A simple but effective design that provides easy and quick installation, good thermal insulation characteristics - all these advantages distinguish stainless steel sandwich chimneys. The technologies used during the production of insulated smoke exhaust sandwich systems provide long-term and practically trouble-free operation for 25-30 years.

Sandwich pipe for a chimney - what is it

The chimney sandwich chimney is a three-layer construction providing good draft characteristics and virtually no condensation. The main elements of the pipe:

• The outer contour is made of "black", alloyed or stainless steel, with a thickness of up to 0.5-0.6 mm.
• Intermediate layer - between the inner and outer contour, laid. The thickness of the insulation is 3-4 cm.
• The inner contour - the core is made of stainless acid-resistant steel. Wall thickness from 0.6-0.8 mm. (customized, up to 1 mm.)

Sandwich pipe device

The three-layer pipe has a male-female design, which greatly facilitates the installation of a chimney sandwich. Joints are sealed with sealing gaskets that can withstand heating up to 250-300°C.

To properly assemble a chimney from a sandwich pipe with your own hands, you will need a minimum of building skills and an understanding of the structure. The work is carried out taking into account the following points:

• For installation, only branded components are used. It is forbidden to install home-made tees, adapters during installation.
• The assembly is carried out "by condensate". The liquid resulting from temperature changes must flow freely down the pipe into the condensate trap.
• At the joints, two tightening clamps are installed for each pipe to increase the strength of the connection.

Instructions for the correct installation of a chimney from a sandwich pipe are attached to each set of branded factory products. Following the manufacturer's instructions, you can make a competent connection to the heating equipment, even without the help of specialists.

It is impossible to make a sandwich pipe with your own hands, with the same thermal characteristics as those of factory products. Homemade smoke exhaust systems quickly burn out and cannot provide the proper level of security.

Scope of sandwich chimneys

Sandwich chimneys, due to their design, are suitable for connection to most types of heating equipment used. According to the operating instructions, it is allowed to install a smoke exhaust system for the following units:

The operating instructions for heating equipment describe in detail the types of chimneys that can be installed as a smoke exhaust system.

Service life of a chimney made of insulated sandwich pipes

The service life of a double-walled stainless steel sandwich chimney depends on several factors:

1. Thickness and other characteristics of the inner tube.
2. Features of operation.
3. Manufacturer.

As customer reviews show, a quality factory product will last at least 10 years. Some European manufacturers assure that their products are guaranteed to last 15-20 years.

Technical characteristics of sandwich chimneys are very different. There are models designed for solid fuel stoves and fireplaces, gas equipment and liquid fuel units. As a rule, pipes made of stainless steel AISI 430/439, with an internal contour thickness of 1 mm, stand the longest.

Fire safety sandwich smoke exhaust system

Permissible flue gas temperature inside the sandwich pipe is about 650°C. The internal contour maintains short-term heating up to 700-800 °C. Despite the temperature of the exhaust gases, the maximum heating of the pipe surface will not exceed 40-45 ° C. Such indicators make it possible to install sandwich systems inside buildings with a high risk of fire: wooden houses, buildings from a block house, imitation timber, etc.

Temperature fluctuations are reflected in steel. Over time, the material begins to deform, the connections between the pipes weaken. To prevent this, be sure to crimp the joints of the sandwich pipe with clamps when connecting to each other. This measure will ensure the safety of the system for the entire period of operation.

Advantages of double-circuit sandwich pipes

Although sandwich systems are inferior to ceramic chimneys in terms of their thermal performance, they are very popular with domestic consumers due to the following advantages:

At the moment, the most versatile type of smoke exhaust pipe is the stainless steel sandwich chimney. The consumer is offered systems that can withstand temperatures up to 900 ° C, which occur during soot burning, without damaging the integrity of the pipe.

Disadvantages of sandwich pipes

Any steel, regardless of the marking and the presence of heat-resistant characteristics, burns out over time, and this is precisely the main disadvantage of sandwich pipes. The design of the smoke exhaust system is sensitive to errors made during installation. Pipes deteriorate during dismantling, so it is important to assemble the chimney correctly the first time.

Another disadvantage, related mainly to low quality products, is the loss of tightness of the chimney due to open seams. A rupture of the inner pipe made of stainless steel is possible if arc or semi-automatic welding was used during the manufacture of the structure. The high quality of the seam can be ensured exclusively by conveyor assembly, with minimal human participation.

Some flaws are the result of improper assembly. Here are a few of the most common mistakes:

• The sandwich cannot be used as the first pipe installed on the combustion unit. The connection will be made using an adapter or a steel sleeve.
• A crimp clamp for stainless steel sandwich pipe ties must be installed at each junction of the structure.
• The procedure for assembling a sandwich pipe for condensate - a violation leads to the accumulation of acid emissions at the joints of the structure, which often leads to a rapid burnout of the pipe walls.
• Additional sealing of joints with sealant and other means is prohibited. Silicone o-rings provide a tight connection between the pipes. The use of sealant leads to thinning and destruction of the gasket. In the future, it will be necessary to deal with soot smudges, and over time, completely replace the assembly.

Compliance with the above recommendations will increase the life of the chimney several times.

How to install a chimney from a sandwich pipe

Before starting any construction project, all the necessary calculations are made, taking into account the design features, the required elements of the chimney are purchased (extensions, rotary couplings, gaskets, condensate collector, etc.), fasteners, consumables, and only after that they proceed to assemble the chimney .

Passage of a chimney from a sandwich pipe through a wall

The SNiP and PB describe the requirements for smoke exhaust systems. The rules are mainly aimed at preventing potentially dangerous situations. The minimum distances to combustible surfaces of wooden structures when using a chimney sandwich and other requirements related to the operation of the system are indicated.

They assemble the pipe through the condensate, starting with the outlet of the boiler, gradually leading the chimney to the street. To connect using a special adapter - an adapter.

The passage of a sandwich chimney pipe through the ceiling

The requirements and fire safety rules for insulating a sandwich chimney when passing through a wooden floor are almost identical to those when passing through walls.

• Minimum distances to load-bearing structures: beams, rafters - at least 1 m.
• The surface of the casing of the sandwich chimney can heat up to a temperature of 40-45°C. In this regard, the following PB rules apply. A hole with a diameter of 25 cm is made in a floor slab made of combustible materials.
  When using a sandwich chimney with passage through the ceiling, a PPU unit is needed. The design of the PPU unit is designed in such a way as to level the effects of thermal effects and expansion of the metal. After installing the PPU unit, mandatory thermal insulation is carried out.
• There is no need to additionally insulate the chimney when passing through an unheated attic space.
• The ceiling cutting space between the pipe and the floor slab is insulated with basalt insulation.

You can mount the cutting in the interfloor ceiling using the PPU of the node yourself. You just need to accurately cut the required hole and fix the penetration.

The passage of the chimney sandwich through the roof

Mounting the chimney on the roof and passing through the roof covering is considered the most difficult part of installing a smoke extraction system. When performing work, the existing SNiP and PB are taken into account. Additionally, calculations are made regarding the height of the chimney above the roof.

The work is carried out in accordance with the following recommendations:

Rubber seal is suitable for any finishing material. With the help of a master flash, a reliable sealing of the passage on the roof, with ceramic and metal tiles, ondulin and slate, is carried out.

How to properly mount an external chimney from insulated sandwich pipes

The installation technology of an attached external chimney made of sandwich pipes is somewhat different from installing a smoke exhaust system inside the building. The advantage of an open installation is the ability to simultaneously connect several heating units at once.

Designs differ in functionality. Systems with forced exhaust are popular, which significantly improves the characteristics of smoke draft.

What should be considered when installing an attached chimney?


It is recommended that the external chimney be assembled by a specialized installation team. There are many subtleties in the installation of sandwich chimney elements, which learn to take into account only with experience and are almost impossible to describe in one article.

Mast-mounted installation of sandwich smoke exhaust pipes

During mast installation, the chimney sandwich pipe structure consists not only of standard components: connection adapter, adapters, condensate collector, rotary couplings, etc., but also a free-standing metal structure (mast) that acts as a base.

The mast method is used if:

• Other installation methods for stand-alone sandwich chimneys cannot be applied due to existing safety regulations. For example, this form of installation is often used for a stainless steel sandwich chimney on the outside of a wooden building.
• Creation of an industrial or collective smoke exhaust system.

There are several differences that significantly distinguish the mast smoke exhaust system from the adjacent chimney:

• Farms for free-standing sandwich pipes - are made of a metal profile and are a welded structure, to which a chimney is attached with clamps. The mast has one or more bearing profiles.
• Foundation - a concrete pad with a poured anchor plate is used as the foundation.

The mast structure is used to connect several separate chimneys at once. As insulation, non-combustible stone wool is used, with a thickness of at least 40 mm. To insert a horizontal outlet, a tee with a condensate trap is used.

The thickness of the thermal insulation in the sandwich pipe for mast-type installation must be 40 mm. This is due to the fact that the main part of the pipe will always be outside, at sub-zero temperatures.

How to choose a sandwich pipe for a chimney

Choosing the right fume extraction system is much easier than you might think. To begin with, determine which sandwich chimney will be used. Then they make all the necessary calculations and calculate how many are needed: tees, adapters, clamps and extension cords. After that, you can choose the right product.

They are guided by the final cost of a ready-made kit for a smoke exhaust system, as well as having studied reviews of sandwich chimneys regarding various product manufacturers.

Manufacturers of sandwich elements for chimneys

Literally ten years ago, the domestic consumer, when choosing products, focused mainly on foreign companies. Manufacturers of double-circuit insulated stainless steel sandwich chimneys, if they existed in Russia, produced far from the best goods.

At the moment, the production of sandwich pipes has been established at several large domestic enterprises. The quality of products is practically not inferior to foreign analogues.

For ease of choice, below are several Russian and foreign companies with the highest rating among sandwich chimney manufacturers:

• Baltvent is a company that occupies the first place due to careful quality control of products, the ability to make certain details of complex configurations to order. The influence of people on the assembly process is minimized thanks to the robotic assembly line. The range includes stainless, steel and enameled sandwich systems.
• Vulkan is a factory specializing in the production of smoke exhaust systems for sauna stoves, fireplaces and solid fuel boilers. The range includes smoke exhaust systems with a special storage tank installed on the chimney for heating hot water in the process of firing a sauna stove.
• Bofill is an Italian company specialized in the production of pipes for over 100 years. The advantage of the products is full compliance with the requirements of the industrial safety standard, certification in accordance with European and Russian standards, use in the production of steel marked AISI 304 and 316. It is distinguished by thermal stability and a long service life.
• Ferrum is a domestic company specializing in the production of industrial smoke extraction systems. Products are assembled on a conveyor basis. All nodes, without exception, are checked for compliance with quality standards. The Ferrum product range includes chimneys for connection to solid fuel and gas heating boilers.
• Teplov and Sukhov is a company whose factories are located in Russia, focusing on the needs of domestic and foreign consumers. In the product line Teplov and Sukhov, equipment for baths, private and apartment buildings. The recently released EuroTiS insulated chimney system deserves special attention.
• Jeremias is a German manufacturer. Impeccable build quality, durable heat-resistant weld, the presence of all necessary components. Jeremias offers products of the highest quality. The only thing that somewhat reduces the popularity of systems is the high cost of models.

The cost of a chimney from modular sandwich pipes

To independently calculate the cost of a chimney from a sandwich pipe, you need to consider several important points:


Calculations are performed individually for each house, but a standard design, 5 m high, will cost approximately 20-40 thousand rubles. Colored painted sandwich pipes are 10-15% more expensive.

Answers to frequently asked questions

Over the years of operation of sandwich pipes, consumers have the same questions. To facilitate the work of specialists of service and advisory centers, recommendations appear from time to time that specify the most common problems associated with installation and subsequent operation.

How to clean an insulated chimney made of stainless steel sandwich modules?

The mechanical method of cleaning the internal channel is best used as a last resort. Chemical soot removers effectively clean the pipe. In fact, this is an ordinary briquette, which, when burned, releases chemicals that corrode soot and remove it from the chimney.

The use of chemicals is quite simple. They are simply added to the furnace of a boiler or furnace during kindling. It is necessary to carry out such cleaning every six months.

What is the best way to connect the chimney - at 90° or 45° degrees?

Normative documents of SNiP indicate that horizontal pipe sections should not exceed 3 m in total. It happens that the segment passing through the wall is longer than 1 m. To increase the traction, you can run the pipe under a slope. For a boiler with a horizontal nozzle in such a situation, the angle is set to 45 ° degrees.

When carrying out work, observe the installation conditions through the wall at an angle. The hole must be widened so that if the building shrinks, the chimney pipe is not damaged. Installation work is carried out with the obligatory use of a pass-through node.

What is the best way to install sandwich pipes - through the roof or along the wall?

In order to properly mount a chimney from a sandwich pipe inside or outside the house, you must first prepare a project for the chimney system. The documentation will indicate all the necessary parameters of the future chimney.

When deciding on the feasibility of indoor or outdoor installation, it is taken into account that any turns, horizontal sections, reduce traction characteristics. But for internal installation, it will be necessary to make penetrations for roofing and floor slabs.

As a rule, it is considered that internal installation is best done during the construction of the building, if it is planned to replace an existing smoke exhaust system, it is better to stop at an external chimney installation.

The term "sandwich" was coined in 1762. So called closed sandwiches in honor of Earl John Sandwich. Nowadays, this term is used in structural materials as a designation for multilayer composite structures. The advantages of a composite of several layers are well known, these are increased structural strength, the ability to use a soft or fragile material as a core, such as insulation, for example. The application in construction is varied. It is worth considering another application of a multilayer device - a sandwich pipe for chimneys. More details in our material.

Read in the article

Multilayer pipes for furnaces: why are they needed

A chimney is a necessary element of a heating system that works by burning fuel, it ensures the removal of combustion waste: carbon monoxide and smoke. Working conditions can hardly be called easy. Due to the fact that the height of the chimney reaches large dimensions, the material must withstand high vertical loads, work when exposed to an open flame and high temperatures also makes its own demands. In addition, the material must withstand constant fluctuations in temperature outside the surface of the pipe and inside it.

The surface inside the chimney must be smooth and allow the chimney to be cleaned, since during combustion, in addition to gaseous products, soot and soot are formed, which settle on the inner surface of the chimney, making it difficult to remove the chimney and threatening the risk of fire and subsequent fire.

All requirements for chimneys are met by sandwich pipes for a chimney. These pipes consist of an internal channel made of stainless, heat-resistant steel, covered with a layer of mineral insulation. A protective sheath is installed on top of the insulation, made of stainless or galvanized steel or sheet metal coated with a protective powder coating.

The connecting seam of the outer shell can be welded by means of an automatic weld or sealed with a seam seam.

For the manufacture of the inner tube, stainless alloy steels of the following grades are used:

• AISI430, relatively inexpensive stainless steel, normally withstands temperature fluctuations. Fastening most often with a seam seam, since this metal is poorly welded;
• AISI439, steel alloyed with titanium, which made it possible to achieve increased heat resistance, has good anti-corrosion characteristics;
• AISI316, nickel-molybdenum alloy steel of increased heat resistance, recommended for oil-fired boilers and gas heaters;
• AISI304, a close inexpensive analogue of 416;
• AISI321, the most demanded heat-resistant alloy steel, has excellent anti-corrosion and heat-resistant characteristics;
• AISI106S, a relatively rare heat-resistant alloy, extremely high thermal stability characteristics, practically does not give in to corrosion. It is used for expensive products operating at high thermal loads.

sandwich pipe

It should be noted that both galvanized carbon steels and inexpensive alloyed steels are used for the outer shell, the second option is more resistant to external factors, but at the same time, the cost of products with its use is quite high.

As a heater for sandwich pipes, mineral, non-combustible types of mineral wool or basalt are usually used.

To connect the pipe modules to each other, one end of the pipe or fitting has a bell, on the other side there is a corrugated narrowed area, which serves to wedging in the bell and creating a reliable connection impervious to gas and smoke.

Sandwich pipes for chimneys - a luxury or a panacea?

The traditional materials for the chimney were brickwork, metal, ceramic and modern sandwich pipes for. The disadvantages of such chimneys are known, but it is worth comparing the advantages and disadvantages of various chimney systems:

• Brick chimney. The reliability and functionality of such a design depends entirely on its weight. Therefore, we need reinforced t under. A brick chimney is heavy, which affects its foundation, and also requires large investments in construction and maintenance. The construction of a brick pipe is a laborious and complex process. Bricks crumble and deform from the effects of temperature changes; over time, brickwork requires repair. The maintenance of such a pipe is also complicated, due to irregularities on the inner surface, soot and soot begin to accumulate there, which must be periodically cleaned;
• Steel pipe, as a furnace. Again, due to the high temperature loads on the wall, its sufficient thickness is required, and the thicker the wall, the heavier the product itself. In addition, steel, under the influence of temperature, can burn out, and condensate on its surface can lead to metal corrosion, and subsequent failure of the pipe. The installation of such a chimney is also complicated, requiring either the use of a one-piece product, or the use of special connection methods, such as. The advantage of such a chimney device is its price;
• Ceramic pipes, clay mixture products, subjected to heat treatment, has high heat-resistant characteristics, is quite well mounted. Durable. The disadvantage is high weight and, compared with metal, low strength characteristics.
• Chimney sandwich. Lightweight construction consisting of separate, easily connected modules. Installation does not require special equipment and experience. The design can be displayed in any direction, including in a horizontal or inclined position. It should be noted the simplicity of the device: fasteners and individual modules. Sandwich stove pipe consists of three layers: an inner channel made of heat-resistant steel, a layer and an outer, protective pipe. The chimney itself is quite light, so fixing it will not cause any special problems. The inner surface of the pipe is smooth, made of heat-resistant alloy steel, which greatly facilitates its cleaning. The insulation will protect the steel from condensation and corrosion. The outer, protective shell serves to protect against the effects of the external environment.

It is clear that chimneys and chimneys of a sandwich construction are slightly more expensive than conventional steel ones, but during the service life (which is 25 years) all the costs of the composite will fully pay off, since, unlike steel, these chimneys do not burn out and do not rust.

Reviews of sandwich pipes for the chimney are also sustained in a positive way. Users appreciated the ease of installation of the structure, its durability and appearance.

Related article:

From this review you will learn: varieties, average prices and design features; rules, requirements for work and features of the installation of the chimney, recommendations of specialists.

Dimensions of sandwich pipe modules

A sandwich pipe for chimneys with a diameter of 115-120 mm is considered the main one for a small country house or cottage. in such houses rarely exceeds 3.5 kW. For systems of higher power (from 5 kW), pipes with a diameter of 180 mm are used, for heating systems with a power of more than 7 kW, pipes with a diameter of 220 mm or more are used. The range of sizes of the sandwich pipe for chimneys is wide and you can quickly and easily select the required diameter according to the norms of SNiP.

When calculating the diameter of a sandwich, one should not forget about other elements of the chimney: fasteners, clamps, start-sandwich, slide damper module, transitions through ceilings or walls.

But, not only the diameter of the sandwich pipe for the chimney matters, the height of the module is no less important. It is necessary to calculate the length of the chimney, taking into account the exit of the pipe above the ridge of the house to a height of up to 1.5 meters, the height of the exit of the pipe depends on a number of factors and it must be selected individually, but on average the length of the exit is 0.5-1 meter above the roof ridge. Sandwich pipe modules are supplied in several versions, common: 0.25, 0.5 and 1 meter high.

At the word "chimney" many of us imagine a bulky brick pipe - a whole structure resting on a solid foundation. But such structures are gradually fading into the past, and soon they can be found no more often than a living dinosaur. Nowadays, sandwich chimneys are much more popular and in demand, which we will talk about now.

What is a sandwich chimney

This design is also called a modular chimney. Modules are parts from which you can assemble a chimney of any configuration: pipe sections, tees, bends with an angle of 45 and 90 degrees, revisions, condensate collectors, etc. Each element is made of stainless steel, wrapped in stone wool (one of the most effective heat insulators ) and is enclosed in a protective and decorative casing made of cheap stainless steel or galvanized steel. Wealthier customers purchase sandwich chimneys in a protective casing made of copper or aluminum.

Sandwich pipe consists of three layers: metal, insulation, metal

Each module is equipped with structural elements that provide a reliable hermetic connection with other parts of the structure.

In addition to the modules, all additional parts that may be needed when installing a chimney are made: brackets, mounting clamps, cuttings (used at the intersections of building structures with a chimney), aprons for sealing the passage through the roof, spark traps, deflectors and much more.

The list of advantages of a sandwich chimney looks very convincing:

Stainless steel, from which the inner tube is made, has three advantages at once:

1. It has a smooth wall, to which soot does not adhere well.
2. It does not absorb condensate, which means it cannot be destroyed when it freezes (in contrast to steel, brick and mortar are porous materials).
3. It warms up quickly, as a result of which condensate during kindling is formed in minimal volumes.

A sandwich chimney is inferior to a brick chimney only in strength and durability (it lasts about 15 years). As for the cost, a brick pipe, taking into account the payment for the work of a professional bricklayer, will cost much more.

The main set of a sandwich chimney consists of the following parts:

The spark arrester is installed under two conditions: the roof is covered with combustible material (bituminous tiles, ondulin, rolled materials), and the heat generator connected to the chimney runs on solid fuel.

Which sandwich pipe to choose

Modules for a sandwich chimney differ in the following parameters:

• inner diameter;
• brand and thickness of stainless steel, from which the inner (working) part is made;
• brand and thickness of insulation.

Let's consider each of the characteristics in more detail.

Pipe inner diameter

Diameter selection is a key point in chimney design. Errors both up and down can lead to serious consequences: in the first case, the thrust will be weak due to the high aerodynamic resistance of the pipe, in the second - due to excessive cooling of the flue gases. In the general case, engineers perform a rather complex calculation that takes into account many factors - from the type and moisture content of the fuel to wind speed.

And even in the case of using software systems, you have to tinker a lot until you can find a good combination of parameters. But in the simplest version, when it comes to a straight vertical pipe of constant cross section with a height of 5 m or a little more, you can use the ready-made data given in the table.

Table: dependence of the inner diameter of a sandwich pipe on the power of the boiler

These values ​​should be considered as minimum, that is, when choosing a chimney from a standard range of diameters, you need to choose the nearest larger one, and not the smaller one.

Owners of factory-made boilers and furnaces must take into account that the chimney cannot have a section smaller than the flue pipe of the installation.

Steel grade and thickness

Flue gases from various heat generators differ both in temperature and in content (the acidity of the condensate depends on it). It is important to choose a steel that would have a reasonable cost and at the same time fully meet the specific conditions. The exhaust temperature of installations running on gas and diesel fuel is the lowest.

The hottest products of combustion are produced by solid fuel heat generators, especially coal ones. As for acidity, the most caustic exhaust is from liquid fuel heaters (they are also diesel) and solid fuel stoves such as "Professor Butakov" or "Buleryan", operated in smoldering mode. The latter combine low temperature of flue gases (moisture condenses abundantly) and incomplete combustion of fuel, as a result of which a large amount of heavy hydrocarbon radicals escape into the pipe (when reacting with water, they form a caustic acid cocktail).

Sandwich chimneys connected to furnaces that operate in smoldering mode have the heaviest mode of operation.

Typically, the buyer is offered the choice of the following grades of stainless steel:

1. AISI 430: The cheapest stainless steel with the least amount of alloying components. Only casings are made of such stainless steel. If the working part is also made of it, then it is better not to buy such a sandwich chimney, since its service life will certainly be short.
2. AISI 439: similar in composition to the previous version, but with the addition of titanium. The latter increases the strength and corrosion resistance of steel and thus makes it suitable for the manufacture of chimneys for low-power gas installations.
3. AISI 316: steel resistant to acids and high temperatures (up to 800 o C), due to the presence of nickel, molybdenum and titanium in the composition.
4. AISI 304: identical in composition to AISI 316, but all additives are used in smaller quantities to reduce costs. As a result, the material is less resistant to temperatures and acids, and therefore does not last so long. The purpose is the same as that of AISI 316 - gas installations (a thickness of 0.5 mm is sufficient).
5. AISI 321: this steel exhibits increased resistance to aggressive factors, which allows it to be used in chimneys of fireplaces and heating and cooking stoves (with a thickness of 0.5 to 1 mm), sauna stoves (required thickness from 0.8 to 1 mm ), solid fuel boilers (from 1 mm), gas turbine and gas piston engines (1–1.5 mm).
6. AISI 309 and 310: ultra-hard, expensive steels with high amounts of nickel (about 20%) and chromium (about 25%). With a thickness of 1 mm, they work great with solid fuel equipment. There is a variety with increased thermal stability: AISI 310S steel operates at temperatures up to 1000 o C. It is the most expensive, but it can successfully work even with the highest power pyrolysis heat generators.

The best option for installations running on gas fuel, regardless of power - AISI 316. There are varieties:

• AISI 316L: designed for use in chimneys of liquid fuel installations (0.5 mm thickness is sufficient);
• AISI 316Ti: with a thickness of 1-1.5 mm, it can be used in chimneys of diesel generators, gas turbines and gas piston installations.

The steel grade is the most important characteristic of a sandwich chimney, so it must certainly be indicated in the documentation or as a stamp on the product itself. You can distinguish real stainless steel from ordinary steel used in fakes using a magnet: it is not attracted to stainless steel.

Of course, stainless steel cannot be “tasted” like a gold coin, but its quality can be approximately determined by the type of sparks that form when the workpiece is processed with an emery wheel. There are guides - and they are published on the Internet - which, according to the description and photographs of sparks, allow you to determine the group or even the grade of steel.

The steel grade can be approximately determined by the spark: for example, food grade stainless steel gives a plentiful bunch of light yellow sparks under the emery wheel, with almost no branching at the ends

Brand and thickness of insulation

As you know, natural draft is due to the high temperature of the flue gases, so insulation plays a crucial role in the functioning of the chimney. It should be noted that the heat insulator is exposed not only to high temperatures, but also to temperature changes, that is, the operating conditions are quite difficult. All of the above prompts when choosing a sandwich chimney with special attention to the quality of the thermal insulation used.

The heat-insulating layer of a sandwich chimney works in difficult temperature conditions, so when choosing a pipe, it needs to be given close attention

It is best to choose products for which mineral wool of a well-known brand was used, such as Paroc Roborrockwool Wired.

The thickness of the heat-insulating layer can be from 25 to 100 mm. If the chimney is supposed to be placed on the street, it is advisable to purchase modules with the thickest possible insulation. For internal placement, the thickness should be selected taking into account the temperature of the flue gases:

• for the “coldest” installations running on gas or liquid fuels (exhaust temperature below 250 o C), you can buy a sandwich chimney with a minimum layer of insulation - 25 mm;
• for wood - 50–75 mm;
• for coal and pyrolysis - 100 mm.

Self-installation of a sandwich chimney

Before proceeding with the installation of the chimney, you need to decide whether it will be located outside or inside. Each option has both advantages and disadvantages.

Advantages of internal placement:

Flue gases cool less, therefore:

• traction is maintained at a good level;
• the moisture contained in the smoke condenses in minimal volumes;
• you can save on insulation.

Disadvantages:

Note that in the case of using a furnace designed for the smoldering mode (“Buleryan” and the like), only the external location of the chimney is possible. This is due to the fact that extremely toxic condensate is abundantly formed from the flue gases of such installations.

Having decided on the placement method, you need to draw a chimney diagram. The following restrictions are taken into account:

• the number of channel bends should not exceed three;
• the maximum allowable length of the horizontal section is 1 m;
• when passing through a ceiling or roof, the pipe should be placed as far as possible at an equal distance from the beams or rafters between which it ended up.

In the scheme, it is necessary to provide sections with revisions through which it will be possible to clean the chimney and visually monitor its condition.

In the chimney diagram, it is necessary to display all structural elements with their markings and dimensions

Connecting the chimney to the heating unit

The heat-resistant sealant makes the connection very strong, so it will not be easy to disassemble it in case of a mistake. In view of this, it is advisable to first assemble at least the initial section of the chimney without sealant, and only then, after carefully trying everything on and fixing the brackets in the right places, put the parts on the sealant.

Methods for connecting sandwich pipes

A few words should be said about the ways of connecting modules. There may be three of them:

• flanged;
• bayonet;
• bell-shaped (the most common).

In the case of a bayonet or socket connection, the chimney can be assembled in two ways:

• insert the next part into the socket of the previous one. Such a connection in the best way contributes to the draining of condensate, which is why it is called “by condensate”. But in this case, smoke can seep through the gap between the sections;
• put the next part on the previous one. Such a connection, on the contrary, contributes to the unimpeded movement of smoke, which is why it is called a “smoke connection”. Now the condensate runs the risk of seeping into the insulation.

Sandwich chimney modules can be connected in two different ways

The outer shell (street part) is always assembled in only one way: the casing of the next part is pushed onto the casing of the previous one (“through the smoke”).

Many people use a heat-resistant sealant in all connections, and not just on the flue pipe. The chimney, regardless of the method of assembly, is completely impenetrable, but also somewhat more expensive.

When installing a new module, perform the following procedure:

1. The thermal insulation with the casing is moved as far as possible, exposing the edge of the inner element.
2. Next, the parts are mated, after which the edge of the casing of the previously installed module is lubricated with sealant.
3. The previously shifted thermal insulation on the new module is returned to its place, while the edge of the casing is put on the casing of the previous module and pulled together with a clamp.

If the flue outlet of the heat generator points upwards, the chimney can be supported directly on it. If the branch pipe looks to the side and the chimney is supposed to be launched along the wall, even inside the house, even outside, it is necessary to fix a support bracket with a supporting platform and a tee on it. A horizontal section of the chimney coming from the boiler will rest against the branch of the tee.

The horizontal section must necessarily be laid with a slope of 3 degrees from the heat generator, necessary for the condensate to drain. Given this, some manufacturers even make the angle of the tee outlet not 90, but 87 degrees.

A condensate collector with a drain cock is attached to the lower branch pipe of the tee, if it was not included in the set of the support platform.

At the transition point of the horizontal section to the vertical one, a special wall bracket is placed, which takes on the main weight of the structure.

Installation of a vertical section of the chimney

1. The chimney is increased to the desired height by screwing it with clamps to the wall brackets. The latter should be located in increments of no more than 2 m on vertical sections and no more than 1 m on horizontal or inclined ones.

   On vertical and inclined sections, the chimney is attached to the wall with clamps and brackets.

2. If necessary, another support bracket with an unloading platform is installed on the wall near the roof.
3. If the pipe was brought out through the roof and rises above it by more than 1.5 m, the head should be fixed with stretch marks. To do this, a special clamp with equidistant lugs (3 pieces) is put on it, to which you need to attach extensions.

   With a high height of the roofing part of the chimney, it is additionally strengthened on stretch marks using a special clamp

4. A deflector, spark arrestor or other element is installed on the head, the use of which is required in each specific case.

Video: do-it-yourself sandwich chimney installation - nuances, tips

Features of the passage of the chimney through the roof and floors

Separately, it should be said about the intersection of the wall, ceiling and roof with a chimney. If the wall or ceiling is made of combustible material, an opening is made in them of such dimensions that its edges are at least 200 mm from the outer surface of the pipe. Inside, this opening is upholstered with fireproof material - basalt cardboard or mineralite, after which a passage block is inserted into it. This block, consisting of two concentric parts (frame within a frame), is easy to make yourself. The pipe is inserted into the inner frame, after which the passage block is filled with non-combustible insulation and sewn up on both sides with decorative elements or simply tin. In the wall opening, basalt or glass wool is used as a heater, in the ceiling - most often expanded clay.

In the place of passage through the floors, a metal box with insulated walls is mounted, then a pipe is inserted and the remaining space is filled with non-combustible insulation

Thanks to a well-thought-out marketing policy on the part of manufacturers and sellers of basalt (stone) wool, many today consider this material to be the most modern and advanced, while glass wool has been declared obsolete, prickly, unsafe, etc. In fact, glass wool is in no way inferior to basalt wool, especially since today there are technologies that make it possible to obtain the finest fibers, and this material has long ceased to be prickly.

So, you should not refuse mineral wool, and the choice in its favor will also save money: the prices for basalt wool, due to its “hype”, are significantly overstated. At the same time, it must be remembered that both materials produce fine, pungent dust, the ingress of which onto the mucous membranes, into the respiratory tract or eyes is fraught with serious consequences, so you need to work with them with gloves, goggles and a respirator. Clothing should be discarded after installation.

Ready-made walk-through blocks of different sizes, already filled with insulation, can be purchased complete with a sandwich chimney.

To facilitate installation work, it is advisable to purchase a ready-made block with a heater

In a wall or ceiling made of non-combustible materials, the installation of a pass-through block is not required. It is enough to place the chimney in a sleeve made of asbestos pipe or basalt cardboard.

When making an opening in the roof, the rolled materials are cut crosswise, after which the resulting “petals” are bent and sewn to the crate. A pipe is installed in the opening, after which a plastic part is put on it - a roof, which will close the gap between the chimney and the roof. The lower edge of the roof, if possible, is launched under the roofing, after which it is fixed on the pipe with a comfrey. All gaps must be filled with sealant for outdoor use.

Instead of the regular one, you can use the Master Flash cover, made of an elastic polymer. Due to its flexibility and elasticity, it fits more tightly to the pipe and roof.

Rat "Master Flash" is made of heat-resistant rubber or silicone, so it can accurately take the shape of any surface, carefully sealing all joints

It is forbidden to place the joint of the sandwich chimney modules inside the building structure: for safety reasons, it must remain visible and at least 25 - 30 cm from the wall or ceiling.

Video: device for fireproof chimney passage through the ceiling

Operation of a sandwich chimney

At the beginning of the heating season, check the condition of the chimney and, if necessary, clean it. A straight vertical pipe can be examined with a mirror: you need to bring it into the revision hole and evaluate how wide the pipe lumen is. It is quite possible that you will have to climb to the roof: by the end of summer, bird nests are often found in the head.

The chimney should be cleaned before each heating season.

The chimney is cleaned with brushes and scrapers with stackable handles. To reduce the intensity of soot formation, it is useful to periodically burn various prophylactic preparations in the furnace, for example, the Chimney Sweep Log, which is popular today.

It is forbidden to burn out the soot accumulated in the chimney, as this, firstly, reduces its service life, and secondly, it can provoke a fire.

Video: cleaning a sandwich chimney

Having built your house, the question arises of how to insulate it, how to make it optimally livable.

The main type of heating in modern homes is using autonomous heating units that run on wood, natural or liquefied gas.

The products of combustion must be removed through the chimney system. In today's market, there are many companies offering installation and production of chimneys.

To choose the right chimney, you need to understand their design and application.

There are two types of chimneys

A double-circuit (sandwich chimney) consisting of two pipes, between which a heater is laid, as a rule, which is not only a good insulator from the cold, but also a good fire-retardant material.

The outer tube is stainless steel 409.439.

Thickness 1mm or 0.5mm can be matte or mirror finish.

The inner tube is galvanized and also stainless steel.

The choice of steel and its thickness affects the durability of the structure and, accordingly, its cost. This does not affect the parameters and quality of removal of combustion products. A single-circuit chimney is an ordinary pipe, which can be made of stainless or galvanized steel.

The cost of a single-wall chimney is several times less than a double-circuit one! But why then is it recommended to install a sandwich chimney, despite the fact that its cost is more expensive?

The design of the double-circuit chimney does not allow the accumulation of moisture and prevents the formation of condensate. It all depends on the difference between the temperature of the outgoing combustion gases and the temperature of the outside air.

With a large temperature difference, condensate forms on a single-circuit chimney, since the warm air of the exhaust gases comes into contact with cold air, the formation of condensate reduces its service life.

Soot from combustion products forms on the inside of the pipe, interacting with water droplets leads to a faster corrosion process and chimney failure. The production method of the double-circuit chimney prevents the formation of condensate.

Installing an insulated chimney will save you from this problem and increase the life of the system. The chimney kit includes: tees, plugs, bends, steam traps and much more.

Installation starts from the heating unit, with the pipe exiting through the wall of the house or through the ceiling, followed by passage through the roof. In this case, pass-through devices are used for ease of installation.

Particular attention must be paid to fire safety. To ensure good traction, it is necessary to bring the pipe to a certain height, at a certain distance from the ridge of the house, in order to avoid air currents that are formed by the wind.

If the pipe outlet is not positioned correctly, backflow can result. This is a phenomenon in which air from the street enters the pipe back.

Exhaust gases will not be removed, but will accumulate in the house, which can lead to serious consequences ... To select all the necessary elements of the chimney, you must contact the experts.

It is possible to install the chimney by a team of installers in the presence of all components within one working day.

Buy a sandwich chimney http://tp-service.com.ua/catalog/sendvich-dymohod-uteplennyj from proven and well-established companies on the market.

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We select and install a sandwich pipe

The choice of a chimney is an important event, on which the quality and safety of the removal of combustion products, the fire safety of the entire dwelling, will depend. Today, the market offers numerous options for chimney pipes that can be mounted according to various schemes, but today we will focus on such a type as a sandwich pipe.

Materials for sandwich chimneys: galvanized steel, stainless steel.

This design got its name due to the peculiarities of manufacturing, the pipe itself is a composite meter sections, which are assembled from two separate pipes separated by heat-insulating material. The outer surface is reliably protected by a casing made of stainless or galvanized steel, with such a chimney you can not worry about the danger of accidents.

Pros and cons of the device

Like any design, sandwich pipes have their advantages and disadvantages, which may be due to installation methods, the use of certain materials, and so on. We propose to consider the positive and negative sides in more detail in order to determine how reliable such a design will be during operation.

First, let's talk about the disadvantages of such a chimney. There are quite a few such minuses, which greatly distinguishes chimney sandwich pipes from other analogues. It should be noted here:

• the constituent elements of the structure have a rather high cost;
• short service life - only ten to fifteen years, while it is believed that ordinary chimneys can last several decades;
• the constant narrowing-expansion of sections due to temperature changes causes a decrease in the tightness of the pipe.

But the advantages of such chimneys often outweigh the disadvantages, since there are many more of them. Let's find out what is attractive about such a chimney:

• simple and affordable installation, which distinguishes systems of this type from those requiring specialist control;
• compactness of pipes;
• versatility of the design, the conclusions can go up and into the walls;
• layering, ensuring the absence of condensate on the pipe, the deposition of a large amount of soot;
• such pipes are not affected by chemically active products, high temperatures; aggressive environments that appear during operation;
• of all the options that exist today, sandwiches are the most fireproof;
• during installation, the truss system is not a significant hindrance.

As we can see, sandwiches today are the best option, which helps to establish a reliable, safe, durable design for the removal of combustion products from stoves in a private house or bathhouse. The disadvantages that are inherent in such pipes do not stand out from the rest, while the advantages are often the decisive factor in the purchase and installation.

The sandwich chimney device is quite simple, its design includes elements such as:

• anti-corrosion inner coat made of special steel (often stainless steel);
• outer casing;
• basalt thermal insulation layer.

Such furnace structures are assembled according to a scheme that ensures fire safety. Such pipes can be used in houses built from any material, they are not only convenient, but also optimal for stoves of any design.

Installation rules

During installation, sandwiches must be installed in full compliance with all the rules and recommendations, in this case, the work will be performed with high quality, safety of operation is observed.

The pipe, in case of its exit to a flat roof, must be installed in such a way that it protrudes slightly above the roof, from about five hundred millimeters. When the structure is located relative to the ridge, it is mounted at a distance of less than 1.5 m, the height of the pipe must be at least 500 mm from the highest point of the ridge.

In the manufacture of roofing material from combustible components, the pipe must be above the roofing ridge by a meter and a half. This indicator fully complies with all fire regulations.

DIY assembly

Assembling a sandwich chimney with your own hands is not so difficult, although it differs in some features. For installation, it is necessary to prepare the following tools and materials:

• a set of modules according to the terms of delivery;
• special through passage roofing assembly master flush;
• asbestos cardboard;
• basalt wool, steel sheet;
• sandwich mesh;
• screwdriver, hacksaw, silicone sealant, roofing scissors.

At the same time, it must be remembered that placing chimneys closer than 260 mm from the wall surface is prohibited!

The assembly procedure for the sandwich chimney is as follows:

1. Preparation of all necessary technological holes in the roof, ceiling, based on the fact that the minimum distance from the pipe to unprotected structures should be from 380 mm. If this distance is less, then it is necessary to lay a layer of basalt wool and nail the prepared steel sheet on top.
2. Next, a sandwich grid is installed, that is, a starting module that increases efficiency, the resource of the chimney. Installation of such a module directly on the furnace is not allowed due to the installation conditions. This greatly simplifies installation.
3. We start the assembly in this way: the outer pipes - through smoke, the inner ones - through condensate. We insert the inner part into the lower tube, the outer part onto the outer tube of the lower module. In this case, all joints are carefully processed with prepared silicone sealant;
4. When passing through the ceiling part, asbestos paper is used, in which a hole was previously cut to fit the diameter of the pipe. The box for installation is filled with foam glass, expanded clay or any other loose insulation;
5. A master flash assembly will be needed to install the chimney through the roof. Outside, the pipes are fastened with clamps and self-tapping screws. We put a special protective umbrella at the top of the pipe so that precipitation and debris cannot get inside and clog it.

Be sure to follow the assembly instructions provided by the manufacturer during installation: the safety of using the pipe and furnace will depend on this.

The sandwich chimney device has some features that must be considered when installing it yourself. We offer some useful tips from experts that will help you correctly and efficiently complete all installation work in a short time:

1. The best option for constructing a sandwich chimney is to install it indoors with the subsequent output of its outlet to the roof. The method of bringing into the wall is used extremely rarely, its effectiveness is much lower.
2. Most of the pipe should be inside the room, as this can minimize heat loss, temperature difference. Such a system will work very efficiently for a long time.
3. Chimneys must have a special draft level adjustment system, this is achieved by installing a gate inside the main pipe, which makes it possible to use fuel in any weather.
4. Outside, at the end of the pipe, it is necessary to install a deflector, which provides protection against precipitation, from locking smoke in the pipe during very strong gusts of wind.

As you can see, the device of sandwich pipes is extremely simple and reliable, subject to all the necessary rules and requirements. We must not forget about the rules for caring for such pipes, cleaning them from foreign objects that can cause smoke blockage.

We hope you have appreciated all the key parameters of such a chimney and now you will treat the purchase of such pipes with understanding and all seriousness.