Diameters of chimney pipes made of stainless steel. Sandwich pipes for a chimney: their device, advantages and installation rules. Calculator for calculating the minimum diameter of a sandwich chimney for solid fuel stoves

A sandwich chimney pipe removes combustion products in a fireplace, stove or boiler, creates draft and ensures fire safety. Its installation does not take too much time and is made taking into account the characteristics of the room.

Two pipes nested one inside the other and having a heat-insulating layer in the middle are called a sandwich pipe. A special place is occupied by pipes made of heat-resistant stainless steel, they are less prone to clogging, easier to maintain. The heat insulator inside prevents condensation. In the form of insulation, non-combustible materials are used: basalt fiber or mineral wool. They are obtained from molten rocks, the low thermal conductivity of the material is achieved due to the high content of air in the mineral fibers.

Chimney made of sandwich pipes

Advantages and disadvantages

Among the main advantages of sandwich pipes for the chimney are the following:

• light weight;
• installation speed;
• the presence of smooth inner walls (improves traction and reduces the formation of soot);
• the ability to bypass the truss system.

The main disadvantage: after 15-20 years, the heat-insulating layer wears out, and the boiler loses its original performance. Moreover, the more often the equipment is turned off, the faster the chimney from the sandwich pipes fails.

A cap is installed on top of the pipe - protection from atmospheric precipitation

Loss of tightness is a serious reason to replace the pipe. To prevent this from happening, purchase a quality product and trust the installation to professionals.

Device

The chimney is part of a looped system. It is through it that smoke is removed, due to which a rarefaction occurs in the furnace or in the fireplace and a portion of air is sucked in. The cycle then repeats over and over again.

A brick chimney can only be built vertically, but sometimes there are situations when, due to the characteristics of the room, it is not possible to build a strictly perpendicular structure. In this case, it is the modular system that will become best solution: with the help of transitions, elbows, tees, you can bypass a place that is inconvenient for cutting.

The inner diameter of the sandwich pipe is made of stainless steel, and the outer diameter is either made of galvanized iron or stainless steel of acid-resistant grades. Therefore, the service life of the product is long.

Boiler chimney device

When arranging a sandwich chimney, consider the following.

• The temperature of the incoming gases depends on the type of fuel used and the type of boiler. The higher it is, the more intense the pipe heats up.
• You can lead the outlet pipe from the stove, fireplace or boiler through the walls of the room. This option is used when a chimney system is being erected in an already built building. For each heat generating device, it is better to build its own smoke channel.
• If necessary, it is allowed to mount no more than two deviations from the vertical plane with an inclination angle of not more than 30 °.
• The horizontal section has a limit of 1 m.
• The total height of the chimney to the top of the pipe should be 5 m. This creates the necessary draft and ensures vacuum.
• The distance between a wooden (or other combustible surface) and the stove must be at least 50 cm.
• Incorrect assembly may cause a fire.

Modular Sandwich Pipe Size Chart

If the pipe passes through wooden floor, from the inner pipe of the "sandwich" to the wooden element, a distance of 38 cm must be maintained. The entire space between them must be filled with fireproof material - galvanized sheet. The chimney pipe must pass through the ceiling in its entirety, without joints. The chimney itself is mounted through a passage pipe - a metal box.

Variants of placement and connection of chimneys are different. It depends on the conditions of the room in which you want to install. You can install a smoke exhaust system during the construction of the house and after completion construction works. They choose a place for the chimney so that when it is installed, the integrity of the house structure (logs, truss system) is not violated.

System installation rules

The device is assembled according to the principle of the designer. The pipe must be inserted into the pipe for a length equal to at least half of its diameter. The size of the sandwich pipe for the chimney determines its throughput.

Video: installing a chimney

Connection types

There are 2 ways to connect pipes: "by smoke" and by "condensate".

• "Through the Smoke"

The pipe of the lower leg enters the inside of the upper leg of the "sandwich". In this case, the smoke moves freely upwards.

• "By Condensation"

The inner top tube is inserted into the bottom tube. And for the outer pipe, on the contrary: the lower one is placed in the upper one. The condensate moves freely downwards. This option is usually used in modern boilers running on gas. In metal, cast iron, the smoke temperature is about 300 °. Steam begins to condense at temperatures below 100°C. During the kindling, the steam turns into drops of water, which rolls down into the condensate trap.

The second method of assembly "by condensate" is more acceptable. The passage through the roof is done in the same way as the passage through the ceiling. The gap between the rafters and the pipe must be maintained at least 150 mm.

Roof cutting makes the pipe outlet airtight

Fire safety

Subject to the norms of SNiP, you can be sure of the safety of the structure under construction.

• If the chimney is installed in wooden house, use cuttings - enclosing elements made of non-combustible materials. The dimensions of the cuts are as follows: 38 cm - to the parts protected from fire, and 50 cm - to the non-protected ones.
• The building is protected with a layer of plaster of 25 mm on a metal sheet or mesh with fireproof materials (silica mats, basalt wool).
• Between wooden beams and chimneys located with them in the same wall must maintain an interval of 50 cm (if the beam is not insulated) and 38 cm (if the beam is protected by thermal insulation).
• The chimney should protrude 50 cm or more above the top of the roof.
• The scheme of the chimney from the sandwich pipes is drawn up at the design stage of the house.

Backdraft and fire are the consequences of a rash choice of a smoke exhaust system. But a modern chimney is not only durable and safe. It must withstand condensate containing acids and withstand high flue gas temperatures. Only in this case the design will last a long time.

Any heating appliance, be it a fireplace, a boiler or a stove in a bath, requires the installation of a chimney. A lot depends on how well this element is made. This is both safety and good reliable traction in any weather and practicality with a beautiful appearance. To date, the most optimal and advanced solution for the removal of combustion products will be a sandwich pipe for a chimney. But what the sandwich pipe is made of and how the installation of chimneys of this type is carried out, we will consider below ...

Sandwich pipe device, their dimensions and diameters

Installation of a chimney from a sandwich pipe

From the name itself it is clear that "fashionable" chimneys consist of several layers, like a sandwich pie. There is an inner diameter of the pipe and an outer one. Between them is a mineral fiber. As a rule, this is basalt wool or other non-combustible mineral insulation.

External and internal sleeves of pipes are made of stainless or galvanized steel. The thickness of the metal in this case can be 0.5 or 1 mm. This, of course, affects the price of the pipe and its durability. Stainless steel in all its characteristics is much superior to galvanization, so draw your own conclusions.

IN Lately enameled sandwich chimneys became popular. Special enamel not only gives a certain aesthetic appearance, but also perfectly protects the metal from high temperatures, condensation and soot.

Modern design solutions can be quite exclusive. Today we are moving away from those stereotypes that have been around for centuries. Now you can position and remove the chimney almost anywhere: vertically, horizontally, on a slope.

One of the options for mounting a sandwich pipe

For ease of installation of such systems, the following components may be included in the package for sandwich pipes: head umbrellas, support consoles, wall mounts, various clamps, rings and ties, corners and turns, gates (latches) and tees, ceiling and roofing cuttings, starting adapters and plugs. You can list for a long time, in a word - this is a "constructor for adults" ...

Depending on the power of the installed boiler or furnace, the sizes of the sandwich pipes are different. Here we can distinguish the following standard diameters of the inner and outer pipes, respectively: 310, 300/380. All dimensions are naturally in millimeters. The usual length of one pipe element is 1 meter.

Advantages and disadvantages of sandwich chimneys

Like any design, sandwich pipes have their advantages and disadvantages. Of course, there are much more pluses and this is due to the original and practical device. As they say, everything ingenious is simple. Here are some advantages of sandwich pipes:

• Due to its design feature, sandwich chimneys have high fire safety
• Lightweight and compact design of the entire chimney. This does not require the organization of an additional foundation and, as a result, unnecessary financial costs.
• Versatile mounting options: really make any bold design decisions. Turns, bends, rounding various obstacles, this is a common thing
• Ability to lead the chimney through the ceiling or through the wall
• Due to the double circuit and insulation, little condensate forms in the pipe. The absence of moisture inside the chimney contributes to insignificant deposits of soot on the inner walls of the pipe
• Due to the smooth surface of the metal, good traction is formed in the sandwich pipe
• Simple and easy installation of chimneys
• Sandwich chimneys are virtually maintenance free. They are not subject to corrosion, have good smoke impermeability and excellent resistance to high temperatures, aggressive environments, etc.

Now about the shortcomings that still exist:

• Relatively high cost. A chimney of this type, especially with various "bells and whistles", will fly into a tidy sum
• Relatively long service life: 10-15 years. When compared with brickwork, then the sandwich pipe serves much less
• Over time, thermal expansion and contraction can cause slight depressurization of the flue duct.

Installation of sandwich pipes: highlights

All work on the installation of sandwich chimneys begins with marking and sawing out all the necessary technological holes. This refers to the ceiling or wall, as well as the roof itself. It should be borne in mind that the distance from the pipe to unprotected wooden structures should not be less than 40-45 cm. For fire safety purposes, let it be more than less. Otherwise, the use of protective screens is a must!

Installation of the "designer-chimney" begins to be carried out from the bottom up. First of all, a single-circuit pipe is installed on the furnace. Due to the absence of insulation, heat transfer is significantly increased. For example, a single-circuit sandwich pipe for a bath can be equipped with a hanging water tank. It is possible to use a cylindrical metal mesh for stones, which greatly increases the efficiency of the stove. The use of special economizers-convectors on the first segment of the chimney also enhances the heat transfer coefficient.

On the installed “single-circuit sleeve”, the so-called starter adapter is mounted. It is needed in order to reliably and beautifully connect a single-walled pipe with a sandwich. Then a gate is mounted to adjust the draft level or a double-circuit chimney immediately goes.

Such a nuance should be clarified: the assembly of sandwich pipes can be carried out in two ways (“by smoke” and “by condensate”). “Smoke” is when the top tube is inserted into the bottom one. The smoke does not encounter any obstacles. "According to condensate" - the opposite is true: the upper segment is mounted on the lower one. For an optimal result, we put on the outer sleeves of the pipes “by smoke”, and the inner ones - “by condensate”. For a better sealing effect, it is advisable to use a special heat-resistant sealant and crimp clamps.

Calculate the height of the chimney to the ceiling in such a way as to exclude the junction of the segments in the overlap area. This will increase the degree of fire safety. And now the most important moment. Many consider sandwich chimneys to be the absolute standard of safety and do not install a passage box in the ceiling passage, relying only on the thermal insulation of the pipes themselves.

The result is often very deplorable. Passage ceiling box must be used. He will protect wooden structures from heat and fire. It can be covered with expanded clay, foam glass, but not with sand. It is possible to use mineral wool as a heat insulator.

When conducting a chimney through the roof, it is wise to use an element such as a flash master. This is a special sealant for roof passages, which is commonly called a "flash drive". The element is necessary and practical, you can’t do without it. A metal roof cutting element is also used here, which ensures a reliable and stable position of the chimney.

Depending on the design of the chimney, a "revision" is sometimes installed in the lower part. This sandwich pipe element is usually installed on an attached chimney that has a horizontal section. There is a small door for cleaning the smoke channel. Very convenient and right moment.

On the upper part of the chimney, spark arresters, deflectors-umbrellas are installed. Purpose: to extinguish sparks and protect the pipe from precipitation and debris.

When installing a sandwich pipe for a chimney, it is necessary to exclude their contact with various communications (electrical wiring, gas pipeline, plumbing and sewer pipes, ventilation ducts). Following the manufacturer's instructions for assembling such a "constructor", you can easily install a chimney from sandwich pipes with your own hands. This will not be difficult, although you still have to “wiggle your brains” and work with your hands.

Chimney from sandwich pipes