pipe with the help of ties, clamps, plastic or metal bandage. Like many polymers, the material does not tolerate long-term exposure to sunlight, therefore, an open above-ground pipeline, when using PU foam shells, needs a cover layer, for example, from galvanized steel.
For underground channelless placement, heat-insulating products are laid on waterproof and temperature-resistant mastics or adhesives, and are insulated from the outside with a waterproof coating. It is also necessary to take care of the anti-corrosion treatment of the surface of metal pipes - even glued interlock connection shells are not tight enough to prevent condensation of water vapor from the air.
Expanded polystyrene (polyfoam, PPS)
It is produced in the form of shells, outwardly practically no different from polyurethane foam - the same dimensions, the same tongue-and-groove locking connection. But the temperature range of application, from -100 to +80 ° C, with all this external similarity, makes it impossible or limited to use it for thermal insulation of a heating pipeline.
SNiP 41-01-2003 "Heating, ventilation and air conditioning" states that in the case of a two-pipe heat supply system, the maximum supply temperature can reach 95 ° C. As for the return risers of heating, everything is not so simple here: it is believed that the temperature in them does not exceed 50 ° C.
Foam insulation is more often used for cold water and sewer pipes. However, it can be used over other heaters with a higher allowable application temperature.
The material has a number of some disadvantages: it is highly combustible (even with the addition of fire retardants), it does not tolerate chemical influences (it dissolves in acetone), it crumbles with balls during prolonged exposure to solar radiation.
There are other, non-polystyrene foams - formaldehyde, or shortly, phenolic. In fact, this is a completely different material. It is devoid of these shortcomings, is successfully used as thermal insulation of pipelines, but is not so widespread.
Installation
The shells are fixed on the pipe with a bandage or foil tape, it is allowed to glue them to the pipe and to each other.
Foamed polyethylene
The temperature range at which the use of foamed high-pressure polyethylene is allowed is from -70 to +70 °С. The upper bound is inconsistent with maximum temperature heating pipes, usually taken in the calculations. This means that the material is of little use as a thermal insulation of pipelines, but can be used as an insulating layer over a heat-resistant one.
Polyethylene foam insulation has found practically no alternative application as protection against freezing of water pipes. Very often it is used as a vapor barrier and waterproofing.
The material is produced in the form of sheets or in the form of a flexible thick-walled pipe. The latter form is more often used, as it is more convenient for insulating water pipes. The standard length is 2 meters. The color varies from white to dark gray. An IR reflective aluminum foil coating may be available. The differences relate to internal diameters (from 15 to 114 mm), wall thickness (from 6 to 30 mm).
The application ensures that the temperature on the pipe is above the dew point, which means it prevents the formation of condensate.
Installation
An easy way with worse vapor barrier results is to cut the foam material into a small indentation along the side surface, open the edges and put it on the pipe. Then wrap along the entire length with mounting tape.
A more complicated solution (and by no means always feasible) is to turn off the water, completely disassemble the insulated sections of the water supply and put on solid sections. Then put everything back together. Secure the polyethylene with zip ties. In this case, only the junction of the segments will become a weak point. It can be glued or also wrapped with tape.
foamed rubber
Foamed synthetic rubber with a closed cell structure is the most versatile material for keeping warm and cold. Designed for temperature range from -200 to +150 °С. Conforms to all requirements of ecological safety.
It is used as insulation for cold water pipelines, insulation for heating pipes, often found in refrigeration and ventilation systems. Heating pipes laid inside buildings and insulated with rubber do not require the installation of a vapor barrier layer.
Outwardly similar to polyethylene foam, it is also available in the form of sheets and flexible thick-walled pipes. Installation is also practically the same, except that such thermal insulation of pipes can be attached to glue.
Liquid heaters
A technology has been successfully applied that allows self-spraying foam from a polyurethane composition onto ready-made structures. Excellent adhesive properties allow it to be used not only for insulating pipelines, but also applied to other elements that need insulation: foundation, walls, roofing. The coating, in addition to thermal protection, provides hydro, vapor barrier, provides anti-corrosion resistance.
Conclusion
Properly performed installation of thermal insulation is a guarantee that the pipe will not lose heat, and the consumer will not freeze. Freezing of the cold water supply pipeline invariably leads to its rupture. Until recently, in hidden and open heating mains, glass wool was the usual insulating material. Its shortcomings stem from one another. Such coverage requires constant monitoring.
Even with a slight damage to the protective surface layer, vapor permeability and hygroscopicity nullify all savings. Moisture causes low thermal resistance and premature failure. Modern insulating materials with a cellular structure that are inert to the effects of steam and water will help to significantly improve the situation: polyurethane foam, foamed rubber, polyethylene foam.
The vast majority of regions of our country are characterized by very harsh winters. Frosts of minus 20 degrees and below - you will not surprise anyone. And even in the southern regions, with a mild climate, the weather sometimes presents "surprises" when the thermometer drops below zero for quite a long time. That is, at almost any point in the conduct of private construction, you have to think about how to protect against freezing.
Frozen water in pipes is not only and even not so much a temporary loss of one of the communal “amenities”. Most often, such troubles entail literally catastrophic consequences - they end with a rupture of the walls of pipes, a complete failure of the entire home system, the need for large-scale repair and restoration work. And hoping for some kind of illusory luck, they say, this will not happen to me is extremely short-sighted. In any case, it is impossible to do without high-quality insulation of the system.
Let's see what kind of thermal insulation can be used for water supply pipes, we will deal with the types of materials, with their advantages and disadvantages. And with the main question - what should be the thickness of this insulation layer.
What methods are used to protect water pipes from freezing
It doesn't matter if he gets a private house distribution of water from the central collector (and this also often happens), or will be used offline source(well or borehole), it is still assumed that the pipe is laid, where negative external temperatures are likely. An exception can be considered only those rare cases when the well is drilled directly in the basement of the house. And even then - on the way to the points of consumption, there may also be sections of the passage of the water supply through an unheated basement or basement. But in order to put the water supply system out of action, a very short, uninsulated segment is enough.
What approaches are being taken to protect water pipes from freezing?
- First of all, the water main, if possible, should be laid below the level of soil freezing in this region. At such a depth of the route (and it is taken with a margin - the freezing level plus another 300 ÷ 500 mm), the temperature should never reach negative values. That is, the probability of getting an "ice plug" tends to zero.
However, this approach is not always fully feasible. In some regions, the soil freezes to a very significant depth, and digging such deep trenches significantly complicates the implementation of the project. Such areas are not uncommon, where the features of the soil completely exclude such an arrangement of pipes.
In many regions, the level of soil freezing reaches very significant depths. It is not always possible to dig such deep trenches for laying water pipes. In addition, the pipe, one way or another, must be lifted up so that it enters the house. And in any case, it will pass through “dangerous” sections - the upper sections of the route, the passage through the foundation, through the basement, basement or even just an unheated room, where negative temperatures can be observed in winter.
How an autonomous water supply system is built in a private house
Much depends on the source of water, on its location on the site, the distance from the residential building, on the climatic conditions of the region and the design features of the building itself. Read more about that in a special publication of our portal.
- Those same “problem areas” of the water supply route can be artificially heated using electrical energy. For these purposes, special heating cables are used, which are laid on the pipe walls under a layer of thermal insulation, or even placed directly in the pipe cavity.
On sale in our time there are many varieties of such cables, as well as blocks automatic control heated, which turn on the power when it is required.
How to organize the heating of the water supply?
The appearance of heating cable systems removed a lot of problems in organizing autonomous water intakes in private homes. By the way, if you strictly follow the instructions of manufacturers of such products, then it is quite possible to mount and run it yourself. More details in a special publication of our portal.
- In the basement, basement or other premises of the house, in which a negative temperature level is not excluded, the laying of a “heat satellite” is sometimes practiced. This is a pipe running parallel to the water pipe and enclosed in a common thermal insulation shell, which is nothing more than one of the branches of the general heating circuit of the house.
Such a campaign, of course, complicates both the plumbing system and the heating system. But on the other hand, you can no longer worry about the integrity of areas with such heating. True, only when the heating is on.
- One of radical ways To prevent freezing of water in pipes is to maintain a constant high pressure in them. To do this, the autonomous water supply system is supplemented with special equipment, and the pipes themselves must be able to withstand these increased loads.
Although the approach is effective, it is rather complicated both in organization and in everyday operation. In addition, it turns out to be more costly in terms of energy consumption. Such systems have not gained much popularity.
- The most common method is the thermal insulation of pipes, that is, what, in fact, this publication is devoted to. The use of various heaters helps to avoid freezing of the water supply, if, of course, the material and thickness of the insulation are correctly selected.
All this will be discussed in more detail below.
A special type of insulation is sometimes referred to as the creation of a fixed air gap between the water pipe and the casing, which prevents direct contact of the pipe with the ground. In a nutshell, this can be described as a "pipe in a pipe."
But, in truth, in its “pure form” this method is not used. Hollow space, if only for precise positioning water pipe inside the outer shell, is still filled with insulating material. Which, in principle, is a heater only because of its ability to create a layer of immobilized air. So the result is a classic thermal insulation of the pipe with the creation of an outer casing. And, by the way, it is always welcome, for protection and insulation, and the pipe itself from mechanical influences, from ground moisture, from damage that can be caused by rodents living underground, attracted by heat in winter.
In practice, a combination of most of the listed methods for protecting water pipes from freezing is usually used. That is, they try to deepen the route from the well or well as much as possible, insure the most vulnerable areas with additional heating and, of course, provide for reliable thermal insulation, usually along the entire length of the water pipe.
Such an integrated approach is also necessary for the reasons that even high-quality insulation often does not guarantee the complete security of the water supply. The table below shows the heat losses calculated for pipes of different external diameters, enclosed in a layer of thermal insulation of different thicknesses. The coefficient of thermal conductivity of the insulation is taken average, characteristic of most thermal insulation materials used in the role in question - 0.04 W / (m × K).
Naturally, the amount of heat loss depends directly on the temperature difference between the environment and the liquid pumped through the pipe. The table gives several options - from Δt = 20 ℃ to Δt = 60 ℃. For example, if the temperature of water from a well (well) in winter is + 2 ÷ 4 ℃, and on a pipe passes through the basement of the house, frozen to -15 ℃, then just the temperature difference can be considered as 20 degrees.
| Thickness of the insulation layer | Temperature difference (Δt, °С) | Pipe outer diameter (mm) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 15 | 20 | 25 | 32 | 40 | 50 | 65 | 80 | 100 | 150 | ||
| Average heat loss (W per linear meter of pipeline) | |||||||||||
| 10 mm | 20 | 7.2 | 8.4 | 10 | 12 | 13.4 | 16.2 | 19 | 23 | 29 | 41 |
| 30 | 10.7 | 12.6 | 15 | 18 | 20.2 | 24.4 | 29 | 34 | 43 | 61 | |
| 40 | 14.3 | 16.8 | 20 | 24 | 26.8 | 32.5 | 38 | 45 | 57 | 81 | |
| 60 | 21.5 | 25.2 | 30 | 36 | 40.2 | 48.7 | 58 | 68 | 86 | 122 | |
| 20 mm | 20 | 4.6 | 5.3 | 6.1 | 7.2 | 7.9 | 9.4 | 11 | 13 | 16 | 22 |
| 30 | 6.8 | 7.9 | 9.1 | 10.8 | 11.9 | 14.2 | 16 | 19 | 24 | 33 | |
| 40 | 9.1 | 10.6 | 12.2 | 14.4 | 15.8 | 18.8 | 22 | 25 | 32 | 44 | |
| 60 | 13.6 | 15.7 | 18.2 | 21.6 | 23.9 | 28.2 | 33 | 38 | 48 | 67 | |
| 30 mm | 20 | 3.6 | 4.1 | 4.7 | 5.5 | 6 | 7 | 8 | 9 | 11 | 16 |
| 30 | 5.4 | 6.1 | 7.1 | 8.2 | 9 | 10.6 | 12 | 14 | 17 | 24 | |
| 40 | 7.3 | 8.3 | 9.5 | 10.9 | 12 | 14 | 16 | 19 | 23 | 31 | |
| 60 | 10.9 | 12.4 | 14.2 | 16.4 | 18 | 21 | 24 | 28 | 34 | 47 | |
| 40 mm | 20 | 3.1 | 3.5 | 4 | 4.6 | 4.9 | 5.8 | 7 | 8 | 9 | 12 |
| 30 | 4.7 | 5.3 | 6 | 6.8 | 7.4 | 8.6 | 10 | 11 | 14 | 19 | |
| 40 | 6.2 | 7.1 | 7.9 | 9.1 | 10 | 11.5 | 13 | 15 | 18 | 25 | |
| 60 | 9.4 | 10.6 | 12 | 13.7 | 14.9 | 17.3 | 20 | 22 | 27 | 37 | |
As you can see, even with a fairly thick layer of insulation of 40 mm, a pipe with a diameter of 32 mm in the conditions taken above for example will lose almost 5 W of thermal energy per linear meter. It seems like a little, but if there is no movement of water in the pipe for several hours, an ice plug may occur in such a section. So, these heat losses will have to be replenished in one way or another.
That is, when designing your water supply system, you must carefully analyze theoretically vulnerable areas, and strengthen thermal insulation on them (if possible) or take steps to heat these "dangerous" zones. Which, by the way, are usually just located in close proximity to the house or even directly in it. Although, it also happens that the entire route from the source to the house has to be heated, since, for example, rocky soil or a high location of groundwater makes it impossible to dig trenches below the freezing level.
But even in this case, the importance of pipe insulation only increases. The heat generated by the heating system should not be wasted, but should fulfill its intended purpose. And without high-quality thermal insulation, this cannot be achieved.
Thermal insulation requirements for water pipes
So, we will go directly to the thermal insulation for water pipes. And first of all, let's figure out what requirements it should ideally meet.
From the foregoing, it should already be clear that the thermal insulation of pipes is designed to perform two key interrelated tasks:
Protection of the water supply system from a drop in its temperature below zero - in order to avoid freezing of water, resulting in a loss of system performance and rupture of pipes.
In areas with forced heating - minimization of heat losses for efficient and economical operation of the heating cable.
A high-quality insulation must meet the following criteria:
- In the first place, of course, should be put its thermal insulation qualities. The lower the thermal conductivity coefficient, the more efficiently heat is retained, the thinner the thermal insulation layer can be provided.
- The water supply in an autonomous system is mainly located in the ground, that is, in a moist soil environment. This means that thermal insulation must be resistant to moisture, best of all - hydrophobicity. Wet insulation always sharply loses its thermal insulation qualities. Need protection from moisture and those sections of pipelines that pass in the open air.
Not all materials meet this criterion equally. But this is partly solved by enclosing insulated pipes in a waterproof sheath or casing.
- The soil is very often saturated with very aggressive chemical compounds. This means that both the insulation itself and the layer protecting it must be inert to such an impact.
- An important criterion is the mechanical strength of the material. The insulation layer in the ground will experience serious ground pressure. In open areas, external mechanical influences cannot be excluded.
- The laying of a water supply system, especially in buried areas, is done with the expectation of many years of operation. This indicates the need for a pronounced durability of the insulation material.
- Good modern thermal insulation should not cause difficulties in installation. Very often, when creating a water supply system, they use turnkey solutions- already insulated pipes, which can only be mounted in a common line, and then insulated joints.
- Of course, the availability of the material always remains an important criterion - both in terms of supply in stores and in terms of cost. But here it should be immediately noted that high-quality modern pre-insulated pipes cannot be cheap a priori.
Now let's see what materials are used to insulate water pipes.
Insulating materials for thermal insulation of water pipes.
Mineral wool of various types, polystyrene foam, polyurethane foam, polyethylene foam are widely used for insulation of water pipes. Recently, a relatively new insulation has been increasingly used - foamed rubber.
Mineral wool
This is perhaps the most affordable thermal insulation material for such purposes. But it is far from the most convenient.
Of the three existing types Mineral wool for the insulation of pipelines is actually used only two - glass wool and stone (basalt). The so-called slag wool, made from metallurgy waste, is poorly suited for such purposes. She loses in thermal insulation qualities, quickly absorbs water, far from everything is in order with her and with chemical composition, which under certain conditions can become a catalyst for active corrosion of metal pipes.
What are dignity mineral wool insulation:
- Low thermal conductivity.
- One of important benefits before many other heaters - plasticity. Mineral wool can be used to insulate curved or flat surfaces, tees, bends, valves and other fittings without any problems and without the need to purchase additional products.
- Chemically inert to most acidic or alkaline compounds found in soil moisture.
- A variety of forms of release, any of which, in principle, can be used for pipe insulation. So, mineral wool is also produced in mats, including pierced ones, in separate slabs (blocks) of various thicknesses. This allows, by the way, to independently vary the thickness of the created insulation layer, depending on the initial conditions.
Made from mineral wool and special products for thermal insulation of pipes - half-cylinders ("shell" in common parlance) of various internal and external diameters, with or without an external coating. Very convenient for quick installation on straight sections of the pipeline.
- Mineral wool is a practically non-combustible material. For underground sections of the water supply system, this quality may not be so important, but for open sections it will be useful.
Now let's go through shortcomings this material:
- First of all, it should be noted the hygroscopicity of many types of mineral wool. To a greater extent, this applies to fiberglass materials. They can quite actively absorb moisture, losing their insulating characteristics. And when the wet mineral wool freezes, its destructurization occurs, strong shrinkage.
Basalt types of mineral wool usually undergo a special hydrophobic treatment, and are more resistant to contact with water.
But in any case, such a heater must necessarily be protected from direct contact with wet soil. This is achieved by creating a surface protective layer of aluminum foil, roofing material or even just a dense polyethylene film. The task is not particularly difficult: such an outer coating is simply wound on top with a certain overlap (overlap) of turns, and then fixed with wire or other clamps. But at the same time - such additional operations complicate the installation of thermal insulation.
As we saw above, some types of mineral wool pipe insulation are already equipped with an applied external coating. This greatly simplifies thermal insulation work, but such materials are also more expensive.
- Working with mineral wool requires certain precautions and the use of protective equipment for the skin, eyes, and respiratory organs. The fibers are brittle (again - glass wool suffers more from this, basalt fibers have much better elasticity), and sharp microscopic fragments often cause serious irritation skin and mucous membranes.
- Another disadvantage is the tendency of mineral wool to gradually caking, to lose in volume (in the thickness of the insulation layer). The reason for this is the same fragility of the fibers, which can increase under adverse conditions (waterlogging + negative temperatures) or vibration exposure.
The shrinkage of mineral wool insulation should be taken into account when planning the thermal insulation of pipes. How this is taken into account will be discussed below.
Expanded polystyrene insulation (PPR)
Expanded polystyrene (or, as it is often called - polystyrene) is very widely used precisely for the purpose of thermal insulation of various sections of the building. The plumbing is no exception.
By the way, this material is rightly criticized for a number of very negative qualities that limit its use in residential premises. First of all, these include unfavorable conditions from an environmental point of view, flammability and extremely toxic combustion products. But in terms of using underground sections of the water pipeline for thermal insulation, these qualities are completely unimportant. So the use of PPR should not cause any special concerns.
The advantages of expanded polystyrene include:
- Excellent thermal insulation performance.
- Low density - the material is light, very easy to process and install.
- High-quality PPR is not afraid of exposure to moisture - it practically does not penetrate into its structure.
- The cost of PPR products is low - the cost of insulation will be small.
- The material is durable if it is protected from external mechanical damage and from contact with organic solvents.
The most convenient way, of course, is to use a “shell” for pipe insulation - half-cylinders with the required inner and outer diameter. High-quality products of this type are also equipped with a tongue-and-groove lock that prevents the appearance of cold bridges at the border of the two halves.
Such half-cylinders are put on the pipe on both sides, connected in locks, and then connected with tape or even just wire clamps. On straight sections of the water supply route, thermal insulation will not take much time.
disadvantages in addition to those already listed above, we can consider the following:
- The material is quite fragile, and the "shell" is easy to break with careless handling.
- The complete absence of any kind of plasticity. That is, even at a small bend in the route, this section will have to be isolated separately, and then again switched to half-cylinders.
True, many companies involved in the production of such "shells" also offer in their assortment special shaped parts for turns, tees and some other assemblies. But, traditionally, the cost of such fittings is much higher than the price of "linear" elements. Therefore, many experienced craftsmen try to independently cut out the required parts for bends, tees, etc. from half-cylinders. Or these areas are insulated with mineral wool, followed by closing with a waterproof casing.
Used to insulate plumbing and polystyrene foam boards. For example, they are laid on top of the pipe before backfilling the trench - a kind of screen is obtained that prevents the vertical penetration of cold into the depths.
Another option is to build a box at the bottom of the trench from expanded polystyrene plates, in which pipes are laid. After installing the water supply, the box is closed with a lid from the same plate, and then the soil is backfilled.
With the affordable cost of white foam boards, this insulation option will probably be the least expensive.
- Expanded polystyrene cannot be attributed to chemically resistant polymers. Even conventional fuels and lubricants can cause its destructuring.
Therefore, such insulation should be used with caution if the soil is saturated with oil products (which often happens, for example, near a car park). Or, what would be more accurate, to provide external protection for the "shell", for example, from a dense polyethylene film.
Polyurethane foam insulation for pipes
With a certain external similarity with expanded polystyrene (more precisely, with its extruded variety), polyurethane foam significantly surpasses it in almost all respects.
As a rule, in "pure form" polyurethane foam insulation for pipes is not produced. But manufacturers offer a wide range of already pre-insulated pipes. On such products, ready for installation, the pipe is already protected by a layer of high-quality polyurethane foam insulation, and an external coating that is resistant to mechanical stress, moisture, and chemical attack. By the way, polyurethane foam is already much more resistant to various aggressive compounds. Moreover, sprayed onto the outer walls of the pipe, it also becomes their excellent anti-corrosion protection.
Consumers are offered a wide range of metal pipes in ready-made polyurethane foam thermal insulation. But their diameter usually starts from 57 mm and above. As a rule, when installing an autonomous water supply system, it is necessary to use not so large pipes.
Therefore, some well-known companies have launched the production of plastic or metal-plastic pipes of small diameter, also having PPU thermal insulation and an external polymer coating. Such ready-made solutions greatly simplify the entire process of installing a water supply system, laid both in the ground and in open areas - in basements, basement floors, unheated premises.
On both sides of these pipes, a small “bare” area protrudes from the thermal insulation, which is sufficient for connection by welding or fitting. After that, a heat-shrinkable sleeve previously put on the pipe is pushed onto this connecting unit. It remains to fill the cavity of the coupling mounting foam(which itself is also polyurethane foam), so that after the foam hardens, a perfectly insulated tight joint is obtained.
As can be seen in the figure above, customers are also offered ready-made parts for the installation of individual sections of the water supply - bends with different angles of rotation, tees, transitions, etc. That is, the installation of the system turns into a kind of "assembly of the designer."
By the way, despite the fact that polyurethane foam cannot be called too plastic material, some polymer pipes in such thermal insulation with an external coating still have a certain flexibility, which allows laying curved sections without the use of additional bends.
An example of this is the product Russian company Polymerteplo Group, Isoproflex pipes. The pipe itself is made of PEX-A cross-linked polyethylene reinforced with high-strength fiber, has a protective anti-diffusion layer, a semi-rigid polyurethane foam insulation, and an externally protective coating of durable polyethylene.
Such pipes are sold in bays, which in itself speaks of their flexibility. The installation task becomes even easier - if there are no sharp turns, then one sleeve, already pre-insulated and protected from the outside, can be laid from the water intake to the very entrance to the house, without making a single extra joint.
Polyethylene foam insulation
Another material widely used for insulation of pipelines. In its closed cell structure, filled with air, it is very similar to polyurethane foam. Pretty glare and their thermal conductivity - both are excellent thermal insulators. But unlike polyurethane foam, polyethylene foam also has high flexibility and plasticity. Not at the expense of durability.
The material is very light - usually its density does not exceed 30 ÷ 35 kg / m³, that is, no special physical efforts will have to be applied during the installation of thermal insulation. The closed cell structure becomes an insurmountable barrier to water, the material itself practically does not absorb moisture - no more than 1.5% of the volume even when completely immersed.
A clear advantage is the chemical inertness - it is difficult to imagine which of the compounds that got into the soil could cause the destructurization of polyethylene foam. The temperature range of operation is also impressive - from minus 55 to plus 85 ℃, which is more than enough for a water supply system.
Various forms of such a heater are produced. It can be just rolls, as a rule, with one foil side - many craftsmen prefer just such a material. But still, ready-made sleeves for pipes of different diameters and with different thicknesses of the insulation layer, usually 2 meters long, are currently more popular.
Installation of such sleeves is not difficult - they have a seam along the entire length on the side, along which they can be opened. The insulation is put on the pipe, and then this seam is glued almost without a trace due to the applied self-adhesive layer.
But, again, the most convenient solution is the use of ready-made plastic pipes, already "dressed" in insulation and in an outer protective sheath. Such products are offered in a wide range by several leading manufacturers.
For example, the FLEXALEN company offers products with a pressure pipe made of polybutene, with a multilayer insulation made of polyethylene foam and an external protective casing made of polyethylene low pressure(PND).
Traditionally, the products of Uponor (the old name Ecoflex may be used) and Watts- microflex". The pressure part of the pipes is made of cross-linked polyethylene, the insulation is several layers of foamed polyethylene, and the outer sheath is HDPE.
Please note that in the model range of all these companies there are samples with two or more pressure pipes in a common layer of thermal insulation and a protective casing. This can also be very convenient if, for example, water is sent to two different places, or in heating systems - for supply and return pipes, or for the heat satellite already mentioned above.
Find out how to insulate plumbing with a heating cable from our new article -
Concluding the review of insulating materials, we should also mention thermal insulation made of foamed rubber. In terms of thermal conductivity, this material outperforms polyethylene foam and competes almost equally with polyurethane foam. And at the same time, it is distinguished by excellent plasticity and all other properties necessary for high-quality insulation material.
The traditional form of release for such a heater is similar - in the form of insulating sleeves (cylinders). And how insulation is carried out, including complex sections of the water supply - is well shown in the video brought to your attention:
Video: Thermal insulation of water pipes with Kaiflex foam rubber sleeves
It would be logical to complete the review of materials with a comparative table with the main parameters of the heaters mentioned above.
Comparison table of key parameters of popular pipe insulation
| material, product | Average density in the insulation structure, kg/m3 | Thermal conductivity of insulation (W / (m × K)) for surfaces with temperature (°С) | Operating temperature range, °C | Flammability group | |
|---|---|---|---|---|---|
| 20 and up | 19 and below | ||||
| Mineral wool pierced plates | 120 | 0.045 | 0,044-0,035 | -180 to +450 for mats, fabric, mesh, fiberglass canvas; up to 700 - on a metal mesh | non-combustible |
| 150 | 0.049 | 0,048-0,037 | |||
| Thermal insulation slabs made of mineral wool on a synthetic binder | 65 | 0.04 | 0,039-0,03 | -60 to +400 | non-combustible |
| 95 | 0.043 | 0,042-0,031 | |||
| Semi-cylinders and mineral wool cylinders | 50 | 0,04 | 0,039-0,029 | -180 to +400 | non-combustible |
| 80 | 0,044 | 0,043-0,032 | |||
| 100 | 0,049 | 0,048-0,036 | |||
| 150 | 0,05 | 0,049-0,035 | |||
| 200 | 0,053 | 0,052-0,038 | |||
| Glass staple fiber mats with synthetic binder | 50 | 0,04 | 0,039-0,029 | -60 to +180 | non-combustible |
| 70 | 0,042 | 0,041-0,03 | |||
| Mats and wool made of superfine glass fiber without binder | 70 | 0,033 | 0,032-0,024 | -180 to +400 | non-combustible |
| Mats and wool made of super-thin basalt fiber without a binder | 80 | 0,032 | 0,031-0,24 | -180 to +600 | Non-combustible |
| Thermal insulation products made of expanded polystyrene | 30 | 0,033 | 0,032-0,024 | -180 to +70 | combustible |
| 50 | 0,036 | 0,035-0,026 | |||
| 100 | 0,041 | 0,04-0,03 | |||
| Thermal insulation products made of polyurethane foam | 40 | 0,030 | 0,029-0,024 | -180 to +130 | combustible |
| 50 | 0,032 | 0,031-0,025 | |||
| 70 | 0,037 | 0,036-0,027 | |||
| Thermal insulation products made of polyethylene foam | 50 | 0,035 | 0.033 | -70 to +70 | combustible |
| Thermal insulation products made of foamed ethylene-polypropylene rubber Aeroflex | 60 | 0,034 | 0.033 | -57 to +125 | Slightly combustible |
What thickness of insulation is needed?
Surely an interested reader will have a question - what should be the thickness of the insulation layer in order to guarantee the protection of the water pipe from freezing.
Answering this is not so easy. There is a calculation algorithm that takes into account the mass of the initial values, and includes several formulas that are difficult even for visual perception. This technique is set out in the Code of Rules SP 41-103-2000. If anyone wants to find this document and try to make an independent calculation, you are welcome.
But there is an easier way. The fact is that specialists have already taken on the brunt of the calculations - in the same document (SP 41-103-2000), which is easy to find by any search engine, the application contains many tables with ready-made values for the thickness of the insulation. The only problem is that it is physically impossible to present these tables here in our publication. They are compiled for each type of insulation separately, and - with a gradation also by location - soil, open air or room. In addition, the type of pipeline and the temperature of the pumped liquid are taken into account.
But if you spend 10 ÷ 15 minutes studying the tables, then there will certainly be an option in them that is as close as possible to the conditions that interest the reader.
It would seem that this is all, but it is necessary to dwell on one more important nuance. It applies only to cases of warming the water supply with mineral wool.
When it came to this thermal insulation material, in a series of shortcomings of mineral wool, its tendency to gradual caking and shrinkage was indicated. And this means that if you initially set only the estimated thickness of the insulation, then after some time the thickness of the insulation layer may become insufficient for full thermal insulation of the pipe.
Therefore, when performing insulation, it is advisable to pre-lay a certain margin of thickness. The question is what?
This one is easy to calculate. There is a formula, which, I think, does not make sense to demonstrate here, since the online calculator offered to your attention is based on it.
The two initial values for calculation are the outer diameter of the insulated pipe and the recommended value of the thermal insulation thickness found from the tables.
One more parameter remains unclear - the so-called "densification factor". We take it from the table below, focusing on the selected thermal insulation material and the diameter of the pipe to be insulated.
| Mineral wool insulation, insulated pipe diameter | Compaction factor Kc. |
|---|---|
| Mineral wool mats | 1.2 |
| Thermal insulation mats "TEHMAT" | 1.35 ÷ 1.2 |
| Mats and sheets made of super-thin basalt fiber (depending on the conditional diameter of the pipe, mm): | |
| → Doo | 3 |
| 1,5 | |
| → DN ≥ 800, at an average density of 23 kg/m³ | 2 |
| ̶ the same, with an average density of 50-60 kg/m³ | 1,5 |
| Mats made of glass staple fiber on a synthetic binder, brand: | |
| → M-45, 35, 25 | 1.6 |
| → M-15 | 2.6 |
| Mats made of glass spatula fiber "URSA", brand: | |
| → M-11: | |
| ̶ for pipes with DN up to 40 mm | 4,0 |
| ̶ for pipes with DN from 50 mm and above | 3,6 |
| → M-15, M-17 | 2.6 |
| → M-25: | |
| ̶ for pipes with DN up to 100 mm | 1,8 |
| ̶ for pipes with DN from 100 to 250 mm | 1,6 |
| ̶ for pipes with DN more than 250 mm | 1,5 |
| Mineral wool boards on a synthetic binder brand: | |
| → 35, 50 | 1.5 |
| → 75 | 1.2 |
| → 100 | 1.1 |
| → 125 | 1.05 |
| Glass staple fiber board grades: | |
| → P-30 | 1.1 |
| → P-15, P-17 and P-20 | 1.2 |
Now, armed with all the initial values, you can use the calculator.
It is necessary to protect from the cold not only building structures, but also engineering Communication. Proper insulation of heating pipes reduces heat loss, reduces the risk of freezing if hot water circulation has stopped for a long time due to accidents and repairs. The consumption of fuel and energy resources increases along with monthly utility bills.
Requirements for thermal insulation of heating pipes
Technical requirements for thermal insulation of pipelines are established by SP 61.13330. During operation, it is exposed to influences of a different nature - mechanical, chemical, thermal, moisture, so it must be not only energy efficient, but also reliable, durable, and safe.
Characteristics of materials that are taken into account when choosing:
- Thermal conductivity, density - determine the thickness of the insulation layer, the load on the pipe, its supports.
- Heat resistance - determines the invariance of the initial properties in contact with a hot surface.
- Elasticity, compressive strength - are responsible for the stability of the shape and structure during caking, laying in the ground.
- Water resistance - eliminates the absorption of water, allows you to maintain thermal insulation properties.
- Biostability, resistance to aggressive environments are important for long-term operation.
- Combustibility, content harmful substances- must meet sanitary and hygienic requirements, fire safety standards.
From a practical point of view, convenient, simple installation is important. It saves time, eliminates additional costs for installation materials.
Functions of insulating materials
Pipelines of heating systems are insulated for any type of laying - underground and above ground on the street, in technical rooms of apartment buildings, private houses, industrial, public buildings. The tasks of materials and structures do not depend on the location of communications.
Thermal insulation for heating pipes must:
- Maintain the temperature of the coolant to ensure comfort in residential and working premises.
- Reduce heat losses in the pipeline, maintain them at an acceptable level, reduce fuel or energy costs.
- Ensure safety in contact with the surface, as the temperature of hot water in the pipes reaches 1050C.
- Protect the system from freezing, corrosion, deformation, damage, extend its maintenance-free service life.
Properly selected and installed insulation performs all functions during the estimated service life.
Types of materials for thermal insulation of heating pipes
Technical solutions for pipe insulation differ in design, materials and characteristics.
Mineral wool
Technical insulation made of basalt rock wool for heat insulation of high-temperature pipelines is produced in coiled cylinders, slabs and mats, including those with one-sided foiling. It is chemically inert, bioresistant, non-combustible, has a thermal conductivity of about 0.04 W / m * K and a density of 100-150 kg / m3.
The materials are effective, affordable, but have drawbacks. The use of mineral wool insulation for insulating heating pipes in attics, basements, technical undergrounds is limited due to high humidity. The tendency to caking, the absorption of moisture lead to a violation of the structure, wetting, a rapid deterioration in heat-shielding properties.
Styrofoam and expanded polystyrene
Heat-insulating materials from extruded polystyrene foam and polystyrene are made in the form of plates, segments in the form of half-cylinders. They are used to protect house heating pipelines, to assemble a closed or U-shaped box when laying a pipeline in the ground.
The insulation has a density of 35-40 kg/m3, a thermal conductivity coefficient of about 0.035-0.04 W/m*K, and low water absorption, does not rot, and is easy to install. The disadvantages include combustibility, a narrow range of operating temperatures from -600 to + 750C. Pipes must be treated with an anti-corrosion compound before installation in the ground; with open laying, the insulation must be protected from UV rays.
polyurethane foam
For insulation of heating pipes, PPU shells with and without foil coating are used. The material is characterized by low thermal conductivity of 0.022-0.03 W / m * K and water absorption due to the closed cellular structure, high strength, long term service, not subject to rotting, quickly mounted. Uncoated shells are used only indoors, as polyurethane foam is destroyed by UV rays.
Insulation of large diameter pipelines can be performed using sprayed polyurethane foam insulation. It has an increased density and fire resistance, significantly reduces heat loss due to a continuous coating without "cold bridges".
Foamed synthetic rubber
Rubber technical thermal insulation is produced in rolls and tubes. It is non-combustible, environmentally friendly, resistant to chemical and biological influences, has a density of 65 kg/m3 and a thermal conductivity of 0.04-0.047 W/m*K.
The materials are used to insulate pipelines in rooms laid above and below ground; they may have an aluminized coating to protect against mechanical damage and UV rays. The main disadvantage is the high cost.
Foamed polyethylene
Thermal insulation for heating pipes made of foamed polyethylene with an elastic porous structure is used in any conditions, does not absorb water, maintains a low thermal conductivity of 0.032 W / m * k with temperature changes. It is available in the format of tubes, rolls, mats, easy and quick to install.
The material is used indoors, heating points, when laying pipes in the open air, in the ground. For above-ground installation, it is necessary to provide a cover layer, for underground - a casing.
Comparison of the characteristics of heating pipe insulation
| Characteristics | Mineral wool | Styrofoam | polyurethane foam | foamed rubber | Foamed polyethylene |
|---|---|---|---|---|---|
| Thermal conductivity, W/m*K | 0,04 | 0,035-0,04 | 0,022-0,03 | 0,038-0,045 | 0,032 |
| Density, kg/m3 | 105-135 | 35-40 | 60 | 65 | 35 |
| Water absorption, % | 10-15 | 4 | 1-2 | 0,6 | 0,6 |
| Application temperature, С0 | -180 to +680 | -60 to +75 | -180 to +140 | -60 to +105 | -80 to +100 |
| Ease of installation | May require winding, fixing with ties, wire rings | Glued together, pulled together with fastening bandages or assembled in a box | It is put on the pipe, fixed with thermal tape | Fixed with glue or clips | Attached with adhesive tape |
| Chemical and biostability | high | high | high | high | high |
| combustibility | NG | G3-G4 | G2-G4 | G1 | G1 |
The advantages of using polyethylene foam for thermal insulation of heating pipes are obvious. Foamed polyethylene insulation wins in operational, physical and economic properties. It is versatile, energy-efficient, retains heat-shielding properties throughout its service life, and is used at medium and low-price facilities due to its affordable cost.
