Work on thermal insulation of pipelines. Constructive solutions for thermal insulation based on thermal insulation products made from fibrous materials for industrial pipelines and equipment
Mats with one-sided lining can be used, in which case the mats are installed with the lining towards the frame (inside the structure). Fully prefabricated structures based on mats stitched into facings can also be used. 4.6. Thermal insulation of cold storage tanks drinking water in water supply systems. For thermal insulation of storage tanks cold water In water supply systems, it is recommended, first of all, to use stitched mats covered with fiberglass on both sides. The design of thermal insulation is similar to that given in paragraphs 4.5.4 - 4.5.5 (with a frame made of wooden blocks) and is distinguished by the presence of a vapor barrier layer. Stitched mats produced by ISOROK CJSC are installed in one or two layers, depending on the calculated insulation thickness, between the racks wooden frame, fastened with pins and tied with galvanized wire along the pins (Fig. 59 - 64).
Technologies for installing thermal insulation of pipelines
FIELD OF APPLICATION OF THERMAL INSULATING MINERAL WOOL MATS PRODUCED BY IZOROK CJSC 1.1. Thermal insulation mats, pierced mineral wool, are intended for use in industrial thermal insulation at temperatures of insulated surfaces from minus 180°C to plus 700°C and in accordance with the recommendations of sections 2 and 3. It should be taken into account that at a temperature of the insulated surface above 600°C the period The service life of stitched mats is significantly reduced.
1.2. Wiring mats can be used to insulate industrial equipment of industrial and housing and communal services facilities, including:
- vertical and horizontal cylindrical technological devices of chemical, oil refining, gas, metallurgical, etc. enterprises.
Stitched mats made of mineral wool - to make pipes last longer!
Info
CUTWOOL®MP tufted mats are made of mineral basalt wool on a synthetic binder with carpet stitching with glass roving, covered with fiberglass on both sides of the mat, according to TU 5762-002-89646568-2013. Marking: CUTWOOL®MP2 M50-2400.100.1000, TU 5762-002-89646568-2013, where: MP – symbol stitched mats; 2 — fiberglass lining on both sides; M50 – product brand; 2400 – mat length (mm); 100 – mat thickness (mm); 1000 – mat width (mm). Specifications: Length (mm) 2400 Width (mm) 1000 Thickness (mm) from 50 to 120; Density, kg/m3 from 30 to 100; Compressibility, % no more than 20 Humidity, % no more than 0.5 Thermal conductivity, W/mK 0.033 Flammability group NG Application temperature* from -180 to +600; * standard application temperature is +4000C, more on special order.
Advantages of tufted mineral wool mats
They are characterized by low smoke generation and also effectively prevent the spread of fire, providing additional time to rescue personnel and equipment.
- Excellent sound insulation. Stitched mats guarantee excellent sound insulation for both residential premises and industrial workshops.
- Ability to withstand high temperatures. Mineral wool pierced mats are a material that can withstand loads of up to 700°C! And some types of material, for example, having a combined composition with the addition of mullite silica, work at temperatures up to 1100°C!
- Chemical resistance.
Stitched mineral wool mats are not afraid of the effects of organic substances such as oils, alkalis, and solvents. - Low water absorption. An important ability of tufted mineral wool mats is to resist the influence of moisture.
Thermal insulation products of Isorok JSC. part 2
To compensate for temperature deformations, crimping of coating elements or other design solutions can be used. 4.3.14. The design of the protective coating of the vertical apparatus is shown in Fig. 47 and 48. Attaching the protective coating vertical devices This can also be done using 4x12 self-tapping screws with anti-corrosion coating or rivets.
Attention
Screw (rivet) installation pitch: vertically 150 - 200 mm, horizontally - no more than 300 mm. 4.3.15. The height of the protective coating of the device must include expansion joints, in which the protective coating elements rest on unloading devices or hinged brackets (Fig. 79) and are not fastened horizontally (circumferentially). Hinged brackets can be installed on the covering sheets of the previous row.
Unloading devices are installed along the height of the apparatus in height increments of no more than 3-4 meters.
403 forbidden
In terms of density, mats are produced in grades 100. 2.3. The maximum application temperature is determined by the temperature resistance of mineral wool and lining materials. The maximum temperature for using mats depending on the type of covering material is given in Table 2.1. Table 2.1. Temperature of application of stitching mats.
Name of lining material Without lining material or with fiberglass lining on one side (install with the fabric facing out) 600-700 (see clause 1.1.) Fabric, mesh, fiberglass canvas (with lining material sewn on both sides) 450 2.4. Stitched mineral wool mats grade 100 with and without linings belong to the group non-combustible materials(NG) according to GOST 30244. 2.5. The nominal dimensions of the mats indicating the maximum deviations are given in Table 2.2. Table 2.2.
Permissible temperature difference (to - tк) Air temperature, t0, °С Relative humidity air, φ, % 50 60 70 80 90 Design difference, (to - tк) °С 10 9.8 7.3 5.1 3.1 1.5 12 9.9 7.3 5.1 3.1 1 .5 14 10.1 7.4 5.2 3.2 1.5 16 10.2 7.6 5.3 3.3 1.5 18 10.4 7.7 5.4 3.3 1.5 20 10.5 7.8 5.4 3.4 1.5 22 10.7 7.9 5.5 3.4 1.5 24 10.9 8.0 5.6 3.5 1.6 26 11 .0 8.2 5.7 3.5 1.6 28 11.2 8.3 5.8 3.6 1.6 30 11.4 8.4 5.9 3.6 1.6 5.3.4. The heat transfer coefficient, (αн), should be taken in accordance with Appendix 2.1. 5.3.5. When designing, the thickness of the thermal insulation in the structure should be taken as a multiple of 10 mm, taking into account the current nomenclature of pierced mineral wool mats produced by ISOROK CJSC, and should only be rounded up.
5.3.6.
Unloading devices are also installed at the upper and lower bottoms of the devices. To impart rigidity to the structure of the protective coating, the coating elements can be zigged. 4.4. Thermal insulation of gas ducts and rectangular air ducts. 4.4.1. Thermal insulation mats are recommended to be used for insulating gas ducts of thermal power plants, ferrous and non-ferrous metallurgy facilities, etc., and air ducts of rectangular cross-section. A variant of the design of thermal insulation of a rectangular gas duct is shown in Fig. 49. Fastening of the heat-insulating layer is provided using pins (welded, plug-in) and bandages. At the corners of the thermal insulation of rectangular gas ducts, metal linings made of the coating material are installed under the bandages or wire rings replacing them.
Thermal insulation of pipelines with stitched mats
Temperature conditions of water heating networks, ºС 95-70 150-70 180-70 Pipeline Design coolant temperature, ™ ºС Supply 65 90 110 Return 50 50 50 b) design temperature of the external environment, at a laying depth to the top of the channel of 0.7 m or less : — for year-round operation of the heating network — average annual outside air temperature; - when operating only during the heating period - average for the heating period; c) if the depth of the top of the channel is more than 0.7 m - the average annual soil temperature at the depth of the pipeline axis. 5.4.3. The recommended thickness of insulation from heat-insulating pierced mineral wool mats of grade 100, which meets the heat flux density standards for pipelines of heating networks of two-pipe underground channel laying located in the European region of Russia, is given in Table 5.4.2.
Thermal insulation of pipelines with stitched mats
The calculated thickness of thermal insulation made of pierced mineral wool mats produced by ISOROC CJSC at an indoor air temperature of 20ºC and relative humidity of 60, 70 and 80% is given in Table 5.3.2. 5.3.7. When the temperature and humidity of the air in the room differ from those indicated, the thickness of the insulation should be determined using formulas (6) or (7), since with an increase in the relative humidity of the air in the absence of ventilation, the thickness of the insulation increases significantly. Table 5.3.2. Recommended thickness of thermal insulation made of pierced mineral wool mats, preventing condensation of moisture from the air on the surface of the insulation of pipelines and equipment located in the room.
Outer diameter, mm Relative humidity of ambient air.
“Technical regulations on the safety of buildings and structures”, order of the Ministry of Regional Development of the Russian Federation dated December 30, 2009 No. “On approval of the List of types of work on engineering surveys, on the preparation of design documentation for the construction, reconstruction, and major repairs of capital construction projects that affect the safety of capital construction projects.”
This standard was developed in development of the normative provisions of SP 60.13330.2012 “SNiP 41-01-2003 Heating, ventilation and air conditioning” and SP 61.13330.2012 “SNiP 41-03-2003 Thermal insulation of equipment and pipelines”.
Authors' team: A.V. Samsonenko(Role Isomarket LLC), A.V. Busakhin(LLC "Third Installation Directorate "Promventilation"), Ph.D. econ. Sciences D.L. Kuzin(BUT "APIK"), doc. tech. spider A.M. Grimitlin(NP "NW Center ABOK"), G.K. Osadchiy(MAXHOL Technologies LLC), F .IN. Tokarev(NP "ISZS-Montazh").
STANDARD OF THE NATIONAL ASSOCIATION OF BUILDERS
1 Application area
1.1 This standard applies to thermal insulation structures (hereinafter referred to as thermal insulation structures) intended for equipment, pipelines and air ducts of utility networks located in premises of categories B, D, D (according to SP 12.13130, clause 4.1).
1.2 This standard establishes requirements, rules and control of implementation thermal insulation works using thermal insulation structures and their elements made of pipes or rolls of foamed polyethylene or synthetic foam rubber, as well as cylinders or mats of mineral or glass fiber.
2 Normative references
This standard uses normative references to the following standards and codes of practice:
Ensure that the temperature of the outer surface of the thermal insulation structure is safe for humans in accordance with SP 61.13330 (clause 4.2).
5.5 Installation of thermal insulation structures must be carried out in accordance with the requirements of SP 61.13330 and this standard.
6 Technology for performing thermal insulation work
6.1 General provisions
6.1.1 Thermal insulation work should be carried out only when the facility is completely ready. Construction and installation work is considered fully completed if the pipelines and equipment are in the designed position and pressure tested in accordance with the work project, which must be confirmed by the relevant acts.
6.1.2 Installation of thermal insulation is carried out according to working documentation in accordance with the project for carrying out work on thermal insulation and taking into account the construction organization project.
6.1.8 In order to increase productivity and achieve high quality of thermal insulation work, it is recommended to use prefabricated thermal insulation structures manufactured in workshops.
6.2 Installation of thermal insulation of pipelines of heating networks of heating systems, hot and cold water supply, technological systems
6.2.1 In thermal insulation structures on pipelines, thermal insulation products in the form of tubes should be used as thermal insulation, and if there are no tubes of the required standard size in the manufactured range, thermal insulation products in the form of rolls should be used.
6.2.2 Fastenings thermal insulation products on pipelines, depending on the type of material, must be performed in the manner recommended by the manufacturer. Requirements for the installation of tubes and rolls made of materials with a closed cell structure are set out in series 5.904.9-78.08.
6.2.3 To attach tubes to pipelines, the longitudinal and transverse seams of the products should be glued with contact adhesive recommended by the manufacturer. It is recommended to additionally seal the seams of the products with reinforced self-adhesive tape.
1 - bandage; 2 - ribbon
Notes
1 For the bandage, it is allowed to use metal tapes with an anti-corrosion coating made of stainless steel, aluminum alloys or polyamide.
2 The material of the bandage used to secure the covering layer must match the material from which the coating is made.
3 The material used to make the buckle (Pos. 2) must match the material from which the bandage is made (galvanized or stainless steel, aluminum alloy sheets).
6.2.5 To attach sheets (rolls) to pipelines, the seams of the products should be glued with contact adhesive recommended by the manufacturer. It is recommended to additionally seal the seams of the products with reinforced self-adhesive tape, and also secure the products with bandages made of reinforced self-adhesive tape, located in increments of 500 to 600 mm.
6.2.6 For thermal insulation of bends, tees, transitions and fittings, thermal insulating elements made of products in the form of tubes, cylinders, sheets or mats should be manufactured at the work site. The figure shows two options for thermal insulation of branches, differing in pipeline diameters.
a) insulation of the outlet with thermal insulating tubes (D n≤ 160 mm);
b) insulation of the outlet with thermal insulation sheets (D n> 160 mm)
1 - tube made of heat-insulating material at D n≤ 160 mm; 2 - sheet of thermal insulation material at D n> 160 mm; 3 - glue; 4 - reinforced self-adhesive tape
6.2.7 In multilayer thermal insulation structures intended for pipelines, the installation of the second and subsequent layers of thermal insulation is carried out by overlapping the seams of each previous layer. The seams of all layers of thermal insulation are glued together with contact adhesive. It is recommended to additionally seal the seams of the outer layer with reinforced self-adhesive tape.
Two-layer thermal insulation of a tee coated with metal shells and fastened with self-tapping screws is shown in the figure.
1
- tube made of heat-insulating material; 2
- sheet of thermal insulation material;
3
- glue; 4
5,6
- metal shells;
7
- self-tapping screw with press washer, galvanized, drill tip
Bandages are installed in increments of 500 to 600 mm. The figure shows the design of a thermally insulated pipeline with a metal shell using bandage fastening.
1
- tube made of heat-insulating material at D n≤ 160 mm (sheet of thermal insulation material at D n> 160 mm); 2
- glue; 3
- reinforced self-adhesive tape;
4
- metal shell; 5
- bandage with buckle
6.2.11 For thermal insulation vertical pipelines with metal covering material, depending on the thickness of the thermal insulation and the height of the pipeline, support structures (unloading devices) can be provided to prevent deformation and sliding of the covering material.
Unloading devices are located in increments of 3 to 4 m along the height of the pipeline or equipment. In these same places, expansion joints are provided in the metal covering material. The design of unloading devices should not have through heat-conducting inclusions.
Unloading devices are made of metal or lumber. Unloading devices made from lumber must be impregnated with antiseptic compounds or fire retardants in accordance with GOST R 53292 and GOST 20022.5.
6.3 Installation of thermal insulation of reservoirs of heating networks of heating systems, hot and cold water supply, technological systems
6.3.1 In thermal insulation structures of tanks, thermal insulation products in the form of rolls and mats should be used as thermal insulation.
6.3.2 Fastening thermal insulation products to tanks, depending on the type of material, must be performed in the manner recommended by the manufacturer. For example, the requirements for installing rolls made of materials with a closed cell structure are set out in series 5.904.9-78.08. An option for performing thermal insulation on a horizontal tank is shown in the figure.
6.3.3 If the temperature of the insulated surface is below +90 °C, it is recommended to use products in the form of rolls with a self-adhesive backing.
6.3.4 Installation of coatings (linings) and linings on vertical tanks (Figure ) should be carried out from bottom to top with an overlap of 40 to 50 mm.
1
- sheet of heat-insulating material; 2
- glue; 3
- metal shell;
4
- aluminum self-adhesive tape; 5
- silicone sealant
1 - sheet of thermal insulation material; 2 - glue; 3 - aluminum self-adhesive tape
6.3.5 In multi-layer thermal insulation structures for tanks, the installation of the second and subsequent layers of thermal insulation is carried out by overlapping the seams of the previous layer. Sheets (rolls) of each subsequent layer must be glued to the previous one. The seams between products of the same layer are taped with reinforced self-adhesive tape.
6.3.6 Installation of thermal insulation of supports and tank heads is carried out in accordance with the working documentation.
6.4 Thermal insulation of equipment, pipelines and air ducts of ventilation and air conditioning systems
6.4.1 To ensure the quality of work performed when installing thermal insulation, the requirements of , , , and this standard should be followed.
6.4.2 Fastenings of thermal insulation products on pipelines and air ducts, depending on the type of material, must be carried out in the manner recommended by the manufacturer. For example, the requirements for installing materials with a closed cell structure are set out in series 5.904.9-78.08. The figure shows a thermal insulation structure made with self-adhesive thermal insulation material.
The thermal insulation structure, shown in the figure, is made using self-adhesive thermal insulation materials and a self-adhesive metal shell.
1 - sheet of self-adhesive thermal insulation material; 2 - glue;
3 - reinforced self-adhesive tape
6.4.3 When installing thermal insulation structures designed to prevent moisture condensation from the outside air on the surface, materials with a closed cellular structure should be selected as thermal insulation materials.
6.4.4 Installation of the covering (lining) and cladding must be carried out with an overlap of 40 to 50 mm along the longitudinal and transverse seams.
1 - sheet of self-adhesive thermal insulation material; 2 - glue;
3 - self-adhesive metal shell; 4 - silicone sealant
7 Monitoring the performance of thermal insulation work
7.1 Monitoring the performance of work on thermal insulation of engineering systems in buildings and structures should be carried out based on the requirements and provisions of the working documentation.
When monitoring implementation installation work Compliance with the requirements must be checked - taking into account factors 5.1, as well as provisions 7.2 - 7.8.
Quality certificate.
7.3 Upon final acceptance of the thermal insulation structure at the facility, it is necessary to check that the temperature on the surface of the thermal insulation structure corresponds to the safe temperature (SP 61.13330). Temperature is measured by any verified instrument that has a verification mark in the device passport or a verification certificate in accordance with the requirements of SP 61.13330.
7.4 Operational control of the performance of thermal insulation work is carried out in accordance with the Appendix.
7.5 When carrying out operational control of a thermal insulation structure, the following is checked:
a) before laying the thermal insulation material:
Cleanliness of the insulated surface - visually;
Availability of anti-corrosion protection - visually;
Compliance of the thickness of the heat-insulating material used with the requirements of the RD, measuring the thickness, for example, using a thickness gauge according to GOST 28702 (Tables 1 - 3);
Compliance of the cover layer material with the material specified in the RD;
b) during installation of thermal insulation material:
Gluing seams and joints of heat-insulating material with glue and tape - visually;
The absence of counter overlaps (against the direction of flow of rainwater or flowing moisture) on the cover layer - visually;
No damage to the thermal insulation layer - visually;
Overlap assembly seams in multilayer structures - visually;
c) after completion of installation of thermal insulation material and structural design:
Fastening of the covering layer - visually;
No damage to the surface of the coating layer - visually;
Absence of damage to the surface of the coating (lining), if any, visually;
Correspondence appearance and constructive design of thermal insulation according to working documentation - visually.
7.6 Acceptance control of thermal insulation work is carried out after completion of installation of thermal insulation structures.
During the acceptance inspection process, defects are identified, which should include:
Deviation from the data given in the working documentation regarding materials, structures and method of installation of insulation;
Inconsistency of the thickness of the thermal insulation layer with the data of the working documentation;
Mechanical damage to insulation;
Loose fit of the heat-insulating layer to the surface of the insulated object;
Lack of thermal insulation at the locations of the supports;
Failure to comply with the rules for the location of longitudinal and transverse seams of coatings (linings) and claddings.
7.7 After comparing the installed thermal insulation structure with the data from the working documentation and taking into account the changes made during the installation process, a final defective list is drawn up, which includes all the actual indicators established during acceptance (Appendix).
8 Requirements for reporting and technical documentation
8.1 Reporting and technical documentation is completed for transmission to the technical customer at the stage of delivery and acceptance of completed work.
8.2 For high-quality installation work and compliance with all technological operations working documentation accepted for production must satisfy.
8.3 Standard series of working drawings of thermal insulation can be used as working drawings. Thus, for polymer insulation with a closed cell structure, you can use the standard series 5.904.9-78.08.
8.4 If technical solutions for thermal insulation are used in the working documentation accepted for production standard series with the corresponding drawings, the technical installation sheet must contain a link to the sheets of the series, which show the corresponding designs.
8.5 The technical installation list must comply with GOST 21.405 (the form is given in the appendix of this standard) and, in addition, contain general data related to the thermal insulation structures being performed:
Information about the estimated ambient temperature;
Results of thermal engineering calculations;
Purpose of thermal insulation for certain types of equipment and pipelines;
Requirements for the manufacture of thermal insulation structures and their installation
8.6 Equipment specifications are drawn up according to technical installation sheets and working drawings.
8.7 The equipment specification is drawn up in accordance with the application and must contain the following sections:
Thermal insulation products;
Cover layer products and materials;
Fastening products (including adhesives, self-adhesive tapes, etc.).
9 Rules for safe work performance
9.1 Before the start of thermal insulation work, premises must be allocated at the construction site for storing materials and tools, as well as a workshop for preparing thermal insulation structures and performing technological operations.
9.2 Work must be performed in special clothing.
9.3 Before starting thermal insulation work, it is necessary to ensure safety standards in accordance with SNiP 12-04-2002 (section 12).
Operational control of thermal insulation work
|
Object |
Before laying thermal insulation material |
During installation of thermal insulation material |
|||||||
|
Cleanliness of the insulated surface |
Availability of anti-corrosion protection |
Correspondence of the thickness of the thermal insulation material specified in the RD |
Compliance of the cover layer with that specified in the RD |
Gluing the seams and joints of the heat-insulating layer with glue |
Taping seams and joints of the heat-insulating layer |
No counter overlaps (against the flow of rainwater) on the cover layer |
No damage to the thermal insulation layer |
Overlap installation seams in multilayer designs |
|
|
Fittings |
|||||||||
|
Air ducts |
|||||||||
|
Capacities |
|||||||||
|
Technological equipment |
|||||||||
Continuation of the table
|
Object |
After completing the installation of thermal insulation material |
|||
|
Attaching the cover layer |
Absence damage cover layer |
Absence damage on surfaces coatings (linings) |
Correspondence appearance thermal insulation designs according to RD |
|
|
Pipelines for heating and water supply systems |
||||
|
Refrigeration piping |
||||
|
Fittings |
||||
|
Air ducts |
||||
|
Capacities |
||||
|
Technological equipment |
||||
Defective statement form
|
No. |
Object |
Characteristics of defects |
Description of work to eliminate defects |
Unit of measurement |
Quantity |
Note |
In the practice of private construction, it is not so common, but there are still situations when heating communications need to be not only distributed throughout the premises of the main house, but also extended to other nearby buildings. These can be residential outbuildings, extensions, summer kitchens, utility or agricultural buildings, for example, used for keeping domestic animals or poultry. The option cannot be ruled out when, on the contrary, the autonomous boiler room itself is located in a separate building, at some distance from the main residential building. It happens that a house is connected to a central heating main, from which pipes are extended to it.
There are two options for laying heating pipes between buildings - underground (ducted or ductless) and open. The process of installing a local heating main above the ground seems less labor-intensive, and this option is used more often in conditions of independent construction. One of the main conditions for the efficiency of the system is properly planned and high-quality thermal insulation for heating pipes on outdoors. It is this issue that will be addressed in this publication.
Why do you need thermal insulation of pipes and the basic requirements for it?
It would seem nonsense - why insulate the already almost always hot pipes of the heating system? Perhaps someone may be misled by a peculiar “play on words”. In the case under consideration, of course, it would be more correct to conduct the conversation using the concept of “thermal insulation”.
Thermal insulation work on any pipelines has two main goals:
- If pipes are used in heating or hot water supply systems, then reducing heat losses and maintaining the required temperature of the pumped liquid comes to the fore. The same principle is also true for industrial or laboratory installations, where technology requires maintaining a certain temperature of the substance transmitted through pipes.
- For cold water supply pipelines or sewer communications, the main factor is insulation, that is, preventing the temperature in the pipes from falling below a critical level, preventing freezing, leading to failure of the system and deformation of the pipes.
By the way, such a precaution is required for both heating mains and hot water supply pipes - no one is completely immune from emergency situations on boiler equipment.
The cylindrical shape of the pipes itself predetermines a very considerable area of constant heat exchange with environment, which means significant heat loss. And they naturally increase as pipeline diameters increase. The table below clearly shows how the amount of heat loss changes depending on the temperature difference inside and outside the pipe (Δt° column), on the diameter of the pipes and on the thickness of the thermal insulation layer (data given taking into account the use of insulation material with an average thermal conductivity coefficient λ = 0.04 W/m×°C).
| The thickness of the thermal insulation layer. mm | Δt.°С | Pipe outer diameter (mm) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 15 | 20 | 25 | 32 | 40 | 50 | 65 | 80 | 100 | 150 | ||
| The amount of heat loss (per 1 linear meter of pipeline. W). | |||||||||||
| 10 | 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 | 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 | 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 | 8.31 | 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 | 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 the thickness of the insulation layer increases general indicator heat loss is reduced. However, please note that even a fairly thick layer of 40 mm does not completely eliminate heat loss. There is only one conclusion - it is necessary to strive to use insulation materials with the lowest possible thermal conductivity coefficient - this is one of the main requirements for thermal insulation of pipelines.
Sometimes a pipeline heating system is also required!
When laying water supply or sewer lines, it happens that due to the local climate or specific installation conditions, thermal insulation alone is clearly not enough. We have to resort to forced installation of heating cables - this topic is discussed in more detail in a special publication on our portal.
- The material used for thermal insulation of pipes, if possible, should have hydrophobic properties. There will be little current from insulation soaked in water - it will not prevent heat loss, and will soon collapse under the influence of negative temperatures.
- The thermal insulation structure must have a reliable external protection. Firstly, it needs protection from atmospheric moisture, especially if insulation is used that can actively absorb water. Secondly, materials should be protected from exposure to the ultraviolet spectrum sunlight, which has a detrimental effect on them. Thirdly, we should not forget about wind load, which can damage the integrity of the thermal insulation. And fourthly, there remains the factor of external mechanical impact, unintentional, including from animals, or due to banal manifestations of vandalism.
In addition, any owner of a private house is probably not indifferent to the aesthetic appearance of the installed heating main.
- Any thermal insulation material used on heating mains must have an operating temperature range that corresponds to the actual conditions of use.
- An important requirement for insulating material and its external cladding is durability of use. No one wants to return to the problems of thermal insulation of pipes even once every few years.
- From a practical point of view, one of the main requirements is the ease of installation of thermal insulation, in any position and in any difficult area. Fortunately, in this regard, manufacturers never tire of delighting with easy-to-use developments.
- An important requirement for thermal insulation is that its materials themselves must be chemically inert and not enter into any reaction with the surface of the pipes. Such compatibility is the key to long-term trouble-free operation.
The issue of cost is also very important. But in this regard, the range of prices among specialized ones is very large.
What materials are used for insulation of above-ground heating mains
The choice of thermal insulation materials for heating pipes when external laying– big enough. They come in roll type or in the form of mats; they can be given a cylindrical or other shaped shape that is convenient for installation; there are insulation materials that are applied in liquid form and acquire their properties only after hardening.
Insulation with foamed polyethylene
Foamed polyethylene is rightly classified as a very effective thermal insulator. And what is also very important, the cost of this material is one of the lowest.
The thermal conductivity coefficient of foamed polyethylene is usually around 0.035 W/m×°C - this is a very good indicator. The smallest bubbles, isolated from each other, filled with gas, create an elastic structure, and with such material, if you purchase a roll version, it is very convenient to work on pipe sections with complex configurations.
Such a structure becomes a reliable barrier to moisture - if installed correctly, neither water nor water vapor will be able to penetrate through it to the pipe walls.
The density of polyethylene foam is low (about 30 - 35 kg/m³), and thermal insulation will not make the pipes heavier.
The material, with some assumption, can be classified as low-hazard in terms of flammability - it usually belongs to class G-2, that is, it is very difficult to ignite, and without an external flame it quickly extinguishes. Moreover, combustion products, unlike many other thermal insulators, do not pose any serious toxic danger to humans.
Rolled foam polyethylene for insulation of external heating mains will be both inconvenient and unprofitable - you will have to wind it in several layers to achieve the required thickness of thermal insulation. It is much more convenient to use material in the form of sleeves (cylinders), which have an internal channel corresponding to the diameter of the insulated pipe. To put it on pipes, an incision is usually made along the length of the cylinder on the wall, which after installation can be sealed with reliable tape.
Putting insulation on a pipe is not difficult A more effective type of polyethylene foam is penofol, which has on one side. This shiny coating becomes a kind of thermal reflector, which significantly increases the insulating qualities of the material. In addition, it is an additional barrier against moisture penetration.
Penofol can also be of a roll type or in the form of profile cylindrical elements - especially for thermal insulation of pipes for various purposes.
And all foamed polyethylene is rarely used for thermal insulation of heating mains. It is more likely to be suitable for other communications. The reason for this is the rather low operating temperature range. So. if you look at the physical characteristics, the upper limit balances somewhere on the verge of 75 ÷ 85 degrees - above that, structural disturbances and the appearance of deformations are possible. For autonomous heating, more often than not, this temperature is sufficient, although on the edge, and for the central temperature, thermal stability is clearly not enough.
Insulation elements made of polystyrene foam
The well-known expanded polystyrene (in everyday life it is more often called polystyrene foam) is very widely used for a variety of types of thermal insulation work. The insulation of pipes is no exception - special parts are made from foam plastic for this purpose.
Usually these are half-cylinders (for pipes large diameters there can be segments of a third of the circumference, 120° each), which, for assembly into a single structure, are equipped with a tongue-and-groove locking connection. This configuration makes it possible to provide reliable thermal insulation completely over the entire surface of the pipe, without remaining “cold bridges.”
In everyday speech, such details are called “shells” for their obvious resemblance to it. There are many types of it available, for different outer diameters of insulated pipes and different thicknesses of the thermal insulation layer. Typically the length of the parts is 1000 or 2000 mm.
For production, polystyrene foam of the PSB-S type of various grades is used - from PSB-S-15 to PSB-S-35. The main parameters of this material are shown in the table below:
| Estimated material parameters | Brand of expanded polystyrene | ||||
|---|---|---|---|---|---|
| PSB-S-15U | PSB-S-15 | PSB-S-25 | PSB-S-35 | PSB-S-50 | |
| Density (kg/m³) | up to 10 | up to 15 | 15.1 ÷ 25 | 25.1 ÷ 35 | 35.1 ÷ 50 |
| Compressive strength at 10% linear deformation (MPa, not less) | 0.05 | 0.06 | 0.08 | 0.16 | 0.2 |
| Bending strength (MPa, not less) | 0.08 | 0.12 | 0.17 | 0.36 | 0.35 |
| Thermal conductivity in dry condition at a temperature of 25°C (W / (m×°K)) | 0,043 | 0,042 | 0,039 | 0,037 | 0,036 |
| Water absorption in 24 hours (% by volume, no more) | 3 | 2 | 2 | 2 | 2 |
| Humidity (%, no more) | 2.4 | 2.4 | 2.4 | 2.4 | 2.4 |
The advantages of polystyrene foam as an insulating material have long been known:
- It has a low thermal conductivity coefficient.
- The light weight of the material greatly simplifies insulation work, which does not require any special mechanisms or devices.
- The material is biologically inert - it will not nutrient medium for the formation of mold or mildew.
- Moisture absorption is negligible.
- The material can be easily cut and adjusted to the desired size.
- Polystyrene foam is chemically inert and absolutely safe for pipe walls, no matter what material they are made of.
- One of the key advantages is that polystyrene foam is one of the most inexpensive insulation materials.
However, it also has many disadvantages:
- First of all, this is a low level fire safety. The material cannot be called non-flammable and does not spread flame. That is why, when using it to insulate above-ground pipelines, fire breaks must be left.
- The material does not have elasticity, and it is convenient to use it only on straight sections of pipe. True, you can also find special figured parts.
- Polystyrene foam is not a durable material - it is easily destroyed under external influence. Ultraviolet radiation also has a negative effect on it. In a word, above-ground sections of the pipe, insulated with polystyrene foam shells, will definitely require additional protection in the form of a metal casing.
Usually, stores that sell foam shells also offer galvanized sheets, cut to the required size, corresponding to the diameter of the insulation. An aluminum shell can also be used, although it is of course much more expensive. The sheets can be secured with self-tapping screws or clamps - the resulting casing will simultaneously create anti-vandal, anti-wind, waterproofing protection and a barrier from sunlight.
- And yet this is not even the main thing. The upper limit of normal temperatures for operation is only around 75°C, after which linear and spatial deformation of parts may begin. Whatever one may say, this value may not be enough for heating. It probably makes sense to look for a more reliable option.
Insulation of pipes with mineral wool or products based on it
The most “ancient” method of thermal insulation of external pipelines is using mineral wool. By the way, it is also the most budget-friendly, if it is not possible to purchase a foam shell.
For thermal insulation of pipelines, various types of mineral wool are used - glass wool, stone (basalt) and slag. Slag is the least preferable: firstly, it absorbs moisture most actively, and secondly, its residual acidity can have a very destructive effect on steel pipes. Even the cheapness of this cotton wool does not in any way justify the risks of its use.
But mineral wool based on basalt or glass fibers is fully suitable. It has good thermal resistance to heat transfer, high chemical resistance, the material is elastic, and it is easy to install even on difficult sections of pipelines. Another advantage is that you can, in principle, be completely calm in terms of fire safety. It is almost impossible to heat mineral wool to the point of ignition in the conditions of an external heating main. Even exposure to an open flame will not cause a fire to spread. That is why mineral wool is used to fill fire gaps when using other pipe insulation materials.
The main disadvantage of mineral wool is its high water absorption (basalt wool is less susceptible to this “disease”). This means that any pipeline will require mandatory protection from moisture. In addition, the structure of the wool is unstable to mechanical stress, is easily destroyed, and should be protected with a durable casing.
Usually use durable plastic film, which is securely wrapped in a layer of insulation, with the obligatory overlap of the strips by 400 ÷ 500 mm, and then the whole thing is closed on top metal sheets- exactly by analogy with polystyrene foam shells. Roofing felt can also be used as waterproofing - in this case, 100 ÷ 150 mm of overlap of one strip over another will be sufficient.
Existing GOST standards determine the thickness of protective metal coatings for open sections of pipelines for any type of thermal insulation materials used:
| Protective cover layer material | Minimum metal thickness, with outer diameter of insulation | ||
|---|---|---|---|
| 350 or less | Over 350 and up to 600 | Over 600 and up to 1600 | |
| Stainless steel strips and sheets | 0.5 | 0.5 | 0.8 |
| Sheets made of thin sheet steel, galvanized or polymer coated | 0.5 | 0.8 | 0.8 |
| Aluminum or aluminum alloy sheets | 0.3 | 0.5 | 0.8 |
| Aluminum or aluminum alloy tapes | 0.25 | - | - |
Thus, despite the apparent inexpensive price the insulation itself, its full installation will require considerable additional costs.
Mineral wool for insulation of pipelines can also act in another capacity - it serves as a material for the manufacture of finished thermal insulation parts, by analogy with polyethylene foam cylinders. Moreover, such products are produced both for straight sections of pipelines and for bends, tees, etc.
Typically, such insulating parts are made from the densest material - basalt mineral wool, and have an external foil coating, which immediately eliminates the problem of waterproofing and increases the efficiency of insulation. But you still won’t be able to get away from the outer casing - a thin layer of foil will not protect you from accidental or intentional mechanical impact.
Insulation of heating mains with polyurethane foam
One of the most effective and safest modern insulation materials is polyurethane foam. It has a lot of various advantages, so the material is used on almost any structure that requires reliable insulation.
What are the features of polyurethane foam insulation?
Polyurethane foam for pipeline insulation can be used in various forms.
- PPU shells are widely used, usually having an outer foil coating. It can be collapsible, consisting of half-cylinders with tongue-and-groove locks, or, for pipes small diameter– with a cut along the length and special valve with a self-adhesive back surface, which greatly simplifies the installation of insulation.
- Another way to thermally insulate a heating main with polyurethane foam is to spray it in liquid form using special equipment. The resulting layer of foam, after complete hardening, becomes an excellent insulation material. This technology is especially convenient at complex junctions, pipe turns, in units with shut-off and control valves, etc.
The advantage of this technology is that, thanks to the excellent adhesion of polyurethane foam spraying to the surface of the pipes, excellent waterproofing and anti-corrosion protection is created. True, the polyurethane foam itself also requires mandatory protection - from ultraviolet rays, so again it will not be possible to do without a casing.
- Well, if you need to lay a sufficiently long heating main, then, probably, the most optimal choice will be the use of pre-insulated (pre-insulated) pipes.
In fact, such pipes are a multilayer structure assembled in a factory:
— The inner layer is, in fact, the steel pipe itself of the required diameter, through which the coolant is pumped.
— The outer coating is protective. It can be polymer (for laying a heating main in the thickness of the soil) or galvanized metal - what is required for open sections of the pipeline.
— Between the pipe and the casing, a monolithic, seamless layer of polyurethane foam is poured, which performs the function of effective thermal insulation.
Left at both ends of the pipe installation area for carrying out welding work when assembling the heating main. Its length is designed in such a way that the heat flow from the welding arc will not damage the polyurethane foam layer.
After installation, the remaining uninsulated areas are primed, covered with a polyurethane foam shell, and then with metal belts, comparing the coating with the overall outer casing of the pipe. It is often in such areas that fire breaks are organized - they are tightly filled with mineral wool, then waterproofed with roofing felt and still covered on top with a steel or aluminum casing.
The standards establish a certain range of such sandwich pipes, that is, it is possible to purchase products of the required nominal diameter with optimal (regular or reinforced) thermal insulation.
| Outer diameter of steel pipe and minimum thickness its walls (mm) | Dimensions of galvanized sheet steel shell | Estimated thickness of the thermal insulation layer of polyurethane foam (mm) | |
|---|---|---|---|
| nominal outer diameter (mm) | minimum thickness of steel sheet (mm) | ||
| 32×3.0 | 100; 125; 140 | 0.55 | 46,0; 53,5 |
| 38×3.0 | 125; 140 | 0.55 | 43,0; 50,5 |
| 45×3.0 | 125; 140 | 0.55 | 39,5; 47,0 |
| 57×3.0 | 140 | 0.55 | 40.9 |
| 76×3.0 | 160 | 0.55 | 41.4 |
| 89×4.0 | 180 | 0.6 | 44.9 |
| 108×4.0 | 200 | 0.6 | 45.4 |
| 133×4.0 | 225 | 0.6 | 45.4 |
| 159×4.5 | 250 | 0.7 | 44.8 |
| 219×6.0 | 315 | 0.7 | 47.3 |
| 273×7.0 | 400 | 0.8 | 62.7 |
| 325×7.0 | 450 | 0.8 | 61.7 |
Manufacturers offer such sandwich pipes not only for straight sections, but also for tees, bends, expansion joints, etc.
The cost of such pre-insulated pipes is quite high, but their acquisition and installation solves a whole range of problems at once. So such costs seem quite justified.
Video: the production process of pre-insulated pipes
Insulation – foam rubber
Thermal insulation materials and products made from synthetic foam rubber have recently become very popular. This material has a number of advantages that bring it to a leadership position in matters of insulation of pipelines, including not only heating mains, but also more critical ones - on complex technological lines, in machine, aircraft and shipbuilding:
- Foam rubber is very elastic, but at the same time has a large margin of tensile strength.
- The density of the material is only from 40 to 80 kg/m³.
- The low thermal conductivity coefficient provides very effective thermal insulation.
- The material does not shrink over time, completely retaining its original shape and volume.
- Foamed rubber is difficult to ignite and has the property of rapid self-extinguishing.
- The material is chemically and biologically inert; there are no pockets of mold or mildew, no nests of insects or
- The most important quality is almost absolute water and vapor tightness. Thus, insulating layer immediately becomes an excellent waterproofing for the surface of the pipe.
Such thermal insulation can be produced in the form of hollow tubes with an internal diameter from 6 to 160 mm and a thickness of the insulation layer from 6 to 32 mm, or in the form of sheets, which are often given a “self-adhesive” function on one side.
| Name of indicators | Values |
|---|---|
| Length of finished tubes, mm: | 1000 or 2000 |
| Color | black or silver, depending on the type of protective coating |
| Temperature range of application: | from - 50 to + 110 °C |
| Thermal conductivity, W/(m ×°C): | λ≤0.036 at 0°C |
| λ≤0.039 at a temperature of +40°C | |
| Vapor permeation resistance coefficient: | μ≥7000 |
| Fire hazard level | Group G1 |
| Allowable length change: | ±1.5% |
But for heating mains located in the open air, ready-made insulation elements made using the Armaflex ACE technology and having a special ArmaChek protective coating are especially convenient.
ArmaChek coating can be of several types, for example:
- "Arma-Chek Silver" is a multi-layer PVC-based shell with a silver reflective coating. This coating provides excellent protection of the insulation from both mechanical stress and ultraviolet rays.
- The black Arma-Chek D coating has a fiberglass base that is highly durable but retains excellent flexibility. This - excellent protection from all possible chemical, weather, mechanical influences, which will keep the heating pipe intact.
Typically, such products using the ArmaChek technology have self-adhesive valves that hermetically “seal” the insulating cylinder on the pipe body. Curved elements are also produced that allow installation on difficult sections of the heating main. Skillful use of such thermal insulation allows you to quickly and reliably install it, without resorting to creating an additional external protective casing - there is simply no need for it.
Probably the only thing that slows me down wide application such thermal insulation products for pipelines – the price for real, “branded” products is still prohibitively high.
Prices for thermal insulation for pipes
Thermal insulation for pipes
A new direction in insulation - thermal insulation paint
You can't miss another one modern technology insulation. And it’s all the more pleasant to talk about it, since it is the development of Russian scientists. It's about about ceramic liquid insulation, which is also known as heat-insulating paint.
This is, without any doubt, an “alien” from the sphere of space technology. It is in this scientific and technical field that the issues of thermal insulation from critically low (in outer space) or high (during the launch of ships and landing of descent vehicles) are especially acute.
The thermal insulation qualities of ultra-thin coatings seem simply fantastic. At the same time, such a coating becomes an excellent hydro- and vapor barrier, protecting the pipe from all possible external influences. Well, the heating main itself takes on a well-groomed, pleasing appearance.
The paint itself is a suspension of microscopic, vacuum-filled silicone and ceramic capsules suspended in liquid state V special composition, including acrylic, rubber and other components. After applying and drying the composition, a thin elastic film is formed on the surface of the pipe, which has outstanding thermal insulation properties.
| Names of indicators | Unit of measurement | Magnitude |
|---|---|---|
| Paint color | white (can be customized) | |
| Appearance after application and complete hardening | matte, smooth, homogeneous surface | |
| Film elasticity when bending | mm | 1 |
| Coating adhesion based on pull-off force from the painted surface | ||
| - to the concrete surface | MPa | 1.28 |
| - to a brick surface | MPa | 2 |
| - to steel | MPa | 1.2 |
| Resistance of the coating to temperature changes from -40 °C to + 80 °C | no changes | |
| Resistance of the coating to temperatures of +200 °C for 1.5 hours | no yellowing, cracks, peeling or bubbles | |
| Durability for concrete and metal surfaces in cold-temperate climates (Moscow) | years | at least 10 |
| Thermal conductivity | W/m °C | 0,0012 |
| Vapor permeability | mg/m × h × Pa | 0.03 |
| Water absorption in 24 hours | % by volume | 2 |
| Operating temperature range | °C | from - 60 to + 260 |
Such coverage will not require additional protective layers– it is strong enough to cope with all impacts on its own.
This liquid insulation is sold in plastic cans (buckets), just like regular paint. There are several manufacturers, and among the domestic ones we can particularly note the brands “Bronya” and “Korundum”.
This thermal paint can be applied by aerosol spraying or in the usual way - with a roller and brush. The number of layers depends on the operating conditions of the heating main, climatic region, pipe diameter, and average temperature of the pumped coolant.
Many experts believe that such insulation materials will eventually replace conventional thermal insulation materials on a mineral or organic basis.
Video: presentation of ultra-thin thermal insulation of the Korund brand
Prices for thermal insulation paint
Thermal insulation paint
What thickness of heating main insulation is required?
To summarize the review of materials used for thermal insulation of heating pipes, the performance indicators of the most popular of them can be listed in the table - for clarity of comparison:
| Thermal insulation material or product | Average density in finished design, kg/m3 | Thermal conductivity of thermal insulation material (W/(m×°C)) for surfaces with temperature (°C) | Operating temperature range, °C | Flammability group | |
|---|---|---|---|---|---|
| 20 and above | 19 and below | ||||
| Mineral wool slabs pierced | 120 | 0,045 | 0.044 ÷ 0.035 | From - 180 to + 450 for mats, on fabric, mesh, fiberglass canvas; up to + 700 - on a metal mesh | Non-flammable |
| 150 | 0,05 | 0.048 ÷ 0.037 | |||
| Thermal insulation slabs made of mineral wool with a synthetic binder | 65 | 0.04 | 0.039 ÷ 0.03 | From - 60 to + 400 | Non-flammable |
| 95 | 0,043 | 0.042 ÷ 0.031 | |||
| 120 | 0,044 | 0.043 ÷ 0.032 | From - 180 + 400 | ||
| 180 | 0,052 | 0.051 ÷ 0.038 | |||
| Thermal insulation products made of foamed ethylene-polypropylene rubber "Aeroflex" | 60 | 0,034 | 0,033 | From - 55 to + 125 | Low flammable |
| Half-cylinders and mineral wool cylinders | 50 | 0,04 | 0.039 ÷ 0.029 | From - 180 to + 400 | Non-flammable |
| 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 | |||
| Thermal insulation cord made of mineral wool | 200 | 0,056 | 0.055 ÷ 0.04 | From - 180 to + 600 depending on the material of the mesh tube | In mesh tubes made of metal wire and glass thread - non-flammable, the rest are low-flammable |
| Glass staple fiber mats with synthetic binder | 50 | 0,04 | 0.039 ÷ 0.029 | From - 60 to + 180 | Non-flammable |
| 70 | 0,042 | 0.041 ÷ 0.03 | |||
| Mats and wadding made of superfine glass fiber without binder | 70 | 0,033 | 0.032 ÷ 0.024 | From - 180 to + 400 | Non-flammable |
| Mats and wool made of superfine basalt fiber without binder | 80 | 0,032 | 0.031 ÷ 0.024 | From - 180 to + 600 | Non-flammable |
| Perlite sand, expanded, fine | 110 | 0,052 | 0.051 ÷ 0.038 | From - 180 to + 875 | Non-flammable |
| 150 | 0,055 | 0.054 ÷ 0.04 | |||
| 225 | 0,058 | 0.057 ÷ 0.042 | |||
| Thermal insulation products made of polystyrene foam | 30 | 0,033 | 0.032 ÷ 0.024 | From - 180 to + 70 | Flammable |
| 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 | From - 180 to + 130 | Flammable |
| 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 | From - 70 to + 70 | Flammable |
But surely an inquisitive reader will ask: where is the answer to one of the main questions that arises - what should be the thickness of the insulation?
This question is quite complex, and there is no clear answer to it. If you wish, you can use cumbersome calculation formulas, but they are probably understandable only to qualified heating engineers. However, not everything is so scary.
Manufacturers of finished thermal insulation products (shells, cylinders, etc.) usually lay required thickness, calculated for a specific region. And if mineral wool insulation is used, then you can use the data from the tables that are given in a special Code of Rules, which is designed specifically for thermal insulation of pipelines and technological equipment. This document can be easily found online by asking search query "SP 41-103-2000".
Here, for example, is a table from this reference book regarding the above-ground placement of a pipeline in Central region Russia, when using mats made of glass staple fiber grade M-35, 50:
| Outer diameter pipeline, mm | Heating pipe type | |||||
|---|---|---|---|---|---|---|
| innings | return | innings | return | innings | return | |
| Average temperature regime coolant, °C | ||||||
| 65 | 50 | 90 | 50 | 110 | 50 | |
| Required insulation thickness, mm | ||||||
| 45 | 50 | 50 | 45 | 45 | 40 | 40 |
| 57 | 58 | 58 | 48 | 48 | 45 | 45 |
| 76 | 67 | 67 | 51 | 51 | 50 | 50 |
| 89 | 66 | 66 | 53 | 53 | 50 | 50 |
| 108 | 62 | 62 | 58 | 58 | 55 | 55 |
| 133 | 68 | 68 | 65 | 65 | 61 | 61 |
| 159 | 74 | 74 | 64 | 64 | 68 | 68 |
| 219 | 78 | 78 | 76 | 76 | 82 | 82 |
| 273 | 82 | 82 | 84 | 84 | 92 | 92 |
| 325 | 80 | 80 | 87 | 87 | 93 | 93 |
In a similar way, you can find the necessary parameters for other materials. By the way, the same Code of Rules does not recommend significantly exceeding the specified thickness. Moreover, the maximum values of the insulating layer for pipelines have been determined:
| Pipeline outer diameter, mm | Maximum thickness of thermal insulation layer, mm | |
|---|---|---|
| temperature 19 ° C and below | temperature 20 ° C or more | |
| 18 | 80 | 80 |
| 25 | 120 | 120 |
| 32 | 140 | 140 |
| 45 | 140 | 140 |
| 57 | 150 | 150 |
| 76 | 160 | 160 |
| 89 | 180 | 170 |
| 108 | 180 | 180 |
| 133 | 200 | 200 |
| 159 | 220 | 220 |
| 219 | 230 | 230 |
| 273 | 240 | 230 |
| 325 | 240 | 240 |
However, do not forget one thing important nuance. The fact is that any insulation with a fibrous structure inevitably shrinks over time. This means that after a certain period of time its thickness may become insufficient for reliable thermal insulation of the heating main. There is only one way out - even when installing insulation, immediately take into account this adjustment for shrinkage.
To calculate, you can use the following formula:
N = ((D + h) : (D + 2 h)) × h× Kc
N– thickness of the mineral wool layer, taking into account the correction for compaction.
D– outer diameter of the pipe to be insulated;
h– required insulation thickness according to the table of the Code of Rules.
KS– shrinkage (compaction) coefficient of fiber insulation. It is a calculated constant, the value of which can be taken from the table below:
| Thermal insulation materials and products | Compaction coefficient Kc. |
|---|---|
| Stitched mineral wool mats | 1.2 |
| Heat-insulating mats "TEKHMAT" | 1.35 ÷ 1.2 |
| Mats and canvases made of super-thin basalt fiber when laid on pipelines and equipment with a nominal diameter, mm: | |
| Du | 3 |
| 1,5 | |
| DN ≥ 800 at medium density 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 from glass staple fiber "URSA" brand: | |
| M-11: | |
| ̶ for pipes with DN up to 40 mm | 4,0 |
| ̶ for pipes with DN 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 over 250 mm | 1,5 |
| Mineral wool slabs with synthetic binder brand: | |
| 35, 50 | 1.5 |
| 75 | 1.2 |
| 100 | 1.10 |
| 125 | 1.05 |
| Glass staple fiber slabs brand: | |
| P-30 | 1.1 |
| P-15, P-17 and P-20 | 1.2 |
To help the interested reader, below is a special calculator, which already contains the indicated ratio. You just need to enter the requested parameters and immediately get the required thickness of mineral wool insulation, taking into account the correction.
If the thermal insulation of pipelines is carried out correctly, this will significantly increase the service life of the system and ensure maximum efficient operation. The thermal insulation of heating pipelines itself must be carried out in accordance with all established norms and standards.
Basic rules of thermal insulation
So, in general, there are several basic requirements (recommendations, rules) that should be observed when installing thermal insulation:- For thermal insulation, materials should be used high quality, the characteristics of which are suitable for operating conditions.
- Installation of thermal insulation is carried out exclusively by specialists; this is the only way to guarantee the correct and high-quality execution of all work.
- Completion of all metalwork and welding work;
- Checking the density and strength of the surface;
- Coating of the pipeline with anti-corrosion agents.
Installation of thermal insulation: cylinder design
Thermal insulation of process pipelines will be most effective if it is a prefabricated or fully prefabricated system. In other words, it will be a cylindrical structure. The essence of the work is quite simple: laying thermal insulation on the pipe with its further adjustment and strengthening.When performing work, some requirements for thermal insulation of pipelines must be observed:
- Installation should begin from the flange connections, while the thermal insulation cylinders should be mounted as tightly as possible;
- The seams should not form one continuous horizontal line;
- Special bandages are used as fastening: two per cylinder (in increments of 40-50 cm);
- The bandage is attached using buckles, which are made of aluminum or packing tape.
It should be noted that insulation materials such as perlite cement, foam diatomite and siliceous lime segments are often used as thermal insulation. After the volume of thermal insulation of the pipeline has been calculated, the material in the form of mats should be laid in such a way that all seams are covered; then the insulation is fixed to the pipes using wire hangers in increments of 50 cm.
What is noteworthy is that in the event of a thermal insulation element of the structure failing, you can easily selectively dismantle the thermal insulation of pipelines and replace the damaged element with a new one.
Thermal insulation and temperature of the structure features
It should be remembered that the calculation of the thickness of the thermal insulation of pipelines depends on some important factors, for example, the temperature of the substance transported through the pipes. If the substance has a very high temperature, then thermal insulation is carried out using cylinders that are laminated with aluminum foil. For of this type No protective coating is used for thermal insulation. It is recommended to use aluminum-based material as a bandage.In the event that water passes through the pipeline, the temperature of which does not exceed 12 ° C, the thickness of the thermal insulation of the pipelines can be increased, and hydrofibized cylinders are used as an insulator. As additional protection, a vapor barrier is installed, and the seams of the structure must be properly insulated (taped).
Attention! If the vapor barrier layer is damaged, it should be properly glued or completely replaced with a new one.
In general, it becomes clear that the calculation of thermal insulation of pipelines is carried out depending on the type of insulation, climatic factors and fluid that is conveyed through pipes.
At the moment, more and more attention is being paid to reducing heat loss in the structures of buildings and structures, in pipelines in industrial equipment, in vehicles, etc. The growing interest in this topic is caused by the permanent increase in the cost of non-renewable energy resources.
So, what are thermal insulation works according to SNiP and what are the features of their implementation?
Goals and implementation features
Thermal insulation work is aimed at reducing the degree of thermal conductivity various designs and, as a result, minimizing heat loss and increasing energy efficiency.
Thermal insulation work is divided into:
- Construction;
- Assembly.
Construction work involves the installation of thermal insulation of buildings, structures and enclosing structures.
Installation work extends to thermal insulation of heating pipelines, refrigeration equipment, thermal units, etc.
Types of Insulation Materials
Collection 26, according to GOST 16381-77, subdivides thermal insulating materials according to the following number of main characteristics:
- in accordance with production raw materials – organic and inorganic;
- in accordance with the structure - fibrous, loose, granular and cellular;
- in accordance with the shape - flat (mats, slabs, felt, etc.), loose (perlite and cotton wool), shaped (segments, cylinders, half-cylinders, etc.) and corded.
- according to the degree of flammability - combustible, difficult to combust and non-combustible.
Installation technology
In accordance with the standard dimensions and configuration of the thermally insulated surface, one or another type of thermal insulation material and method of its installation are selected.
The instructions for the manufacture of thermal insulation fences involve the implementation of work using the following methods:
- laying and fixing large-sized industrial products (blocks, slabs, segments);
- laying soft rolled materials (cords and mats);
- laying bricks and other small-piece products;
- pouring and spraying;
- coating;
- backfill.
Important: the most labor-intensive at the moment are considered to be thermal insulation work carried out by backfilling and coating.
The main disadvantage of the method is the need to comply with measures that exclude the possibility of self-sealing of the heat-insulating material and, as a result, prevent the formation of voids.
Relatively new methods are pouring and spraying. This type of thermal insulation application has found wide application abroad, while in the post-Soviet space it has been used for the last 10-15 years. During the implementation of such work, we mainly use polymer materials in the form of curing foam.
Thermal insulation work by pouring and spraying is carried out using both polymer compositions that foam and harden during the drying process (for example, polyurethane or phenolic compositions) and pre-made polymer foams prepared by mixing liquid polymers with foaming agents.
Scope of application
The production of thermal insulation works covers almost all areas of the national economy. Thermal insulation systems are necessary wherever there is a need to minimize heat loss. Be it the construction of a house or the construction of a water supply system, in both cases it is impossible to do without the use of thermal insulation materials.
Important: thermal insulation work, for the most part, is a complex measure that, in addition to applying and fixing the thermal insulation material, provides for the arrangement of its vapor and waterproofing and the manufacture of means of protection against mechanical impact.
Thermal insulation of pipelines
The installation of vapor and waterproofing is necessary when the thermal insulation layer is permanently moistened, in particular on pipelines located underground or in the open air. Also, work on thermal insulation of pipelines is required if one of the sides of the thermally insulated structure is exposed to critical temperatures. This rule is relevant for refrigeration units, construction projects located in harsh climatic conditions etc.
Thermal insulation work on pipelines in this case involves installing a vapor barrier on the warmer side of the insulated structure, since condensation occurs on a cold surface. In order to protect the thermal insulation layer from mechanical damage, the entire structure is lined with dense materials or plastered.
Modern insulation systems in industrial scale, in addition to construction, are used to isolate a wide range of engineering communications, such as pipeline systems for water supply, heating networks, sewerage, oil and gas and process pipelines.
Advantages of modern pipeline insulation
The use of fundamentally new categories of thermal insulation materials allows us to minimize the leakage of thermal energy through the thermal insulation and protective layer.
Despite the not-so-budgetary cost of thermal insulation work, the following qualities:
- High moisture resistance. This indicator is very important, since the accumulation of moisture in the thickness of the insulation provokes a significant decrease in thermal insulation qualities and the intensive development of corrosion processes on the metal of the pipes.
- Long service life. Water pipes are characterized by a certain service life, after which it is not possible to use them for their intended purpose. According to statistics, the use of correctly installed thermal insulation allows you to double the service life of pipes without reducing technical and operational characteristics.
- Protection against condensation. Thermal insulation materials with low vapor permeability are used on pipelines through which technical liquids are transported in a cooled state. The optimal protection against condensation is considered to be a polyurethane foam shell, which is characterized not only by low thermal conductivity, but also by hydrophobicity.
This insulator is a double shell, the cavity of which is filled with polyurethane foam. In addition to polyurethane foam shells, synthetic rubber or polyethylene foam can be used to insulate water pipes.
- Fire safety. Modern thermal insulation, used to protect a number of industrial pipelines, is characterized by increased fire safety that meets fire resistance requirements. Protective materials made from foam glass and basalt fibers have proven to be the best in terms of fire safety.
- Resistance to critically high temperatures. Certain technological processes require heating to 600-700 degrees Celsius above zero. Thermal insulation of such pipelines becomes possible thanks to basalt materials.
Among the main requirements for thermal insulation of pipelines, the following should be noted:
- resistance to the aggressive effects of chemically active substances;
- increased electrical resistance;
- resistance against rodents and microorganisms.
The practice of using thermal insulation for water pipes shows that weak electric currents arising on the surface of pipes provoke the development of metal corrosion, which becomes the cause of leaks. Again, chemically aggressive environments, rodents and microorganisms can cause harm to both the thermal insulation shell and the pipes.
However, professional selection of materials and well-implemented thermal insulation measures guarantee a long service life of both the pipes and the insulation itself.
How much does it cost to install thermal insulation?
Have you decided to thermally insulate a residential building, pipeline or other structures with your own hands to save money? It may be possible to save money, but it is much more likely that an unprofessional approach to work will result in excessive consumption of materials and a waste of time.
A completely different result is ensured if thermal insulation work is performed by qualified specialists who have the necessary experience and have all the necessary tools.
Speaking about the criteria that determine the cost of thermal insulation of pipelines, first of all it is necessary to take into account how high the price of the thermal insulating material is.
In addition, the cost of finished insulation and the cost of work on thermal insulation of the pipeline is formed in accordance with such parameters as:
- ease of installation;
- scale of work;
- availability of technological capabilities to ensure pipe protection;
- location of the object;
- time of year.
Conclusion
If you have any questions while reading the material, watch the video in this article.