The operation of pipelines for various purposes assumes that the liquid and gaseous media that are transported through them must move in a certain direction. Having made 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 long time keep them up and running.
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 caused 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 may differ both in their appearance and dimensions, and 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:
- frame, inner part which form two communicating cylinders;
- a locking element, which can be a ball, flap or spool;
- spring, which ensures that the locking element is pressed against seat located at the outlet of the valve opening.
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.
There are many check valves on the market today. 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:
- coupling, on the body of which is cut external thread;
- 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.
- Into the inner threaded hole the tee is screwed into the coupling. 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 perpendicular hole 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 it is not too tight so as not to impede the flow of water passing through through the device. In addition, it is necessary to perform very high quality threaded connections 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 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.
- 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.
- 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.
- 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 put rubber gaskets. This will reduce noise and vibration levels in your ventilation system.
- 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.
- The exhaust pipe, in which the plate with the film pasted on it, is already installed, must be installed in ventilation duct using dowels or self-tapping screws for these purposes. 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.
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, average rating: 5,00
out of 5)
Summer is the most successful season for innocent water fun in the country and surrounding areas. Why at cottages? Because, I would not use this valve at home. What are we talking about?
Let's try to figure it out.
And so, let's get started!
In fact, this part of automation is still completely unexplored for me,
However, I would like to find a budget option for experiments. Fortunately, there is a dacha and often, for certain reasons, the possibility of my presence on it does not coincide with the desired schedule for the distribution of water ... What exactly is this for?
There are a lot of options - automatically distribute water to certain areas of the dacha, automatically pour an additional container (because the water supply is limited in time, and the water pressure does not allow you to do everything at once).
Thread 1/2, there is no outer casing, the coil is cast, there is a metal mesh at the inlet to the valve, on the body there is a water supply arrow (inlet-outlet), the principle of operation is a membrane, which closes the valve under the action of a spring. The valve is normally closed.
The seller sends with a track that is absolutely not tracked.
Seller details: 
Data from the device:
I want to say right away that the seller's data does not match reality, although the data on the nameplate are more reliable (except for zero pressure).
Firstly, and this is the most important factor - for systems with low pressure, the valve WILL NOT work! He needs support to open the membrane.
Secondly, the current consumed by the coil is 2! (TWO) times more - 430 mA, and at long work, it heats up considerably. True, the valve begins to open at about 7-8 V.
Now let's start preparing the patient:
We unscrew 4 screws and see: a whole cast plastic frame, a rubber valve, a cylindrical flask, which contains a metal core and a spring supporting the valve in the closed state. On the left in the photo - the entrance of water, on the right - the exit.
As you can see, there is a risk of leakage and there is a risk of failure due to the core and spring not being protected from rust.
PROS: simple design, low cost.
CONS: plastic thread and housing, high current consumption, no additional sealant other than a rubber membrane, inability to use in systems with low pressure.
It remains to test it in combat conditions.
I plan to buy +39 Add to favorites Liked the review +25 +55Any electric machine works thanks to the presence of many special parts. We offer to consider what a normally closed solenoid valve is, its principle of operation and where to buy it.
General information
The electromagnetic solenoid water or gas valve is an electromechanical device designed to control the flow of liquid or gas in appliances with a power up to v308 (EV220B, Tecofi, Castel, ESM, EVR, GBP, GBV, NBR, PARKER, SCE, SYDZ, automatic transmission, KSVM, ZSK, ISP, Burkert, KSP). This valve is controlled by electric current, which passes the coil. When current is applied, a magnetic field is created and causes the piston inside the coil to move. Depending on the design, the piston will open when electricity is applied, or the flow valve will close. When the current stops flowing to the valve coil, it will return to its normal state.
Photo - Danfoss solenoid valveMechanisms are:
- direct and indirect type of action;
- vacuum, hydraulic, pneumatic valve;
- 2-, 3-, multi-way.
Electric valves direct action open and close the hole inside the valve. In experimentally controlled valves (they are also called shut-off devices), the piston opens and closes the hole. High pressure valves (for example, a flanged valve) use pistons and special seals that control the condition of the orifice.
Video: Danfoss solenoid valves
Description of the construction of the standard device
The simplest solenoid valve has two ports: inlet and outlet. Additionally, there may be three or more ports.
Photo - Solenoid valve design Water or gas enters through the inlet (2). Any substance must pass through the tank opening (9) before entering the outlet (3). The outlet is closed by a piston (7).
The solenoid valve in the photo above is a normally closed solenoid valve type ASCO, TORK or Danfoss. It works as follows: these devices are connected to a spring (8), which presses on the piston against the opening of the flow area. The sealing material at the tip of the piston contains a protection (gasket) against water or gas entering the holes, as long as the piston is lifted by electromagnetic field generated by the coil. The diagram demonstrates the operation of the standard.
Photo - Solenoid valve There are many valve design variations. Conventional valves may have multiple ports and pistons. The two-way valve of indirect action (return) has 2 ports - EV1140, DU50, DU32, DU100, DU15, DU25, RU16 series; if the valve is open, two ports are connected and liquid moves between them; if the valve is closed, the ports are isolated. If the valve is open, then the solenoid is not energized, then the valve is called normally open (NO). Similarly, if the valve is closed, then the solenoid is not energized, such a valve is called normally closed, say, YCD21, YCPS31, YCWS1. There are also three or more ports complex structures devices, their designation looks like 30 (3, 33, etc.). The three-way valve has 3 ports for motor control; it connects one port or two of them (usually an intake port and an exhaust port).
A small solenoid valve can generate limited force. The approximate relationship between the required electromagnetic forces Fs, the fluid pressure P and the orifice area A for a direct acting valve is:
Fs \u003d P * A \u003d P * pi * d 2 / 4
Where d is the hole diameter.
In some solenoid valves, electromagnetic forces act directly on the main valve. Others use small, full solenoid valves, known as manned valves. Piloted valves require much less power, but they are much slower. Such solenoids usually need full power all the time to fully open and hold that position.
The design and purpose of the piloted valve
Gas shut-off pilot valve SCE238A002 (200 bar), Nemen, VIKING, SPOOL, JOUCOMATIC, EVELEN, SMART TORK, consists of two main parts: a throughput device and a direct-acting valve. The pass mechanism converts electrical energy into mechanical energy, which, in turn, opens or closes the part. A direct acting valve controls the flow of a liquid or gas.
Photo - Solenoid valve Solenoid valves can use metal seals or rubber seals, and it is also easy to control. The spring is used to keep the valve normally open or closed when not in use.
Pressurized water enters the chamber. The inlet is an elastic membrane, and above it is a spring that pushes it down. The diaphragm has a hole through the center, it allows you to control the amount of water, often a very small part is skipped. This water fills the cavities on the other side of the diaphragm so that the pressure is equal on both sides of the valve.
After the diaphragm is closed by the valve, the bottom outlet pressure decreases and more pressure keeps the valve closed. So the spring has nothing to do with closing or opening the valve.
If current is passed through the diaphragm solenoid, the water in the chamber flows out through the direct passage faster than the chamber is replenished. The incoming pressure raises the diaphragm.
When the solenoid turns off again, the passage is closed by a spring, very little force is needed to push the diaphragm down, the main valve closes again. In practice, there is often no separate spring; The elastomer diaphragm is adapted so that it works like its own source, mostly in a closed form.
Photo - Solenoid valves Sirai It can be seen from the explanation that this type of valve depends on the pressure difference between inlet and outlet, since for it to work, the inlet pressure must always be greater than the outlet pressure. If the outlet pressure is, for any reason, higher than the inlet pressure, the valve will open too quickly for this to be prevented by a difference in size of less than half an inch.
To increase pressure, a plastic seal is often used, which is fixed in the area of \u200b\u200bthe inlet.
The connection method for each device is slightly different, so we highly recommend that you read the certificate when buying, check the passport of a specific model. The instructions describe in detail the installation of each individual valve.
Application area
The scope of application directly depends on the material of the valves. A part whose main material is brass is not used in aggressive environments, say, to control diesel fuel, an acid-based fluid.
Solenoid valves are used to control hydraulic and pneumatic systems, to control cylinders or large industrial valves with large diameters.
Photo - Two-way solenoid valve Most often, production uses a valve for mechanisms and devices where a limited supply of water, gas, air, etc. is necessary. - washing machine, dishwasher, heating system control. The double-acting pulse valve is used as a device for supplying air and water in dental offices, for watering the earth, feeding various appliances with diesel fuel, controlling the operation of a machine with a mini gas installation, and even for a refrigerator.
Price overview
You can buy a solenoid air, deluge or gas valve with a power of up to 380 volts in Russia, Ukraine, Belarus, at any specialized store. You will find devices of this type: Freon, Honda, SVM, CEME (CEME), SKN for a variety of installations. Each manufacturer offers its own price list, we have collected average prices for valves made in Russia, Italy, Germany and the CIS countries:
All companies provide a guarantee for their products for a year, the sale is carried out in official dealer stores.
The main thing in gardening is to ensure regular watering of the site. Without it, any garden will not survive even one season. Watering by hand requires high costs time and labor. For good garden need modern system water supply, where important element is a solenoid valve for irrigation.
Advantages of automatic watering
The main elements of the irrigation system are as follows:
- dosing of water consumption;
- uniformity of application;
- profitability (watering at night reduces the evaporation of moisture);
- the system is underground;
- saves labor and time of the gardener.
Purpose of the solenoid valve
An electromagnetic valve for irrigation is always needed, even if there is no irrigation system. It is used together with a timer that turns it on at the right time. It is especially needed to fill storage tank. When water is supplied according to the schedule, the timer opens the valve and the tank is filled. It is advisable to water the site at the same time. All this is done in the absence of the owner. He can only water hard-to-reach places.
The main purpose of the valve is to supply water to the irrigation system at a given time. A 1-inch device is suitable for this, passing 50-100 l / min at a pressure of up to 10 atm. It can also be used in short watering areas, as it allows you to adjust the desired local flow rate. It is suitable for spray and drip irrigation when the pressure in the system is weak.
One or more valves are installed on a gravel drainage pad and closed with a box. This can be done in any convenient place.
Solenoid valve device
The valve is very simple. It contains the following details.
The male inlet and outlet threads are 1/4" or more depending on the flow rate. The least amount of water passes through the solenoid valve for drip irrigation. Small devices are built into the pipeline with water and work on a timer that sets different modes irrigation.
Recently, models combined with a switch have appeared. Can be purchased through the online store of the company "Yulmart": solenoid valve for watering C 1060 plus GARDENA, which has become popular. It automatically switches the water supply to garden irrigation.
Solenoid valve for irrigation: scheme of work
Connecting the solenoid valve to the garden watering system
For a small garden better fit solenoid valve for watering -12 volts (NT8048). It is safe, because if water gets on the contacts and if you touch it with wet hands, there will be no electric shock. The ability to connect it to a 15 Ah battery allows you to work without recharging for a week. It will also be easy to make power from the shield through the network adapter.
Water is supplied from a storage tank installed at a height of at least 2 m. The water in it is collected from a centralized system. Filling is controlled by a float switch connected to a plug valve. The absence of a pump eliminates many problems. Watering the garden by gravity occurs within a few hours and does not need to be controlled. All irrigation control will be taken over by an electronic timer connected to the outlet.
The valve is installed in the pressure line of the irrigation system. The electromagnet coil is connected to the adapter output via a cable using terminals. They can be closed on top with sealant to protect against water.
The whole device is conveniently placed in the utility room, where you can hold a socket. A timer, an adapter and an electromagnet coil are connected in series to it. It remains to set the irrigation mode. The time is chosen morning and evening, so that there is a minimum of evaporation, and the plants do not burn in the sun. The duration of irrigation is set, which is then selected experimentally.
On the different types plants watering should be different. The system can be gradually improved by adding new valves. You can connect your own timer to each of them or install a common microcontroller, setting the irrigation program.
Valves from old washing machines can be installed on the outlet pipelines, which will save a lot on the cost of the irrigation system.
Do-it-yourself solenoid valve for watering
Electric valves are expensive, but cheaper solutions can be found. The most accessible here is a valve from a failed washing machine. His device is as follows:
- plastic case;
- rubber membrane;
- core electromagnet;
- spring;
- mesh filter;
- pad.
The mechanism is highly sensitive to dirt and can easily fail. It is protected, but for a garden system it is advisable to put another one at the valve inlet, since your own will quickly become clogged.
The solenoid valve is normally closed, i.e. in the off state it shuts off the water. When turned on, the core retracts, lifting the rubber membrane and allowing water to pass through.
To remove the contaminated washing liquid, a drain valve is used, which is similarly designed. The principle of operation is the same and it can be successfully used for irrigation.
Washing machine solenoid valves have the following characteristics:
- supply voltage - ;
- power - 8 W;
- water pressure - up to 10 atm;
- inlet hose diameter - 3/4 ";
- liquid consumption - 10 l/min.
Faults and repairs
No voltage on the coil | 1. Malfunction of the supply cable. 2. Coil failure. | 1. Repair the break. 2. Check the integrity of the wire with a tester. A burnt coil is usually not repairable. |
Valve does not open when energized | 1. Broken spring. 2. Accumulation of dirt in the moving joint. | 1. Replace solenoid. 2. Disassemble and wash the structure. |
Large pressure drop | 1. Clogged orifice. 2. Coil parameters do not match the applied voltage. | 1. Clean. 2. Replace coil. |
Valve does not close | 1. Residual voltage on the coil. 2. Pollution of the hole. 3. Valve seat contamination. 4. Broken spring. | 1. Check relay contacts and electrical connections. 2. Clean. 3. Clear. 4. Replace. |
Conclusion
It takes a lot of time and effort to maintain a garden and vegetable garden. A real savior for the owner is an electromagnetic valve for irrigation, which serves to fill the storage tank in his absence, pump water from the well, and especially in the irrigation system.
For automatic control various hydraulic systems electric valves are required. Finished products are quite expensive. Let's look for a cheaper solution.
The most accessible valves are from failed washing machines.
The coils of such devices are designed for a voltage of 220 volts. alternating current which limits their possibilities. Sometimes it is more convenient to control the valve with a low voltage of 12 volts.
I needed such a device to regulate the mode of the heater of the passenger compartment of a VAZ car. Suitable valves from foreign cars are outrageously expensive, and with the appreciation of the currency they become a luxury item. Let's try to convert the solenoid valve from the washing machine to the on-board voltage of the car.
First, let's see how it all works.
We remove the coil by inserting a thin screwdriver into the gap between the solenoid and the housing. In this case, you can slightly compress the petals that fix the solenoid coil with pliers.
To operate at 12 volts, the valve solenoid (coil) must be replaced.
The most suitable solenoid was found in the EPPKh VAZ 2105 air valve.
Since no images of the insides were found on the Internet, I will give them for the curious.
Let's start disassembly
The simplest thing is to cut off the rolling on the emery or cut it with a file along the outer edge.
Valve cover (view from inside):
Stock, he's a cork. The air flow is blocked by a rubber insert at the end. On the opposite end there is a recess for the spring:
Steel washer to close the magnetic flux and non-magnetic guide in which the stem moves:
Coil:
1. In the case.
2. Taken out.
Oval o-rings seal the leads from the inside of the housing. We will need one of them in the future, so save them.
And finally, the case from the inside. The end face of the fixed magnetic circuit with a protrusion for the spring is visible:
The next step is to refine the hull. On the emery we grind the tube with a rivet on the back side, and putting the case upside down, gently knock out the remnants of the internal magnetic circuit with a beard. If the body is washed inward, we eliminate the deformation. Next, the central hole is drilled to a diameter of 9mm.
To create a magnetic system similar to the valve system from a washing machine, it is necessary to cut two strips from tin from a can - one 15 mm wide, the other 10 mm wide. The length of the strips should be such that a ring of about 1.5 turns is wound on the valve stem from the washing machine.
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