How to make a homemade valve. Check valve for water: how to choose and install it yourself

This device belongs to safety devices and its purpose is to provide a free flow of liquid in one direction and seal it off in the event of a reverse flow in the pipes.

The design is simple and makes it easy to make a check valve with your own hands from scrap materials.

For some pump designs, which include widely used centrifugal pumps, the presence of a check valve is mandatory. The impeller of such units cannot suck in water if it is not in the pump housing (snail).

The check valve, as applied to borehole pumps, is installed directly at the point of water intake, that is:

• for deep and any other submersible pumps, it is installed directly between the body and the outlet hose;
• on surface pumps, it is mounted on a suction hose or pipe.

In various plumbing systems, valves of various designs are used, such as:

• ball spring devices for horizontal structures;
• ball gravity products for vertical installation;
• petal;
• petal bivalve;
• wafer, and other designs depending on the place of installation.

According to the material of manufacture, they are divided into:

• brass;
• cast iron;
• steel;
• plastic.

In our case, brass products are most often used.

Check valve manufacturing

To make a check valve, we will use a standard tee with a female connecting thread.

Preparation of the suction pipe

Before installing it, you need to prepare a seat for the locking ball in the following order:

1. Clamp the part in a vice for the smooth part.
2. With a drill, the diameter of which is 5 - 6 mm larger than the inner diameter of the nozzle, make a chamfer of 1.0 - 1.5 mm at an angle of 60 ° (standard drill sharpening).
3. Place a ball in the hole and hit it easily with a hammer several times. In this case, an even seat for the ball is formed due to the splashing of roughness and irregularities in the metal of the pipe in the place of its contact with the ball. Important! The degree of deformation of the pipe must not extend to the shape of the pipe, that is, its outer dimensions must remain unchanged.

Spring making

When selecting a material for this product, a stainless unannealed wire with a diameter of 0.5 - 0.8 mm is preferable. In this state, it remains quite elastic and retains this property for a long time, at the same time, when annealed, it will quickly lose them. You can do it like this:

1. Measure the inside diameter of the tee.
2. Pick up a rod, the diameter of which is 0.65 - 0.7 of the measured size on the tee.
3. Clamp the rod in a vice, drill a hole with a diameter slightly larger than the diameter of the selected wire, which should freely enter it.
4. Insert the end of the wire into the hole, bend it.
5. Tightly, turn to turn, wind the wire around the rod, remove from it without cutting off the end.
6. Measure the parameters of the spring: the diameter is two millimeters less than the internal size of the tee; the length should be sufficient to hold the ball in the entry portion when fully compressed. This will keep it in the housing when the pump is running.
7. Cut the spring to length. Bend the outermost turns inward by ¾ of the diameter, grind.

Valve assembly

• install the suction pipe;
• install the plug on the opposite outlet, having previously placed the spring and the ball inside the body. The length of the spring should ensure a tight fit of the ball to the end of the inlet pipe; if necessary, stretch the spring.
• the spring compression force is adjusted by screwing (unscrewing) the plug.

Fig. 2 Check valve arrangement

Obviously, the technology for manufacturing a check valve does not involve any complicated operations and is quite affordable to make a check valve on your own. The disadvantage of the design is the large overall dimensions, since a filter must also be installed on the intake pipe. Thus, its placement in the well is limited by its size - the inner diameter of the casing.

Equipment and materials

The list is not long:

1. Locksmith vices.
2. Drill.
3. Drill to match the diameter of the spring wire
4. Rod, size depending on the size of the spring.
5. Spring wire.
6. Standard tee.
7. Plug.
8. Steel ball from the bearing in accordance with the size of the inlet pipe.
9. Consumables for installation (FUM tape, tow, etc.).

In-line gravity check valve

Its design allows it to be used reliably inside the well. Installed directly on the pump outlet if the submersible version is used. When using an outdoor unit, the check valve is placed at the lower end of the intake pipe.

An inlet pipe is installed in the outlet of the submersible pump. A ball is selected depending on its inner diameter. The bed for the ball is prepared in the same way as for the spring valve in order to prevent water from flowing at high column pressure in the intake pipe (hose). The outlet is attached to the body from the opposite side and connected to the intake hose.

A design feature is the need to hold the ball in the body in order to prevent it from rising by the flow to the outlet. Otherwise, it will simply cut off the water.

This can be done by installing a wire stop. A through hole with a diameter of 2 - 2.5 mm is drilled in the body, a wire made of copper or aluminum is inserted into it. The ends of the insert must be riveted, and this must be done with high quality in order to ensure the tightness of the case. Basically, all that remains is to put the valve back in place before running the system into the casing.

When the pump is off, the ball under its own weight closes the bottom hole. When it turns on, negative pressure is created in the intake pipe, which raises the ball and opens the water inlet.

Flap valve

It is such a device:

It is quite possible to make such a device yourself if you have access to turning and milling work. The simplicity of the design ensures its long-term operation.

conclusions

The price of various valves ranges from 700 to 3000 rubles. And made from scrap materials at home will cost 300 rubles. Plus its own work, and even that is not much.

Almost every one of us wants to have free access to hot water all the time and not to depend on seasonal outages, repair work, or neighbors. It is difficult to imagine a comfortable living without hot water supply. To ensure uninterrupted availability of hot water, you should definitely buy and install a water heater at home.

Non-return water heating valve

The most popular water heating devices used in domestic conditions today are electric models of boilers. Any apartment can be equipped with similar units. An electric boiler is convenient and easy to operate, besides, it can be installed without additional procedures in agreement with the competent services and without drawing up a project. All the installation work required to install a water heater, each owner can carry out independently.

However, in order to carry out the installation of the water heater correctly, avoiding errors that lead to serious consequences, you should carefully read the process features associated with such a part as a safety valve.

Failure to install this small, inexpensive and affordable part can lead to accidents that are so often shown in TV coverage and extreme news broadcasts. It is about such consequences that the housing and emergency services always warn us.

The piping of an electric water heating unit must necessarily include a non-return valve.

How the valve works

Before talking about what the valve device is, it is necessary to clarify that it will not just be a check valve for a water heater, but a safety valve, in which several functions are combined at once. Both devices are very similar to each other, but there is one significant difference, which is a determining factor in ensuring the safety of using an electric boiler.

To understand what is the difference between these two details, you need to understand each separately:

1. Check valve. It looks like a cylinder made of a metal material, on both sides of which there are threaded sections. With their help, it is screwed into a straight pipe of a suitable diameter. Inside there is an inclusion in the form of a poppet valve - a disc with a rubber seal in a circle on the stem (central axis). The spring-loaded state of the disc makes it possible to block the passage of water inside the channel.
   On the "body" of the part, there is always an arrow indicating the permitted fluid flow. When water flows in the direction of the arrow, the pressure inside the pipe compresses the spring, opening the passage. When the pressure drops, the valve will automatically return to the closed position.
   This part is necessary in order to ensure constant filling of the tank with water. However, to ensure 100% safety of the boiler operation mode, the installation of such a valve is not enough.
2. Safety valve. The part has the form of two cylinders perpendicularly connected to each other. Inside the cylinder, which has a larger diameter, the installation of which is carried out along the course of the water, the same valve is placed, which prevents the liquid from moving in the opposite direction. On the side from which the liquid is supplied, there is a thread for tapping into the water supply. On the other hand, there is a threaded sleeve that can be installed on the cold water boiler supply pipe.
   To the large cylinder, which has a check valve, an additional smaller cylinder is attached perpendicularly. It contains a poppet-type valve and a spring, which is an order of magnitude more powerful. It is this element that is the safety stall valve.
   Behind the cylindrical "plate" in this cylinder there is a discharge pipe, where excess water is removed at the moment of valve actuation.
   At the end of the cylinder, which has a drain valve, there may be an element in the form of a screw plug. There is an adjusting screw behind this element. Safety parts with an additional lever are also very common, the purpose of which is to manually open the valve and discharge the liquid through the pipe. The branch pipe, in turn, is embossed so that it is possible to put on thin hoses that drain water into the sewer system.
   A manual type of valve control may be required when, due to repair or preventive work, it is necessary to discharge the contents of the water heater.
3. An arrow is necessarily marked on the body of any valve, which indicates the direction of the flow of cold liquid to the electrical device. Often on the "body" of the part there is also an indication of the ultimate pressure at which the valve is triggered. This indicator can vary from 0.1 to 10.0 MPa.

Function of the safety element in certain cases

In order to understand why it is still necessary to install a check valve and what is its importance, it is worth considering specific situations where it and the system are working properly, as well as moments of failure or absence of this part.

Safety part installation diagram

After installing the electric water heater and its piping, the process of filling with water begins. Cold water opens and a hot tap on one of the mixers. The pressure level inside the pipe of the plumbing system is sufficient for the check valve to open so that liquid can pass through it unhindered. When the tank is gradually filled, the air will be displaced. The moment the liquid flow passes from the mixer signals the full filling of the container, therefore, the liquid supply stops. At the same time, the pressure in the water heater and in the water supply is approximately the same.

1. A situation when there is no check valve or it is faulty.
   The balance of pressures in the device and the water main, which was established during the filling of the tank, will soon be violated due to the fact that the pressure in the pipe is less than the pressure. Since the taps on the mixers are closed, the already heated water will begin to come out in the other direction. As a result, hot water may start to flow from the cold tap or accumulate in the toilet cistern. In this case, the thermostat of the water heater, not understanding what is happening, does not give a signal to turn off the heating elements. The result is that electricity will be wasted.
2. Another situation is associated with the pressure difference in the water supply system and the device. Quite often, in apartment buildings, the pressure level in the pipes drops to critically low levels. Line accidents or planned preventive maintenance are the reasons for this change. If there is no valve at this moment, then all the liquid from the heater tank will simply drain into the pipes. The most important thing here is that the boiler has protection against dry heating. If there is none, then the heating elements will heat the air, and this will either lead to their burnout, or to the cracking of the enamel coating inside the tank.
3. The principle of operation of the valve becomes well understood in a situation where the pressure level in the heater is excessive. When the boiler is turned on, the heating and temperature rise process starts. Based on thermodynamic laws, pressure increases in a closed space.

Valve characteristics

Only a comprehensive return safety valve should be purchased and installed in your home. Only with its help it will be possible to ensure the safe operation of the water heating device.

Today, manufacturers of modern water heaters put a certain resource in the device, thanks to which it can function up to specific pressure indicators. This information is spelled out in the technical documentation. If the pressure level approaches the maximum allowable reading, a spring will be compressed on the valve, after which excess fluid is discharged into the drain pipe. The result is that the work of the system will return to normal without tragic consequences.

If in such a situation there is no valve, then a bomb effect will be created. The pressure inside the container will increase, and in conditions of isolation, the temperature indicator of boiling water increases. The increasing pressure can deform the walls of the tank, form cracks in the enamel or weld. Then, with a sharp drop in pressure, the temperature indicator of water boiling will decrease, and all the liquid will boil with lightning speed, and a large amount of vapor will be released. The result is a huge explosion.

Therefore, it is very important to obtain the correct safety valve that matches the specifications of the water heater.

How to choose a valve

1. Choosing the right part is not difficult. Most modern boilers already have the required valve in the kit. If you need to replace this part, then you need to focus on the parameters specified by the manufacturer. The price of the valve varies from 250 to 300 rubles.
2. When choosing a part, it should be understood that installing a "weak" valve will provoke water leakage; a product with an excessively powerful spring will not ensure that the boiler is operated in a safe mode.
3. It is possible to install the valve directly on the cold water supply pipe in the water heater. It is better to seal the joints using linseed tow in combination with a sealing compound.
4. To facilitate the implementation of preventive measures, a drain valve is added between the safety part and the boiler. The installation must be done correctly, that is, the valve is placed on the branch of the tee, since any shut-off element on the channel from the boiler to the valve is prohibited.

Before installing and putting into use any electrical device on the territory of your home, you should carefully familiarize yourself with all the features of the work, thereby ensuring the safety of yourself and your loved ones.

The check valve cannot be called a basic necessity, but in some cases it is truly necessary. An example is the construction of a vacuum chamber, when it is precisely a check valve that needs to be used to pump out air. Of course, you can buy it in specialized stores, but you can also build it at home, which we propose to do right now.

First of all, let's watch a video on making a homemade valve:

To make a check valve, we need:
- threaded fitting 15;
- plumbing hose for toilets with two fittings;
- 3 mm bolt 4-5 cm long;
- two nuts;
- a piece of rubber from a car camera.

Let's start manufacturing the check valve from its main part. For this we need our bolt and a piece of rubber. We cut out a round gasket from the rubber and make a hole in the middle to pass a bolt through it.

We put on the bolt one by one a piece of iron, a nut, a washer, a piece of rubber and a guide.

The blanks are ready, which means that you can start assembling the check valve.

With the assembly of the main part of the valve, everything is clear, since we have done this part above. After that, we insert this part into the threaded fitting so that the elastic comes out slightly from the bottom of the fitting. If necessary, you can adjust the length by screwing or unscrewing the nut on the bolt.

On the lower part of the fitting we tighten the second nut with the second fitting. Here the author gives preference to the fitting that is used on gas pipes in houses.

From above, the author winds a small faucet, but this is not necessary. The faucet can be freely replaced with an ordinary nut, however, you should pay attention to the fact that the diameter of the upper hole of the nut is less than the diameter of the fitting in order to fix the iron rectangle.

Often, the ventilation system works ineffectively and part of the air enters from the ventilation duct back into the apartment. The effect of reverse draft of ventilation is especially noticeable in kitchens or in bathrooms of apartments. Check valves will help fight unpleasant odors.

The principle of operation of the ventilation check valve

exhaust fan with non-return valve

Non-return valves in ventilation are called a group of protective devices to prevent the rotation of the air flow in exhaust ventilation systems or simply reverse ventilation in apartments. The valve allows air to flow in the desired direction, inhibiting reverse movement. Check valves for exhaust ventilation work automatically and this is the main plus of their use. In ventilation systems of residential and public buildings, check valves are used to prevent air from entering the common ventilation duct into separate rooms.

Exhaust check valves operate in natural and mechanical draft systems. The valve prevents insects and dust from entering the household ventilation.

Drafts may occur if the system is not fitted with a non-return valve.

rectangular metal check valve

The main structural part of any check valve for natural ventilation is the shutter. It is he who does not let air pass in an undesirable direction.

There are two types of round and rectangular non-return valves for ventilation:

• with a slide valve;
• with shutter in the form of a disc or flapper.

The first ones are used to work with liquid media. The latter are designed specifically for ventilation. They are available with a horizontal or vertical axis of rotation, as well as single-leaf and double-leaf.

There are rectangular and round check valves for ventilation with different cross-sectional diameters.

The main parameter when choosing a check valve is its capacity.

Natural ventilation check valves are easy to manufacture and very reliable.

They are made of plastic or metal, the material is selected depending on the features of the system. In vertical pipelines, the air flow moves vertically, so the valve is mounted horizontally to ensure correct operation of the valve.

The most commonly used round and rectangular check ventilation valves with a capacity of 4 to 6 m / s. They work quietly and efficiently. They are installed both independently and complete with an exhaust device.

All rectangular or round check valves for ventilation are also divided into:

• Heated. Such check valves for ventilation with an electric drive have the advantage: condensation does not collect in the system, and the structure will not be covered with ice in severe frosts;
• Without heating. Good for indoor use only.

The presence of an electric drive at the check valve for ventilation requires the participation of an electrician in its connection.

Although the device is cheap, a check valve for ventilation can be assembled with your own hands, but more on that later.

Check valve design for ventilation

round bivalve check valve

The check valve design is very simple: the flapper disc is attached to an axle, allowing it to swing freely. A plumb line is attached to cover the valve when the fan stops. Ventilation valves can be rectangular, round or square.

Industrial models differ from check valves for domestic ventilation in diameter and material, they are classified in the explosion-proof category, although the device is the same.

The diameter of a round or rectangular check valve for industrial ventilation can be from 125 to 1000 mm, they are installed in explosion-hazardous industries. The double blade butterfly valve is widely used.

Butterfly devices are made more often of metal, the axis for attaching the blades is installed in the middle of the section. As soon as the fan stops, the blades cover the section and the reverse draft of ventilation in the apartment stops. The diameters of the butterfly valves range from 100 to 315 mm.

The improved version of the "butterfly" is equipped with seals that reduce the noise during the operation of the blades.

It is very often used for ventilation in the kitchen a check valve in the form of shutters or petals (inertial grille). There are several blades in the structure, they are located on the horizontal axes.

How to choose a check valve

When purchasing a check valve for kitchen ventilation or a bathroom, you need to take into account the speed of air movement, because the shutter must respond to even the slightest flow. Poor draft in the system is the main problem when organizing a natural ventilation system. Therefore, most owners combine a valve with an exhaust fan. To cover the structure from the side of the room, a beautiful ventilation grill is installed.

But for the natural ventilation system to work flawlessly, it is important to choose the right check valve. Otherwise, reverse draft in the ventilation of an apartment building will continue to poison the existence of residents.

Pay attention to:

• sectional shape;
• section diameter;
• valve material;
• valve device;
• valve purpose;
• the manufacturer (affects more the price than the quality of the simplest mechanism).

You can purchase a ready-made kit of a fan and a non-return valve. Here it is necessary to pay attention to the fan power. For the kitchen, it is suitable with a coefficient of 10, and for the bathroom and toilet, 7 will be enough.

When purchasing a check valve for household ventilation of a private house, it is important to take into account the climatic conditions. For example, a "butterfly" will be covered with ice faster than a uniaxial structure. In private houses, in contrast to apartment buildings, the tenants are annoyed not by the reverse draft in the apartment, but by blowing wind into the ventilation and the penetration of rodents into it.

the simplest homemade check valve for ventilation

Do-it-yourself installation of a ventilation check valve is especially relevant for residents of the last floors of houses, where the problem of tightening "foreign" odors through the air ducts of the general exchange system is common.

We offer an improved version of the motorized ventilation check valve with a fan.

For the base of the check valve for kitchen ventilation, thick plastic or textolite is suitable. You will need a plate overlapping the outlet of the exhaust duct and no more than 4 mm thick. Markings are made on the plate: a grill the size of a fan hole, as well as holes for fastening to the wall (in the corners) and for attaching the fan.

The larger the mesh of the lattice, the denser the material for the sashes should be!

markings on the base for the non-return valve

To prevent air from "walking" between the base and the fan, a rubber gasket is used.

To prevent not only back draft in the ventilation of the apartment of an apartment building, but also the penetration of insects, a small plastic mesh or even nylon from tights is attached to the base grill. The latter is easily replaceable. And so that the residents are not disturbed by the vibration from the fan motor, rubber shock absorbers are used during installation.

Rubber dampers for quiet fan operation

Sashes are used from thick polyethylene (not less than 0.1mm). The film should be perfectly smooth, the smallest waviness will break the tightness of the ventilation, and the reverse draft in the apartment of an apartment building will resume. The sash can be fixed on tape with a fabric base. Detailed instructions for making flaps for a plastic ventilation check valve in the video:

We recommend cutting the flaps in place, from an already glued piece of film. Moreover, if it is slightly wrinkled during operation, it must be changed. Two flaps are cut together only at the very end of the process. You need to cut with a sharp construction blade.

To avoid a gap between the homemade plastic ventilation check valve and the wall, use self-adhesive foam tape.

During operation, it is necessary to periodically clean or change the plastic mesh clogged with dust.

When properly manufactured, such a homemade plastic check valve for ventilation will last for more than one year. And the tenants of the apartment will get rid of the back draft typical for the ventilation of apartment buildings for a long time.

strojdvor.ru

Diy check valve for ventilation: manufacturing in steps

The ventilation system is designed to supply the room with clean air and remove waste, saturated with odors and dust.

But what to do if the ventilation shaft, on the contrary, becomes a source of extraneous "aromas", or in a strong wind, frosty air blows into it from the street? We will figure out why reverse thrust can occur, how to deal with it and how to make a check valve for ventilation with our own hands.

Purpose of the check valve in ventilation

A ventilation check valve is needed to prevent the draft from overturning. Why this can happen:

• There is not enough supply air (there is no supply ventilation, or it is clogged, does not function).
• Incorrect position of the chimney on the roof (in the area of ​​the wind shade).
• If the apartment has several exhaust openings, and in one of them, for some reason, the draft increases (for example, the time when one fan was turned off coincided with the intensive work of another).
• A similar situation occurs in houses with stove heating. In the chimney, during combustion, the draft increases, and in the duct with natural ventilation, a reverse current is obtained.
• The role of a powerful hood can also be played by a staircase in a two-story cottage.
• In multi-storey buildings, an intensive forced draft in one apartment can disrupt the flow of flows in other apartments.
• Backdraft can lead not only to the penetration of extraneous odors, but also gas poisoning, frost entering the house, in those periods when the ventilation is turned off.

Check for proper traction with a candle flame or a sheet of paper. You need to open the window, and bring the sheet to the ventilation hole. If the flow is "correct", the paper will not fall, but will remain hanging on the wall.

Design

The design of any check valve for natural ventilation is based on a shutter that opens with a flow only in one direction. When changing the direction of movement, the shutter, on the contrary, slams and stops the reverse.

For ventilation systems, disk-shaped structures are used. They can be of several models.

Types of ventilation check valves

The axis of rotation of the check valve shutter is:

1. Horizontal.
2. Vertical.

Execution material:

Metallic ones are purchased less frequently today. Although they are more durable, they can become covered with condensation droplets, rust, and pop a lot when working.

Plastic models are lighter and quieter.

Based on where the ventilation check valve is used, it can be:

1. Heated.
2. Without heating.

Simple valves are installed indoors. If the device comes into contact with either warm or cold air, it is equipped with heating to avoid the formation of ice.

The valve structure can be:

1. Single leaf.
2. Membrane.
3. Bivalve ("Butterfly").
4. "Blinds".

Vent valve diaphragms

Single-leaf is a damper fixed on a horizontal axis, which opens and closes the passage, turning with an air flow.

The membrane variant is very sensitive. It uses a thin flexible flap that deflects, even from small, natural draft.

The butterfly has an axis in the center of a circular hole and two flaps that return to their original position thanks to the springs. Used on powerful forced installations.

A "louver" is a set of blades on multiple axes that are horizontally positioned. Other model names are lobe-type ventilation check valve or gravity check valve.

By the type of section of the ventilation duct or hole, you can choose:

1. Rectangular.
2. Round appliances.

The size of the product can also be different.

During the closing of the flaps, there is a clap. Improved models are supplemented with a seal that dampens the noise from the operation of the device.

For forced draft systems, it is important to select a device with a suitable capacity. And where natural air circulation is used, many valves will not work, since the weak draft may not be enough to open it!

Diy check valve for ventilation

Often, to take up the reproduction of this element of ventilation, the owner is forced not only by the desire to save money, but also by the fact that it is difficult to find an industrial model that natural draft can cope with.

The homemade version is very sensitive, even to the slightest air movement. And everything is done very simply.

For the manufacture of a membrane valve for ventilation, you will need:

1. Flexible plastic or film.
2. Lavsan tape.
3. Stationery knife and ruler.

Making a ventilation valve step by step

Film requirements:

• The size should be slightly larger than the ventilation duct opening.
• The thickness depends on the size of the cells - the more, the thicker. And from the strength of the flow - it should be enough to bend the curtain.
• Film with a rough surface will not work.
• Do not use wrinkled material for the membrane.

Steps instruction:

1. Marking is made on the lattice - the location of the future halves of the membrane.
2. With the help of scotch tape, a large piece of film (not yet cut) is attached to the grill. The tape should not be stretched when fastening.
3. The contours of the sashes are cut out with a knife (right and left, like shutters on windows).
4. The structure must be sealed. This means that when closed, the membrane must completely cover the openings of the grid, be free from defects and irregularities. And the sash attachment points are glued very carefully.

For greater comfort, you can equip a homemade valve with a mesh or nylon filter. It will prevent insects from entering the house.

The cost of finished structures

The most affordable are galvanized butterfly valves for round ducts.

The price of a valve for ventilation of this type (depending on size) is from 200 to 900 rubles. The cross section can be from 10 cm and more.

Rectangular air ducts are less common, so it can be more difficult and more expensive to choose a valve for it. For example, a frame of petal blinds measuring 30 by 15 cm can cost about 2 - 3.5 thousand rubles.

Conclusion

We can say that a check valve is not the most necessary part in a ventilation system. She often works so well that she does not remind of herself.

But if there are malfunctions, wind blowing, the penetration of foreign odors into the home, etc. - installing a valve for ventilation will solve all the problems at once. Instead of purchasing expensive models or flapping butterflies, you should try to make the simplest valve yourself.

Video on the topic

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microklimat.pro

Why do you need a check valve for ventilation and how to make it yourself

During operation of the ventilation system, the direction of the air draft may change. In this case, the effect will be the opposite - bad odors will penetrate into the room, air exchange will stop. To provide this, you must make your own check valve for ventilation or purchase a ready-made factory model.

Check valve purpose

The change in the direction of thrust can occur for various reasons. It is important that this does not affect the indoor microclimate. Most often, a similar situation appears for complex ventilation systems, where several pipes are docked into a common line. A change in pressure in one of them leads to a problem.

Installing a check valve is necessary to prevent the following situations:

• Insufficient volume of supply air masses. In this case, they will start coming from the receiving trunk.
• Incorrect position of the pipe on the roof. It is located in the zone of winds that create reverse thrust.
• Air inflow has increased in one of the exhaust ducts. At the point of joining with other pipelines, the pressure will change the direction of movement.

A correctly installed non-return valve will automatically shut off the flow, thereby preventing the air from changing direction. As soon as the direction changes to the correct one, the shutter or damper will open under the influence of pressure.

Read how to install a supply valve here.

Overview of design features

The check valve for ventilation is a shut-off and control device located in a small branch pipe. It should be installed at the joints of the pipes, at the outlet of the line. It is important that the diameter of the closing shutter is 0.5-1 mm less than the cross-section of the pipeline.

For self-manufacturing of a check air valve, it is recommended to take one of the factory models as a basis. They differ in design and can be of the following types:

• Single or double leaf. Striker plates are located on a hinge or spring pin. The normal state is closed. Under the influence of pressure, the valves are displaced, which increases the useful diameter of the pipeline. With reverse thrust, another effect appears - the plates block the line.
• Membrane. A disc of rubber or similar material is attached to a spring pin. Under pressure, the spring is compressed and the diaphragm displaced. Reverse flow will block the pipe.
• Blinds. Can have manual or automatic control. Application area - industrial ventilation systems. For a private house or apartment are not set.

For self-production, it is recommended to choose a design with a curtain, since it is easiest to implement at home. If the pipeline is rectangular, it is best to stop at one or two-piece valve.

Self-production

It should be noted right away that a home-made design cannot be more reliable than a factory one. The average cost of a check valve for a steel pipeline will be 350 rubles, for a plastic one - 320 rubles. If the desire to do it yourself is associated with a non-standard configuration of the highway, you need to choose the optimal scheme.

To do this, you will need to perform the following actions:

1. Purchase a branch pipe, the size of which corresponds to the diameter or section of the ventilation. It must have a mounting socket for installation in the pipeline.
2. Cut out a disc from a plastic sheet, the diameter of which is 0.5-1 mm less than the size of the line.
3. Using glue or a soldering iron, attach the thick wire loops.
4. Take the iron pin and fix it in the central part of the pipe.
5. Place the plastic disc on the pin, fix it on the hinges. He must remain mobile.
6. Solder the opening stops to the inner surface of the pipe. They must stop the movement of the disc to block the line during the appearance of reverse thrust.

This technology allows you to make a safety device for any ventilation systems.

The video shows a simple example of making a check air valve from available tools:

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The role of the air valve in the ventilation system of the apartment

The air valve plays a key role in the ventilation of the apartment. If the ventilation installed in the apartment does not function well, then part of the air flow returns from the common building channel back to the living quarters. Accordingly, an unpleasant smell is clearly felt in the apartment. This phenomenon is typical for bathrooms, bathrooms and kitchens. The problem can be solved by installing a check valve in the ventilation system. You can purchase a factory product or make a structure yourself.

What is a check valve

A device that is installed in the ventilation system to prevent the return of air flow is called a check valve. In other words, reverse thrust is eliminated. In addition, this design excludes insects from entering the apartment, protects living quarters from dust and drafts. Regardless of the type and design features, the check valve works in automatic mode and does not need additional settings.

The principle of operation of such devices is quite simple. In the center of the valve there is an axis on which the damper is attached. When the hood is in operation, the damper opens slightly, and the air flow from the apartment goes into the general ventilation shaft. When the fan is turned off, the damper gravity shuts off the duct flow, preventing back draft. Butterfly valves are widely used in apartment buildings. This double-leaf design can be from 100 to 315 millimeters in diameter.

Varieties

These devices may differ in form, principle of operation and method of installation. Let's dwell on each type in more detail.

• Installation. The air valve can be installed both vertically and horizontally. It depends on the location of the duct. For example, if the duct is vertical, then a horizontal check valve must be installed. This will make the device work more efficiently.

• Form. The valves can be round or rectangular. The recommended throughput of such a device can vary from 4 to 6 m / s. The design can be purchased separately or paired with a hood.

• Operating principle. The flap plays a key role in the operation of the check valve. It can be of two types: spool or disk. The first type is designed to work with liquids, so it is not suitable for ventilation. We are more interested in the second option - a disc or plate to prevent backdraft.

The non-return valve for ventilation can have a heating function. This option prevents frost and condensation. The effectiveness of this design in apartment buildings is questionable.

Ventilation in apartments is not in contact with the outside air, so heating is unlikely to be needed. In addition, such devices are more expensive and more difficult to install with your own hands. Therefore, do not succumb to the persuasion of sellers and buy regular models.

How to choose the right check valve

The functionality of the entire ventilation system will depend on the choice of the check valve. Therefore, the choice of these devices must be approached very responsibly. The first thing to pay attention to is the movement of the damper. It should rotate freely on the transverse axis. Thus, the non-return valve will be triggered even by a slight movement of air.

The second parameter worthy of attention is the cost of the product. Usually the price is made up of the following points:

• Valve size and section type;
• Material;
• Manufacturer's popularity.

Almost 30% of the price depends on the last parameter. It is worth considering that the valves made by renowned manufacturers are distinguished by the quality of workmanship. Therefore, it is not worth saving when choosing. In addition, the more expensive models usually come with an exhaust fan.

The efficiency of the check valve depends on the power of the fan. If the draft of the air flow is insufficient, the check valve will function as a conventional damper. The hood power must be commensurate with the internal volume of the room. For example, an exhaust fan with a power factor of 10 is suitable for the kitchen, and "sevens" can be used for the bath and toilet.

Do-it-yourself check valve

If you have no desire to spend money on purchasing a check valve, you can do it yourself. It is worth clarifying right away that it will not be possible to completely avoid costs, the exhaust fan will still have to be bought. So, the scheme for manufacturing a check valve is as follows:

• You will need a solid material for the base. You can use thick plastic or textolite. A plate is cut out of this material that fits the ventilation hole. The plate thickness can vary from 3 to 5 millimeters.
• Holes are drilled in the corners of the base for attaching the plate to the wall. In addition, you will need four more holes for attaching the exhaust fan. Holes are drilled in the center through which the air flow will pass. The number of these holes and their size are at your discretion. It is worth noting that the more cells there are, the higher the ventilation capacity.
• The fan is attached to the base plate. To make the structure airtight, it is recommended to install a rubber gasket at the junction. In addition, small rubber spacers can be fitted under the mounting bolts. This will reduce noise and vibration when the fan is running.
• Now you can start installing the sashes. To do this, you can use a thick plastic film (at least 0.1 mm) or thin plastic. The film is glued to the base in such a way that it completely covers the ventilation holes. Plastic sashes are installed on the base in a solid square. It is necessary to divide the square into two equal halves only after the completion of all work. If you are using plastic wrap, it should be absolutely smooth. Any fold will lead to a violation of the tightness of the structure, respectively, there will be no sense from such an air valve.
• The finished structure is installed in the air duct and fixed to the wall using self-tapping screws or dowel-nails. The gaps between the valve and the wall are sealed with sealant. After installation, the plastic film is cut into two equal parts, these will be the flaps of the check valve. You can use a cutting knife to keep the cut perfectly straight.

Thus, we have a homemade membrane with a check valve function. The structure works as follows:

• With natural circulation, under the influence of the air flow, the folds open slightly. Thus, air from the apartment freely enters the ventilation shaft.
• When the reverse thrust effect occurs, the doors are hermetically closed, not allowing air from the general ventilation to enter the apartment.
• For forced ventilation of the room, a fan is turned on.

This design can last for several years, not inferior in its performance to factory models.

It is worth noting that not only unpleasant odors, but also small insects can penetrate from the ventilation into the apartment. To prevent this phenomenon, it is recommended to glue a fine-mesh plastic mesh or a piece of nylon before installing the sashes. The latter option is preferable. Capron is easier to clean and easier to replace if necessary.

In fact, it does not really matter which version of the check valve you install: purchased or homemade. The main thing is that it provides reliable protection of the apartment from unpleasant odors.

Each private or multi-apartment building has a system. The most important function of ventilation is to constantly circulate and supply fresh air, while at the same time removing dust deposits and odors.

Sometimes it happens that instead of a stream of air, a stench comes from the neighbors.

Here you understand that a reverse-acting valve for ventilation devices is a must. In this article, we will consider all the details of the check valve topic.

Valve structure

The axle with blades is the key content of this part. The curtain, under a certain influence of air, passes it only in a certain direction.

In the event of a cessation of air flow, the blades are closed. The valve itself regulates both the flow of air masses and the volume of clean air.

Why do you need a check valve

When developing , be it or, we recommend that you analyze a number of reasons why a check valve should be installed in your room.

1. Violation of the technology of the location of the exhaust pipes leads to the fact that blown air flows begin to enter.
2. If there are several hoods in the dwelling. This leads to increased outflow, due to increased traction in one of the hoods.
3. If we are considering an apartment building, then there is a possibility of the presence of at least one powerful hood, and when it works, the air flows shift, which leads to the appearance of reverse draft in other apartments.
4. Lack of fresh air supply. This usually happens in the event of a breakdown or clogging.
5. The presence of heating, due to the stove. In this case, during the operation of the stove, the combustion thrust in the pipe increases, and this, in turn, leads to a reverse flow in the pipe.

How to check ventilation draft

The key question.

It's simple:

The plug should go out if the air flow is correct.

It should also be noted that it is better to provide for the installation of a check valve on and installation. Since its price is insignificant, as well as during the operation of ventilation, clogging, deformation and environmental influences are possible, which in turn will lead to a change in the air flow in the ventilation itself.

That's when you have to buy a valve, take the time and embed it into a working system.

The main classification of check valves for ventilation

Based on materials

Plastic (plastic). These are some of the cheapest and most commercial devices. They are often used in office buildings, houses, cottages. They look very attractive, and thanks to the rich color palette of the material, any design can be realized.

Galvanized steel... Widespread in industry and administrative buildings. These models are very durable, this allows them to cope with their task for a long time and with high quality. Valves made of steel do not have such a disadvantage as fire safety, since steel does not burn, unlike plastic.

Combination of materials... The body of the device is made of zinc-plated steel, and the shutter or blades are made of plastic. It is widely used in rooms with natural ventilation. This valve reacts even to small wind movements, providing a high-quality and natural exchange of air.

By form

1. Round.
2. Rectangular.

It all depends, of course, on the shape of the duct. It should be noted that for round valves intended for household use they are produced with a diameter of 100 - 200 mm. - these are the most common sizes. And for industrial systems it is possible to issue 150 - 1000 mm.

Moreover, for everyday life there are mainly round valves, and for industry, rectangular ones.

From installation method

1. Vertically arranged.
2. Horizontally located.

By regulation method

1. Manual - using latches and levers.
2. Automatic - occurs automatically, since it is a complex of supply and exhaust ventilation devices that function as a whole.

By design

Now let's look at the most important classification.

Petal valve

The valve is one-leaf gravitational action. Air, moving from the room, acts on the leaf, fixed on the axis of the valve body. Under the action of this force, the sash opens. In the event of a reverse thrust, the sash will close on its own under the force of gravity.

The presence of one sash makes the design simple and reliable.

When installing this type of valves, a level should be used, since it should only be mounted in a vertical or horizontal position.

This design has two versions:

1. Models where the axis is offset from the center. And usually it is located in the middle.
2. Use of counterweights that are located on the outside or inside of the device.

Butterfly valve or double-leaf valve using springs

In structure, it is similar to a petal valve, only it has two petals located on the same axis. Hence the resemblance to an insect, from which it got its name.

They are usually used in forced ventilation systems.

That is, when the ventilation is turned on, the blades open, and when turned off, they close with the installed springs. Such a device can even be positioned at an angle. Check the sensitivity of the curtains before purchasing. Recently, the sensitivity adjustment is done according to the force of the compression of the springs.

Gravity grid valve

In appearance, they resemble blinds, which can be positioned both vertically and horizontally. When you turn on the ventilation, the air opens and begins to flow, as soon as you turn it off, the blinds close.

Most often placed in walls for protection. The main advantage of these types of valves is their use at subzero temperatures in outdoor conditions.

Flexible Diaphragm Valves

The principle of operation is also similar to that of a petal valve. A thin flexible plate is used only as a curtain, which, when closed, fits snugly around the perimeter.

They are placed mainly in rooms with natural ventilation, since the membrane is very sensitive. The disadvantage is the fact that the membrane will deform if there is excessive reverse thrust.

How to make a check valve for ventilation with your own hands?

It should be borne in mind that the cost of standard check valves is not high, and there is no point in making the valve yourself.

And if the ventilation boxes are non-standard, then you should think about how to make a check valve for ventilation with your own hands.

The simplest mechanism that you can make yourself is a petal or diaphragm valve.

Instead of a curtain, you should choose a rigid plate of metal or plastic. To prevent the passage of air flow, the curtain should fit as tightly as possible to the edges of the case. And also the curtain should be firmly fixed in order to exclude sounds and friction.

A grill should be installed on the ventilation hole so that the membrane does not deform. That's all the structure is ready for use.

How to install a non-return valve for ventilation?

First, you need to decide on the number of valves that we will install.

If the air intake system is simple

So, if you have the only place for air intake, and it enters the mine further, then back draft can be prevented with the help of one valve in this system.

If the air intake system is complex

If ventilation is complex and involves several ventilation openings, then a rule should be applied that regulates the number and location of non-return valves.

• First, the valve is installed on any branch. which connects the air intake and the main line. This is necessary so that the air flows are not redirected towards the hood at the moment when it is turned off.
• Second. The check valve should be installed at the outlet of the system. ventilation. Many will say that this should not be done during the complete sealing of the system, but as experience and practice shows, the presence of a valve in such places is mandatory.

The check valve should be installed in easily accessible places so that it can be quickly and conveniently serviced and cleaned.

Recently, manufacturers of fans and hoods have already provided check valves in their designs. As a result, the installation of additional valves is impractical.

Installation of a non-return valve from the street

simple, we buy a valve taking into account the shape and size of the hole, apply it and mark the places for drilling. We drill, apply and secure, having previously missed the edges of the valve.

It should be noted that for the streets, it is best to buy valves with metal elements. If suddenly ice forms on them, they can be easily cleaned mechanically, and the plastic is likely to break.

Indoor installation of a non-return valve

If you are installing a slip-on check valve in front of the indoor fan, the process is similar to the one described above.

And if you need to install a check valve inside the ventilation shaft, then you will need to dismantle the ventilation device.

1. We mount the non-return valve inside the ventilation chamber housing and markup the mountings.
2. Then we take out the case itself and drill holes in the marked places.
3. After that, we put the body in place and mark the holes on the brick or concrete walls of the well.
4. We drill holes in the concrete with a bolt.
5. After we install the dowels, and put the whole structure together, we carefully fasten everything, we look so that there are no gaps between the valve and the body.
6. If gaps are present, then they should be treated with silicone.
7. Then we install the fan.

Now you do not have to worry about the penetration of unwanted odors into your room.

Finally, I would like to say that at the moment there is a huge selection of models, shapes and sizes of check valves for ventilation on the market.

But it is worth remembering that you should buy from bona fide manufacturers and then you will receive a device with the appropriate properties and quality assurance.

Check valve selection rules

It should also be remembered that if you approach the selection of a check valve in bad faith, this can lead to poor air exchange.

And in order to prevent this from happening, you should follow a number of rules when choosing this device:

1. The check valve must be the same size as the fan. And the power of the fan should be enough to create a flow that will ensure the opening of the petals without any problems.
2. Some devices are for indoor use only. This should be taken into account when choosing a valve model.
3. The best combination is non-return valve + exhaust fan + ventilation grill. This combination will provide maximum air exchange efficiency.

As you can see, the ventilation check valve plays an important role in ensuring a comfortable climate in any room.

When using complex ventilation systems, it is important to correctly place check valves to block air return.

Then the combination of hoods and fans will work flawlessly. Indeed, the service life and the quality of ventilation as a whole depend on the correct installation of these devices.