The basic rule for installing thermal insulation(cylinders are used for insulation): installation work begins from the flange connection, with the cylinders installed close to each other with horizontal seams staggered. The structure is secured with bandages (about two per product) to the pipeline. It is necessary to maintain an interval of 500 mm between the bandages, and the side seams of the cylinders must be staggered. The bandages themselves are secured with buckles. The material used to make the bandage can be painted packaging tape (0.7 x 20 mm) or aluminum tape (up to 30 mm wide).

In the case when thermal insulation of pipes is carried out with half-cylinders made of hard materials (Sovelite, vulcanite, diatomite, etc.), they are installed dry or on mastic. Calc-silica, perlite-cement, foam diatomite, etc. segments are also used. The mats are laid with overlapping seams and secured at intervals of 500 mm with wire hangers. The longitudinal seam is sewn with soft wire with a diameter of 0.8 mm. The outside of the mats is secured with bandages. The following materials are used during installation: bandage buckles ( , TU 36-1492-77), or buckles made of galvanized sheet steel 0.8 mm thick (GOST 7118-78). The material for making bandages is packaging or aluminum tape 0.8 mm thick. According to SNiP 2.04.14-88, the use of rings made of galvanized or black annealed wire with a diameter of 2 mm is allowed; as well as wire rings (diameter 1.2 mm) made of stainless steel.

The cost of a bandage buckle TYPE 1A according to TU 36.16.22-64-92 is 7.30 rubles/piece.
Basically, the protective covering is secured with screws or bands. For internal pipelines with positive temperatures of substances transported through them, cylinders lined with aluminum foil are used. This insulation can be used without protective coating. It is recommended to use aluminum tape as a bandage and aluminum alloys(width 20-30 mm, thickness 0.8 mm) and aluminum buckles. For a cold water supply pipeline (the temperature of the substances transported through it is below 12 degrees C), as well as a process pipeline, an exceptional is used as insulation. In this case, it is necessary to install a vapor barrier layer in accordance with the requirements of SNiP 2.04.14-88 “Thermal insulation of pipeline equipment.” The seams of the vapor barrier layer must be carefully sealed. Tears and punctures of the vapor barrier layer are not allowed. When using aluminum foil-laminated cylinders for installation, it is possible not to use a vapor barrier layer unless the project requires it. However, it is necessary to seal the seams and joints of the installed cylinders well. During installation, ruptures and punctures of aluminum foil are possible. If such damage is present, these places are sealed with sealing materials. When using cylinders,, for thermal insulation of cold water supply and process pipelines, with the temperature of transported substances below 12 ° C, it is recommended to install a protective layer under the metal protective coating to protect the foil from damage. In this case, it is recommended to secure the protective coating with bandages. When using cylinders on vertical sections of pipelines, unloading devices should be installed every 3-4 meters along the pipe height to prevent the thermal insulation layer and coating from slipping. For channel pipelines and tunnels, it is recommended to use it without subsequent installation of a protective coating. Thermal insulating cylinders made of mineral wool based on fiber from rocks are a highly effective environmentally friendly thermal insulation material that meets fire safety requirements. Hydrophobization, fire safety and lower price, compared to imported materials from foam rubber and polystyrene, make the cylinders competitive for use in domestic practice as thermal insulation of cold water supply and technological pipelines negative temperatures. Cylinders, as form-stable products, they can be used in thermal insulation structures of horizontal pipelines without a device supporting structures. They can also be used as a heat-insulating material with the base of coupling and flange fittings small diameters(valves, check valves) and flange connections. Laminated cylinders allowed to be used in rooms and channels ( heating networks, water supply) without installing a covering layer. Also foil-laminated cylinders, it is possible to use without a vapor barrier layer in pipelines with negative temperatures. In this case, it is necessary to ensure sealing of seams and places where the foil is damaged. This insulation option significantly reduces the cost of structures and thermal insulation work. Thermal insulation of pipelines is necessary both to protect the pipelines themselves from the effects of external temperatures, and to avoid losses from the pipelines themselves. For example, cold water supply pipelines are thermally insulated from the effects of low outside temperatures. And steam pipelines, heating networks and hot water supply pipelines are insulated to reduce heat loss to the external environment. For thermal insulation works Various materials are used, but the most popular is foiled mineral wool. However, when insulating high-temperature objects (for example, boiler insulation), it is more effective to use basalt products. This material is the easiest to use. Also except correct selection material, it is necessary to clearly know for what specific purposes the thermal insulation will be used. The wrong choice of thermal insulation materials leads to frequent repairs of pipelines, and sometimes to emergency situations.

To also learn about the possibilities of thermal insulation of tanks, thermal insulation of boilers, thermal insulation of chimneys and more technological equipment, we recommend contacting our specialists by phone or E-mail.

Thermal insulation of pipelines is a method actively used to reduce heat losses of certain systems, to lower the temperature of communications, aimed at safe daily operation. Without the use of this technology, it is quite problematic to guarantee winter time uninterrupted operation of networks, since the risk of freezing and, as a consequence, failure of pipes is extremely high.

Thermal insulation of pipes provides for a number of technical regulatory documents, compliance with which is mandatory when designing, installing and operating engineering systems of residential and public buildings, and other objects for various purposes.

More detailed information is provided on the website:

It should be noted that industrial thermal insulation refers to the thermal insulation of pipelines, containers, as well as equipment and tanks.

Thermal insulation is carried out to prevent cooling of the liquid present in the pipes or to avoid the formation of condensation on the equipment. If heat loss is not so important, then this technological process is necessary to comply with safety regulations.

Various versions of insulators are being considered for insulating pipes used for gas transportation.

Thermal insulation of the gas pipeline is carried out using a special varnish or paint, but usually they resort to modern protective materials that meet all the requirements for this, namely:

• the insulator for the gas pipeline must be endowed with the potential of a monolithic, uniform installation on the pipe;
• the material for thermal insulation of the pipeline must be characterized by a low coefficient of water absorption and have high waterproofing qualities;
• protect the structure from destructive ultra-radiation.

Insulation of underground networks

Thermal insulation is a prerequisite for laying both water supply and sewerage systems. Insulating pipelines will help avoid freezing in winter and eliminate heat loss.

All insulation work must be carried out in accordance with the requirements clearly formulated and prescribed in SNiP.

Thermal insulation requirements

IN regulatory documents contains detailed information about materials and methods of work. The applicable standards for thermal insulation contours are also indicated here, and certain recommendations are presented.

Types of thermal insulation materials

Thermal insulation is divided into types with certain properties and is produced in the following forms:

• sentiments;
• cylinders;
• mats;
• half cylinders;
• rolls.

Types of thermal insulation:

The list outlined above is not exhaustive; the market is regularly updated with new options in this area.

Thermal insulation with mineral wool

Of all the types of insulation presented today, mineral wool is characterized by the lowest cost, and the ease of installation of insulation is also a plus. Thermal insulation of pipelines with mineral wool - process:

• a roll of wool is cut into strips 200 mm thick (across) and they are then wrapped around the pipes, first with a layer of mineral wool (100 mm thick), on top with a tightly layer of fiberglass;
• Mineral wool should be laid evenly and should not wrinkle.

Mineral wool is considered as thermal insulation for pipelines of significant diameter; it is applicable for heating routes of urban networks and for sewerage systems, for sewer systems small diameter and for water supply pipes - not practiced.

Thermal insulation of external pipelines

The choice of thermal insulation materials for external laying heating pipes are quite large and are offered in the form of roll-type mats.

The pliability of the material allows them to be given a shaped shape for ease of installation; insulation materials are offered that are applied in liquid form, their further qualities appear after hardening.

Removable thermal insulation in a galvanized casing is widely used in linear sections of pipelines.

Foam rubber in the form of tubes or rolls, depending on the diameter of the pipes, is used as thermal insulation of pipes and parts of process pipelines; it is installed in several layers, depending on the required thickness thermal insulation.

An interesting method for thermal insulation is a covering layer, the types of which can be found on the website:

Thermo insulating materials, used on pipelines laid on outdoors and directly on the surface of the earth, they will allow hot water not to cool down on the way to the consumer, and all types of pipes are insulated:

• plastic;
• metal;
• polymer;
• metal-plastic;
• composite.

Moreover, when independently thermally insulating communications in a private house, it is easier to work with pre-insulated pipes and self-adhesive insulation, and it is recommended to use additional winding, for example, aluminum tape, as an assistant to eliminate shortcomings.

Calculation of heat loss. The methodology for calculating possible heat losses by a pipeline, taking into account the actual temperatures of the coolant and air surrounding the system, the properties and thickness of thermal insulation, can be found here:

Thermal insulation materials for pipelines, including polyurethane foam and glass wool, are highly effective insulating materials in all their qualities.

Polyurethane foam as pipeline insulation is environmentally friendly and effective insulation. Characterized by a neutral odor, not susceptible to fungus, endowed with increased durability to harmful environments, does not break down, is completely harmless to humans and the environment.

Directly for pipes large diameter The spraying method is used, as a result of which seamless continuous insulation is formed and a peak reduction in heat loss is guaranteed. Spraying is carried out at the work site, using special equipment for thermal insulation of pipelines, the simplicity and speed of the procedure is clear advantage. For work on pipes of small diameter, shells based on polyurethane foam are considered, providing high level thermal insulation, this method is affordable.

Thermal insulation using glass wool meets all the requirements for thermal insulation materials.
The material is offered in the form of rolls, mats, slabs of different thicknesses, sizes and densities. Glass wool is somewhat inconvenient for installation and requires additional insulation and sealing, which increases the cost of the work and its duration.

Drawing up an estimate for pipeline insulation

Work on thermal insulation of pipelines is impossible without drawing up a preliminary estimate, which spells out “step by step” the entire sequence of work performed, on the basis of which the cost of the work is formed.

You can familiarize yourself with the rules for drawing up estimates on the website:

How pipeline insulation work is carried out

Thermal insulation must be carried out in accordance with current standards and regulations, which guarantees effective energy saving and increased useful life

.

Installation of thermal insulation of pipelines, based on the article, can actually be done using various materials, but taking into account certain factors and, above all, the direct purpose of the future installed system.

For example, thermal insulation of pipelines with high temperature It is better to produce the medium transported through it using cylinder insulation (PUF shell), additionally laminated with foil cardboard or foil.

Brief device for thermal insulation of pipelines

Preliminary stage:

• complete completion of installation work (metalwork, welding);
• cleaning with steel shields (manually) or using sandblasting machines the surfaces and joints of the pipeline, degreasing;
• strength and tightness testing welds(visual inspection, pressure test, control (if necessary) using special equipment));
• application of special compounds - epoxy primers (as an example).

It is interesting to visually familiarize yourself with the installation process:

With the greatest effect in thermal insulation structures industrial equipment and pipelines with positive and negative temperatures, the products listed in table can be used. 1 and 2.

Thermal insulation structures for pipelines

For pipelines with outer diameter from 15 to 159 mm incl. for a thermal insulation layer made of tufted mats made of glass staple fiber on a synthetic binder, tufted mats made of mineral and basalt wool, mats made of basalt or glass superfine fiber, the following fastening is used:
for pipelines with an outer diameter of the heat-insulating layer no more than 200 mm - fastening with wire with a diameter of 1.2–2 mm in a spiral around the heat-insulating layer (Fig. 1), while the spiral is fixed on wire rings along the edges of the mats. If mats in covers are used, then the edges of the mat covers are sewn together with glass fiber, silica thread, roving or wire with a diameter of 0.8 mm; for pipelines with an outer diameter of 57 - 159 mm: when laying mats in one layer - with bandages made of 0.7x20 mm tape. The installation step of the bandages depends on the size of the products used, but not more than 500 mm.

When laying mats with a width of 1,000 mm, it is recommended to install the bandages in increments of 450 mm with a distance of 50 mm from the edge of the product. Two bands should be installed on a product with a width of 500 mm (Fig. 2); when laying mats in two layers - with rings of wire with a diameter of 2 mm for the inner layer of two-layer structures, bandages - for the outer layer of two-layer heat-insulating structures. Bandages made from 0.7x20 mm tape are installed on the outer layer in the same way as in a single-layer structure.

Black steel bands should be painted to prevent corrosion.
The edges of the facings are sewn together as indicated above. With two-layer insulation, stitching of the edges of the inner layer linings is not performed.
When using molded products, cylinders or segments for thermal insulation of pipelines, they are secured with bandages. Two bands are installed when insulated with cylinders. When insulating by segments, it is recommended to install bandages with a pitch of 250 mm for a product length of 1,000 mm.
For pipelines with an outer diameter of 219 mm or more, the following fastening is used for the heat-insulating layer of mats:
– when laying products in one layer– bandages made of tape 0.7x20 mm and pendants made of wire with a diameter of 1.2 mm. The hangers are located evenly between the bands and are attached to the pipeline. Fiberglass pads are installed under the pendants when using unlined mats (Fig. 3).

When using mats in linings, no backing is installed. The fiberglass covers are stitched together;
–when laying products in two layers– rings made of wire with a diameter of 2 mm and pendants made of wire with a diameter of 1.2 mm for the inner layer of two-layer structures. The pendants of the second layer are attached to the pendant of the first layer from below. Bandages made from 0.7x20 mm tape are installed on the outer layer in the same way as in a single-layer structure.
The thermal insulation layer is laid with a thickness seal.
In two-layer structures, the mats of the second layer should overlap the seams of the inner layer.
For pipelines with an outer diameter of 273 mm or more, in addition to mats, mineral wool slabs with a density of 35-50 kg/m 3 can be used, although the optimal area of ​​application is for pipelines with an outer diameter of 530 mm or more. When insulating with slabs, the heat-insulating layer can be fastened with bandages and hangers (Fig. 4).

The location of fastening elements - bands, hangers and rings (with two-layer insulation) is selected taking into account the length of the slabs used. Under the pendants, linings made of rolled fiberglass or roofing felt are installed. When using slabs laminated with fiberglass, fiberglass matting, or fiberglass, linings are not installed. The slabs are laid with the long side along the pipeline.
In thermal insulation structures with a thickness of less than 100 mm, when using a metal protective coating, support brackets should be installed on horizontal pipelines.
The brackets are installed on horizontal pipelines with a diameter of 108 mm or more in increments of 500 mm along the length of the pipeline.
For pipelines with an outer diameter of 530 mm or more, three diameter brackets are installed in the upper part of the structure and one at the bottom.
The support brackets are made of aluminum or galvanized steel (depending on the material of the protective coating) with a height corresponding to the thickness of the insulation.
In horizontal thermal insulation structures of pipelines with a diameter of 219 mm or more and with positive temperatures an insulation thickness of 100 mm or more, support rings are installed.
For pipelines with negative temperatures, the supporting structures must have gaskets made of fiberglass, wood or other materials with low thermal conductivity to eliminate “cold bridges”.
When insulating with form-stable thermal insulation materials, such as cylinders, segments of mineral wool or fiberglass, as well as mats such as KVM-50 with vertical fiber orientation (manufactured by Isover) or Lamella Mat, supporting structures on horizontal sections are not required.
On vertical pipelines with an outer diameter of up to 476 mm incl. The heat-insulating layer is fastened with bandages and wire rings. To prevent slipping of rings and bandages, wire strings with a diameter of 1.2 or 2 mm should be installed (Fig. 5).

On vertical pipelines with an outer diameter of 530 mm or more, the heat-insulating layer is fastened to a wire frame with the installation of wire strings that prevent the fastening elements (rings, bandages) from slipping.
Rings of wire with a diameter of 2–3 mm are installed along the length of the pipeline on its surface in increments of 500 mm for slabs 1,000 mm long and 500 mm wide and mats 500 and 1,000 mm wide. Bundles of wire ties with a diameter of 1.2 mm are attached to the rings with a step along the arc of the ring of 500 mm (Fig. 6).

There are four ties in a bundle for one-layer insulation and six for two-layer insulation. When using mats with a width of 1,000 mm, the screeds pierce the thermal insulation layers and are secured crosswise. When using mats with a width of 500 mm and slabs with a width of 500 mm, the screeds pass at the joints of the products.
Bandages made of 0.7x20 mm tape with buckles are installed in increments of 2-3 pieces depending on the width of the product. per product (slab or mat 1,000–1,250 mm wide) with single-layer insulation and along the outer layer with double-layer insulation. Instead of bandages, wire rings with a diameter of 2 mm can be installed along the inner layer of two-layer insulation.
When using mats with a width of 500 mm, two bands (or rings) should be installed on the product.
The edges of the mats in the covers are sewn together with 0.8 mm wire or glass fiber, depending on the type of cover.
The strings can be attached to unloading devices, which are installed in increments of 3-4 m in height, or to rings of wire with a diameter of 5 mm, welded to the surface of the pipeline or its other elements.
On vertical pipelines Unloading devices are installed in increments of 3-4 m in height.
When insulating pipelines cold water, pipelines transporting substances with negative temperatures, as well as pipelines of heating networks underground laying For fastening structural elements, galvanized wire and bandages made of galvanized steel or painted should be used.

Designs for thermal insulation of fittings and flange connections

To insulate fittings and flange connections, depending on the material of thermal insulation of the pipeline, both cylinders and pierced mats made of mineral, basalt or glass wool or super-thin basalt fiber can be used.
As a rule, slabs are not used to insulate reinforcement.
To insulate fittings and flange connections of pipelines, mats can be used in the form of mattresses with fiberglass, basalt or silica fabric coverings on all sides. The type of fabric is determined by the temperature of the insulated surface.
A removable metal casing is installed on top of the mattresses, the fastening of which can be carried out by locks welded directly to the casing, or by bandages with locks installed on top of the casing (Fig. 7 and 8).

Mattresses are attached to the insulated surface with bandages with buckles and tied with wire on hooks.
Cylinders and stitched mats in linings made of metal mesh or fiberglass are used as a thermal insulation layer as part of fully prefabricated thermal insulating structures (cases or half-cases) for insulating fittings and flange connections of pipelines (Fig. 9).

In this case, the mats are installed in a case, pinned onto cotter pins or secured with glue. The case is equipped with bandages or locks. The cases are mounted on flange connections or flange fittings.

Thermal insulation structures for industrial equipment

To insulate equipment, depending on its geometry, slabs of mineral, basalt or glass wool, or super-thin basalt fiber or pierced mats covered with fiberglass and metal mesh can be used.
Canvases made of super-thin basalt fiber or unlined mats for insulating equipment should be used in exceptional cases, if no other material can be provided.
The mats are recommended for insulation of horizontal and vertical equipment with an outer diameter of 530–1,420 mm.
Boards for insulating equipment with a large radius of curvature and for flat surfaces.
For horizontal and vertical devices outer diameter from 530 to 1420 mm incl. (containers, heat exchangers, etc.) KVM-50 brand mats and other products with a corrugated structure can be used as a heat-insulating layer, since this does not require the use of supporting structures (on horizontal devices).
Fastening the heat-insulating layer on horizontal devices with an outer diameter of 530 – 1420 mm can be provided with bandages and hangers similar to fastening pipelines (Fig. 10).

To insulate vertical devices with an outer diameter of up to 1,420 mm, the fastening of the thermal insulation layer is mainly provided on a wire frame using wire strings (Fig. 11).

It is recommended to make rings installed on the surface of the devices from wire with a diameter of 2–3 mm in increments of 500 or 600 mm, depending on the size and type of heat-insulating material used. Bundles of wire ties with a diameter of 1.2 mm are attached along the perimeter of the rings at a distance of 400 or 600 mm from each other when insulated with slabs and 500 mm when insulated with stitched mats. The number of ties is determined by the number of thermal insulation layers: 4 for single-layer insulation, 6 for double-layer insulation.
After fixing the heat-insulating layer with screeds, it is planned to install bandages made of 0.7x20 mm tape. Three bands are installed when insulated with slabs and two bands are installed when insulated with mats 1,000 mm wide.

Fastening the thermal insulation layer on devices with a diameter of more than 1,020 mm

On the surface of devices with an outer diameter of more than 530 mm, as a rule, brackets or bushings must be welded to attach the heat-insulating layer. Staples and bushings are welded to the surface of vessels and apparatus at the equipment manufacturer. The location of the brackets is established by the requirements of GOST 17314-81 “Device for fastening thermal insulation of steel vessels and apparatus. Designs and sizes. Technical requirements" Removable parts are installed during installation of thermal insulation.
As a rule, welded parts on vessels and apparatus are placed:
a) on vertical objects: in vertical and horizontal directions with a step of 500 mm. Welding distance of fastening elements from anchor bolts flange connections or welded joints or welds connecting the bottoms (lids) and bodies of vessels and apparatus can be 70-250 mm. On surfaces (bottoms, covers) facing downwards, staples or bushings are welded in increments of 250x250mm;
b) on horizontal objects:
– in the horizontal direction with a step of 500 mm, departing from the flange connections or welds connecting the bottoms (lids) and bodies of vessels and apparatus, at a distance of 70-250 mm;
– in the vertical direction: on the upper half of the object with a step of 500 mm; on the lower half of the object with a step of 250 mm. The pitch is measured from the plane of the horizontal diameter.
This arrangement of fastening elements causes difficulties when using products with dimensions different from 500x500, 1,000x1,000 or 1,000x500 mm, characteristic of domestically produced slabs and mats, since it requires the use of additional fasteners to secure the heat-insulating material.
It is recommended to fasten the thermal insulation layer made of fibrous materials in the insulation structures of vertical and horizontal devices with an outer diameter of more than 1,020 mm using wire pins with a diameter of 4-5 mm, which are inserted into brackets or bushings welded at the manufacturer.
Thermal insulation products are pinned onto pins, which are then bent. Further fixation of the heat-insulating layer can be carried out by tying the bent pins with wire strings with a diameter of 1.2-2.0 mm and bandages, installed, as a rule, in increments of 500 mm (Fig. 12).

Another step for installing the bands may be provided.
Fastening with bandages (without tying with strings) and bandages and rings with two-layer insulation can be provided (Fig. 13 and 14).

In this case, on horizontal devices, rings and bandages are installed in the spaces between the pins with a pitch of 500 mm when insulated with pierced mats and soft slabs. When insulating with canvases made of super-thin basalt fiber, it is recommended to install the bandages in increments of 250 mm.
When insulating vertical devices and placing bandages and rings in the spaces between the pins, wire strings with a diameter of 2 mm are provided to secure them (Fig. 15).

If the bands are installed on pins, then strings are not provided.
For single-layer insulation, single pins are used; with two layers of insulation - double pins. Mats and slabs of the inner layer are pinned onto pins, one end of which is bent. Then the inner layer is secured with rings of wire with a diameter of 2 mm. The outer thermal insulation layer is secured with pins and bandages made of 0.7x20 mm tape.
The dimensions of welded brackets, single and double pins are regulated by GOST 17314.
In the thermal insulation structures of the bottoms of vertical and horizontal devices, depending on their diameter and configuration, the fastening of the thermal insulation layer made of fibrous heat-insulating materials can be carried out using wire ties and bandages or strings made of wire with a diameter of 2 mm or pins, bandages or strings.

The heat-insulating layer is fastened to the bottoms of devices with a diameter of more than 1,020 mm using pins installed in brackets or bushings, and bandages or strings.

Removable structures can be fully prefabricated - in the form of half-cases or cases, and complete - in the form of mattresses and casings, the type used for insulating fittings (see Fig. 11, 15).
Unloading devices (rings, brackets) with diaphragms are installed at the flange connections and bottoms of vertical devices and in increments of 3-3.6 m along the height of the device. The installation step of unloading devices is determined by the dimensions of the heat-insulating material.
Unloading devices can be welded or with bolted structural elements.
Pins are provided to secure the boards to the insulation surface. Additionally, the plates can be secured with wire with a diameter of 1.2-2 mm (ligation using pins).
In thermal insulation structures of the bottoms of vertical and horizontal devices using thermal insulating mats and slabs, depending on their diameter and configuration, the fastening of the thermal insulating layer of mats or slabs can be carried out using wire ties and bandages or strings made of wire with a diameter of 2 mm, or with pins, bandages or strings.
As a rule, one end of the bandages and strings is attached to a wire ring welded or tied around the pipe, and the other to a wire or support ring (unloading device), which are installed at the bottom (see Fig. 11).
Hatches and flange connections of devices are subject to periodic inspection and therefore removable heat-insulating structures are used for them.
Removable structures can be fully assembled - in the form of semi-cases or cases, and complete - in the form of mattresses and casings.
As a heat-insulating layer in fully prefabricated structures (half-cases), it is recommended to use stitched mats covered with metal mesh or fiberglass.
In this case, as a rule, mats of the MM-50, MM-75 or MS-50, MS-75 brands are attached with cotter pins to the metal surface of the casing. The edges of the metal mesh or fiberglass are embedded inside the metal casing and sewn with wire with a diameter of 0.8 mm.
The half-case is equipped with locks or bandages. The half-cases are installed on flanges on top of the thermal insulation of the device and fastened together. The dimensions and number of half-cases are determined by the dimensions of the flange connection.
For flange diameters greater than 1.5 m, it is preferable to use a complete thermal insulation structure in the form of mattresses and removable casings.
As part of complete structures, it is recommended to use mats in the form of mattresses with fiberglass or silica fabric coverings on all sides. To make mattresses, it is recommended to use mats without covers, which are wrapped in fiberglass (basalt, silica), the edges of the fiberglass are stitched. Mattresses are stitched with glass thread, silica thread or wire with a diameter of 0.8 mm. When using mats with fiberglass covers, the edges of the mats are additionally covered with fiberglass.
Mats in silica fabric stitched with silica thread or wire can be used at temperatures of the insulated surface up to 750 °C.
Mattresses are secured to the insulated surface with bandages with buckles.
When insulating flange connections of large-diameter devices, hooks are sewn to the mattresses. For large diameter flange connections, two or more mattresses may be provided around the perimeter of the flange. When installing mattresses on a flange connection, the hooks are connected with wire (lace), and then bandages are installed on top of the mattresses.
The thermal insulation layer is covered with a removable metal casing, which can be fastened with locks welded directly to the casing, or with bands with locks installed on top of the casing.
For devices, as a rule, metal coatings are provided as a covering layer. For the manufacture of coating elements (covering layer), sheets or strips of aluminum and aluminum alloys, thin-sheet galvanized or roofing (painted), or thin-sheet stainless steel, metal-plastic are provided. The thickness of the coating sheets is from 0.8 to 1.2 mm.
Fastening of the cover layer of thermal insulation of horizontal devices is carried out with self-tapping screws 4x12 with an anti-corrosion coating or rivets. Screw (rivet) installation pitch: horizontally 150 – 200 mm, circumferentially – 300 mm (Fig. 17).

To speed up installation, the elements of the protective coating can be connected by lying seams 8–10 mm wide ( G-G section) into large-sized paintings.
To impart rigidity to the thermal insulation coating structure, the coating elements are ridged at the ends horizontally and circumferentially with a ridge radius of approximately 5 mm. The covering must be supported by support rings or other welded support elements.
Support rings (section A-A) are made from tape 2x30, 3x30, 2x40 or 3x40 mm. Metal support structures for thermal insulation of objects with positive surface temperatures must have low thermal conductivity elements to reduce the temperature on the surface of the protective coating in contact with them. As a rule, supports or spacers made of asbestos cardboard are used.
For vertical devices, as well as for horizontal ones, metal coatings are used. Metal sheets can be collected into pictures. As a rule, joining sheets with a lying seam is used.
The cover layer of vertical devices is also secured with self-tapping 4x12 screws with anti-corrosion coating or rivets. Screw (rivet) installation pitch: vertically 150 - 200 mm, horizontally - no more than 300 mm (Fig. 2 and 18).

Thermal insulation of gas ducts and rectangular air ducts

For thermal insulation of rectangular gas ducts, it is recommended to use thermal insulation boards. The heat-insulating layer can be fastened using pins (welded, plug-in) and bandages (or wire rings) (Fig. 18 and 19).

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.
As a rule, gas ducts have significant fins. If the height of the stiffeners is greater than the thickness of the thermal insulation, then they should be insulated. The design of the insulation depends on the configuration of the fins. Pins, studs, staples and other elements for fastening thermal insulation and coating can be welded to the ribs.
When insulating air ducts supply ventilation The heat-insulating layer of slabs can be fastened with pins, wire rings and strings, or by gluing with bitumen mastics.
Can be used as supporting elements under the coating wooden blocks or structural fiberglass elements that are attached to metal brackets.
Instead of metal brackets, a frame made of wooden blocks installed on the surface of the air duct can be used. In this case, the metal covering layer is attached to the frame with screws.
A vapor barrier layer is installed over the thermal insulation layer. It is also recommended to place the joints of the vapor barrier layer on the bars (elements) of the frame.
When used as a heat-insulating layer of slabs or mats coated with foil on one side, the joints of heat-insulating products must be glued with aluminum tapes with an adhesive layer. These tapes can also be used as bandages for attaching the thermal insulation layer of foil-coated boards and mats.
If welding of pins to the air duct is not allowed, then a wire frame structure can be used, as when insulating pipelines. Metal bands made from 2x30 or 3x30 mm tape with pins welded to them can be used. Such bandages are installed on the surface of the air duct and fastened together with bolts and nuts.
When insulating supply ventilation air ducts, a vapor barrier layer is installed.
To prevent damage to the vapor barrier layer from polyethylene film or aluminum foil when used metal coating with screw fastening, it is recommended to install a protective layer 15-20 mm thick made of fibrous materials (Fig. 20).

Canvas or needle-punched fiberglass fabric or other materials having a small thickness can be used. Other design solutions can be used, for example fastening the covering with strips.

Thermal insulation of steel vertical cylindrical tanks

For thermal insulation of tanks for storing oil and petroleum products, it is recommended to use thermal insulation boards made of mineral and glass wool. The plates are attached to the tank wall with pins welded at intervals of 600x600 or 400x400 mm.
To fasten the metal covering, support structures made of vertically located steel angles or strips can be provided. The protective covering is secured with screws. Elements of the protective coating can be combined into patterns.
A frame made of wooden blocks can also be provided. The covering layer is attached with screws to the frame made of wooden blocks vertically and with screws horizontally (Fig. 20).
The installation step of the supporting structures is determined by the dimensions of the protective coating elements and heat-insulating boards.
Additional fastening of the plates may be provided by tying the pins with wire (in the form of rings or crosswise).
Support shelves must be provided along the height of the tank to prevent the thermal insulation layer from slipping. In the place where the support shelves are installed, there are also expansion joints in the cover layer.
To insulate tanks, mats lined with metal mesh can also be used. The welding pitch of the pins is 500x500 mm.
If bandages are welded to the surface of the tank with a pitch of 3 m, then a design of hanging mattresses made of mats with a heat-insulating layer of mats stitched in linings on both sides made of fiberglass or fiberglass mesh can be used (Fig. 21).

Hanging mattresses must have hooks for attaching to bandages (Fig. 22).

The mattresses are suspended from bandages and attracted to the surface of the tank by rings of wire with a diameter of 2 mm. The installation pitch of the rings should be 500 mm along the length of the mattress (along the height of the tank).
It is recommended to sew the joints of mattresses with wire with a diameter of 0.8 mm.
In this case, the roof of the tank must be insulated with mats that are laid between guides made of steel angle welded to the roof. Instead of a corner, strings made of wire with a diameter of 5 mm can be provided, while the mats are fastened to the strings with wire with a diameter of 2 mm, and the cover layer is secured with clamps.
When insulating cold water tanks, the fibrous insulation structure must have a vapor barrier made of polyethylene film, aluminum foil, or foil materials.
When using materials with a closed-porous structure (foam glass, foam rubber), a vapor barrier layer is not installed.

Thermal insulation of pipelines is a set of measures aimed at preventing the heat exchange of the medium transported through them with the environment. Thermal insulation of pipelines is used not only in heating and supply systems hot water, but also where technology requires 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 through infrared radiation.

The greatest application, expressed in numbers, is thermal insulation pipelines of heating networks. Unlike Europe, a centralized heating system dominates throughout the post-Soviet space. 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 autonomous system heating. Only in a few northern regions private houses are connected to the central heating main with heating pipes placed on the street.

For some types of boilers, for example, powerful gas or diesel boilers, the requirements of the set of rules SP 61.13330.2012 “Thermal insulation of equipment and pipelines” are required to be placed separately from the building - in a boiler room several meters away from the heated object. In their case, a fragment of the piping passing through the street necessarily needs insulation.

On the street, insulation of heating pipelines is required both for open ground placement and for hidden gasket- underground. The latter method is a channel method - a reinforced concrete trench is first laid in the trench, and pipes are already placed in it. Channelless placement method - directly in the ground. The insulating materials used differ not only in thermal conductivity, but also in steam and water resistance, durability and installation methods.

The need to insulate cold water supply pipes is not so obvious. However, you cannot do without it when the water supply is laid open above ground - the pipes must be protected from freezing and subsequent damage. But it is also necessary to insulate water supply pipes inside buildings to prevent moisture condensation on them.

Glass wool, mineral wool

Insulating materials proven by practice. 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, close to crystals in structure.

Glass wool is made from waste from glass production, mineral wool from silicon-containing slag and silicate waste from metallurgy. The differences in their properties are insignificant. Available in the form of rolls, stitched mats, plates and pressed cylinders.

It is important to be careful with materials and know how to handle them correctly. Any manipulations must be performed in protective overalls, gloves and a respirator.

Installation

The pipe is wrapped or lined with cotton wool, ensuring uniform filling density over the entire surface. Then the insulation, without too much pressure, is fixed using a knitting wire. The material is hygroscopic and easily gets wet, so 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 covering layer is placed on top of it to prevent the penetration of precipitation - a casing made of roofing tin, galvanized iron or sheet aluminum.

Basalt (stone) wool

More dense than glass wool. The fibers are made from the melt of gabbro-basalt rocks. Absolutely non-flammable, can withstand temperatures up to 900° C for a short time. Not all insulating materials, like basalt wool, can be in long-term contact with surfaces heated to 700° C.

Thermal conductivity is comparable to polymers, ranging from 0.032 to 0.048 W/(m K). High performance indicators allow it to be used thermal insulation properties not only for pipelines, but also when installing hot chimneys.

Available in several versions:

• like glass wool, in rolls;
• in the form of mats (stitched rolls);
• in the form of cylindrical elements with one longitudinal slot;
• in the form of pressed fragments of a cylinder, the so-called shells.

The last two versions have different modifications, differing in density and the presence of heat-reflecting film. The cylinder slot and the edges of the shells can be made in the form of a tenon joint.

SP 61.13330.2012 contains instructions that the thermal insulation of pipelines must comply with safety and environmental protection requirements. Basalt wool itself fully complies with this instruction.

Manufacturers often resort to tricks: to improve consumer performance - to give it hydrophobicity, greater density, and 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 hygienic certificate.

Installation

The insulation fibers are stronger than glass wool, so it is almost impossible for its particles to enter the body through the lungs or skin. However, it is still recommended to use gloves and a respirator when working.

Installation of rolled sheets is no different from the method of insulating heating pipes with glass wool. Thermal protection in the form of shells and cylinders is attached to the pipes using mounting tape or a wide bandage. Despite some hydrophobicity of basalt wool, pipes insulated with it also require a waterproof, vapor-permeable shell made of polyethylene or roofing felt, and an additional one made of tin or dense aluminum foil.

Foamed polyurethane (polyurethane foam, PPU)

Reduces heat loss by more than half 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, the maximum withstandable for a short time is 150 °C.

The main brands of polyurethane foam belong to the flammability group G4 (highly flammable). When the composition is changed by adding fire retardants, they are assigned G3 (normally flammable).

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 houses residential buildings, and SP 2.13130.2012 limits their height to two floors.

Thermal insulation 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 a protective sheath made of polyethylene.

Installation

The shells are secured to the heating pipe using ties, clamps, plastic or metal bandage. Like many polymers, the material does not tolerate prolonged exposure to sunlight, so an open ground pipeline when using PPU shells requires a covering layer, for example, galvanized steel.

For underground ductless placement thermal insulation products they are laid on waterproof and temperature-resistant mastics or adhesives, and the outside is insulated with a waterproof coating. It is also necessary to take care of anti-corrosion treatment surfaces metal pipes– even the glued interlocking joint of the shells is not tight enough to prevent condensation of water vapor from the air.

Expanded polystyrene (foam plastic, EPS)

It is produced in the form of shells, practically no different in appearance from polyurethane foam - the same dimensions, the same tongue-and-groove locking connection. But the application temperature range, from -100 to +80 °C, with all this external similarity, makes its use for thermal insulation of heating pipelines impossible or limited.

SNiP 41-01-2003 “Heating, ventilation and air conditioning” states that in the case of two-pipe system heating supply, the maximum supply temperature can reach 95°C. As for the return heating risers, not everything is so simple: 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 on top of other insulation materials with a higher permissible temperature of use.

The material has a number of disadvantages: it is highly flammable (even with the addition of fire retardants), does not tolerate chemical influences (dissolves in acetone), and crumbles into balls during prolonged exposure to solar radiation.

There are other non-polystyrene foams - formaldehyde, or phenolic for short. In fact, it is a completely different material. It is devoid of these disadvantages and is successfully used as thermal insulation for pipelines, but is not so widespread.

Installation

The shells are secured to the pipe using a bandage or foil tape; they can be glued to the pipe and to each other.

Foamed polyethylene

Temperature range at which the use of foamed polyethylene is allowed high pressure, from -70 to +70 °C. The upper limit is not compatible with the maximum temperature of the heating pipe, usually accepted in calculations. This means that the material is of little use as thermal insulation for pipelines, but can be used as an insulating layer over a heat-resistant one.

Polyethylene foam insulation has found virtually no alternative use 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. Standard length is 2 meters. Color varies from white to dark gray. There may be a coating of aluminum foil that reflects IR radiation. The differences relate to internal diameters (from 15 to 114 mm), wall thickness (from 6 to 30 mm).

The application ensures the temperature on the pipe is above the dew point, which means it prevents the formation of condensation.

Installation

A simple way with worse vapor barrier results is to cut the foam material along a small depression along the side surface, open the edges and put it on the pipe. Then wrap it along the entire length with mounting tape.

A more complex solution (and not always feasible) is to turn off the water, completely disassemble the insulated sections of the water supply system and put on solid sections. Then put everything back together. Secure the polyethylene with ties. In this case, only the junction of the segments will become a vulnerable point. It can be glued or also wrapped with tape.

Foam rubber

Foamed synthetic rubber with a closed-cell structure is the most versatile material for preserving heat and cold. Designed for a temperature range from -200 to +150 °C. Meets all environmental safety requirements.

Used as insulation of cold water pipelines, insulation of heating pipes, often found in refrigeration systems and ventilation systems. Heating pipes laid inside buildings and insulated with rubber do not require the installation of a vapor barrier layer.

Externally similar to foamed polyethylene, it is also available in the form of sheets and flexible thick-walled pipes. Installation is also practically no different, except that such thermal insulation of pipes can be attached with glue.

Liquid insulation

A technology has been successfully used that allows you to independently spray foam from a polyurethane composition onto already ready-made designs. Excellent adhesive properties allow it to be used not only for insulating pipelines, but also applied to other elements that require insulation: foundations, walls, roofs. The coating, in addition to thermal protection, provides hydro, vapor barrier, and provides anti-corrosion resistance.

Conclusion

Proper installation of thermal insulation is a guarantee that the pipe will not lose heat and the consumer will not freeze. Freezing of a cold water supply pipeline invariably leads to its rupture. Until recently, glass wool was the usual insulating material for hidden and open heating mains. Its shortcomings stem from one another. This coating requires constant monitoring.

Even with slight damage to the protective surface layer, vapor permeability and hygroscopicity reduce all savings to nothing. Moisture causes low thermal resistance and premature failure. Modern insulating materials with a cellular structure, inert to the effects of steam and water: polyurethane foam, foam rubber, polyethylene foam will help to significantly improve the situation.

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

Ways to solve the problem

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

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

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

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

Heating a pipe with a heating cable

This article will discuss the latter method of protecting communications.

Regulatory regulation

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

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

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

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

According to SNiP, thermal insulation is mandatory

Analysis of insulating materials

Polymer insulation

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

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

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

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

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

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

Tubular polyethylene insulation

Fibrous materials

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

Fiber insulation insulation has the following advantages:

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

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

Mineral wool cylinders covered with foil

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

Multilayer structures

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

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

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

Multilayer construction with outer covering made of galvanized steel

Installing thermal insulation on your own

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

Insulation of underground networks

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

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

Insulation of pipes laid in a tray

Thermal protection of external pipeline

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

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

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

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

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

Video instruction: pipeline insulation process

If you adhere to the standard scheme for performing installation work and apply suitable materials, your water supply and sewerage will function smoothly. Good luck!