Do-it-yourself chimney damper - drawings and manufacturing procedure

The main types of gate valves

Swivel gate. It is also called the "throttle valve", which is a metal plate mounted on a rotating axis. The axis, in turn, is mounted inside the chimney pipe. This device has a removable rotary disk, but with prolonged use it may become unusable. However, the scheme of the rotary mechanism allows you to repair and replace it with your own hands.The advantage of this type of device is ease of use. This type of gate does not require constant monitoring by the owner of the house.

Due to the complexity of the do-it-yourself design, the rotary mechanism is less often used when laying a fireplace or stove.

The gate design is necessary for wood-burning stoves and heating devices operating on any solid fuel.

Therefore, for a gas boiler, the most practical solution would be to install a rotary mechanism. The temperature of the exhaust gases is less low than during the operation of solid fuel, so the operation of such a mechanism will be most convenient.

Valve on the insulated chimney

But it is better to refuse to install a rotary mechanism in the bath. The fact is that it will partially pass steam when closed. And in the open form, such a mechanism is difficult to clean.

Made of stainless steel, the slide mechanism will not completely cover the chimney, but at the same time it will exclude the possibility of pulling out flames through the ash pan into the room.

There are three options for installing the gate.

1. Installing a damper in a fireplace insert. To do this, the gate is mounted at a distance of 1 meter from the heating device, which ensures simple operation.
2. The “pipe to pipe” option involves combining the gate with other elements of the heating structure without additional use of fasteners.
3. Installation of a gate valve in a ventilation pipe. But this option is usually used to protect the fan motor from overheating during its operation.

But even if the finished kit comes without this element, the gate can be easily made with your own hands by choosing the most optimal mechanism option for yourself.

Advantages and disadvantages

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

Pros:

• Ability to control traction;
• Fuel economy;
• The dampers help keep the heat in.

Minuses:

• Devices make it difficult to clean chimneys;
• If installed incorrectly, the gate can wedge and adversely affect the movement of gases;
• For correct adjustment, it is necessary to have certain knowledge in the field of smoke extraction systems.

Differences between sliding and rotary gate

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

Why do you need to install a gate

The installed valve ensures the most efficient operation of heating equipment. It plays the role of a regulator damper, the use of which provides a partial overlap of the chimney section. So, the gate valve makes it possible to block the smoke channel after the firebox.

The draft is adjusted in this way: by closing the damper, you can reduce or increase the diameter of the chimney.

The gate valve is needed to control combustion in the fireplace insert. Its installation ensures the regulation of flue gases and air flows in the chimney structures.

Types of dampers for the chimney

1. Retractable system. It is made in the form of a horizontal plate, due to its movement, the cross section of the chimney pipe decreases or increases, adjusting the draft.The smooth shutter is equipped with a small diameter hole, which allows easy and tight movement in the guide grooves. This type of damper is more common and is used in chimneys whose pipes are made of brick or steel.
2. Rotary system (double-walled, throttle). This is a structure that rotates around its axis, closes or opens the smoke channel. It is made in the form of a smooth plate, divided in half by an axis and fixed on it. Adjustable by turning both parts in a circle. It is used in cases where for some reason it is impossible to install a retractable damper. The disadvantage of the rotary design is that the welding that rotates the plate can break or burn off during use.

Damper materials vary, but are most commonly stainless steel or cast iron. They are durable, strong, resistant to high temperatures, and the main difference is weight. Cast iron gates are very heavy, which complicates their installation, so the gate valves are inserted only into brick pipes. Stainless steel dampers, on the contrary, are versatile, lightweight and are used in various types of heating appliances.

Types of gate valves

There are two main types of gate valves - retractable 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 do-it-yourself spark arrester on a chimney?

To enhance the draft, the damper moves back and almost completely goes beyond the chimney, and to reduce the flow, it slides back into the pipe.

Retractable gate

The most popular sliding type chimney damper. It compares favorably with other varieties of reliability in operation with ease of use. The retractable gate is a plate with a smooth, even surface, in which there is a special longitudinal hole. It goes through 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 and considerable effort.

Some models have 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 variety is the 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 share is in the inside of the chimney, but the tip should always remain outside. Against the background of the 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 structure: the damper will open if the mount relaxes.

The rotary gate is notable for its low reliability. But this figure may vary depending on what it was made from.Most often, they turn to it for installation in steel chimneys. And also it is installed in cases where there is not enough space to extend the classic valve.

Cast iron gate

The cast-iron gate has found quite wide application within the framework of furnaces of various types, fireplaces. The disadvantage of such products is their significant mass. At the same time, cast iron itself has long been used in the manufacture of valves for furnaces. This is explained by its high reliability, durability and strength.

Model range of cast iron gates

Gate of steel type

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

• maintaining the efficiency of the furnace;
• small mass;
• long service life;
• not subject to metal corrosion;
• does not allow the accumulation of soot.

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

Valve installation

Installation of any type of gate is carried out at the first stages of installation of the heating system. Installing the structure on the chimney is not at all difficult. You can do this in three ways:

• Near the fireplace insert. The device is connected to the chimney at a distance of one meter from the heaters. Such a convenient installation of the damper allows you to freely control the operation of the gate.
• "Pipe to Pipe" This method involves fastening the slide damper to the chimney without the use of additional clamps.The valve is securely held due to a tight fit to the chimney pipe.
• in the ventilation duct. This installation option is mainly used for cooling the fan motor.

When constructing stoves and fireplaces, the damper is most often installed in the first way. Gate valves are used for both round and square chimneys. Products with a rotating plate are most often installed in chimneys with a cross section in the form of a circle.

Installing a gate in a brick oven

The gate valve is quite often used for brick ovens. It is installed at the stage of construction of the chimney. The valve is placed on the first meter of the pipe. This arrangement of the gate makes it easy to adjust the thrust. To install such a gate, you must:

• two rows of chimney bricks are being laid;
• in the second row, an opening of the required size is cut;
• damper is installed;
• in any brick of the same row, a recess for a rotary handle is punched;

Next, laying the next rows

In this case, attention should be paid to the tightness of the fit to the place where the gate is installed. All cracks should be filled with grout.

When using such a damper, all safety measures should be taken into account. During the operation of the furnace, in no case should the slide valve be closed. Such an action will lead to the ingress of carbon monoxide into the room. Some models have a special fixing element that prevents the pipe opening from being completely closed.

Making a gate with your own hands

If the valve is not included in the kit for the chimney system, then you can purchase it separately or make it yourself.The design of such devices is quite simple, therefore, almost everyone can build a slide gate if they have the skills to work with a grinder and a welding machine:

Initially, measurements of the future product are made

Here it is especially important to correctly size the opening of the chimney pipe, taking into account every millimeter. The size of the inner side of the frame must correspond to the cross section of the pipe

The external value of the sides can be determined by adding twenty-five centimeters to the internal indicators.
The frame is made from durable stainless steel. The shelves of its corners should be four centimeters. All joints of the frame are connected by welding.
After that, a hole is made into which the axle will be inserted. To rotate the plate at an angle, the holes in the frame are drilled diagonally. For a straight turn, it is necessary to make holes in the center of the parallel sides of the frame.
Then the bushings are welded by welding. They are made from a pipe no more than twelve and a half centimeters long. The rod installed through the bushings must rotate freely.
A plate is cut out of a stainless steel sheet using a grinder. Its size must correspond to the cross section of the chimney pipe. All edges of the damper are ground with a grinder with a disc.
The finished plate must be inserted into the frame and attached with a welding machine to the axis, leaving a gap between the frame of more than one centimeter.
On one side of the frame, a limiter is installed to fix the plate in the required position.
A handle is attached to the axis with which you can open and close the damper.

For the plate, steel two or three millimeters thick is used. All parts of the gate must be made of the same heat-resistant material.The end of the handle can be decorated with a wooden handle.

The efficiency and safety of the operation of heating units depends on the quality of the slide gate and its correct installation. Therefore, when buying or self-manufacturing a product, it is necessary to accurately determine the parameters of the chimney and the technical features of the heating system.

DIY manufacturing

The simplicity of the design of the damper plate for the chimney allows you to do it yourself in order to further regulate the draft in it.

Option 1. Making a stainless steel rotary valve

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

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

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

From the materials you should immediately prepare:

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

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

1. Measure the inner diameter of the pipe and mark it on the stainless steel sheet with a compass. step 1
2. Now, using a grinder, cut a circle according to the markup. Step 2
3. We try on the cut-out damper, if necessary, we refine it with a grinding wheel until it clearly enters the pipe. We try on the damper
4. Take the prepared stainless steel tube and attach it to the finished circle. Measure with a marker to the size of the damper. We make it smaller than the inner diameter by 3 mm on each side. Step 4
5. We cut the pipe with a grinder with a cutting wheel.
6. We drill an inner 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.
7. 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 cut chips, it is necessary to return half a turn of the tap on the thread every half turn. Step 5
8. Now you need to make three holes in the damper. Mark immediately with a marker.
9. Clamp the tube and the damper in the clamp and weld the tube to the damper through these holes (weld rivets). We start welding from the central hole, then we release any one clamp and weld it into the vacated hole. Step 6
10. We make markings for future holes on the smoker. In order to clearly match the axis of the holes, wrap the pipe with a tape measure and measure the center horizontally and vertically. Drilling. Making markings
11. We assemble the damper into the tube. Step 7
12. We make a template for the damper retainer. Step 8
13. We transfer the markup to a metal sheet. You can use a compass. Step 9
14. We mark the middle for the holes of the latch, cut and drill according to the markup.
15. We weld to the pipe. We weld the retainer

Option 2. Making a horizontal retractable stainless steel gate

For this option, it is necessary to purchase a ready-made factory stainless steel gate valve. The design represents a frame inside which the mechanism moves.

1. Lay out 2 rows of stove or fireplace according to the ordering scheme used. horizontal sliding gate
2. 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 enter. It is best to use an angle grinder with a wheel for these jobs. But if there is no such professional tool, then you can get by with a file.
3. The damper is installed.
4. In the side brick, it is necessary to cut a recess under the stroke of the damper handle, because it will need to be cleaned of soot during operation. We close the gate with a number of bricks
5. The next row of bricks is laid and all gaps formed are well sealed.

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

How to make a chimney valve with your own hands?

Many owners are interested in the question: how to make valves in round pipes? For a round or square chimney, you can make a valve with your own hands. For round structures, a rotary valve is best suited, however, you can also use a horizontal one.

The gate valve can be made by hand, as its design is very simple. Self-production of this shaped element of the chimney structure is relevant if the nearest stores do not have a valve of the required section.

The step-by-step process for making a chimney valve looks like this:

• First of all, it is necessary to prepare a frame in which the sliding plate will be located. It is recommended to make a frame made of heat-resistant stainless steel. The width of the shelves of steel corners should be from 3.5 to 4.5 cm. The corners are joined using welding equipment.
• At the second stage, you need to make a hole for the axle. It is worth remembering that if you need to make the shutter with a "straight" turn, then it is recommended to drill a hole at a point that corresponds to the center of the parallel sides of the frame. And for devices that rotate at an angle, the hole is made diagonally.
• Next, you need to install special bushings that can be made from ordinary pipes. The sleeve size should be approximately half an inch, which corresponds to 1.25 cm. Welding equipment must be used to install the tubes. Bushings should not interfere with the movement of the axis of the bar.

• Then the workpiece is selected for the gate plate. To do this, you need a sheet of stainless steel of the appropriate thickness, from which you need to cut a part that fits the section of your chimney. It is worth noting that the damper thickness can be higher than 1 mm (for example, 2 or 3 mm).
• At the fifth stage, the finished plate is inserted into the frame and welded to its axis. Experts advise leaving a small gap between the frame and the plate (at least 1 mm).
• The restrictive element is fixed, which is necessary to hold the gate plate in the desired position.
• And, finally, it remains only to attach a handle to the axis, which is necessary to regulate the position of the valve.

Common errors and installation problems

To install the throttle valve, it is necessary to make a marking on the pipe in order to drill holes according to the welded design of the damper.

To do this, you need to measure the pipe with a centimeter tape and make marks for future holes. After making sure that the marks are symmetrical, drill holes for the future rotary knob with a drill.

The throttle valve is installed as follows:

1. The steel circle of the damper with a welded tube is inserted into the chimney pipe.
2. Through the drilled holes in the pipe, a metal rod is threaded through a small tube, the end of which is fixed with a bolt and nut.
3. The end of the rod is bent with rotary knob pliers.

The installation of a sliding gate in a brick chimney occurs during the laying 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 towards the performer. You need to put the valve in the frame and bring it to the closed state.

From above, the frame is covered with mortar and bricks continue to be laid out according to the standard scheme.

To date, there are two main ways to install a gate on a chimney:

1. Installation in a fireplace insert. This installation option implies the location of the gate product in the immediate vicinity of the heating equipment. As a rule, in this case, the distance from the gate to the heater is 1 meter. This arrangement is very convenient for adjusting the valve.
2. Connection with other elements of the heating system. In this case, there is no need to use additional fixing elements, so this option is quite common. Such installation can also be called "pipe to pipe".

The above options for using dampers for chimneys and ventilation systems are used everywhere. It is worth noting that today you can find a huge variety of stoves and fireplaces that differ from each other from a constructive point of view. Such a variety of heating devices also influenced the range of sliding dampers.

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

Varieties of gate valves

Since chimneys are different, our gate valves are also different from each other. Basically, this difference lies in the form and in the way of functioning. There are several types of gate valves:

1. Horizontal slide gate valve that retracts. This is the most common type of gate valve. Inside the structure there is a plate, which is retractable, it is thanks to it that the cross-sectional area is regulated. Most often, this design is used for brick chimneys. So that in the closed position of the element, the smoke channel does not overlap 100%, small holes are made in the plate. This is done for a reason, because the technology of creation corresponds to fire safety.A feature of the horizontal gate is the simplicity of design and ease of installation, as well as the efficiency of work.
2. Swivel gate. It also has a second name - "throttle valve". The design is fundamentally different from the previous version. It is made in the form of a branch pipe, inside of which there is a metal plate. Only it does not extend, but is located on a rotating axis. The device is equipped with a removable rotary disk, which becomes unusable over time. However, due to the scheme of the rotary mechanism, it is easy to repair and replace the part yourself. The valve is located inside the chimney pipe. The principle of operation is to rotate the plate inside. The advantage of this gate valve design is that it is easy to operate. The owner of the house will not need to constantly monitor the position of the gate.

Since the second option is more difficult to implement, this do-it-yourself chimney damper is not made. Most often, it is the first option that is created - a horizontal valve. I would like to note a few more nuances. A gate valve is needed for wood-burning stoves and other heating equipment that runs on solid fuels. If we talk about gas boilers and those running on liquid fuel, then the damper is needed more in order to protect the chimney structure from the penetration of atmospheric precipitation, debris and animals.

If we talk about installing a rotary gate for a bath, then it is better not to do this. Why? During operation, the structure will partially pass steam when closed. And cleaning in the open is difficult to perform.

There are three ways to install the gate:

1. Installation of the product in the fireplace insert.For this purpose, it is installed at a distance of 100 cm from the heating device (stove, fireplace, boiler), which simplifies operation.
2. The pipe-to-pipe method is based on combining the gate valve with the rest of the elements of the heating system, without the use of additional fasteners.
3. Installation of the valve directly in the ventilation pipe. The purpose of such manipulation is completely different. The valve is needed more to protect the channels from the penetration of foreign objects, debris, rainfall and animals. This is done to protect the fan motor.

There are two options for how to proceed if you need to install a valve. The first is to simply buy a kit and do the installation yourself according to the instructions from the manufacturer. The second is to make a chimney damper yourself. We will consider options for creating both a rotary and a horizontal device.

Functions, purpose and characteristics

Being the main draft regulator inside the chimney, the damper regulates the combustion of fuel. To reduce draft and reduce the intensity of the flame in the furnace, it is enough to cover the slide valve. To increase traction, on the contrary, it is necessary to open it.

In fact, the gate is an ordinary metal plate that allows you to adjust the thrust.

It can be installed both in single-wall boiler systems and in double-wall boiler systems.

If the fireplace with the stove is not in use, then during this period the gate valve must be in the closed position.

But on the site of a well-insulated chimney, on the contrary, it is not recommended to install a valve. Especially when it comes to double-circuit pipes.When the metal of the inner and outer pipes expands, the slide gate may jam.

So, the main tasks of the gate valve are:

1. The function of the draft regulator in the chimney.
2. Partial overlapping of the section of the chimney channel.
3. Flame intensity regulator in the furnace.

The gate valve is a thin metal plate, manually adjustable 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 inserted into the pipe and fixed with an axial rod.

The damper in the chimney performs the following functions:

• increases traction power in difficult weather conditions;
• increases the intensity of combustion in the furnace by increasing the flow of oxygen;
• reduces draft with a strong rumble in the chimney during strong winds;
• saves fuel by reducing the intensity of combustion;
• prevents heat leakage after the heater has warmed up.

How to make a gate valve with your own hands

Consider how to make both options for chimney valves - retractable and rotary. Each of them has its own nuances of manufacturing and installation. Let's start with the retractable view.

Preparation of materials and tools

To create the simplest model of a retractable gate, galvanized steel is suitable. It is lightweight, thanks to its smooth surface it is easily cleaned of soot, and if necessary, the moving part can be easily replaced.

Millimeter steel is not suitable, as it easily bends, and if deformed, it will be difficult to slide the plate into the chimney. The minimum sheet thickness is 1.5 mm, and preferably 2-2.5 mm

The main tools are a welding machine, electrodes, a grinder, metal shears (we choose depending on the thickness of the sheet), a drill with a grinding disc, metal drills, a file. Work is best done on a workbench with a vise. Among other things, you will need a sheet of paper for the template, a tape measure, a marker.

Drawing up a diagram (drawing)

Dimensioning must be taken seriously, as even a few millimeters can cause the chimney to malfunction. To find out the dimensions of the frame, you should measure with a tape measure section of the chimney channel - it will match the dimensions of the inside of the frame. To this value, add 20-30 mm on three sides and calculate the outer side of the frame.

Drawing of a damper with a wire frame. A wire frame is more difficult to fix to masonry than a profile with flat, wide sides.

In order for the valve to slide out easily, without effort, it should be slightly narrower in width than the width of the frame (considering the outer sides). To simplify the calculations, it is necessary to draw a design diagram and designate all possible dimensions, so that in the future, while working with metal, you can navigate by them.

For metal pipes, they usually combine the design of a flat damper with a fragment of a chimney located perpendicularly.

Design dimensions for a rectangular pipe. The damper must completely block the chimney, but at the same time have small holes for air penetration drilled with a drill, or a gap

For brick chimneys, a flat frame made of wire or a profile with a valve moving along guides (two parallel sides) is sufficient.

Marking and cutting parts

Having determined the exact dimensions, we cut out the frame for the gate.If the chimney is small (for example, in a bathhouse or in a summer kitchen), you can use a thick wire by bending it in the shape of the letter P.

A more detailed frame is a strong corner profile. To make it, we cut a strip from sheet steel and bend it along at an angle of 90º. To give the profile the desired shape, in places where the corners are marked, we cut one of the planes. When bending, we get a frame. We weld the places of the folds.

Next, cut out the shutter itself. It should be about 5-10 mm narrower than the frame width. We adjust the length so that in the closed state only a small fragment of the valve looks out. You can decorate it in different ways: in the form of an ear with a hole or just a folded edge.

We clean the edges of the cut gate with a disk so that the closing / opening process takes place easily and silently. Details cannot be painted.

Valve installation steps

The photo shows the stages of installing a factory-made gate. By the same principle, a home-made device is mounted.

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In accordance with the scheme of the furnace device, we determine the installation location of the slide gate and mark the bricks that need to be cut

We take out the bricks that serve as the basis for mounting the damper, and cut them to the size of the gate frame with a grinder

We use masonry mortar to fix the valve. We apply it to the installation site, and then to the edges of the frame from above

The valve "stood" on the same level with the rest of the bricks, so there are no obstacles for further masonry, it is done in the usual manner - according to the ordering scheme

Step 1 - determine the installation location

Step 2 - cutting bricks around the perimeter of the hole

Step 3 - planting the gate on the solution

Step 4 - brickwork over the gate

The installation height of the damper largely depends on the design of the stove, in sauna stoves it is lower, in home heating stoves it is higher. The minimum height is 0.9-1 m from the floor, the maximum is about 2 m.

The main functions of the slide gate

The main purpose of the slide gate is to ensure the stable operation of the heating system due to good traction. The purchase of pipes for the chimney provides for the complete set of those with a production gate. If the valve was not included, the product can be created by hand.

The damper helps direct the air flow, accompanying the free outflow of combustion products, so that there is no smoke in the premises.

Overlap functionality

You can regulate the traction force by increasing the pipe flow, pushing or turning the layer, or closing it, returning the disk to its original position.

After everything inside the furnace has burned out, the gate is pushed in to the end, completely blocking the pipe. Do not close the chimney before the coals have cooled down, as combustion products continue to be released for some time and there is a risk of suffocation.