Expansion tanks, hydraulic accumulators, for heating and water supply systems. Hydraulic accumulator for water supply systems: purpose, types, principle of operation and basis of calculations For the hot water supply system

To prevent the pump from turning on every time the tap is opened, a hydraulic accumulator is installed in the system. It contains a certain volume of water, sufficient for a small flow rate. This allows you to practically get rid of short-term pump starts. Installing a hydraulic accumulator is a simple procedure, but you will need a few more devices - at a minimum - a pressure switch, and it is also desirable to have a pressure gauge and an air vent.

Functions, purpose, types

Installation location - in a pit or in a house

In the water supply system of a private house without a hydraulic accumulator, the pump turns on whenever water flows somewhere. These frequent starts lead to wear and tear on the equipment. And not only the pump, but the entire system as a whole. After all, every time there is an abrupt increase in pressure, and this is a water hammer. To reduce the number of pump starts and smooth out water hammer, a hydraulic accumulator is used. The same device is called an expansion or membrane tank, a hydraulic tank.

Purpose

We found out that one of the functions of hydraulic accumulators is to smooth out water hammer. But there are others:

It is not surprising that most private water supply systems have this device - there are many advantages from its use.

Kinds

The hydraulic accumulator is a tank made of sheet metal divided into two parts by an elastic membrane. There are two types of membrane - diaphragm and balloon (bulb). The diaphragm is attached across the tank, a pear-shaped cylinder is secured at the inlet around the inlet pipe.

According to their purpose, they are of three types:

for cold water;
for hot water;
for heating systems.

Hydraulic tanks for heating are painted red, tanks for water supply are painted blue. Expansion tanks for heating are usually smaller in size and lower in price. This is due to the membrane material - for water supply it must be neutral, because the water in the pipeline is potable.

Depending on the type of arrangement, hydraulic accumulators can be horizontal or vertical. Vertical ones are equipped with legs; some models have plates for hanging on the wall. It is the models elongated upward that are most often used for self-creation water supply systems of a private house - they occupy less space. The connection of a hydraulic accumulator of this type is standard - through a 1-inch outlet.

Horizontal models are usually equipped with pumping stations with surface-type pumps. Then the pump is placed on top of the tank. It turns out compact.

Principle of operation

Radial membranes (in the form of a plate) are used mainly in gyroaccumulators for heating systems. For water supply, a rubber bulb is usually installed inside. How does such a system work? As long as there is only air inside, the pressure inside is standard - the one that was set at the factory (1.5 atm) or that you set yourself. The pump turns on, begins to pump water into the tank, and the pear begins to increase in size. Water gradually fills an increasingly larger volume, increasingly compressing the air that is located between the wall of the tank and the membrane. When a certain pressure is reached (usually for one-story houses it is 2.8 - 3 atm), the pump is turned off, and the pressure in the system stabilizes. When you open a tap or other water flow, it comes from the accumulator. It flows until the pressure in the tank drops below a certain level (usually about 1.6-1.8 atm). After which the pump turns on, the cycle repeats again.

If the flow rate is large and constant - you are filling a bathtub, for example - the pump pumps water in transit, without pumping it into the tank. The tank begins to fill after all the taps are closed.

A water pressure switch is responsible for turning the pump on and off at a certain pressure. In most hydraulic accumulator piping schemes, this device is present - such a system operates in optimal mode. We’ll look at connecting the hydraulic accumulator a little lower, but for now let’s talk about the tank itself and its parameters.

Large tanks

The internal structure of hydraulic accumulators with a volume of 100 liters and above is slightly different. The pear is different - it is attached to the body both at the top and at the bottom. With this structure, it becomes possible to fight the air that is present in the water. To do this, there is an outlet in the upper part into which you can connect a valve for automatic air release.

How to choose tank volume

You can choose the tank volume arbitrarily. There are no requirements or restrictions. The larger the volume of the tank, the greater the supply of water you will have in case of a shutdown and the less often the pump will turn on.

When choosing a volume, it is worth remembering that the volume that appears in the passport is the size of the entire container. There will be almost half as much water in it. The second thing to keep in mind is the overall dimensions of the container. A 100 liter tank is a decent-sized barrel - about 850 mm high and 450 mm in diameter. You will need to find a place somewhere for it and the harness. Somewhere - this is in the room where the pipe from the pump comes. This is where all the equipment is usually installed.

If you need at least some guidelines to select the volume of a hydraulic accumulator, calculate the average flow rate from each water intake point (there are special tables or you can look at the data sheet for household appliances). Sum up all this data. Get the possible consumption if all consumers work simultaneously. Then figure out how many and which devices can work at the same time, calculate how much water will be consumed in a minute in this case. Most likely by this time you will have already come to some decision.

To make it a little easier, let’s say that the hydraulic tank volume of 25 liters is enough to meet the needs of two people. It will ensure the normal functioning of a very small system: a faucet, a sink and a small one. If you have other household appliances, the capacity must be increased. The good news is that if you decide that the current tank is not enough for you, you can always install an additional one.

What should be the pressure in the accumulator?

In one part of the accumulator there is compressed air, water is pumped into the second. The air in the tank is under pressure - factory settings - 1.5 atm. This pressure does not depend on the volume - it is the same on a tank with a capacity of 24 liters and 150 liters. More or less may be the maximum permissible maximum pressure, but it depends not on the volume, but on the membrane and is indicated in the technical specifications.

Preliminary check and pressure correction

Before connecting the accumulator to the system, it is advisable to check the pressure in it. The settings of the pressure switch depend on this indicator, and during transportation and storage the pressure could drop, so monitoring is very desirable. You can control the pressure in the hydraulic tank using a pressure gauge connected to a special inlet in the upper part of the tank (capacity of 100 liters or more) or installed in its lower part as one of the piping parts. Temporarily, for control, you can connect a car pressure gauge. Its error is usually small and it is convenient to work with. If this is not the case, you can use the standard one for water pipes, but they are usually not very accurate.

If necessary, the pressure in the accumulator can be increased or decreased. There is a nipple at the top of the tank for this purpose. A car or bicycle pump is connected through the nipple and the pressure is increased if necessary. If it needs to be vented, the nipple valve is bent with some thin object, releasing the air.

What air pressure should be

So should the pressure in the accumulator be the same? For normal operation household appliances require a pressure of 1.4-2.8 atm. To prevent the tank membrane from tearing, the pressure in the system should be slightly higher than the pressure of the tank - by 0.1-0.2 atm. If the pressure in the tank is 1.5 atm, then the pressure in the system should not be lower than 1.6 atm. This value is set on the water pressure switch, which works in tandem with the hydraulic accumulator. These are the optimal settings for a small one-story house.

If the house is two-story, you will have to increase the pressure. There is a formula for calculating the pressure in the hydraulic tank:

Vatm.=(Hmax+6)/10

Where Hmax is the height highest point water collection Most often this is a shower. You measure (calculate) at what height relative to the hydraulic accumulator its watering can is located, substitute it into the formula, and get the pressure that should be in the tank.

If the house has a jacuzzi, everything is more complicated. You will have to select it empirically - changing the relay settings and observing the operation of water points and household appliances. But at the same time operating pressure should not be more than the maximum allowable for other household appliances and plumbing fixtures (indicated in the technical specifications).

How to choose

The main working body of the hydraulic tank is the membrane. Its service life depends on the quality of the material. The best membranes today are made from food-grade rubber (vulcanized rubber plates). The housing material matters only in membrane-type tanks. In those in which a “pear” is installed, water comes into contact only with rubber and the material of the body does not matter.

The flange should be made of thick galvanized steel, but better - stainless steel

What's really important about bulb tanks is the flange. It is usually made of galvanized metal. In this case, the thickness of the metal is important. If it is only 1 mm, after about a year and a half of operation, a hole will appear in the metal of the flange, the tank will lose its tightness and the system will stop working. Moreover, the warranty is only one year, although the stated service life is 10-15 years. The flange usually rots after the warranty period expires. There is no way to weld it - the metal is very thin. You have to search in service centers new flange or buy a new tank.

So, if you want the accumulator to last a long time, look for a flange made of thick galvanized or thin, but made of stainless steel.

Connecting the accumulator to the system

Typically, the water supply system of a private home consists of:

This scheme may also include a pressure gauge for operational pressure control, but this device is not necessary. It can be connected periodically to carry out test measurements.

With or without five-pin fitting

If the pump is of a surface type, the hydraulic accumulator is usually placed next to it. In this case, the check valve is installed on the suction pipeline, and all other devices are installed in one bundle. They are usually connected using a five-pin fitting.

It has terminals with different diameters, just for the devices used for tying the hydraulic accumulator. Therefore, the system is most often assembled on its basis. But this element is completely optional and you can connect everything using ordinary fittings and pieces of pipe, but this is a more labor-intensive task, and there will be more connections.

How to connect a hydraulic accumulator to a well - diagram without a five-pin fitting

With one inch outlet, the fitting is screwed onto the tank - the pipe is located at the bottom. A pressure switch and pressure gauge are connected to the 1/4 inch outlets. The remaining free inch terminals are connected to the pipe from the pump and wiring to consumers. That's all for connecting the gyroaccumulator to the pump. If you are assembling a water supply circuit with a surface pump, you can use a flexible hose in a metal winding (with inch fittings) - it is easier to work with.

A visual diagram of connecting the pump and accumulator - use hoses or pipes where necessary

As usual, there are several options, the choice is yours.

Connect the accumulator to submersible pump similar. The whole difference is where the pump is installed and where the power is supplied, but this has nothing to do with the installation of the accumulator. It is placed in the place where the pipes from the pump enter. Connection is one to one (see diagram).

How to install two hydraulic tanks on one pump

When operating the system, sometimes owners come to the conclusion that the available volume of the accumulator is not enough for them. In this case, you can install a second (third, fourth, etc.) hydraulic tank of any volume in parallel.

There is no need to reconfigure the system; the relay will monitor the pressure in the tank on which it is installed, and the viability of such a system is much higher. After all, if the first accumulator is damaged, the second one will work. There is another positive point - two tanks of 50 liters each cost less than one of 100. The point is more complex technology production of large-sized containers. So it is also more economical.

How to connect a second accumulator to the system? Screw a tee onto the input of the first one, connect the input from the pump (five-pin fitting) to one free output, and connect the second container to the remaining free one. All. You can test the circuit.

A hydraulic accumulator is an expansion tank for water supply that performs several tasks simultaneously. In principle, a hydraulic accumulator is a container divided by an elastic membrane into two parts - for air and water. The air pressure in the air cavity is 1.5-2.0 bar. Water entering the container increases the filling volume, stretching the membrane. At the same time, the pressure in the air cavity of the tank increases. When a certain pressure is reached, the feed pump automatically switches off. When you open the water tap, i.e. when the pressure in the network drops, air squeezes water out of the accumulator into the network, replenishing volume losses and compensating for the drop in water pressure. In this way, pressure is maintained in the system when the pump is turned off, water shocks when the pump is turned on are softened, and the system as a whole has an additional supply of water.

In working condition, the accumulator always contains water and air. The air pressure in the air cavity of the installation may decrease over time, so it should be checked once a year in the hydraulic tank after the water has been completely removed. If the pressure is insufficient, air can be pumped up with a conventional hand pump through the nipple. It will not be possible to fill the hydraulic accumulator completely with water, and the maximum volume of water depends on several factors:

shape and volume of the hydraulic accumulator;
initial air pressure;
elasticity of the diaphragm;
levels for setting the pressure switch to turn the pump on and off.

Hydraulic accumulators are used in water supply systems of both residential and industrial buildings

Why do you need a hydraulic accumulator?

We list all the functions of the hydraulic accumulator:

maintaining pressure in the system when the pump is turned off;
creating a reserve of a certain volume of water ( storage tank);
eliminating the need to frequently turn the pump on and off;
compensation of water volume during peak consumption;
leveling hydraulic shocks in the system when the pump is turned on.

The hydraulic accumulator must be installed as close to the pump as possible. If two accumulators are used, they should be placed side by side to ensure uniform pressure and filling of both containers.

What kind of hydraulic accumulator is needed for water supply systems?

Of all existing species hydraulic accumulators for water supply, we will consider in detail the operation of two, which are usually used in the water supply systems of individual houses.

Balloon accumulators

They are a thick-walled container, inside of which there is an elastic rubber balloon filled with water. The space between the cylinder and the walls of the container is filled with air under a certain pressure. When the cylinder is filled, the air pressure inside the tank increases; when the water pressure in the network drops (the tap is opened), the air “squeezes” water out of the cylinder, replenishing the lack of it in the system. In this case, the overall pressure in the system drops, but gradually, “smoothing out” sudden pressure drops between pump starts.

Membrane accumulators

The principle of operation of such a device is similar to a balloon one. The only difference is in the design: the membrane tank is divided into two parts, between which an elastic sealed membrane is installed. One part of the container is filled with water, the other with air. When the container is filled, the air pressure increases; when the pressure drops, the compressed air “squeezes” water into the system.

Which hydraulic accumulator should I buy for a private home?

Of the two types of hydraulic accumulators, when choosing, we recommend choosing a balloon-type installation. The water in it comes into contact with the rubber wall, unlike membrane models, which can cause corrosion of the metal wall and water contamination

To ensure a sufficient supply of water in the event of a power outage, a hydraulic tank of appropriate working capacity is needed. Vertical and vertical hydraulic accumulators are produced horizontal types. The former are convenient for installation in cramped conditions.

There is now a large selection of hydraulic accumulators in the retail chain. You can buy a hydraulic accumulator at a specialized construction supermarket or trading company. Prices depend on the manufacturer, volume and type of equipment. On the Internet you can find many videos about various types hydraulic accumulators. At the end of the article you will find detailed video about this theme.

How to choose the volume of a hydraulic accumulator

If everything is clear with the choice of design and type of battery in shape, then main characteristic hydraulic tank - its volume - requires detailed explanation. There are complex mathematical calculations on the network for the required capacity of a hydraulic accumulator, but we will make do simple recommendations, based on calculation conclusions and operating experience of similar equipment:

a hydraulic accumulator with a tank volume of 20-24 liters is suitable for 3 people living in a house and a pump capacity of up to 2 m3/h;
a hydraulic accumulator with a tank volume of 50-60 l is sufficient for 4 - 8 residents and a pump capacity of up to 3.5 m3/h;
hydraulic accumulator with a volume of 100 liters or more - for 10 or more residents and a pump capacity of 5 m3/h.

Let's consider several of the most important functions of a hydraulic accumulator with the choice of equipment suitable for the volume. Hydraulic tanks for water supply systems must provide:

Optimal pump operating mode

To ensure that the water supply pump does not turn on frequently (no more than once per hour is considered optimal), the required volume of the hydraulic accumulator can be calculated based on the pump’s performance. With the volume of the water cavity being 50% of the total, in most cases homeowners are quite satisfied with a hydraulic accumulator of 60 - 80 liters.

Optimal network pressure

An important characteristic of a hydraulic accumulator is maintaining normal pressure in the network. For these purposes, a minimum volume of a hydraulic accumulator of 24 liters is sufficient and installed near the pump.

Reserve water supply

The problem of creating a reserve supply of water usually arises in places where there are frequent power outages. The pump often stops, which negatively affects its operation. A solution to the problem here may be to install a hydraulic accumulator with a volume of 100 liters or more, the useful volume of the storage capacity of which is up to 50% of the total.

What kind of expansion tank should the accumulator have?

When talking about the expansion tank of a hydraulic accumulator, it should not be confused with the expansion tank of heating and hot water supply systems. The equipment looks very similar. The fundamental difference is that heating expansion tanks serve to compensate for the thermal expansion of the coolant.

Working pressure is one of the main characteristics of a hydraulic accumulator. This is the pressure in an empty container without water, and its value is indicated on the hydraulic tank body. The indicated pressure should not be lower than the pressure of the height of the liquid in the water supply of the house. With a system height of 10 m, the pressure will be 1 bar.

The pressure when starting the pump must exceed the pressure in the expansion tank of the water supply by more than 0.5 bar. For the most efficient work system, the difference should be 1.5 - 3.0 bar.

The maximum pressure in the tank should not be less than the maximum system pressure if the relay fails. Therefore, the maximum tank pressure is usually 10 bar.

Conclusions: which accumulator is best

Except technical criteria choices discussed above, we present a few more considerations regarding the quality of accumulator materials.

The removable flange in the cylinder is usually made of stainless or galvanized steel. When purchasing, be sure to pay attention to this. If over time you cannot do without replacing the flange, find out where and for how much it can be purchased.
If tap water intended for drinking, you need to make sure that the material from which the “pear” of the accumulator is made is safe for health. Famous manufacturers guarantee the quality of the material, which cannot be said about small, little-known companies. True, this does not matter if you are not supposed to drink such water.
Otherwise, the choice is made based on specific operating conditions: the required volume of water, pressure, optimal pump operation, the required water reserve in case of emergency shutdowns, installation conditions.

When the accumulator is filled with water, the pressure in it and the system is equalized. When you open any tap, liquid is consumed and it falls. When the lower threshold value is reached, the pump automatically (based on a signal from the corresponding relay) turns on. The pressure increases and the flask is filled with the missing amount of water. This process is characterized by dynamics, and with proper adjustment of the accumulator, the pressure in the system remains unchanged.

But provided that the frequency is observed Maintenance device. This mainly concerns the timely release of excess air accumulated in the tank. Frequency technological operation depends on the capacity of the accumulator and the features of the water supply system. General recommendations indicated in the product passport.

Installing a hydraulic accumulator

It is mounted in several standard schemes depending on the characteristics of the system.

For submersible pump

Even minimum consumption water initiates the switching on of the pumping device. Therefore, the hydraulic accumulator must be installed in the circuit after check valve. This allows you to optimize the operation of the pump and ensure its guaranteed service life.

For station

Essentially the same pump, equipped additional equipment. Some models are not initially equipped with a hydraulic accumulator, so it must be purchased separately and installed independently. In this scheme, the main task of the HA is to protect the system from pressure surges, which is observed when the pump is started. Connection - on the section of the main line to the pumping device.

For booster station

Such schemes are implemented with large and constant water consumption. As a rule, the pumping device includes at least two pumps operating alternately. As can be seen in the diagram, the hydraulic accumulator is connected to the pipe supplying water to the consumer.

For DHW system

When switched on in this way, the hydraulic accumulator acts as an expansion tank. If the device is not installed, the flow from the shower head will be unstable due to changes in pressure. Plumbing will also begin to work incorrectly, and this reduces its service life and leads to frequent breakdowns.

Features of installation of a hydraulic accumulator

The fastening is carried out on a solid basis, and always with the use of shock absorbers. For example, RTI gaskets. We must not forget that HA is constantly in dynamics, and rigid fixation will lead to destruction of the surface material or breakage of fasteners. It is impossible to install the device directly on a water pipe, since in addition to vibration, the weight of the accumulator along with the liquid is added. Such installation is guaranteed to lead to leaks or broken connections.
To connect the accumulator with the pipeline, you need to use a flexible connection. The reason is stated above.
Filling the tank with water is done gradually, with low pressure. This is necessary in order to eliminate the risk of damage to the flask if it is caked - with a sharp rise in pressure, the rubber rubber may not have time to straighten out and it is easy to tear.
The location for installing the hydraulic accumulator is selected taking into account the possibility of quick access to the device, its visual inspection from all sides and carrying out maintenance (replacement) work.
If the HA is small in tank volume (up to 50 l), then shut-off valves (valve, tee) are installed to bleed air bubbles - such devices are not equipped with pneumatic valves. This means that it is necessary to provide where and how to drain (discharge) water from the container.

The pressure in the air compartment is adjusted based on the calculated parameters of the water supply system and the manufacturer’s recommendations. All you need is a pump (if necessary), a pressure gauge (can be a car one) and spanners. But it is better to entrust all the required calculations to a professional - the slightest mistake will lead to system failures with all the consequences.

CA capacity calculation

Choosing a hydraulic accumulator based on the volume of the tank is obviously a losing proposition. There is such a thing as capacity filling. Here, a lot depends on the pressure in the air compartment, and often in a GA with a capacity of 200 liters, in fact, only a third is water. The table shows how the difference between the maximum and minimum pressure values to which the relay is set affects the actual volume.

To calculate, you can use the formula:

V = K x Amax x (Pmax+1) x (Pmin +1) / (Pmax- Pmin) x (Pb + 1)

Amax – water flow (l/min).
Pmax and Pmin (bar) – threshold pressure values at which the pump turns off/on.
K – coefficient determined by the total power of the pumping equipment (if several products are installed in the system).
Pb (bar) – pressure in the air compartment of the hydraulic accumulator tank.

The hydraulic accumulator is connected in systems autonomous water supply either to pumping station, or to a pump - submersible or surface. It is also possible to connect two or more hydraulic tanks if necessary. And only then connect the hydraulic tank to the water heater.

Purpose of the hydraulic accumulator

Hydraulic accumulators are often confused with expansion tanks, even despite the fundamentally different problems that these devices solve. An expansion tank is needed in heating and hot water supply systems, since the coolant, moving through the system, inevitably cools and its volume changes. The expansion tank is set up when the system is “cold”, and when the coolant warms up, its excess, which is formed due to expansion, has somewhere to go.

The hydraulic accumulator is needed for completely different purposes: if it is not installed in the water supply system, the pump will be activated every time a tap is opened. If this happens often, then not only the pump, but the entire system wears out faster, since each time the pressure increases abruptly - a so-called water hammer occurs.

As a result, a hydraulic accumulator is installed with the aim of getting rid of water hammer and extending the service life of the system as a whole. In addition, the accumulator has other functions:

Creates a certain supply of water (useful if there is a power outage).

If there are frequent interruptions in water supply, the hydraulic accumulator can be combined with a storage tank

Reduces the frequency of pump startup. The reservoir is filled with a small volume of water. If the flow rate is small, for example, you need to wash your hands or wash your face, water begins to flow from the tank, while the pump remains turned off. It is activated after very little water remains;
Maintains stable pressure in the system. In order for this function to be performed properly, an element called a water pressure switch is provided, which is capable of maintaining a given pressure within strict limits.

All the advantages of hydraulic accumulators make this device an indispensable element of any autonomous water supply system in country houses.

Types of hydraulic tanks

According to their purpose, they are of three types:

for cold water;
for hot water;
for heating systems.

Two types of hydraulic accumulators

Depending on the type of arrangement, hydraulic accumulators can be horizontal or vertical. Vertical ones are equipped with legs; some models have plates for hanging on the wall. It is the elongated upward models that are most often used when independently creating water supply systems for a private house - they take up less space. The connection of a hydraulic accumulator of this type is standard - through a 1-inch outlet.

Horizontal models are usually equipped with pumping stations with surface-type pumps. Then the pump is placed on top of the tank. It turns out compact.

Operating principle of a hydraulic accumulator

Operating principle of a hydraulic accumulator.

When there is air inside the structure, the standard pressure is 1.5 atm. When the pumping equipment is turned on, water is pumped into the container. The more fluid enters, the more the free space of the hydraulic tank is compressed.

When the pressure reaches a given level (for 1-story dachas - 2.8-3 atm.), the pump is turned off, which stabilizes the work process. If you open the tap at this time, water will flow from the tank until the pressure level in the water supply drops to 1.6-1.8 atm. After this, the electric pump turns on and the entire cycle starts again.

If the water consumption is high, the well unit will pump water in transit, it will not enter the hydraulic tank - it is filled only after the taps are closed.

For the inclusion of superficial and deep well pumps Depending on the specified indicators, the automation responds. This is a pressure gauge and pressure switch, thanks to which the operation of the equipment is optimized.

How to choose the right hydraulic tank

A hydraulic tank is a container whose main working body is a membrane. Its quality determines how long the device will last from the moment of connection to the first repair.

Products made from food-grade (isobutane) rubber are considered the best. The metal of the product body is important only for expansion tanks. Where water is contained in the pear, the characteristics of the metal are not decisive.

If not reversed special attention on the thickness of the flange of your purchase, then in a year and a half, and not in 10-15 years, as you plan, you will have to buy a completely new device or, in best case scenario, change the flange itself

When choosing a device, special attention should be focused on the flange, which is usually made of galvanized metal. The thickness of this metal is very important. With a thickness of only 1 mm, the service life of the product will be no more than 1.5 years, since a hole will certainly form in the metal of the flange, which will damage the entire device.

Moreover, the warranty on the tank is only a year with a stated service life of 10-15 years. So the hole will appear just after the warranty period expires. And it will be impossible to solder or weld thin metal. You can, of course, try to find a new flange, but most likely you will need a new tank.

To avoid such misfortunes, you should look for a tank whose flange is made of stainless steel or thick galvanized steel.

Calculation of hydraulic tank parameters

In most cases of inclusions, hydraulic tanks for water supply are installed according to the principle: the larger the volume, the better. But too large a volume is not always justified: the hydraulic tank will take up a lot useful place, the water in it will stagnate, and if power outages occur very rarely, it is simply not necessary. A hydraulic tank that is too small is also ineffective - if a powerful pump is used, it will turn on and off frequently and quickly fail. If a situation arises when installation space is limited or financial resources do not allow you to purchase a large-capacity storage tank, you can calculate its minimum volume using the formula below.

How to correctly calculate the volume of a hydraulic tank in a water supply system

Another calculation method is to calculate the required volume of the hydraulic tank based on the power of the electric pump used.

Recently, modern high-tech electric pumps with soft start and stop, frequency control of the speed of rotation of the impellers depending on water consumption have appeared on the market. In this case, there is no need for a large-volume hydraulic tank - soft start-up and adjustment do not cause water hammer, as in systems with conventional electric pumps. Automatic control units of high-tech devices with frequency control have a built-in hydraulic tank of a very small volume, designed for its pump group.

Table of calculated values of pressure and volume of the hydraulic tank depending on the operating modes of the water supply line

How to connect a hydraulic tank

In addition to the pump and hydraulic tank, you will need a pressure switch and a pressure gauge. In accordance with the diagram for connecting the hydraulic accumulator to the water supply system, all these elements interact through a five-pin fitting. A tank with relays and instrumentation is installed in the boiler room or other room.

Dry-running relays and check valves are used as additional equipment for the system. These devices are responsible for ensuring that there is always water in the pipes and that it does not flow into the well or borehole. But that's if we're talking about about individual water supply systems. After installation, you need to make commissioning works which consist of checking the tightness of connections and adjusting the hydraulic tank.

The established operating parameters are 1.7 bar. At the same time, the pumping equipment is turned on. The relay is set so that it switches off at 2.8 bar. These parameters are considered ideal for most models. Information can be found in the operating instructions for the hydraulic accumulator with pump.

Connection to a pumping station

In this case, work on connecting the hydraulic accumulator to an autonomous water supply system is carried out simultaneously with the installation of automation and adapters. The most common installation cases require the following components:

pressure gauge;
five-inlet fitting;
switching hydraulic relay (pressure switch).

If a submersible pump is used to draw water, the well piping must be equipped with a check valve and a dry inlet relay. If a simpler surface centrifugal pump is used to pump water, it is cheaper and more expedient to buy an assembled pumping station rather than install individual elements. The second option is preferable for those who have little experience but want to install the pump themselves.

Two hydraulic tanks for one pump

Connecting two (or more) hydraulic tanks is a common problem for people faced with a forced increase in water consumption. If the volume of one tank is too small, installation additional hydraulic accumulator- This is not a very burdensome matter.

Install additional elements possible in parallel current system: It is enough to use another adapter fitting, flexible hose or water pipe. A system with two (or more) tanks is both a rational solution and an excellent safety net. If the membrane fails in one of the tanks, you can still use the pump, but not in intensive mode. Such a system will provide enough time to replace the faulty unit.

To submersible pump

You can guess that we are talking about a pump that is immersed in the aquifer of a well or well. For uninterrupted water supply, such a system must be equipped with a check valve: this device will not allow the pumped out water to return to the bottom of the well after use. Accordingly, the pump will not run idle and will last much longer.

In most cases, the check valve is already installed on the pump; additional installation may be required during the repair process. To avoid being left without water for an indefinite period of time, it is recommended to purchase a pump with a spare valve, which is sold separately or supplied with the pump.

Another important point– this is the quality of the pressure pipeline: since the pipe lies at a fairly large depth, a possible breakdown may not be noticed immediately.

The first sign of problems with the pipeline is a sharp drop in pressure; the accumulator takes longer to fill with water; over time, this gap may increase.

To surface pump

Connecting a hydraulic accumulator to a system with an external centrifugal pump also has its own nuances, namely:

first thing you need to check internal pressure tank: it should not exceed 1 bar;
To prepare for connection, you will need a five-pin fitting. This one is small, but very important detail combines the accumulator itself, a pipeline, a pressure switch, a pressure gauge and an external pump. Before the actual installation process, you need to stock up on sealing materials (sealant or plumbing tape);
to connect the fitting to the tank, use a rigid hose or flange with a bypass valve;

after installing the tank, it is worth installing the remaining elements: pressure gauge, relay, water supply leading to the pump unit;
before starting operation, a series of on and off cycles should be carried out to identify possible leaks;
if something goes wrong, you need to find out the cause of the problem and, if necessary, repeat the entire installation cycle again.

Connection to water heater

Hydraulic accumulator in a system with storage water heater acts as an expansion tank. As water heats up, it increases in volume, which also increases the load on the water supply. Since pressure increases in a confined space, the process can become very critical, and the temperature decrease is unacceptable. There is a need to move this somewhere overpressure. This is where the hydraulic accumulator comes to the rescue. Excess heated water will go into the hydraulic tank, which will normalize the pressure in the system. Further, the water from the expansion tank can be used for domestic purposes.

Nuances of connecting a hydraulic accumulator

A device with a pear-shaped container assumes that there is water inside it, not air. This feature gives an advantage over the modification with a flat membrane. The reason is that in the latter case the liquid comes into contact with the metal from which the tank body is made. As a result, pockets of corrosion appear. This must be taken into account when choosing a model.

In addition, the bulb is easier to replace if it fails. This usually happens 10-15 years after connection circulation pump with hydraulic accumulator. In addition to the problem of selection, the following aspects must be taken into account during installation:

The mounting point should be located at the highest possible height. Ideally, this is the attic of the house. This factor allows you to increase the pressure in the pipeline.
Despite the fact that the flanges are galvanized and the body is painted, the room where the accumulator is installed must be dry. High humidity will lead to condensation, rust and premature equipment failure.
It is better to connect using flexible stainless steel braided hoses. It should be secured with inch nuts.
The inlet pipe is where the coarse filter is inserted, which will prevent rust, scale and other suspended solids from entering the container and damaging the membrane.
A ball valve is mounted at the inlet, with which you can cut off the wiring from the supply line if you need to repair it or service the pump. There will be no water in the house.

Before purchasing you must make preliminary calculations. They consist in determining the required operating parameters and characteristics of the hydraulic tank. Be sure to watch this video, where the person tells you how to choose a tank yourself.

The opinion “the larger the capacity, the better” is incorrect. Too much water will cause it to stagnate. As a result, harmful bacteria may multiply, sediment may form, and bad smell. Such a tank takes up a lot of space and weighs heavily. If the consumption is small and the power is rarely turned off, purchasing such equipment is not practical.

A tank that is too small is ineffective because the pump will turn on frequently, which will adversely affect service life. A special formula is used for calculations. As alternative method Determining the required tank volume uses the correspondence between the power of the pumping station and the size of the tank. More productivity – larger size tank.

For this purpose, special tables are used. If the conditions are completely cramped, it makes sense to consider purchasing a pump with a soft start, and not spend money on a hydraulic accumulator. But if it is possible to install both elements, the benefits will also include savings. But most importantly, such a system will work for a long time and without interruption.

Expansion tank piping

Before connecting the hydraulic accumulator for individual water supply systems, prepare the following components: automatic devices, filters and adapter couplings for connecting HDPE pipes. After connecting the electric pump to the HDPE water supply using plastic adapter couplings and placing it in the well, further assembly work is carried out in the following sequence:

At the exit water pipe A ball valve and a coarse filter are installed from the pump to remove sand from the water.
After the filter, a tee with a hole diameter suitable for connecting automation is installed. An adapter coupling is screwed into its upper outlet to connect the relay.
To connect the pressure switch and pressure gauge to the electric pump, a standard five-inlet fitting is used, which is connected to the tee using an adapter.
At the outlet of a fitting with an external thread with a diameter of 1 inch, a ball valve with a union nut is installed - this will allow repairs and replacement of components without draining the water from the entire water main.
To the outlet of the fitting with internal thread 1 inch, using a flexible liner, connect the hydraulic accumulator.
Next, a pressure gauge and a pressure switch are installed in the five-pin fitting, and a dry-running relay is screwed into the tee.
At the end they connect electrical cable power supply to the relay - installation of the automation can be considered complete.

Many people prefer to install all automation using connecting fittings directly at the outlet of the accumulator - this technique does not require an underwater hose.

The hydraulic tank is the main component in automatic systems control of electric pumps, necessary to reduce the load on the water main and reduce the operation cycles of pumping equipment. Its connection to the pipeline and adjustment are quite easy to do with your own hands using the simplest plumbing tools. To correctly select an expansion tank, you can use a not too complicated formula or determine its parameters approximately depending on the flow volume or power of the pumping equipment.

Setting up the hydraulic accumulator when connecting

Before using a water supply system with a hydraulic accumulator in a private house, you need to know what the pressure in the hydraulic accumulator should be for its optimal operation; take a portable pressure gauge to take readings. A typical water line with a standard pressure switch has response thresholds from 1.4 to 2.8 bar, the factory setting of the pressure in the hydraulic tank is 1.5 bar. To ensure that the hydraulic accumulator operates efficiently and is completely filled, the lower threshold for switching on the electric pump is selected at 0.2 bar for a given factory setting. more - a threshold of 1.7 bar is set on the relay.

If during operation or due to a long storage period it is determined that the pressure in the hydraulic tank is insufficient when measured with a pressure gauge, proceed as follows:

Disconnect the electric pump from the power supply.
Remove the protective cover and press the hydraulic tank valve in the form of a nipple head at the outlet of the device - if liquid comes from there, then the rubber membrane has been damaged and needs to be replaced. If air comes from the hydraulic tank, its pressure is measured using a car pressure gauge.
Drain the water from the main, opening the one closest to expansion tank tap.
With help hand pump or the compressor pumps air into the battery tank until the pressure gauge reaches 1.5 bar. If, after automation, the water rises to a certain height (high-rise buildings), the total pressure and operating range of the system are increased based on the fact that 1 bar. equated to 10 meters of vertical water column.

When calculating required pressure in the hydraulic tank for any range, select its value 10% less than the lower threshold of the relay operation. Choice given value guarantees that the built-in membrane will expand and contract within a small range and accordingly increase the service life of its and the entire expansion tank.

Optimal air pressure

To Appliances worked normally, the pressure in the hydraulic tank must be in the range of 1.4-2.8 atm. For better preservation of the membrane, it is necessary that the pressure in the water supply system be 0.1-0.2 atm. exceeded the pressure in the tank. For example, if inside membrane tank pressure is 1.5 atm., then in the system it should be 1.6 atm.

It is this value that should be set on the water pressure switch, which works in conjunction with the hydraulic accumulator. For one-story country house This setting is considered optimal. If we are talking about two-story cottage, the pressure will have to be increased. To calculate its optimal value, use the following formula:

Vatm.=(Hmax+6)/10

In this formula V atm. – optimal pressure, and Hmax is the height of the highest water intake point. As a rule, we are talking about the soul. To obtain desired value, you should calculate the height of the shower head relative to the hydraulic accumulator. The obtained data is entered into the formula. As a result of the calculation it will be obtained optimal value pressure that should be in the tank.

Please note that the obtained value should not exceed the maximum permissible characteristics for other household and plumbing appliances, otherwise they will simply fail.

If we talk about an independent water supply system at home in a simplified way, then it constituent elements are:

pump,
hydraulic accumulator,
pressure switch,
check valve,
pressure gauge

The last element is used to quickly control the pressure. Its constant presence in the water supply system is not necessary. It can only be connected at the moment when test measurements are being made.

When a surface pump is involved in the circuit, the hydraulic tank is mounted next to it. The check valve is installed on the suction pipeline, and the remaining elements form a single bundle, connecting to each other using a five-pin fitting.

The five-pin device is ideal for this purpose, since it has pins various diameters. The incoming and outgoing pipelines and some other elements of the bundle can be connected to the fitting using American connectors to facilitate preventive and renovation work in certain sections of the water pipeline.

However, this fitting can be replaced with a bunch connecting elements. But why?

In this diagram, the connection order is clearly visible. When connecting the fitting to the hydraulic accumulator, it is necessary to make sure that the connection is tight.

So, the accumulator is connected to the pump as follows:

one inch lead connects the fitting itself to the hydraulic tank pipe;
a pressure gauge and pressure switch are connected to the quarter-inch terminals;
There are two free inch terminals left, to which the pipe from the pump is mounted, as well as the wiring going to the water consumers.

If the circuit works surface pump, then it is better to connect the hydraulic accumulator to it using a flexible hose with a metal winding.

The hydraulic accumulator is connected to the submersible pump in exactly the same way. A feature of this circuit is the location of the check valve, which has nothing to do with the issues we are considering today.

Injecting water into the hydraulic accumulator

When already posted correct pressure air, you can connect the hydraulic accumulator to the system. After connecting it, you need to carefully observe the pressure gauge. All hydraulic accumulators indicate normal and maximum pressure values, exceeding which is unacceptable. Manual disconnection of the pump from the network occurs when the normal pressure of the accumulator is reached, when the limit value of the pump pressure is reached. This occurs when the increase in pressure stops.

The pump power is usually not enough to pump the tank to the limit, but this is not even particularly necessary, because when pumping, the service life of both the pump and the bulb is reduced. Most often, the pressure limit for switching off is set 1-2 atm higher than switching on.

For example, when the pressure gauge reads 3 atm, which is sufficient for the needs of the owner of the pumping station, you need to turn off the pump and slowly rotate the nut of the small spring (delta P) to decrease until the mechanism is activated. After this, you need to open the tap and drain the water from the system. While observing the pressure gauge, you need to note the value at which the relay turns on - this is the lower pressure limit when the pump turns on. This indicator should be slightly higher than the pressure in an empty accumulator (by 0.1-0.3 atm). This will make it possible to serve the pear for a longer period of time.

When the nut of the large spring P rotates, the lower limit is set. To do this, you need to turn on the pump and wait until the pressure reaches the desired level. After this, it is necessary to adjust the nut of the small spring “delta P” and complete the adjustment of the accumulator.

Video

An indispensable device in modern water supply systems is not only the pump. Very often it is supplemented with a hydraulic accumulator, which can be included with the pump or purchased and installed separately.

Installing a hydraulic accumulator is very useful solution which improves the quality of work. Let's take a closer look at exactly how this mechanism works, how it works and how it is mounted.

1 The design of the hydraulic accumulator and the principle of its operation

First, we will describe the device of a hydraulic accumulator: it is a container with a metal casing, inside of which there is a membrane (or a cylinder, depending on the design). Pressure is created between it and the walls of the housing - thanks to compressed air pumped into the space.

Most often, the installation is used in water supply, but it is also important to use a hydraulic accumulator for heating - it is also suitable for this.

The objectives of the mechanism are as follows:

Water accumulation.
Maintaining stable pressure in the system.
Providing water to the system when the pump is not running.

The operating principle is as follows: water enters the membrane, pumped by a pump. The membrane is filled and fills the space inside the housing (naturally, to a certain volume).

On the other hand, the pumped air begins to put pressure on the water, thereby displacing it into the water supply system. In this case, the pump operates up to a certain point - until the water pressure inside the tank reaches a certain limit.

After this, the unit turns off, and the air acting on it begins to “squeeze” water into the network. Well, when the liquid leaves the container and the pressure drops to a certain (only now minimum) level, the pump will start working again from the automatic control unit.

1.1 Classification

The range of products on the market is quite extensive, so it will be useful for the buyer to find out in advance what exactly they are, how they are classified, and which model is best to choose.

The differences lie in a number of factors, each of which should be mentioned.

According to the location of the container, the device can be either horizontal or vertical.

There may also be differences in the type of working part. In this regard, there are two variations: membrane or balloon. In the first case, the space inside the container is divided into two parts by a membrane: water flows into one, air is pumped into the second.

In the second case, an elastic cylinder is contained inside the container, into which liquid flows, and air is pumped into the free space between its walls and the walls of the body.

Separately, it is necessary to mention the volume - this is, in fact, the key parameter of any capacity. The most popular sizes are 24, 50, 100 and 200 liters. However, you can also find containers of other sizes on sale - 6, 12, or vice versa - 300 liters.

There are also larger devices - for example, the Aquasystem hydraulic accumulator, which can have a volume of up to 2000 liters. The Reflex hydraulic accumulator has a smaller capacity - the largest model has a volume of 1000 liters. The Wester hydraulic accumulator has the same limits.

The material from which the membrane (balloon) is made also deserves detailed attention. It can be either butyl or rubber. The differences are quite serious:

butyl has an upper temperature limit of +99 degrees;
for rubber this mark is lower - only +50 degrees.

This is very important nuance for those who choose a heating device. However, most often devices modern manufacturers(the same Aquasystem hydraulic accumulator) use butyl.

And finally, we need to mention the manufacturers of products of this type. Several items that are most popular have already been mentioned above. This is a Wester and Aquasystem hydraulic accumulator. Models of these brands are included in the high-budget segment, but the quality is appropriate.

The Reflex hydraulic accumulator is already cheaper, but at the same time it is practically not inferior in quality. In addition to these names, we can also highlight Gilex, which is quite popular on the Russian market for its positive qualities: low cost and reliability.

1.2 How to correctly calculate the volume of a hydraulic accumulator?

In principle, the main point that deserves attention is the volume of the tank. The material of the membrane (cylinder) was also mentioned above, however, such devices are used less frequently for heating, so we will focus on capacity.

It should be said right away that models with a capacity of several hundred liters (for example, the Aquasystem VAV 2000 hydraulic accumulator for 2000 liters or the Wester Line WAV 1000 hydraulic accumulator for 1000 liters) are suitable for providing water to large buildings (hotels, hospitals - for example).

For an ordinary residential building, this volume will be a lot, and buying such a model will be a waste of money. Moreover, they cost quite a lot: for example, the mentioned Wester Line WAV 1000 hydraulic accumulator will cost more than 10 thousand dollars, and the Aquasystem VAV 2000 hydraulic accumulator will cost three dozen.

For a cottage in which 3-4 people permanently live, a capacity of up to 100-200 liters will be sufficient (and this is with a huge margin). Often, buyers in such conditions are limited to models of 24-50 liters (for example, the Aquasystem VAV 50 hydraulic accumulator or the Wester Line WAV 50 hydraulic accumulator).

An increase to 100-200 liters is relevant if there are more residents in the house, and/or there are a large number of water intake points (2 toilets and 5-10 taps, for example). In this case, you should pay attention to the Wester Line WAV 100 hydraulic accumulator or the Aquasystem VAV 100 hydraulic accumulator.

For accuracy, we provide a more detailed calculation that will help the buyer more accurately select the appropriate device.

2 Stages and nuances of installation

We figured out how to perform the calculation and how to choose a device. Now we need to mention how exactly the hydraulic accumulator is connected to the water supply system. If you wish, you can do this work yourself - if you follow the tips below, then there should be no difficulties.

In this case, it does not matter which model is connected - a Reflex hydraulic accumulator for a couple of tens of liters or a tank for 300 liters.

The preparation looks like this:

First of all, you need to choose the place where the equipment will be located: an automatic water supply station and, in fact, the tank itself. They do not have to be placed next to each other, but most often this is how it is done.
The pressure inside the container is checked. It is necessary that this indicator be approximately 0.2-1 atmospheres lower than the parameter set on the automatic pump start relay. Otherwise, you can (and should) adjust it yourself.

Now you need to take care of necessary details to connect:

A fitting with 5 outputs: for the tank itself, for the automatic switch-on relay, for the pressure gauge, for the pump and, in fact, for the water line itself.
Pressure gauge (with a scale up to 10 atmospheres).
FUM tape (for sealing joints).

Now let’s look at how you can make the connection yourself:

The fitting is connected to the container using a hose.
A pressure gauge, relay, pump, etc. are connected to the other outputs of the fitting. Each connection is pre-sealed with FUM tape.

Upon completion of work, you should perform trial run pump - to determine the tightness of the system. To do this, you need to carefully inspect the connection points: there should be no leaks along them.

When connecting the pressure switch with your own hands, be sure to look very carefully at the marks that are marked under its cover. There are two of them - these are "Network" and "Pump", and under no circumstances should they be confused. It is possible that these marks will not appear at all (this happens with some models) - in this case, it is recommended not to make the connection yourself, but to use the help of an electrician.