expansion membrane tank- a mandatory component, without which the functioning of the system is not possible. It is he who creates the necessary pressure for the full operation of the water supply system, makes reserve water supplies and even performs a number of protective functions. In connection with such a high importance of equipment, the question naturally arises: how to choose and correctly install a tank? To understand, let's approach the issue in a complex way: to your attention the structure and principles of operation of the expansion device, its types, features of choice, as well as the connection diagram and useful instruction video setup.
Functions and working principle
A membrane tank is a sealed, predominantly metal tank, consisting of two separated chambers: air and water. A special rubber membrane acts as a separator - it is usually made of strong butyl, which is resistant to the development of bacterial microorganisms. The water chamber is equipped with a branch pipe through which water is directly supplied.
The main task of the expansion membrane tank is to accumulate a certain volume of water and supply it at the request of the user under the required pressure. But the functions of the device are not limited to this - it also:
- protects the pump from premature deformation: due to the water reserve, the pump does not turn on every time the tap is opened, but only when the tank is empty;
- protects against water pressure drops when several taps are used in parallel;
- protects against hydraulic shocks that can potentially occur when the pumping unit is turned on.
Instrument operation
The principle of operation of the tank is as follows. When the pump is turned on, water begins to be pumped into the water chamber under pressure, and the volume of the air chamber at this time decreases. When the pressure reaches the maximum allowable mark, the pump turns off and the water supply stops. Then, as water is taken from the tank, the pressure decreases and, when it decreases to the minimum allowable mark, the pump turns on again and resumes pumping water.
Advice. During the operation of the tank, air can accumulate in the water chamber, which provokes a decrease in the efficiency of the equipment, therefore, at least once every 3 months, it is necessary to carry out maintenance of the compartment - to bleed excess air from it.
Types of membrane tanks
There are two types of expansion membrane tanks:
Advice. When choosing between a replaceable and a permanent diaphragm, consider one important factor: in the first case, the water is completely in the membrane and does not come into contact with the inner surface of the tank, which eliminates corrosion processes, and in the second case, contact is maintained, so it is impossible to achieve maximum protection against corrosion.
Features of choosing a tank
The main factor in choosing a membrane tank is its volume. When calculating the optimal volume of the tank, the following nuances should be taken into account:
- the number of users of the water supply system;
- number of water intake points: taps, outlets for shower and jacuzzi, outlets for household appliances and boilers that work with water;
- pump performance;
- the maximum number of pump on/off cycles per hour.
To calculate the approximate volume of the tank, you can use the following guidelines from specialists: if the number of users is no more than three, and the pump capacity is no more than 2 cubic meters / h, then a tank with a volume of 20-24 liters is enough; if the number of users is from four to eight, and the pump performance fluctuates between 3-3.5 cubic meters / h, a tank with a volume of 50-55 liters will be required.
When choosing a tank, remember: the more modest its volume, the more often you have to turn on the pump and the higher the risk of pressure drops in the plumbing system.
Advice. If you assume that over time there will be a need to increase the volume of the membrane tank, buy equipment with the ability to connect additional tanks.
Tank connection diagram
The membrane tank can be installed both vertically and horizontally, but in both cases the connection diagram will be identical:
- Determine the mounting location. The device must be located on the suction side. circulation pump and before the branching of the water supply. Make sure that the tank has free access for maintenance work.
- Secure the tank to a wall or floor with rubber grommets and ground it.
- Connect a five-pin fitting to the tank nozzle using an American fitting.
- Connect in series to the four free outlets: a pressure switch, a pipe from the pump, a pressure gauge and a branch pipe that supplies water directly to the intake points.
Tank connection
It is important that the cross section of the water pipe to be connected is equal to or slightly larger than the cross section of the inlet pipe, but in no case should it be smaller. Another nuance: between the expansion tank and the pump, it is advisable not to have any technical devices so as not to provoke an increase in hydraulic resistance in the water supply system.
Instructions for setting up equipment
After the membrane tank is installed and connected, it is important to correctly configure and start it. Let's dwell on the main points of this stage.
The first step is to find out the internal pressure of the tank. In theory, it should be 1.5 atm, but it is possible that during the storage of the device in a warehouse or during transportation, a leak occurred, which provoked a decrease in such an important indicator. To make sure the pressure is correct, remove the spool cap and measure with a pressure gauge. The latter can be of three types: plastic - cheap, but not always accurate; mechanical automobile - more reliable and relatively affordable; electronic - expensive, but as accurate as possible.
After measurements, you need to decide which pressure will be the most optimal in your case. Practice shows that for the normal functioning of plumbing and household appliances, the pressure in the membrane tank should vary within 1.4-2.8 atm. Let's assume that you have chosen these indicators - what to do next? First, if the initial pressure in the tank turned out to be lower than 1.4-1.5 atm, it must be increased by pumping air into the corresponding chamber of the tank. Then you should adjust the pressure switch: open its cover and use the large nut P to set the maximum pressure indicator, and with the small nut ∆P - the minimum indicator.
The setup process is simple
Now you can start the system: as you pump water, watch the pressure gauge - the pressure should gradually rise, and after it reaches the maximum set mark, the pump should turn off.
As you can see, without an expansion membrane tank, you really can not even count on the full-fledged operation of an individual water supply. Therefore, if you want to uninterruptedly enjoy the benefits of civilization, thoroughly approach the choice and connection of the device - all the principles and subtleties are in front of you, so we advise you to study them well and only then proceed to action.
Calculation of the volume of the accumulator: video
Membrane expansion tank for water supply: photo
The heating system of a private house (as well as water supply) must be functional and reliable. If during installation any violations were made or something was not done, then it will not last long, even if it works for some time. One of the main elements in any autonomous system related to the use of water is an expansion tank for water supply, the selection, installation, installation of which will be discussed in this material.
What is this?
Even the name itself speaks for itself - an expansion tank is needed to expand the entire heating circuit of the house or water supply pipes through which hot or cold water flows. The fact is that during heating, the liquid increases in volume, and the pipes through which it flows do not change their physical parameters - their elasticity tends to absolute zero. This means that the pressure inside the pipes and the entire installation will increase, which can lead to damage - so-called water hammers occur, and as a result of them - destruction individual elements installations or circuits from pipes. This applies mainly to the heating system, but it also fully relates to hot water supply.
To avoid water hammer, the engineers came up with the idea to include in the system a small reservoir filled with air, that is, the substance that, unlike water, is compressed. And if the pressure in the pipes increases during the heating of the water, then thanks to this tank it will increase very slightly. "P , you can read in our article".
On a note! Expansion tank often installed in other systems, but the purpose of its use is the same - to reduce pressure in pipelines and the risk of air locks.
Another such tank is sometimes used to create a reserve stock cold water and ensures the supply of liquid to any place in the system in a matter of minutes. At the same time, the average volume of the container is about 30 liters.
For a system that provides a house with water, tanks equipped with membranes are most often used. This is a relatively small container, inside which there is a diaphragm made of an elastic material and dividing the device into two parts - with air and airless, or rather, water. When the water supply system is operating, the water chamber is filled with liquid and, acting on the membrane, compresses it, reducing the volume of the air part, increasing the pressure in it. As soon as the pressure reaches a certain level, the pump that pumps water will stop. And its inclusion occurs when the pressure drops to the minimum values.
On a note! The pressure inside the system allows you to monitor the pressure gauge installed in it.
Such a tank allows you to ensure the uninterrupted operation of the water supply system and a steady flow of water in any house, even in a multi-storey one.
Types of tanks
Expansion tanks are of two types - closed and open. They differ from each other in design features.
Table. Types of expansion tanks.
| Type | Description |
|---|---|
| This is a tank that has just a membrane separation between the compartments - water and air. The diaphragm in it is heat-resistant and avoids corrosive activity. Such a tank is airtight, outwardly it looks like a small cylinder or a ball of metal. This element of the system serves for a long time, and if the membrane is damaged, it is easy to replace it with a new one. Also, in addition to this type of expansion tank, a pressure gauge and safety valve Together they form a security system. |
| Such a tank is a container at the bottom of which there is a threaded connector, which allows you to combine the device with the system. It is necessary to install this design in the highest part of the heating system. It is used extremely rarely, as it has a lot of drawbacks - this is an increase in the risk of corrosion in pipes, and fairly decent dimensions, and a quick failure at critical pressure indicators. The liquid level indicators in such a container also directly depend on how much water is in the heating circuit. |
Membrane tanks, in turn, are divided into two types - with a replaceable diaphragm and with a stationary one. The replaceable membrane speaks for itself - if necessary, it can be easily changed by removing it through a flange fixed with a few bolts. An expansion tank of this type serves as long as possible, and the shape of the body can be both vertical and horizontal, which makes it possible to select a container for a specific room.
Attention! In large expansion tanks, the membrane is additionally fixed with a nipple.
In containers with a stationary membrane, this part cannot be replaced - it is tightly attached to the walls of the housing. In case of failure of the unit, it is completely changed. By the way, water in such an installation, unlike the previous type, is in contact with the metal of the tank, as a result of which a corrosion process occurs on its inner surface. Installation can also be both vertically and horizontally oriented.
Expansion tanks are not only mounted, but also floor. They can also have a flat shape, differ in color: blue are for cold water, red for hot water.
Popular Models
Now on the market there is a huge range of different expansion tanks from various manufacturers. Models differ from each other in quality, size, shape and even color, although they are similar in principle to each other. Choosing a tank for a specific water supply system will not be difficult. Attention should be paid to tank models from following firms- Russian "Dzhileks" and Italian Elbi, Aquasystem, as well as Refix (Reflex), Zilmet. , you can read in our article.
The advantages of Gileks tanks are the complete absence of the risk of air jams in the system and the absence of water-air contact, due to which liquid evaporation is excluded, and rust does not damage the pipes. The brand produces tanks of various sizes - from 6 to 700 liters. The disadvantage of containers is that only installations with a volume of more than 24 liters have removable membranes. By the way, the diaphragm is made of high-quality EPDM - ethylene-propylene-diene-rubber. Tanks "Dzhileks" are economical, durable, inexpensive, but at the same time reliable and can have different shape.
Elbi tanks have it all Required documents, including a certificate of conformity and a sanitary and epidemiological conclusion, allowing you to safely use them in residential buildings. There are vertical, horizontal, and also for sanitary water. Vertical tanks belong to the AS / AC series and have interchangeable diaphragms, they can be of different volumes - from 5 to 25 liters - and are used in domestic water supply systems, as well as in irrigation systems and other installations that do not need powerful water pressure. The membranes inside the containers are made of EPDM, working temperature ranges from -10 to +99 degrees. The tank is protected from corrosion by resistant paint.
Elbi tanks of horizontal installation are of the AFH series and have replaceable membranes. They have more capacity than the previous series - from 25 to 100 liters of water. Such installations can already be used in small industries. The tanks are made of durable steel and have a special platform for mounting the pump.
Refix tanks are suitable for use in both technical and drinking water systems and are excellent hydraulic accumulators. All parts that come into contact with water are protected from rust, and the liquid is perfectly stored inside the rubber bulbs. Models DD, DE are designed for water saving use in potable water systems, ideal for use in environments with high levels of rust. The tanks of the DE series have a bulb, which is only replaceable in models with a volume of more than 50 liters. The models of the HW series, designed for individual water supply systems, also have feet for installation on the floor and a place to mount the pump.
The international company Zilmet has been holding a high position in the equipment market for more than 50 years, and in Europe it is considered the largest manufacturer of expansion tanks. Their Hydro-PRO devices are used to work with any water in various types installations. The equipment is made of durable and high-quality carbon steel, and special internal MIG welding is used in the production, thanks to which it is possible to avoid damage to butyl rubber membranes. The inside of the tanks are coated with high-strength powder resin, which prevents rust from prolonged contact with moisture. Operating temperature range - from -10 to +99 degrees.
Aquasystem tanks have replaceable membranes and come in various volumes - from 8 to 50 liters. The maximum coolant pressure is 0.5 MPa, and air - 0.15 MPa. The operating temperature range of the equipment varies from -10 degrees to +110. Tanks are made of black steel, painted with powder paint.
Attention! Don't be fooled by cheapness! As you know, a miser pays twice. The point is that the use quality equipment can lead to serious damage not only to the expansion tank, but also to the system itself, and repair will cost much more than buying high-quality equipment right away.
With regard to the quality of the equipment, Special attention pay attention to the rubber from which the diaphragm is made. Good rubber is not only a guarantee of a long service life of the equipment, but also the safety of those who will use water from a water supply system equipped with a tank.
The choice of accumulator
When choosing an expansion tank, you should pay attention to its characteristics, the materials from which it is made. Be sure to evaluate the material from which the pear or diaphragm is made, its strength and quality, compliance with all hygienic and sanitary standards, allowable temperatures use. From right choice In accordance with the operating conditions, the durability of the work will also depend.
Important point when choosing equipment correct selection required capacity. This will prevent the number of pump starts in the system, which will extend its life. You can calculate the correct volume for the cold water supply system using the formula:
Vt = 16.5*(Qmax/a)*((Pmax*Pmin)/((Pmax – Pmin)*Pprec)),
- Qmax is the maximum water consumption (l / min.);
- a - the optimal frequency of switching on the equipment for 1 hour (varies from 10 to 15 and is indicated in the pump passport);
- Pmax and Pmin are values (measured in bar) that show the pump on and off pressures (pressure switch settings);
- Pprec (bar) - an indicator of the initial pressure in the cavity with air inside the expansion tank (should not be more than Pmin; on the contrary, it is set 0.5 less than Pmin).
Note! When calculating according to this formula, 1 is added to all values. And the value of the tank volume Vt obtained by the formula is always rounded up.
For hot water supply systems, the volume is calculated differently:
V = 0.0221*C / (1-((Pi+1)/(Pf+1)),
- C is the total amount of water in the water heating system;
- 0.0221 - an indicator of thermal expansion, in the range of 10-60 degrees equal to this figure;
- Pi is the pre-injection pressure indicator of the expansion tank;
- Pf is the pressure indicator when the safety valve is bled.
The volume of water used, in turn, is affected by the number of people living in the house, the number of points of water use (faucets, washing machines etc.), the possibility of including several such points at once.
Attention! If you use a tank of the wrong size (with underestimated values), then soon, due to a heavy load, it will begin to leak. Fortunately, with an increase in the number of people living in the house, and hence the load on the equipment, you can install an additional tank without removing the already installed one.
Expansion tanks for water supply systems
For water supply systems, floor heating
non-flow, without shut-off and drain fittings
diaphragm according to DIN 4807 T3
in tanks with a volume of 60 liters or more - the membrane is replaceable
anti-corrosion coating applied to the surface in contact with water
equipped with a pressure gauge with a diameter of 1000 and more
blue color
pre-pressure 4 bar
The main function of expansion tanks is to maintain constant pressure in water supply systems. The price of this equipment in the Moscow Thermal Company is available to a wide range of consumers.
Structurally, an expansion tank for water supply is a container of a certain volume, inside of which there is a membrane made of a bottle. The neck of the membrane, like the membrane itself, is sealed and connected to the vessel lid by a removable pipe. All expansion tanks for water systems from Reflex are equipped with a membrane that can be replaced in the event of equipment failure.
The main advantages of the expansion tank for water supply
Expansion tank for water supply is very popular in closed systems due to its unique technical and operational characteristics:
- polymer coating perfectly protects the tank from corrosive processes;
- a replaceable membrane makes it possible to significantly extend the life of the equipment;
- Ergonomic design fits perfectly into the interior of the room.
At the same time, the chamber-membrane for water is made of rubber wear-resistant material.
If you decide to buy an expansion tank for water supply, first of all, pay attention to such a parameter as the capacity of the vessel. Depending on the volume of the tank, the expansion tank can be used not only as an additional water tank, but also as the main one.
When buying an expansion tank for hot water supply from our company, you are guaranteed to acquire high-quality, reliable and proven over the years equipment specially designed for water supply systems. All products are certified and meet the highest international standards and requirements.
An autonomous water supply system today no longer surprises anyone. Such designs are very convenient and practical, however, their operation often requires devices that a person using only centralized water supply may simply not know about. For example, an autonomous water supply system will long time work smoothly only if an expansion tank for water supply is included in it. Modern industry produces many of the most different models such devices. To choose for yourself best option, you need to navigate the types of equipment and have a good idea of \u200b\u200bthe principle of its operation.
The device and functions of this equipment
Types of membrane tanks
There are two main types of expansion membrane equipment.
Membrane instrument
home distinguishing feature- the possibility of replacing the membrane. It is removed through a special flange, which is held on by several bolts. At the same time, it should be taken into account that in large-volume devices, in order to stabilize the membrane, it is additionally fixed with the back part to the nipple. Another feature of the device is that the water filling the tank remains inside the membrane and does not come into contact with inside tank. What protects metal surfaces from corrosion, and the water itself from possible pollution and significantly extends the life of the equipment. Models are available in both horizontal and vertical versions.
Devices with a replaceable membrane differ more long term service, since the most vulnerable element of the system can be replaced and water does not come into contact with the metal case of the device
Stationary Diaphragm Device
In such devices, the inside of the tank is divided into two parts by a rigidly fixed membrane. It cannot be replaced, therefore, if it fails, the equipment will have to be changed. One part of the device contains air, the other contains water, which is in direct contact with the internal metal surface device, which can provoke its rapid corrosion. To prevent metal destruction and water pollution inner surface the water part of the tank is covered with a special paint. However, this protection is not always durable. Devices of horizontal and vertical types are issued.
A type of device with a rigidly fixed membrane. The design assumes that water is in contact with the walls of the equipment
In our following material the expert's recommendations on the choice of a membrane tank are presented:
How to choose the right device?
The main characteristic on the basis of which equipment is selected is its volume. In this case, the following factors must be taken into account:
- Number of people using the water supply system.
- The number of water points, which include not only showers and taps, but also household appliances, such as washing machines and dishwashers.
- The probability that water will be consumed by several consumers at the same time.
- The maximum number of start-stop cycles per hour for installed pumping equipment.
- If the number of consumers does not exceed three people, and installed pump has a capacity of up to 2 cu. m per hour, a tank with a volume of 20 to 24 liters is selected.
- If the number of consumers is from four to eight people and the pump capacity is within 3.5 cubic meters. m per hour, a tank with a volume of 50 liters is installed.
- If the number of consumers is more than ten people and the performance of pumping equipment is 5 cubic meters. m per hour, choose an expansion tank of 100 liters.
When choosing the right model of the device, it should be borne in mind that the smaller the volume of the tank, the more often the pump will turn on. As well as the fact that the smaller the volume, the greater the likelihood of pressure surges in the system. In addition, the equipment is also a reservoir for storing a certain supply of water. Based on this, the volume of the expansion tank is also adjusted. You should be aware that the design of the device allows the installation of an additional tank. Moreover, this can be done during the operation of the main equipment without labor-intensive dismantling. After installation of a new device, the volume of the tank will be determined by the total volume of the tanks installed in the system.
Except specifications when choosing an expansion tank, special attention should be paid to its manufacturer. The pursuit of cheapness can result in much more significant costs. Most often, the cheapest materials are used to produce models that attract with their cost, and, as practice shows, they are not always of high quality. The quality of the rubber from which the membrane is made is especially important. Not only the service life of the tank directly depends on this, but also the safety of the water that comes from it.
When buying a tank with a replaceable membrane, be sure to clarify the cost of the consumable item. Very often, in the pursuit of profit, not always conscientious manufacturers significantly overestimate the price of a replacement membrane. In this case, it would be more appropriate to choose a model from another company. Most often, a large manufacturer is ready to be responsible for the quality of its products, since it values its reputation. Thus, it is worth considering the models of just such brands in the first place. These are Dzhileks and Elbi (Russia) and Reflex, Zilmet, Aquasystem (Germany).
The volume of the expansion tank for water supply can be different, it is selected based on the needs of users. If a larger volume is subsequently required, an additional device can be installed
Features of self-installation
All expansion tanks can be divided into two groups, determined by the connection method. There are vertical and horizontal models. There are no particular differences between them. When choosing, they are guided by the parameters of the room where the equipment will be placed. During the installation process, the following recommendations should be followed:
- The expansion tank is installed in such a way that it can be easily accessed for maintenance.
- It is necessary to provide for the possible subsequent dismantling of the connecting pipeline for the replacement or repair of equipment.
- The diameter of the connected water supply can not be less than the diameter of the branch pipe.
- It is necessary to ground the device, so electrolytic corrosion can be avoided.
The device is mounted on the suction side of the pump. On the segment between the pumping equipment and the connection point, all elements that are capable of introducing significant hydraulic resistance into the system must be excluded. We connect the make-up line to the circulation circuit of the entire system.
According to the type of installation, expansion tanks of horizontal and vertical connection are distinguished
Also pay attention to the material on what malfunctions most often occur in pumping stations, and how to fix them yourself:
Expansion tank is an integral part autonomous system water supply. It supports, prevents premature damage to the pump and retains a certain supply of water. However, all these functions are performed only under the condition of competent selection and proper installation of the structure. Therefore, in the absence of experience, it is better not to get involved in amateur performances, but to find qualified specialists who will install any device with high quality.
