How to choose an expansion tank for water supply systems? How to connect a hydraulic accumulator to the water supply system Tanks for water supply.

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's 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 - the destruction of individual elements of the installation 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.

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 huge assortment various 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. You should pay attention to the models of tanks from the following companies - 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 various volumes- 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 applied to 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 applications in drinking water systems, ideal for use in environments with increased level rust formation. 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.

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 fact is that the use of low-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 hygiene 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.

Autonomous water supply system for modern home- this is not new. High-quality water supply devices have been tested by users and time.

But it is better for buyers to familiarize themselves with the functionality of all devices. autonomous system water supply before purchase and installation.

Kinds

In order to properly pump water long time, a diaphragm expansion vessel is required.

For the convenience of the system and saving space, three types of these devices are on sale:

• floor;
• hinged;
• flat.

Specialist's note: when choosing between types of expansion tanks, remember that only the floor tank has a replaceable membrane.

Operating principle

Fluid pressure builds up in the system. Then storage tank filled with a certain volume.

In it, the water compartment gradually increases, and the opposite compartment containing air decreases.

This process continues until equilibrium is reached, in other words, desired pressure in system. When the pressure drops below the level of air pressure, timely contraction of the inner membrane occurs.

Due to it, the water supply is normalized. The tank device functions as long as necessary to stabilize the pressure of water and air.

The right choice of instrument

When choosing a model with the necessary functions and volume, consider the fact that the frequency of the pump depends on the total volume of the tank.

The leading characteristic for any tank is not the functionality, but its volume.

At the same time, for each water supply system there are criteria that cannot be neglected, namely:

1. Number of permanent water users. (Daily use).
2. Number of points for water intake. (Appliances, faucets and other plumbing fixtures).
3. Approximate frequency of use of water intake points at the same time.
4. On-off cycle. You need to know exactly the one-hour limit of this cycle for your pump.

Approximate calculation:

When calculating for three permanent consumers, a tank with a total volume of 20-24 liters is installed. However, pumping equipment should produce approximately 2 cubic meters per hour.

When counting on four regular users with a margin, it is better to install equipment from 50 liters. The pump capacity in this case is approximately 3.5-3.7 cubic meters per hour.

If there are more than 10 consumers, then a tank of at least 100 liters is required, and pumping equipment with a rate of more than 5 cubic meters per hour.

To avoid breakage and expensive repairs, you need to carefully read the manufacturer.

In this choice, chasing a cheaper and dubious brand is not necessary. Incorrect savings can lead to breakdowns in the future.

Models with a low retail price inside are made, as a rule, without defects. But consumables are always made from the cheapest materials.

It is better to ask about the material from which the membrane is made. Its environmental friendliness and stability will improve comfort as well as the life of the system.

You may also be interested in the article about.

Read the article on malfunctions and repair of the hydraulic accumulator with your own hands.

How is it different from a hydraulic accumulator

Installation diagram of a membrane expansion tank Accumulator, membrane tanks and are devices that are most in demand in a modern plumbing and heating device.

But it is better to know their significant differences, because the expansion tank creates the effect of pressure smoothing when the liquid is heated.

talking plain language, if not the right space for water that gradually changes its volume, then any non-plastic container will burst. For this, a device with a membrane was created, which normalizes the difference in a working system.

Both devices are appearance very similar. But their device, purpose and performance characteristics various.

The hydraulic accumulator is used to supply water for drinking.

Its main property is the supply of the desired water pressure.

The most important part in the tank and accumulator is the membrane.

The material from which it is made is different in devices for supplying water, including between the tank and the accumulator.

The arrangement of the chambers for air and liquid is also different. The accumulator inside is equipped with a “pear” tank. Air exerts pressure on it, it is between the walls of the tank and the water tank.

For each of the above devices, the most important parameter is the durability and reliability of the membrane. Its quality guarantees the stability of the entire system.

Watch the video in which the specialist explains how to choose a membrane expansion tank for home water supply:

Membrane expansion tanks have found application as pressure compensators in the water supply system.

Currently, heat supply, where water moves under the influence of gravity, is being replaced by communications with forced movement of the coolant.

A compensating device will be required when installing an autonomous water supply or when distributing hot water.

A large number of models complicates the choice, which is made on the basis of knowledge of the principles of operation, specifications devices and communications.

Design features

Despite the small design differences in the models used in water supply and heating, the devices operate according to the same physical principle.

In general, tank design consists of a sealed steel body and a rubber membrane.

"Pears" are divided into two types:

• a diaphragm that divides the container in half;
• rubber container attached to the inlet pipe.

IMPORTANT!
Models of the first type do not have the ability to replace the membrane. In case of malfunction, change the device.

Bulb replacement is easy. To do this, it is necessary to unwind the flange of the inlet (it is written about devices for fastening plumbing fittings and pipelines).

AT heating system models are used in which the coolant is in contact with a metal case.

Devices for water supply isolate water from steel walls. Such models are recommended as small ones.

The contact of the liquid with the body metal is the difference in the two types of tanks.

When the temperature drops or a decrease in water pressure in the "pear" air pushes the liquid into the pipeline.

Right choice

Arriving at the store, remember that expanders are divided according to their use in heating or water supply.

Often, distinguish models externally, impossible, the device is even painted in one color, usually red.

Differences in membrane properties can lead to accidents if a model is installed that does not match the specifications.

Pay attention to features device indicated on the nameplate.

The label contains information about the characteristics of the device.

If it is indicated that the pressure is 10 bar, the temperature is +70 degrees, then the model is intended for pipelines with cold water.

The inscription on the plate: temperature +120 degrees, 3 bar - such a device must be installed for heating.

The next thing to pay attention to is the volume of the steel tank, which is defined as follows:

IMPORTANT! An expander is installed for the boiler, used in cold water supply.

Mounting the device

Proper installation of the expander will affect the operation of communications and the service life of the device itself.

First of all, fix the tank on the wall or floor in the position indicated in the manufacturer's instructions.

The next step is to install shutoff valves at the point where the tank is connected to the line (you may need it).

This will help to carry out maintenance, repair or replacement of the membrane tank.

Water from the expander is drained through a special fitting, which is installed in the gap between the tank and the fittings.

This will drain the liquid before dismantling the device (the price of a cutting screw pipe thread indicated).

For heating systems

If the manufacturer did not indicate the orientation of the expander, then the device is fixed with the inlet down.

The vertical position allows you to continue working if the membrane is damaged. Air located on top will continue to press on the liquid without entering the pipeline.

Tank installation is possible both on the forward branch and on the return line. This applies to heating based on gas or liquid boilers.

In systems with solid fuel boilers the expander is installed on the return line. The setting is carried out using the spool located on top.

After the installation of the membrane tank, the system is filled with coolant, periodically bleeding air.

It is necessary to measure the water pressure at the outlet of the boiler and compare it with the pressure in the expander.

Tank parameters should be 0.2-0.3 bar lower than in a pipeline.

For larger and smaller values, air is pumped in or bled through the spool.

For plumbing

oriented in the room, depending on the convenience of the location.

Orientation of the nozzle down doesn't matter.

A drain device and shut-off valves are installed in front of the storage tank in the form ball valve ().

The cold water expander is configured differently than for heating.

The pressure in the system is created by the pump, for which I set the threshold for switching on and off (about the repair of the pressure switch pumping station written by hand).

Based on the characteristics of the pump, the pressure in the tank is set to 0.2 bar lower than the threshold of the pumping equipment.

This will avoid the possibility of water hammer..

When installing the tank on the line hot water set the pressure to 0.2 bar higher than the upper threshold of the station. This value will allow water not to stagnate in the pipes.

Finally

A seemingly simple design will require knowledge, experience and accuracy during installation. The expander plays a significant role in pipelines of an autonomous, closed type.

The service life of the tank and communications as a whole depends on the quality of the installation.

It is worth remembering that a competent approach is necessary when installing any element of plumbing or heating.

What is it needed for membrane tank in system autonomous water supply private house, you will find out while watching the video.