Why do you need a chimney damper and how to make it yourself? Do-it-yourself chimney damper

The operating efficiency of a stove or fireplace largely depends on the draft force created in the pipe. The easiest way to regulate this parameter is to install a special damper. Let's look at what a chimney damper is, how it is designed and works, what it is intended for and what its functions are, what types exist and what are their features, as well as how to choose and install it correctly.

Retractable chimney damper made of stainless steel Source strojdvor.ru

What is it and what is it for?

Damper (from the German Schieber - damper) is a device for completely or partially blocking the movement of gases in the chimney. It has been used since the appearance of the first Russian stoves. Made from cast iron or steel. In modern engineering it has found application both in smoke exhaust structures and in ventilation systems.

Damper functions:

Regulating draft and maintaining heat in the room.

The chimney is closed after use to prevent warm air from being drawn from the room into the chimney. Using a damper, you can reduce or increase the working cross-section of the chimney.

Saving fuel consumption.

The valve can be used to regulate the intensity of oxygen flow to the flame, and accordingly increase or decrease the efficiency of the heater.

This statement is true only for furnaces and boilers without blowers and forced air supply devices.

How the gate works

Structurally, the gate is a locking device with an adjustable valve. It is thanks to the displacement of the valve that the movement of gases in the chimney is regulated. Can be installed in chimneys of round, square and rectangular cross-section. It is a metal plate that moves inside the smoke channel in a certain way.

Gate valves can be of two types:

Retractable. Moves in one plane back and forth.
Rotary. Regulates air access by rotating around its axis.

In addition, valves can be manual or equipped with an electric drive. The cost of the latter is an order of magnitude higher and they are not used in chimneys.

Functions, purpose and characteristics

The damper is a partition that is located inside the chimney. It follows the shape and area of its cross-section and, when closed, almost completely covers it. Changing the position of the damper allows you to increase or decrease the opening of the chimney pipe, increasing or decreasing the air flow. Using the damper, you can stop the movement of air after lighting the stove.

The gate valve is a thin metal plate that is manually adjusted using a special handle. The latter is located outside the chimney pipe so that the user can manually adjust the position of the plate.

Depending on the design and type of damper, it is installed using a special metal frame, or is inserted inside the pipe and fixed with an axial rod.

Important! Do not assume that the valve completely seals the pipe in the “closed” position. According to fire safety requirements, the damper must have a small hole through which weak gas exchange occurs.

The damper in the chimney performs the following functions:

increases traction force in difficult weather conditions;
increases the intensity of combustion in the furnace due to increased oxygen flow;
reduces draft when there is a strong hum in the chimney during strong winds;
saves fuel by reducing combustion intensity;
prevents heat loss after the heater has warmed up.

Very important! You can close the chimney with a damper only after the wood has completely burned and the flame has gone out. If you close the damper prematurely, this can lead to a dangerous situation due to the release of large amounts of carbon monoxide into the room. If the damper is closed too late, the efficiency of the furnace will be reduced, because Most of the heat will go out through the chimney.

Installation recommendations

When installing gate valves in a pipeline, the following recommendations must be observed:

Before installation, you should make sure that the connecting flanges are cleaned of dirt, scale, rust, and there are no scratches on them.
You should also check the linearity of the pipeline - the valve is not designed to align it, and if it is installed at misaligned ends, there is a high possibility of leaks and even cracks in the body.
Water hammer in the system, which can be caused by rapid opening of valve gates, should be avoided.
It is advisable to tie the bodies of heavy shut-off valves with a soft tape sling. Under no circumstances should the valve be secured to the handwheel or actuator.
During installation, you should avoid impacts and friction - this can lead to the destruction of the protective coating of the housing and its accelerated corrosion.
Be sure to install the fittings along the arrow on the body, indicating the direction of movement of the transported flow.
Gate valves are supplied with a loose gland. All bolts must be tightened before installation.
The gate valve can be installed in any position with the exception of the vertical bottom.
For heavy products of large dimensions installed horizontally, supporting supports should be provided.

Rice. 18 Installation rules

Gate valves are widely used in many industries and the national economy, where gases and clean or contaminated liquids are transported through pipelines and without them. Due to the wide range of uses, gate valves have a fairly large number of design options, materials for manufacturing the main components, which are bodies, gate valves and seals.

Types of gate valves

There are two main types of gate valves - sliding and rotary (throttle). The design features are clear from the name: the first type works due to the perpendicular movement of the metal plate relative to the chimney pipe.

We recommend that you read: How to make a spark arrestor for a chimney with your own hands?

To increase draft, the damper is moved back and almost completely extends beyond the chimney, and to reduce the flow it is pushed back into the pipe.

Retractable gate

The most popular damper for a retractable type chimney. It compares favorably with other varieties in terms of reliability and ease of use. The retractable gate is a plate with a smooth, even surface, in which there is a special longitudinal hole. It runs along the grooves in the chimney.

This type of valve is installed strictly horizontally. To change the draft force in the chimney, it is enough to move the damper in the desired direction, increasing or, conversely, reducing the cross-section for the pipe.

This option is suitable for steel pipes, but is more suitable for stoves made of brick. Its installation does not require special knowledge or significant effort.

Some models provide a small cut-out area. This ensures the safety of the structure: even if this valve is completely closed, the movement of carbon monoxide in it will continue.

Rotary gate

Another type is a rotary gate. It is a plate made of metal, which is fixed in the central part of the guide by welding.

Dimensions and principle of operation of the rotary gate

Its main portion is located in the inside of the chimney, but the tip should always remain outside. Against the background of rotation of this plate relative to its own axis, the draft in the chimney is regulated.

The disadvantage of this type is the need for fastening by welding. It is this place that is the weak point of the design: the damper will open if the fastening becomes loose.

The rotary gate is characterized by low reliability. But this indicator may vary depending on what it is made from. Most often it is used for installation in steel chimneys. It is also installed in cases where there is not enough space to extend the classic valve.

Cast iron gate

Cast iron dampers have found quite wide application in various types of stoves and fireplaces. The disadvantage of such products is their significant mass. At the same time, cast iron itself has been used for a long time in the production of valves for furnaces. This is explained by its high reliability, durability and strength.

Model range of cast iron gates

Steel type gate

A gate unit made of stainless steel is not the cheapest option. But the design is characterized by high quality and excellent performance characteristics. Its advantages are as follows:

maintaining furnace efficiency;
small weight;
long service life;
not subject to metal corrosion;
prevents soot accumulation.

These gates may have different designs depending on the characteristics of the furnace. They are relevant for chimneys made of steel or brick.

We recommend: Calculating the diameter of pipes for heating with forced circulation

Varieties

Gate valves come in sliding and rotary types. The first works due to the perpendicular movement of the partition. The second type involves a rotating mechanism located inside the chimney.

Retractable

This type of gate is a comfortable and effective way to control traction. Its main difference is its long service life, which is achieved by the absence of temporary wear at the attachment points. Due to this, it is possible to maintain the high quality of the damper even in bad weather conditions.

Turning

The principle of its operation is based on the rotation of the partition about its axis. If you turn it counterclockwise, the damper will close the air flow. If the turn occurs in the opposite direction, then there will be no obstacles in the way of air. To regulate this process, you need to operate a special knob.

In addition, the gate differs in the type of material:

Cast iron is strong and durable. Typically used in brick chimneys.
Steel - made of stainless steel, is a universal option for installation in fireplaces, stoves and chimneys.

Safety precautions

When talking about gate valves, first of all we should focus on safety precautions. Already from the definition it becomes clear that this device is capable of completely blocking the natural flow of air from the room through the stove and chimney to the street. The oven can be in such a locked state only under one condition - there is nothing in it that is still smoldering even a little, much less burning.

As you know, burning wood in a stove leads to the release of carbon monoxide, which is poisonous to humans. The danger of poisoning with this gas is that a person may simply not feel the harmful effects of the gas until he begins to lose consciousness, and then it may be too late. This danger should not be underestimated: for example, it is known that the famous French writer Emile Zola died in Paris in his bedroom from carbon monoxide.

We recommend a video review of the features of gate valves of various designs.

An attentive reader may notice that valve manufacturers produce them with special holes that prevent complete blocking of the chimney. However, with regular use over time, soot and resin accumulate on these holes, which gradually reduce their throughput, and then can completely block them. Obviously, the chimney periodically needs to be cleaned and the damper is no exception, but in practice this procedure is carried out much less frequently than required by safety regulations.

Methods of use

Gate valves with a gate design are used in treatment and filtering installations and various pipelines (usually of the “dirty” type). This means that durable and reliable dampers do an excellent job of blocking the movement of powerful mud flow. They can be installed on pipelines carrying high pressure

refers to rock, oil, all kinds of liquids with granules, pulp and other impurities, solid inclusions and particles.

Based on the diverse range of pumped media, gate valves are classified into models intended for use in various industries. In particular, the most popular areas of use of such valves are:

chemical industry;
oil and gas industry;
production of building materials;
public utilities;
mining industry;
pulp and paper industry;
electric power and so on.

Gate valves, due to their ability to filter and crush particles passing through it, as well as to pass large volumes of working fluid, are widely used and used in sewer systems and drains. They are also quite in demand for chemical plants, where they are equipped with technological lines for the production of ammonia, mastics, acids and all kinds of mineral fertilizers. In the mining industry, gate valves help filter and dispense useful components, preparing them for subsequent processing.

A separate area of application, which is regulated by regulatory documentation GOST 55020-2012, is the oil and gas industry. In this area, gate valves are used on main pipelines as part of Christmas tree fittings

Differences between retractable and rotary gates

So far we have been talking about the retractable type of damper on a stove chimney, although there is another type - a rotary one. Let's look at how they differ.

The purpose of both types is the same - to partially or completely block the flow of flue/heated gases. The differences relate to the design.

A retractable model is a metal plate that is fixed in a frame and moves along guides in a horizontal position. There are no strict requirements for the dimensions of the device, since they must correspond to the cross-section of the chimney and completely depend on its parameters.

Thus, the valve consists of two main parts:

frame , which is fixed in the smoke exhaust duct and is motionless;
plate moving inside the frame.

Typically, both parts are made from the same material to maintain performance when heated or cooled.

A properly designed and installed damper should never completely block a stove chimney. A small gap is necessary for fire safety purposes.

The design of the rotary (throttle) gate does not extend, but rotates along an axis, as the name suggests.

A round or rectangular plate (depending on the cross-section of the chimney) is fixed on a metal rod, the free end of which extends beyond the channel and serves as an adjustment tool.

The simplest model of a rotary gate with a diameter of 120 mm. Manufacturing material – stainless steel. The smoke exhaust channel is closed by turning the handle with a curved end

Gate valves are considered more reliable and wear-resistant devices. The weak point of the rotary devices is the connection between the rod and the plate, which becomes loose over time and renders the valve unusable.

Types and designs

The chimney damper is available in several versions.

Retractable

It is a round or rectangular frame with a plate. The plate extends and retracts, thereby adjusting the cross-section of the chimney.

This option is most often used with brick and ceramic channels. To ensure incomplete sealing and avoid carbon monoxide poisoning, a small hole is made in the plate. The main advantage of this option is ease of installation.

Rotary throttle

A rotary or throttle valve (also known as a hog valve) is a plate made of steel or cast iron that rotates around an axis. The axis is a metal rod welded inside the chimney. Used in steel chimneys.

It is less reliable - over time, the welding fastening of the plate and axle weakens. You should avoid installing a rotary damper in the bathhouse - even when closed, this type of damper partially allows steam to pass through.

In addition, gate valves differ in material (the most common are stainless steel and cast iron) and the method of adjustment.

Differences between retractable and rotary gates

The retractable damper allows you to adjust the working cross-section of the chimney, while the rotary damper only allows you to open or close the pipe. Of course, some tricks are possible - such as securing the hog in an intermediate position in different ways, but the factory equipment does not provide for this. In addition, the rotary gate complicates mechanical cleaning of the pipe.

The hog is often installed in metal chimneys, and the retractable one is installed in brick chimneys.

Which material is stronger

In addition to structural differences, types of gate valves may differ in the material of manufacture. The only possible option is metal, since it is the only one that does not burn or deform at high temperatures, and over time, even in an aggressive environment, does not change its characteristics.

For production, either cast iron or stainless steel is used. It is not possible to build a damper from cast iron yourself, since this requires, at a minimum, a forge. However, you can find both nondescript and beautifully designed cast iron dampers on sale.

Cast iron rotary gate with a comfortable handle. This design is suitable for a brick chimney with a rectangular cross-section, capable of supporting the fairly heavy weight of the device

Steel products look simpler, but their characteristics are similar to their cast iron counterparts. The advantage of steel fixtures is their light weight.

If a cast iron damper for a stove chimney is installed only on a durable, permanent structure, then a steel damper is suitable for any smoke exhaust ducts - brick and steel, rectangular and round, solid and light.

Samples of a galvanized steel damper, chimney cross-sectional diameter – 150 mm. Galvanization, unlike ordinary steel, does not react to moisture (condensation) and does not corrode

When choosing a material, you need to focus on the characteristics of the chimney pipe and the features of the interior.

For a country heating stove, a modest steel valve is sufficient, while for upgrading a Russian stove in a cottage, a custom-made cast iron valve is better suited.

Specifications

General technical specifications for gate valves used in main oil pipelines are given in GOST R 55020-2012. Some provisions of this document:

Nominal diameters (DN). The indicator (sometimes designated as DN) is equal to the cross-section of the internal passage channel, the main standard sizes are: 100 - 150 - 200 - 250 - 300 - 350 - 400 - 500 - 600 - 700 - 800 - 1000 - 1050 - 1200 mm.
Nominal pressure (PN). Indicates the pressure characteristics of the transported medium at operating temperature parameters, typical range: 16 – 25 – 40 – 63 – 80 – 100 – 125 bar.
Maximum pressure drops when the damper is opened: 16 – 25 – 30 – 40 – 50 – 63 – 70 – 80 – 100 bar.
Temperature of the transported medium: - 15 to + 80 °C.
Tightness: class A without visible leaks.
Drive: manual with steering wheel, gear, electric.

Rice. 7 Drive types

Climatic modification: U1 (ambient temperature up to - 40 °C) and HL1 (up to - 60 °C).
Installation options: underground and above ground.
Direction of movement of the working fluid: two-way.
Percentage of suspended matter in the supplied medium: no more than 20%.
Type of connection to pipes: welded (with welded nozzles or with welded coils), flanged, with mating welded flanges, combined (one nozzle with a flange, the other for welding).
Body design: cast, cast-welded, cast-stamp-welded, stamp-welded.
Flange designs: cast, butt welded and flat welded.
Service life: at least 50 years.
Designated service life: from 30 years.

Rice. 8 Design and manufacturing materials of a gate valve using the example of Omal brand products of the Pal series (Italy)

Full and assigned life: 3000 and 1500 cycles, respectively.
Service life and resource of replacement parts: 15 years and 750 cycles, respectively.

Since gate valves are used not only in pipelines with petroleum products, the above provisions of GOST R 55020-2012 are not mandatory for their manufacturers.

Many companies produce products in a wider range of nominal diameters from 50 to 2000 and even up to 3000 mm.

Also, in comparison with GOST R 55020-2012, the pressure characteristics of manufactured products may differ - for example, any indicator in the range from 1 to 10, 25 or 40 bar, as well as their temperature parameters, drive types (hydraulic and pneumatic drive). Many manufacturers supply products with a wider range of climate options.

Rice. 9 Dimensional and physical parameters of gate valves using the example of products of the PA 570 series

Selecting a location option

There are three main options for placing the damper in the chimney:

pipe-to-pipe fastening;
placement in a fireplace insert;
installation in a ventilation pipe.

Brick chimney with damper

If you place a gate valve in the outlet pipe or in the furnace firebox, that is, build this element into its design, the damper is placed on a section of pipe as close as possible to the heating boiler. This guarantees ease of control and ease of turning the valve. This is explained by the fact that the handle will not touch either the portal or the cladding area. If it is located according to the “pipe to pipe” option, no additional fastenings are required for connection with other elements of the furnace.

If you place the damper assembly in a pipe intended for ventilation, overheating of the fan motor during its operation is prevented.

Typically, ready-to-install chimneys are offered, which are equipped with everything necessary, including a slide valve. In this case, it is placed in the system in accordance with the manufacturer's instructions. If it is not provided for one reason or another, it is quite possible to manufacture and install this element yourself.

Make it yourself or order it

The choice between a homemade or a ready-made damper should be based on the type of chimney and the degree of its readiness. So, you can install a self-made retractable structure into a ceramic or brick channel.

If we are talking about a stainless chimney that is in the process of assembly, in this case it is better to choose a finished product. The damper is usually included in the chimney system and is mounted using pipe-to-pipe technology, which I will talk about later.

In addition, it is not always possible in the store to select a product specifically for your chimney shape.

Tips for choosing a gate valve

It must be remembered that the correct selection of an element such as a slide damper is reflected in the future not only on the draft indicator, but also on the safety of the heating system, of which the chimney is a part. Installation of the damper is carried out on any model of fireplaces and stoves, except for the most modern ones, which have a deflector.

We recommend: Open heating system and closed one - which is better and what to choose?

The main recommendations for choosing slide valves for smoke exhaust communications are as follows:

If the heating device operates by processing gas, it is better to purchase a rotary valve model. This is due to the fact that such models exclude the possibility of completely blocking the smoke exhaust channel. Thus, the heating system will be safer. The chimney, which removes combustion products from the gas stove, must be closed by at least 40 percent during operation;
There are heating systems that operate intermittently (periodic). A closed damper installed in such a heating structure, as a rule, allows steam to pass during supply, and an open damper contributes to the formation of a large amount of soot on the pipe, which is located below the plate;
It is strictly not recommended to use rotating elements for installation in sauna chimneys.

A rotating device is the most suitable option for a gas-consuming system

Note! The chimney damper is a shaped part of the chimney service, so if you purchase everything necessary for laying a chimney, it will be included with the pipes. Such shutters can be purchased at any specialized store or ordered using an online store on the Internet.

Experts recommend carefully measuring the cross-section of the smoke exhaust duct before purchasing a gate product. Perhaps this is the main thing that needs to be done before purchasing a gate.

Adjustment

When operating heating units, an important aspect is the correct adjustment of the traction force, which affects the efficient operation and safety of the heating system. The sliding element, even with full penetration into the chimney channel, does not completely protect the bathhouse from the penetration of carbon monoxide. Closing is carried out after the end of the firebox, the firewood should have time to burn out and become covered with an ash layer.

If this is not followed, there is a risk of inhaling harmful gaseous substances. As carbon monoxide leaks out, it fills the room. It should be remembered that installing draft control devices (vane, deflector, weather vane) does not exempt you from regular cleaning of the pipe. If equipment is not cleared of soot in time, unpleasant consequences cannot be avoided.

It is necessary to carefully monitor the condition of the chimney structure and the presence of sufficient draft force.

To control traction, a formula has been developed for calculating the optimal value for the gate element, which is called the “alpha” coefficient. When setting the required value, uniform combustion of wood materials is ensured with minimal ash formation.

Features of installation of gate valves

To install the throttle valve, it is necessary to make markings on the pipe in order to drill holes according to the welded valve structure.

To do this, you need to measure the pipe using a measuring tape and make marks for future holes. After making sure that the marks are symmetrical, use a drill to drill holes for the future rotary handle.

The throttle valve is installed as follows:

A steel damper circle with a welded tube is inserted into the chimney pipe.
A metal rod is threaded through the drilled holes in the pipe through a small tube, the end of which is secured with a bolt and nut.
The end of the rod is bent using pliers for a rotary handle.

Important! It is advisable to install a wooden element at the end of the rod, which will serve not only as decoration, but also as protection from touching hot metal, since the damper will become very hot during operation.

Next, you can install the resulting structure in the chimney pipe. To do this, the first piece of pipe is put on the furnace pipe of the stove heating, onto which a structure with a gate valve is installed on top. The next piece of metal pipe is put on the gate. All connections are treated with liquid silicone sealant.

Installation of a retractable damper in a brick chimney occurs during the masonry process. To do this, after 6-8 rows of bricks, a layer of cement masonry mortar is applied, on which a wire frame is installed with the open side facing the performer. You need to insert a latch into the frame and bring it into the closed state.

The frame is covered with mortar on top and bricks continue to be laid according to the standard pattern.

Attention! The slide damper is allowed to be installed in the first section of the chimney, at a height of up to 1 m above the firebox. This will ensure ease of adjustment of the damper and good aerodynamic properties of the chimney.

Rotary throttle

rotary butterfly valve
Rotary valves are not as widespread as the previous version. The operation is based on a rod, which is located in the center. A metal sheet is installed on it with rotation around its own axis. Due to this, the space is regulated and blocked if necessary.

This is a simple design that can be made on your own without any problems. But the moving part of the mechanism cannot boast of high reliability. Periodic replacement is required, which involves additional costs.

For installation, the socket and flange method is used. The differences lie in the fastening elements, which become relevant in each case.

DIY making

The simplicity of the design of the damper plate for the chimney allows you to make it yourself to ensure further regulation of the draft in it.

Option 1. Manufacturing a rotary gate from stainless steel

We offer detailed instructions for manufacturing the damper already with a finished stove heating, when the design is completed, but the damper mechanism was not provided.

To make and install a gate valve with your own hands, you will need the following materials:

grinder, cutting and grinding abrasive wheel;
drill;
tap;
oil for lubricating the tap when cutting threads;
hammer;
vice;
pliers;
welding;
core;
electrodes for stainless steel;
compass;
roulette;
permanent marker.

The materials you should immediately prepare are:

stainless steel sheet 1.5 -2 mm thick.
stainless steel tube with an internal diameter of 6 mm;
2 bolts 8mm,
nail (or metal rod).

When all the tools and materials are prepared, you can begin to carry out the work.

Measure the inside diameter of the pipe and mark it on the stainless steel sheet using a compass.

step 1
Now, using a grinder, cut out a circle according to the markings made.

Step 2
We try on the cut-out damper and, if necessary, modify it with a grinding wheel until it clearly fits into the pipe.

Trying on the damper
Take the prepared stainless steel tube and apply it to the finished circle. Use a marker to measure the size of the flap. We make it smaller than the internal diameter by 3 mm on each side.

Step 4
We cut the pipe with a grinder and a cutting wheel.
We drill an internal hole in the 6.8 mm tube for threading. When drilling, it is necessary to periodically lubricate the inner surface of the tube with machine oil.

Drilling out the tube
We cut an 8mm thread on both sides of the tube with a tap, not forgetting to lubricate the tap in the process. To remove the cutting chips, it is necessary to make a half turn back every half turn of the tap along the thread.

Step 5
Now you need to make three holes in the damper. Immediately use a marker to make marks.
Clamp the tube and the valve in a clamp and weld the tube to the valve through these holes (welded rivets). We start welding from the central hole, then release any one clamp and weld it into the free hole.

Step 6
We mark the future holes on the smoker. To ensure that the axis of the holes clearly coincides, wrap the pipe with a tape measure and measure the center horizontally and vertically. Let's drill.

Making the markings
We assemble the damper into a tube.

Step 7
Making a template for the damper clamp.

Step 8
We transfer the markings to the metal sheet. You can use a compass.

Step 9
Mark the middle for the fastener holes, cut and drill according to the markings.
We weld it to the pipe.

We weld the clamp

Option 2. Manufacturing a horizontal sliding gate from stainless steel

For this option, you need to purchase a ready-made factory stainless steel gate valve. The design represents a frame within which the mechanism moves.

Lay out 2 rows of the stove or fireplace according to the ordering pattern used.

horizontal sliding gate
On the row where the valve will be installed, we cut grooves in the brick. These are small grooves into which the metal element will fit. It is best to use an angle grinder with a wheel for this work. But if you don’t have such a professional tool, then you can get by with a file.
The damper is installed.
It is necessary to cut a recess in the side brick for the movement of the damper handle, because it will need to be cleaned of soot during operation.

We block the gate with a row of bricks
The next row of bricks is laid and all the resulting gaps are well sealed.

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As you can see, making a gate does not require much time or much experience. At the same time, this is a very important detail that will significantly increase the efficiency of the boiler or fireplace.

Where are gate valves installed?

The ventilation damper is installed at the end of the air duct in front of the fan. When they are installed together, the device acquires the purpose of a starting damper. It prevents a running fan motor from overheating.

To prevent the fan from breaking down prematurely, the damper must be closed when it is turned on. After gaining speed, it opens.

Galvanized steel is considered the best for air ducts, therefore it is advisable to purchase installed throttle valves from the same material. The resistance and pressure in the air duct directly depends on this. The smallest resistance is created when the damper is open, the maximum when it is closed.

The damper helps to equalize the resistance of air masses and regulate their flow between the main part of the air duct and its branches. If it is necessary to regulate such a process, the device is installed at the branch points.

Pipe installation

A gate valve can also be installed on a pipe. To do this, select a section of it where there is no insulation, otherwise it simply jams due to expansion as the element heats up. Experts recommend placing it about 1 meter short of the firebox.

The following procedure is suggested:

Fastening the first part to the pipe with coating of the joints with a sealant characterized by heat-resistant properties.
Installation of the gate on this segment or on the tee.
Placement of the second trim for the pipe, which will connect the structure with the insulated sections of the chimney.

Due to the tight fit of all elements of this design, no additional fastenings are required. The installation technique is suitable for rotary and retractable gates. Sometimes a rotation limiter is additionally provided.

Installing a gate valve on a pipe

How does the installation work?

The rotary damper for the chimney is installed as follows. The height of the product is determined by the craftsman based on the actual structure of the furnace. The minimum height is 0.9-1 meters from the floor, and the maximum is approximately 2 meters. As a rule, installation does not take more time and proceeds in several successive stages:

Selecting the installation location and setting marks on the bricks that need to be trimmed.
Cutting bricks using a grinder.
Fixing the chimney partition with masonry mortar.
Brickwork according to a row pattern.

Installing a damper on a chimney

Today, there are two main ways to install a damper on a chimney:

Installation in a fireplace insert. This installation option implies the location of the gate product in close proximity to the heating equipment. As a rule, in this case the distance from the damper to the heating apparatus is 1 meter. This arrangement is very convenient for regulating the valve.
Connection with other elements of the heating system. In this case, there is no need to use additional locking elements, so this option is quite common. This type of installation can also be called “pipe to pipe”.

Helpful information! In addition, it is worth noting that the gate product can also be installed in the ventilation system. A gate valve for ventilation is necessary to prevent the fan motor from overheating. The fan motor may overheat during shutdown.

The above options for using valves for chimneys and ventilation systems are used everywhere. It is worth noting that today you can find a huge variety of stoves and fireplaces, which differ from each other from a constructive point of view. This variety of heating devices also influenced the range of gate valves. Therefore, the choice of a damper for a chimney depends entirely on the characteristics of the heating device and the chimney design in a particular case.

Expert advice

Where to install the damper on the chimney

There are 3 options for placing the damper relative to the chimney:

Placement in the firebox of a fireplace or stove;
Fastening according to the “pipe to pipe” principle;
Installation in a ventilation pipe.

Let's consider the first 2 options:

By placing the valve in the furnace firebox or in the outlet pipe

In this case, the damper is located at a height of no more than 1 m from the firebox, on an uninsulated section of the pipe. This location is convenient for adjusting the damper.

Pipe in pipe

Applicable for metal chimneys. This installation option does not require additional fasteners. When purchasing a ready-made system, you should install the valve strictly according to the manufacturer’s instructions.

How to adjust traction

Adjusting the draft using a slider is quite simple. By changing the position towards increasing the gap, we increase the flow of air to the fire and the flame flares up stronger. Reduce the gap - traction decreases. The valve is closed after the flame has completely died out - this way the oven cools down much faster.

The latest boiler models are made with built-in automatic baffles. All other heating units require the mandatory installation of a damper.

Advantages and disadvantages

Like any engineering solution, a gate has a number of advantages and disadvantages.

Pros:

Possibility of traction control;
Fuel economy;
Dampers help retain heat.

Minuses:

The devices make it difficult to clean chimneys;
If installed incorrectly, the gate may jam and negatively affect the movement of gases;
To make the correct adjustment, you must have some knowledge in the field of smoke exhaust systems.

Design features of the device

The design of a gate valve or “knife” valve is quite simple. It consists:

From a body that is a tee with a central extension and hollow branches. Can be equipped with a lid.
Sedel. These elements perform a guiding function and ensure the tightness of the shutter.
Locking unit (damper). This element is located perpendicular to the flow of the medium and regulates the throughput of the valve.
A rod in the upper part of the housing, responsible for moving the damper.
Control mechanism - screw, lever, drive.
A stuffing box assembly that ensures the tightness of the rod-housing pair.

Gate valve design advantages and disadvantages:

The main advantage of the fittings is their simplicity of design, low hydraulic resistance and the ability to be used for transporting media with solid inclusions.

Disadvantage: low tightness, high construction height. Such products cannot be used to carry hazardous substances, the leakage of which could be critical.

Visual demonstration of the efficiency of a gate valve (video)

Closed gate:

Open gate:

In most cases, the gate is made of stainless steel with a thickness of no more than 1 mm. This part can withstand temperatures up to 9000C, is resistant to corrosion and has a low coefficient of thermal expansion.

In order to ensure maximum ease of operation of the chimney and good soot removal, the surface of the damper must be polished.

The joints are joined using the rolling method.

A standard damper covers up to 85% of the chimney, which is the optimal indicator for the effective removal of combustion products.

Purpose and application

A ventilation damper is an ordinary damper, a valve, the main purpose of which is to regulate air flow. It can be used to increase or decrease air flow, and, if necessary, to stop it completely. In its most general form, a ventilation damper looks like a flat damper with a thickness of about 1 mm. It is made mainly from galvanized steel sheets.

Of course, the ventilation system will work without a damper, but will it be of high quality? After all, the ventilation of premises under any conditions and circumstances will always be the same. It’s another matter when ventilation systems are equipped with dampers. In this case, it becomes possible to completely control the flow of fresh air and reduce or increase its amount in the room if necessary.

So, having figured out what a damper is and why it is used in ventilation systems, let’s look at what they are like.

Frequent errors and problems during installation

Installation of a valve in an insulated area. Under the influence of thermal expansion, the damper may jam;
Installation of a cast iron part in a metal chimney (cast iron weighs a lot);
Using too thin steel or stainless steel with a low nickel content for the manufacture of valves. Such a product quickly deforms under the influence of hot gases and can burn out;
Installation of a gate with a non-smooth surface;
Installation of a valve without a hole for carbon monoxide release;
Installation of handles that do not allow monitoring the position of the valve (applies to rotary elements).

Size calculation

Even an extra gap of a few millimeters can be the cause of improper operation of the air vent.

Step-by-step steps to resolve the issue are as follows:

First, take a tape measure to measure the size of the internal channel.
20-30 mm is added to the result. The result is the size of the outer frame.
An opening for gas release is required for the finished valve.
The position for the welding holes is also marked as accurately as possible.

Features of gate maintenance

The gate, made of stainless steel, is usually polished to perfect smoothness. Soot settles on it poorly, but still settles. Therefore, it must be cleaned periodically.

The horizontal valve can be cleaned simply by pulling it out to the maximum and applying a special solution. Rotary - cleaned through the chimney with a special plastic brush. You should also ensure that the damper moves freely along the guides. It is allowed to periodically lubricate them with an anti-corrosion compound.