The water supply tank (expansion tank) is a container used for autonomous heating and water supply. It prevents overpressure and protects the system from water hammer. Expansion tanks are selected individually for each system, taking into account all parameters and characteristics. They must be resistant to high blood pressure and not susceptible to corrosion.

The main task of expansion tanks for water supply is to maintain optimal pressure in the system. For these purposes, compensators are used in the tanks, which equalize the load on all parts of the water supply system. The tank and membrane in contact with water are made of materials that do not affect the taste of water. Such materials must be certified and meet sanitary and hygienic requirements.

Tank for water supply: principle of operation.

Inside the expansion tank there is a rubber membrane dividing the tank into two parts. Air is pumped into one, the other part remains empty. The empty part of the tank after starting the water supply is filled with water. The part with the injected air is designed to maintain a given pressure. Air pressure forces water out of the tank into the pipelines, thereby creating a stable state of the system. without drops and overloads.

Expansion tank for water supply: features of work.

Water entering from the well into the tank, being under pressure, increases the membrane and reduces the volume of air, while creating some pressure. After reaching the required pressure level, the pump turns off, water is consumed and the pressure drops. To maintain pressure, the pump is switched on again.

Among others positive qualities, the diaphragm tank compensates for water hammer, thereby greatly reducing the frequency of switching on the pump. This increases the life of the system elements and saves energy. In addition, when the electricity is turned off, the water supply tank can play the role of an “additional use” device. Those. water will be supplied to the consumer for some time.

Expansion tanks are horizontal and vertical, open and closed. The volume of water, like operating pressure, also vary.

The design of the accumulator is not too complicated: it consists of a hermetically sealed oval-shaped container. Tanks for water supply systems have two internal chambers: air and liquid. These units differ from similar heating units in the presence of a separating membrane, as well as the nature of the material for its manufacture.

In order not to harm high quality drinking water, it is made from environmentally friendly rubber with excellent hygienic properties. As for the size of the tanks, they can be completely different, ranging from 8 to 100 liters.

Water supply tank volume

When calculating the volume of the tank, the initial pressure of the air contained in the empty compartment of the tank and the working pressure (at maximum load). The calculation of the required water pressure is considered fundamental. Although it is enough for the consumer to know the ratio of the volume of the tank to the volume of the entire system, an improperly selected tank leads to a quick failure of equipment and pipelines.

open tank

Such devices are installed at the most elevated points of the heating system (attics, roofs of buildings). The water pressure is only compensated atmospheric pressure, due to which there is no possibility of adjustment and there is a risk of leakage with excess liquid. Bucky now open type are used extremely rarely.

In order for the choice of equipment to be optimal, several rules should be adopted:

• It is necessary to take into account in which particular system the units will be involved.
• It is worth considering what temperature regime planned.
• Pay attention to the technical parameters of the equipment that were set by the manufacturer.
• If you plan to opt for a membrane type tank, then you need to keep in mind that the pump here has a limited number of inclusions. However, this remark is not relevant if water is to be accumulated under high pressure.
• If the system uses a pump surface type, then a small hydraulic accumulator should be attached to it, since it has more connections per minute than a submersible pump.
• Diaphragm tanks for water supply systems with a horizontal installation method should only be used in tandem with surface pumps.
• It is necessary to take into account the specific characteristics of the water supply system.

As a result, the purpose of the tank comes down to several basic principles:

• The equipment helps to avoid water hammer occurring inside the complex.
• With its help, the pressure inside the system is stabilized and maintained at the same level.
• Thanks to the presence of tanks, the functions of the pump are optimized, since it will be protected from too frequent switching on.
• Helps extend pump life.

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.

Today it is difficult to surprise anyone autonomous water supply. Such a system is very convenient and practical, but for its uninterrupted operation very often used additional devices, which a common person may not even guess. One of these elements is an expansion tank for supplying cold water. On the modern market water supply there are many different models of such products. Therefore, in order not to make a mistake in choosing such a device, you need to understand what the principle of its operation is based on.

Design features and functionality

The main purpose of expansion tanks is maintaining a stable pressure level v autonomous system cold water supply. Most often, a membrane device is used in water supply systems. closed type.

Such a product resembles a tank, inside which a membrane is mounted, made of rubber and dividing it into two separate chambers for air and water. After starting the system by means of an electric pump, the water part of the tank is filled. In turn, the air chamber begins to lose its volume. The less air left, the more pressure builds up.

When the pressure in the air chamber exceeds set parameters, will happen automatic shutdown pumping equipment. In turn, the pump will turn on only when the pressure level in the expansion tank drops below the minimum value. In this case, the cycles of starting and stopping the equipment occur automatically.

For convenience, many models of expansion membrane tanks equipped with a pressure gauge for pressure control. Also modern devices have the ability to adjust the operating range to the parameters suitable for the consumer. Installing an expansion tank in a cold water supply system provides for the following functions:

• maintaining a predetermined pressure level when the pump is idle;
• protection of an autonomous water supply system from unforeseen water hammer, which can be triggered by a voltage drop in the power supply network or the formation air locks in the pipeline;
• maintaining a certain volume of water under constant pressure;
• additional protection of the pump against wear.

The installation of expansion tanks for cold water supply allows, with a slight consumption of water resources, in general do not use pumping equipment, but to cover the demand due to the liquid accumulated in the reservoir.

Expansion tank with removable membrane

Basic distinctive feature such equipment is the ability to change the membrane as it wears out. To do this, it is simply removed through a special flange device, fixed with several bolts. At the same time, it is important to take into account that in tanks of large volumes, in order to stabilize the membrane, it is additionally attached with the back side to the nipple.

Another feature of such a product is that the liquid entering the tank, located inside the membrane, which prevents contact with the inner walls of the tank. Due to this, the metal of the device body remains protected from corrosion, which significantly increases its operational life. At the same time, models of both vertical and horizontal types are presented on store shelves.

Expansion tank with diaphragm

A feature of such a device is the division of the tank into two separate tanks using a rigidly fixed diaphragm. Therefore, in the event of its failure, you will have to change the entire product as a whole. In such a container, in the part with liquid, there is direct contact of water with metal case device, leading to corrosion.

To solve this problem, the internal walls of the device are opened with special dyes. However, such protection is short-lived and after a while rust still appears on the case. As well as expansion tanks with a removable membrane model with a diaphragm, they are vertical or horizontal.

How not to make a mistake with the choice of the device?

First of all, when choosing expansion membrane tanks for cold water supply, their volume must be taken into account. In addition, we should not forget about the following factors affecting basic parameters of the device:

According to the advice of experts, the choice of an expansion tank for cold water supply should be based on the following standard indicators:

• if the family does not use water in the house more than three person, and pumping equipment produces 2 cubic meters. meters of liquid within an hour, it is better to give preference to tanks with a volume of up to 24 liters;
• if from 5 to 7 people live in private or suburban housing construction, and the pump delivers up to 3.5 cubic meters. meters for an hour, an expansion tank of 50 liters is mounted;
• if the number of residents exceeds 10 people and a powerful 5 cubic meters pump is installed, then it is advisable to use an expansion tank with a volume of 100 liters.

In the process of choosing a suitable model of a diaphragm expansion tank for cold water supply, it is necessary to take into account what smaller sizes capacity, the more often the pumping equipment is switched on and off. Also using a small tank leads to sudden pressure drops. in the water supply system. Plus, such a device should accumulate a certain supply of water resources. Only on the basis of these parameters it is necessary to select the volume of the expansion tank.

You should also be aware that in most tank designs it is possible to install additional water tanks. At the same time, all improvements can be carried out without interrupting the operation of the main water supply system. After installing an additional tank, the total volume of the tank will be the sum of the used tanks.

Apart from technical parameters when choosing an expansion tank for cold water supply, you need to pay attention to the manufacturer. In pursuit of savings, you can purchase a product that will keep breaking and the homeowner will spend the money to repair it.

Often to reduce costs finished products companies use cheap materials with low quality. Of particular importance is the quality of the rubber used to make the membrane. This affects not only the operational life of the membrane tank, but also the safety parameters of the water coming from it into the house.

If a device with replaceable membranes is purchased, it is necessary to find out the cost of spare elements. Very often unscrupulous manufacturers for the purpose of profit cost of replacement parts artificially high. In such a situation, you should think about purchasing a model from another company. Often, large manufacturers are ready to take responsibility for their products, since reputation comes first for them. Therefore, it is advisable to give preference to models of expansion tanks of well-known brands.

Independent installation of the expansion tank

All models of expansion tanks are separated into two main groups, which are determined by the method of connection to a cold water supply. On the market there are models of vertical and horizontal design. At the same time, there are no special differences in the design of such devices. Placement features are of primary importance water pipes in the room where the equipment is installed. At the same time, during the installation of the membrane tank, one should adhere to certain recommendations of experts:

• The installation of the expansion membrane tank must be carried out in a place to which there is free access. This is necessary for regular maintenance of equipment.
• It is important to provide for the possibility of dismantling the connecting pipes in order to replace or repair the tank in the event of a breakdown.
• It is important to consider that the diameter of the pipes to be connected must correspond to the inlet pipes of the expansion tank.
• When installing the device, it must be grounded, which reduces the likelihood of electrolytic corrosion.

An expansion membrane tank is installed on the suction side of the pumping equipment. At the same time, there should not be any additional elements capable of making hydraulic resistance into the plumbing system.

Expansion tanks are an integral part of any autonomous cold water supply system. This device supports required level pressure in the water supply system, premature wear of pumping equipment is prevented and a certain supply of water resources is preserved. However, this can only be achieved with right choice and device installation.

Most modern private houses and cottages are equipped with autonomous heating systems, one of the important elements of which is an expansion tank. The structural element serves to prevent excess pressure in the system, which can occur due to the expansion of the coolant with an increase in its temperature. They are an indispensable attribute of heating systems, fire extinguishing systems, they widely use an expansion tank for water supply.

There is a wide range of all kinds of expansion tanks of various sizes on the market, which differ in design features, but their principle of operation is similar.

The market offers a wide range of expansion tanks for any well or heating system.

Expansion tanks for heating and water supply systems are of two types: closed (membrane) and open.

Expansion tank open type

An open-type expansion tank is a container with a threaded connector to the heating system at the bottom. Place this tank at the highest point of the heating system. V modern systems it is rarely used for heating, since it has a rather impressive list of disadvantages:

• leaking, which leads to corrosion;
• a bulky, large tank can even be wider than a doorway;
• cannot work with high pressure systems;
• The water level in such a tank depends on the volume of liquid in the system.

Membrane tank of closed type

Unlike an open one, a membrane expansion tank is closed and does not have the above disadvantages. It is a sealed container, balloon or flat type, most often oval or spherical in shape, the cavity of which is divided by a rubber heat-resistant membrane. The membrane can be balloon or diaphragm type. Diaphragm membranes are used in expansion tanks of small volume. Tanks with membrane balloon type are more durable, because the water is inside the membrane, not in contact with the walls of the tank. In addition, the balloon-type diaphragm can be replaced if it fails.

The principle of operation of the expansion tank in case of inclusion in the heating system

Two chambers are formed inside the tank - air and liquid. Air (or gas) is compressed and is under a certain pressure. In the air chamber - set special valve to bleed air in case of overpressure in the system.

The principle of operation of an expansion tank of a membrane (closed) type is that the coolant heated in a closed circuit expands. At the time when the increase in volume reaches the tank, the membrane is stretched, the proportion of air space is reduced. The pressure in the tank and the entire system increases. Mandatory requirement when installing it is the presence safety valve and manometer.

How to choose the right unit?

When selecting an expansion tank, you need to pay attention to several important nuances. In order to choose the right expansion tank for heating, you should pay attention to the compliance with the maximum permissible limits of the pressure range in the heating system.

Another point that you need to pay attention to is the quality and type of the membrane, its performance characteristics:

• compliance with sanitary and hygienic standards;
• service life (durability);
• Operating temperature range;
• diffusion resistance.

The internal structure and principle of operation of the membrane tank

To calculate the expansion tank and determine its required volume, the total volume is taken as the main value specific system heating. It can be calculated taking into account the form heating appliances and boiler output.

• radiators - 10.5 l / kW;
• warm floor, panel radiators– 17 l/kW;
• convectors - 7 l / kW.

For calculations, use the formula Vtank = (Vsyst * k) / D, where Vtank is the volume of the expansion tank; Vsyst - the total volume of the heating system; K is the expansion coefficient of the liquid% (For water at a temperature of 95 ° C, it is 4%).

To determine the efficiency of the expansion tank (D), use the following formula:

D \u003d (Pmax-Pstart) / (Pmax + 1), where Pmax is the maximum pressure in the system to which the safety valve is set (2.5 bar is enough in a private house); Pstart - initial pressure in the air chamber of the tank.

Connection rules and possible difficulties

How to install an expansion tank? Installation of the expansion tank is carried out according to the project, according to the instructions. It is best, of course, to entrust this matter to a specialist or, according to at least, consult with knowledgeable people. There is a great risk of making a mistake that will have to be corrected, spending additional time and money.

V open systems heating use open expansion tanks with threaded connection in the day required to connect to the system. Install them at the highest point heating system, which is due to the elementary laws of physics, and is necessary so that water does not spill out of the system. This type systems are now rare, since the installation of an expansion tank of this type is not always convenient.

In closed-type heating systems, closed-type expansion tanks are used, which is divided inside into two parts. On the one hand, a heating system is connected to it, and on the other, there is a valve that allows you to adjust the pressure: bleed air, or, on the contrary, pump it up. Initially, the entire internal volume of the tank is filled with gas, which is under overpressure. This value needs to be adjusted.

Installation of the expansion tank is carried out according to the project, according to the instructions

The connection of a closed-type expansion tank can be performed almost anywhere in the system, except that it is worth avoiding a tie-in directly after the pump in order to avoid jumps in the heating system. The principle of operation is simple - when the coolant is heated, it expands, the excess fills the space in membrane tank which prevents pressure buildup in the system. When the temperature drops, the missing liquid is squeezed back into the system.

It is best to install a diaphragm expansion tank next to the boiler, connecting it to the return pipe before the pump. The mount must be strong, since during operation its mass increases significantly, since the tank is filled with water or other coolant that circulates in the system.

• in the immediate vicinity of the fixing point, the connection diagram of the expansion tank must provide for the installation of a safety valve and a pressure gauge;
• it is not allowed to install filters and install valves on the branch that connects the heating system and the tank;
• connects shut-off valves;
• the tank must be connected taking into account the perspective and ease of its maintenance.

Expansion tank - necessary and important element heating systems, both closed and open. At the stage of choosing an expansion tank for own house you need to make sure that you have a quality certificate. It will not be superfluous to familiarize yourself with the safety certificate, since the heating system is an important element of comfort and life support. With this approach, one can hope that the selected expansion tank will be functional, reliable and durable, which is important for a zealous owner.

The value of the expansion tank for water supply in an autonomous system

To date, an autonomous cold water supply system for a private house or cottage has become quite widespread and is no longer a novelty for anyone. And all because these devices have proven their reliability and effectiveness in practice, however, it should be noted that to maintain them in working condition, special mechanisms are needed, about which the so-called "unenlightened layman", that is, a person who throughout his life used exclusively centralized water supply at home without even realizing it.

Take at least into account the fact that the operation of an autonomous water supply system for a private house or cottage will be able to function for a long period of time only when an expansion tank (special tank) for water supply is included in it (they are just talking about and go) - its required volume (100, 200 liters or less) will be selected individually. Now it is possible to purchase any suitable model without any difficulties, however, in order to purchase a suitable model, you still need to have general ideas about the types of equipment and clearly understand the principle of operation of this device.

In addition, choose suitable option capacity is only a smaller part of the matter - the greatest difficulty is connecting the expansion boiler to an autonomous system.

How does the expansion tank work and how is it arranged (regardless of the volume of the special tank - 100, 200 liters or less)?

The main function of this device is to maintain pressure in the system that supplies water to a private house or cottage. In most cases, water supply is used closed devices membrane type. Rexpansion tank for water supply of this type -This is a container with built-in rubber membrane, which, in turn, divides the expansion (storage) tank, regardless of the volume - 100 liters or less, into two cavities - one of them will be filled with water, and the second with air. After the system is started, the electric pump will fill the first chamber. Naturally, the volume of the chamber in which the air will be located will become smaller. According to the laws of physics, when the volume of air in the tank decreases (again, regardless of whether the volume of the tank is 100 liters or less), the pressure will increase.

When the pressure reaches a certain level with a subsequent increase, the pump turns off automatically. It can only be activated again if the pressure drops below the set value. As a result, water will begin to flow from the water chamber of the tank ( separate container). A similar mechanism of action (its constant repetition) is automated. The pressure indicator is controlled by a special pressure gauge, which is installed on the device. It is possible to change the initial settings.

The main functions of an expansion tank built into an autonomous water supply system (as a special container) are as follows.

A membrane expansion tank (special container) installed in a system or a dacha performs several functions at once:

1. Ensuring stable pressure in the event that at a certain moment the pump does not function.
2. The container protects the water supply system of an honest house or cottage from a likely hydraulic onslaught, which may occur due to a sharp change in voltage in the network or if air enters the pipeline.
3. Saving under pressure a small (but strictly defined) amount of water (that is, this device, in fact -) .
4. Maximum reduction of wear of the water supply system of a private house.
5. The use of an expansion tank allows you not to use the pump, but to use the liquid from the reserve.
6. One of the most important purposes of such devices (in this case we are talking exclusively about membrane expansion vessels) is to ensure the supply of maximum pure water residents of a private house.

Varieties of expansion (membrane) tanks

There are two main types of these containers.

• Expansion tank with replaceable membrane. As the name implies, the main characteristic feature is to replace the membrane, which provides certain advantages. Its recess is carried out by means of a special flange, fixed with several bolts. There is some nuance - in devices designed for a large volume, in order to stabilize the membrane, it is fixed to the nipple. In addition, the liquid that fills the tank is present inside the membrane and does not interact with inside devices - in turn, this property makes it impossible for metal corrosion and deterioration of water quality. Naturally, thanks to this feature, tanks with a replaceable membrane function much longer. It should be noted that such devices are made in both horizontal and vertical versions.
• storage tankequipped with a fixed diaphragm. Naturally, such models are inferior to the above devices in a number of parameters. Firstly, due to the fact that water comes into direct contact with inner wall tank, metal corrosion and water pollution occur. The membrane, if it fails, cannot be replaced -storage tank you will have to buy a new one (the difference in price is very noticeable). Some models are covered from the inside with special moisture-resistant paints, but they do not provide any protection at all. There are also horizontal and vertical type device.

How to make a competent choice of an expansion tank?

No matter what, dominant technical specifications when choosing an expansion tank, this is its volume. And already the need for a certain amount of volume is dictated by a wide variety of conditions:

Approximate figures given by leading experts as an example:

The most common average family, which includes no more than three people, needs water supply, the pump capacity does not exceed 2 cubic meters. m / h, then the most reasonable choice would be to purchase an expansion tank with a capacity of 20 to 24 liters. With an increase in the number of consumers to eight people, it is worth purchasing a device with a volume of less than 50 liters. There are more than ten consumers - at least 100 liters are needed. These are the most optimal values ​​- and not a lot, and not a little. In the event that you are in doubt - it is better to take with a margin, a little more - this certainly will not damage your autonomous water supply system in any way.

Important! When choosing an expansion tank, it is necessary to take into account the need for a reservoir for storing a certain amount water.

Manufacturer brand selection

Remember the most important thing: the water supply system is not something you can save on. In the event that you purchase a low-quality expansion tank (even if at a bargain price), then you should understand that you risk being left without water supply at all for an indefinite time and with the need for very significant financial costs that differ from the difference in the cost of these tanks for a couple " zeros." As you have most likely already correctly understood, the costs will be associated with one that has failed due to the poor quality of the expansion tank.

Particular attention should be paid to the quality of rubber - the main component of the membrane (this component affects not only the durability of the device, but also the quality of the supplied water).
As a reliable manufacturer, we can safely recommend the following brands: Elbi, Reflex, Zilmet, Aquasystem.

A few words about how to install an expansion

According to the connection method, it is customary to separate horizontal and vertical tanks. The choice in this case (regarding only this parameter) is based on which device will be easier to place in the room allotted for it.