A non-return valve cannot be called a necessity, but in some cases it is truly necessary. An example is the construction of a vacuum chamber, when it is necessary to use a non-return valve to pump out air. Of course, it can be purchased in specialized stores, but it can also be built 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 toilet bowls 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. To do this, we need our bolt and a piece of rubber. We cut out a round gasket from rubber and make a hole in the middle to pass a bolt through it.

We put on the bolt alternately 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 rubber band comes out a little from the bottom of the fitting. If necessary, you can adjust the length by screwing or unscrewing the nut on the bolt.

On the bottom of the fitting, we twist the second nut with the second fitting. Here the author gives preference to the fitting, which 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 a regular nut, however, attention should be paid to the fact that the diameter of the upper hole of the nut is smaller than the diameter of the fitting in order to fix the iron rectangle.

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 independently make a check valve for ventilation or purchase a ready-made factory model.

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

The installation of a check valve is necessary to prevent the following situations:

• Insufficient volume of supply air masses. In this case, they will begin to flow from the receiving line.
• Incorrect location of the pipe on the roof. It is located in the zone of winds that create reverse thrust.
• In one of the exhaust ducts, the air flow increased. At the junction with other pipelines, the pressure will change the direction of movement.

A properly 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.

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 mounted at the junction of pipes, at the outlet of the line. It is important that the diameter of the locking shutter be 0.5-1 mm smaller than the cross section of the pipeline.

For self-manufacturing check 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 sided. Locking plates are located on a hinge or pin with a spring. Normal condition- 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 highway.
• Membrane. A disk made of rubber or similar material is mounted on a pin with a spring. Under pressure, the spring is compressed and the membrane is displaced. Reverse flow will block the pipe.
• Blinds. May be manual or automatic control. Scope - industrial ventilation systems. For a private house or apartment are not installed.

For self-production, it is recommended to choose a design with a curtain, since it is most easily implemented at home. If the pipeline has a rectangular shape, it is best to stop at a single or double-leaf valve.

Self-manufacturing

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

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

1. Purchase a branch pipe, the size of which corresponds to the diameter or cross section of the ventilation. It must have a mounting socket for installation in the pipeline.
2. Cut out a disk from a plastic sheet, the diameter of which is 0.5-1 mm smaller than the size of the line.
3. Using glue or a soldering iron, attach thick wire loops.
4. Take an iron pin and fix it in the central part of the pipe.
5. Install a plastic disk on the pin, fasten it on the hinges. He must remain mobile.
6. Solder the opening limiters to the inner surface of the pipe. They must stop the movement of the disk 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 non-return air valve from improvised means:

This device belongs to safety devices and its purpose is to ensure the free flow of fluid in one direction and hermetically shut it off when a reverse flow occurs in the pipes.

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

For some pump designs, which include the widely used centrifugal pumps, a check valve is required. 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 water intake point, 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 the intake hose or pipe.

Valves of various designs are used in various plumbing systems, such as:

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

According to the material of manufacture 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 use a standard tee with a female connecting thread.

Preparation of the intake pipe

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

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

Spring manufacturing

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

1. Measure the inner diameter of the tee.
2. Choose a rod whose diameter is 0.65 - 0.7 of the measured size on the tee.
3. Clamp the rod in a vise, 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.
5. Tightly, coil to coil, 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 must ensure that the ball is held in the input part when fully compressed. This will keep it in the housing while the pump is running.
7. Cut the spring to length. Bend the extreme turns inward by ¾ of the diameter, grind.

Valve assembly

• install the suction pipe;
• install a plug on the opposite outlet, having previously placed a spring and a ball inside the housing. 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 force is adjusted by screwing (unscrewing) the plug.

Obviously, the check valve manufacturing technology does not contain any complicated operations and is quite affordable to make a check valve yourself. 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 great:

1. Vice locksmith.
2. Drill.
3. Drill according to the diameter of the spring wire
4. Rod, size depending on the size of the spring.
5. Spring wire.
6. Tee is standard.
7. Stub.
8. Steel ball from the bearing in accordance with the size of the inlet pipe.
9. Consumables for installation (FUM tape, tow, etc.).

Direct Flow Gravity Check Valve

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

In the outlet pipe submersible pump inlet pipe is installed. Depending on its inner diameter, a ball is selected. The bed for the ball is prepared in the same way as for the spring valve in order to prevent water from flowing when high pressure pillar in the intake pipe (hose). The outlet pipe is attached to the body on the opposite side and is connected to the intake hose.

A design feature is the need to hold the ball in the body to prevent it from rising to the outlet with the flow. Otherwise, it will just shut off the water.

This can be done by installing a wire fence. A through hole with a diameter of 2 - 2.5 mm is drilled in the body, a copper or aluminum wire is inserted into it. The ends of the insert must be riveted, and this must be done with high quality to ensure the tightness of the body. In principle, it remains only to install the valve 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 is turned on, negative pressure is created in the intake pipe, lifting the ball and opening 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. Simplicity of a design provides its long-term work.

conclusions

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

Pipeline operation for various purposes assumes that the liquid and gaseous media that are transported through them must move in a certain direction. By making a check valve with your own hands or by purchasing its serial model, you can ensure this requirement for the operation of the pipeline and its elements of equipment, which will allow them to be maintained in working condition for a long time.

Purpose and principle of operation of the device

Backflow in piping systems can occur for a variety of reasons. In the case of liquid media, this may be due to a pump shutdown, and in the case of ventilation, an incorrect installation of the chimney or a small amount of incoming air. Whatever causes the reverse flow of the working medium in the pipeline system, such a phenomenon is highly undesirable, since it can lead not only to incorrect operation of the elements of such a system, but also to their failure.

To prevent the formation of a backflow in the pipeline system, as mentioned above, check valves are installed on it, which can differ both in their appearance and dimensions, and in their design. The main function of such a device, installed on pipelines through which liquid and gaseous media are transported, is to pass the working flow in one direction and block its movement at the moment when it starts to move in the opposite direction.

The design of check valves, regardless of their type, consists of the following elements:

• a body, the inner part of which is formed by two communicating cylinders;
• a locking element, which can be a ball, flap or spool;
• a spring that presses the locking element against the seat located at the outlet of the valve passage.

The principle of operation of the check valve is quite simple and is as follows.

• After the flow of the working medium entering the valve reaches the required pressure, the spring pressing the locking element is pressed out, allowing the gas or liquid to freely pass through the internal cavity of the device.
• If the pressure of the flow of the working medium in the pipeline drops, then the spring returns the locking element to the closed state, blocking the flow in the opposite direction.

On the modern market many check valves available various types, which allows you to select such devices for solving certain purposes. Meanwhile, many home craftsmen, guided by a natural desire to save money, make check valves with their own hands and share drawings and diagrams of their homemade products on the Internet.

Self-manufacturing of a check valve for water

A home-made check valve for installation on a pipeline through which water is transported does not require expensive Supplies and complex equipment, which makes it possible to save a lot. So, in order to make a check valve yourself, you need to prepare:

• a coupling on the body of which an external thread is cut;
• tee with internal thread;
• a spring, the diameter of which allows it to freely enter the tee;
• a steel ball, the diameter of which is slightly smaller than the cross section of the internal cavity in the tee;
• screw plug;
• FUM sealing tape.

A spring, if you have not found a suitable diameter, can be made independently, using a rod of the appropriate diameter and hard steel wire for this. In the rod, on which the homemade spring will be wound, it is necessary to drill a hole, the end of the wire will be inserted into it. To make it more convenient to wind the spring, the rod can be clamped in a vice, and the wire itself can be wound using pliers.

After all the materials for the manufacture of a homemade check valve have been prepared, you can proceed with the assembly, which is performed in the following sequence.

• A coupling is screwed into the internal threaded hole of the tee. This is done in such a way that it overlaps the side hole by approximately 2 mm. It is necessary to fulfill such a requirement when tightening the coupling so that the ball, which will be located in the inside of the tee, does not jump out into its side hole.
• A ball is first inserted into the hole located on the opposite side of the tee, and then a spring.
• The hole in the tee, into which the ball and spring were inserted, is plugged with a screw plug, which is screwed in using an FUM tape.

The check valve made according to the proposed scheme will work as follows: the water flow entering such a device from the side of the coupling will repel the ball pressed by the spring and exit through the perpendicularly located opening of the tee.

The most important thing when making a check valve of the proposed design with your own hands is to correctly adjust the spring so that it does not deviate at the moment when the water pressure in the pipeline decreases, and at the same time is not too tight so as not to impede the flow of water passing through through the device. In addition, all threaded connections must be made very high quality in order to ensure absolute tightness of the non-return valve.

How to make a check valve for ventilation systems

The question of how to make a check valve to equip the ventilation system is no less relevant than the manufacture of such a device for water supply or sewerage. By installing a check valve in the ventilation system, you will reliably protect your home from polluted and cold air entering such a system from the outside.

It should be noted that the check valve of the proposed design, when compared with serial models, has no less efficiency and can successfully serve you for two to three years.

So, the manufacture of a home-made check valve for equipping the ventilation system is carried out in the following sequence.

1. First of all, it is necessary to make the main element of the check valve - a plate on which the flaps will be fixed. To create such a plate, which is cut strictly according to the shape and size of the ventilation duct, you can use sheet textolite or other durable plastic with a thickness of 3–5 mm.
2. Along the edges of the sawn plate, it is necessary to drill holes with which it will be connected to the fan and fixed in the exhaust duct. In addition, holes must be drilled in the central part of the plate. This is necessary so that air can freely pass through it. The throughput of your ventilation system will depend on how many holes you drill in such a plate.
3. The plate, using a sealant and a gasket, should be fixed in the chimney. Under the places where the plate will be fixed with screws, it is also necessary to place rubber gaskets. This will reduce noise and vibration levels in your ventilation system.
4. According to the shape and dimensions of the plate, a piece of dense film is cut, the thickness of which should be at least 0.1 mm. From the film, which is glued to the plate along its edge, the flaps of a self-made check valve will be formed in the future.
5. The exhaust pipe, in which a plate with a film glued to it, is already installed, must be installed in the ventilation duct using dowels or self-tapping screws for this purpose. After installing a check valve in the ventilation duct, it is necessary to securely seal the gaps between the walls of the duct and the exhaust pipe.

The final step in installing a homemade check valve in the ventilation system is to cut the film pasted on the plate into two identical halves. When performing such a procedure, for which it is best to use a sharp mounting knife, it is necessary to ensure that the cut is perfectly even.

The principle by which the check valve of the design proposed above works is quite simple and is as follows.

• Nothing interferes with the flow of air that passes through such a valve in the direction from the room: the flaps open and let it through freely.
• When a back draft occurs in the ventilation system, the flaps of the check valve close securely, preventing outside air from entering the room.

Thus, this membrane-type check valve reliably protects the ventilated room not only from polluted and cold air, but also from foreign odors.

1 , average rating: 5,00 out of 5)

In all systems where water is used, its flow is implied in a certain direction.

Backflow can be caused by various reasons, which we will discuss later, and is considered an abnormal situation.

A check valve will help prevent a failure in the systems. With your own hands, this mechanism can also be made. Consider how to make a check valve for a pump, a sewer with your own hands, where the device is used and how it works.

Check valves may vary according to appearance and structures, but the essence of their work is the same: they easily pass water (or the flow of another substance) in one direction, and block its movement in the opposite direction.

It helps protect plumbing and plumbing equipment from damage.

The principle of operation of the check valve

The design of the valve is:

• Two cylinders at right angles to each other.
• Inside is a single cavity.
• One of the cylinders is equipped with a thread on both sides for installation in a pipe system.
• The other cylinder is blank.
• In the cavity there is a simple mechanism (different, depending on the type - a ball, a valve, etc.), which opens in one direction.

If you often hear unusual sounds from water pipes, you need to diagnose what happened. : search for causes and problem solving.

Read about how to properly seal water meters.

Some plumbing repairs can be carried out without the involvement of specialists. Among such works is the replacement of gaskets in the crane. In this topic, you will learn how to do it yourself, depending on the type of faucet.

Application area

Here are just a few examples of the use of check valves in private and municipal water supply, heating and sewerage systems:

• It happens that due to pressure surges in the water supply (including from the pump), hot water is squeezed through cold water. i.e. when the tap is opened cold water some time is running hot water. In this case, the installation of a check valve on the cold supply pipe is shown.
• The device, installed before the water pump, will prevent water from draining into the well, and also protect the equipment from breakage in case of reverse spinning of the working blades.
• in front of the water meter. The pressure of water and the vibration that is created can harm appliances and distort meter readings. Vibration does not propagate after shut-off valves.
• Double-circuit gas (solid fuel or other boilers) must also be equipped with an appropriate valve so that already heated water does not return.
• Solar collector. Here, circulation disturbances can be associated with a small difference in the temperature of the liquid at the inlet and outlet, or a small difference in height (if the water heater is small). It would be nice to equip the inlet pipe of the solar water heater with a backstop protection.
• Drainage pumps begin their work by filling the device with water. Many owners find this procedure tiresome and come up with ways to avoid it. To prevent water from pouring out of the unit, a valve is placed on the suction hose.
• Where the high rise ground water, it is important to install a check valve on the pipe connecting drain hole and a house so that when the liquid level rises, it does not go back.