How to connect a hydraulic accumulator to a water supply system. We stabilize the work of autonomous water supply systems: a hydraulic accumulator for private houses Water supply in a private house choosing a hydraulic accumulator

A hydraulic accumulator is a special metal sealed container containing an elastic membrane inside and a certain volume of water under a certain pressure.

A hydraulic accumulator (in other words, a membrane tank, a hydraulic tank) is used to maintain stable pressure in the water supply system, protects the water pump from premature wear due to frequent switching on, and protects the water supply system from possible water hammer. In the event of a power outage, thanks to the hydraulic accumulator, you will always have a small supply of water.

Here are the main functions that a hydraulic accumulator performs in a water supply system:

Protecting the pump from premature wear. Due to the water reserve in the membrane tank, when the water tap is opened, the pump will turn on only if the water supply in the tank runs out. Any pump has a certain rate of inclusions per hour, therefore, thanks to the accumulator, the pump will have a supply of unused inclusions, which will increase its service life.
Maintenance of constant pressure in the plumbing system, protection against drops in water pressure. Due to pressure drops, when several taps are turned on at the same time, sharp fluctuations in water temperature occur, for example in the shower and in the kitchen. The hydraulic accumulator successfully copes with such unpleasant situations.
Protection against water hammer, which can occur when the pump is turned on, and can spoil the pipeline in order.
Maintaining a supply of water in the system, which allows you to use water even during a power outage, which happens quite often in our time. This feature is especially valuable in country houses.

Hydraulic accumulator device

The hermetic case of this device is divided by a special membrane into two chambers, one of which is designed for water, and the other for air.

Water does not come into contact with the metal surfaces of the body, as it is in a water chamber-membrane made of strong butyl rubber material that is resistant to bacteria and meets all hygienic and sanitary standards for drinking water.

In the air chamber there is a pneumatic valve, the purpose of which is to regulate pressure. Water enters the accumulator through a special threaded connection pipe.

The accumulator device must be mounted in such a way that it can be easily disassembled in case of repair or maintenance, without draining all the water from the system.

The diameters of the connecting pipeline and the discharge pipe should, if possible, match each other, then this will avoid unwanted hydraulic losses in the system pipeline.

In the membranes of accumulators with a volume of more than 100 liters, there is a special valve for bleeding air released from the water. For small-capacity accumulators that do not have such a valve, a device for bleeding air must be provided in the water supply system, for example, a tee or a tap that shuts off the main line of the water supply system.

In the air valve of the accumulator, the pressure should be 1.5-2 atm.

The principle of operation of the accumulator

The hydraulic accumulator works like this. The pump supplies water under pressure to the accumulator membrane. When the pressure threshold is reached, the relay turns off the pump and the water stops flowing. After the pressure begins to drop during water intake, the pump automatically turns on again and supplies water to the accumulator membrane. The larger the volume of the hydraulic tank, the more effective the result of its work. The operation of the pressure switch can be adjusted.

During the operation of the accumulator, the air dissolved in water gradually accumulates in the membrane, which leads to a decrease in the efficiency of the device. Therefore, it is necessary to carry out preventive maintenance of the accumulator by bleeding the accumulated air. The frequency of preventive maintenance depends on the volume of the hydraulic tank and the frequency of its operation, which is approximately once every 1-3 months.

These devices are available in vertical and horizontal configurations.

The principle of operation of the devices does not differ, except that vertical accumulators with a volume of more than 50 liters in the upper part have a special valve for bleeding air, which gradually accumulates in the water supply system during operation. Air accumulates in the upper part of the device, therefore the location of the bleed valve is chosen exactly in the upper part.

In horizontal devices for bleeding air, a special tap or drain is mounted, which is installed behind the accumulator.

From devices of small sizes, regardless of whether they are vertical or horizontal, the air is bled off by completely draining the water.

When choosing the shape of a hydraulic tank, they proceed from the dimensions of the technical room where they will be installed. It all depends on the dimensions of the device: which one fits best into the space allotted for it, this will be installed, regardless of whether it is horizontal or vertical.

Hydraulic accumulator connection diagram

Depending on the assigned functions, the scheme for connecting the accumulator to the plumbing system may be different. The most popular hydraulic accumulator connection diagrams are shown below.

Such pumping stations are installed where there is a large water consumption. As a rule, one of the pumps at such stations operates constantly.
At the booster pumping station, the accumulator serves to reduce pressure surges during the activation of additional pumps and to compensate for small water intakes.

Such a scheme is also widely used when there is a frequent interruption in the supply of electricity to booster pumps in the water supply system, and the presence of water is vital. Then the supply of water in the accumulator saves the situation, playing the role of a backup source for this period.

The larger and more powerful the pumping station, and the more pressure it must maintain, the larger the volume of the hydraulic accumulator, which acts as a damper, should be.
The buffer capacity of the hydraulic tank also depends on the volume of the required water supply, and on the difference in pressure when the pump is turned on and off.

For long and uninterrupted operation, a submersible pump must make from 5 to 20 starts per hour, which is indicated in its technical specifications.

When the pressure in the plumbing system drops to the minimum value, the pressure switch automatically turns on, and at the maximum value it turns off. Even the smallest water flow, especially in small water supply systems, can lower the pressure to a minimum, which will instantly give a command to turn on the pump, because water leakage is compensated by the pump instantly, and after a few seconds, when the water supply is replenished, the relay will turn off the pump. Thus, with minimal water consumption, the pump will run almost idle. This mode of operation adversely affects the operation of the pump and can quickly disable it. The situation can be corrected by a hydraulic accumulator, which always has the necessary supply of water and successfully compensates for its insignificant consumption, and also protects the pump from frequent switching on.

In addition, a hydraulic accumulator connected to the circuit smooths out a sharp increase in pressure in the system when the submersible pump is turned on.

The volume of the hydraulic tank is selected depending on the frequency of switching on and the power of the pump, the water flow per hour and the height of its installation.

For a storage water heater in the connection diagram, the accumulator plays the role of an expansion tank. When heated, the water expands, increasing the volume in the water supply system, and since it does not have the ability to compress, the most minimal increase in volume in a confined space increases pressure and can lead to the destruction of the elements of the water heater. Here, too, a hydraulic tank will come to the rescue. Its volume will directly depend and increase from an increase in the volume of water in the water heater, an increase in the temperature of the heated water and an increase in the maximum allowable pressure in the water supply system.

The hydraulic accumulator is connected in front of the booster pump along the water course. It is needed to protect against a sharp decrease in pressure in the water supply network at the moment the pump is turned on.

The capacity of the accumulator for the pumping station will be the greater, the more water is used in the water supply system and the smaller the difference between the upper and lower pressure scales in the water supply before the pump.

How to install a hydraulic accumulator?

From the foregoing, it can be understood that the device of a hydraulic accumulator is absolutely different from an ordinary water tank. This device is constantly in operation, the membrane is constantly in dynamics. Therefore, the installation of a hydraulic accumulator is not so simple. The tank must be strengthened during installation securely, with a margin of safety, noise and vibration. Therefore, the tank is fixed to the floor through rubber gaskets, and to the pipeline through rubber flexible adapters. You need to know that at the inlet of the hydraulic system, the cross section of the liner should not narrow. And one more important detail: for the first time, the tank must be filled very carefully and slowly, using a weak pressure of water, in case the rubber bulb sticks together from long inactivity, and it can be damaged with a sharp pressure of water. It is best to remove all air from the bulb before commissioning.

The installation of the accumulator must be carried out so that during operation it can be freely approached. It is better to entrust this task to experienced specialists, since very often the tank fails due to some unaccounted for, but important trifle, for example, due to a mismatch in pipe diameter, unregulated pressure, etc. It is impossible to conduct experiments here, because the normal operation of the plumbing system is at stake.

So you brought the purchased hydraulic tank into the house. What to do with him next? Immediately you need to know the level of pressure inside the tank. Usually, the manufacturer pumps it up to 1.5 atm, but there are cases when, due to a leak, the indicators decrease by the time of sale. To make sure that the indicator is correct, it is necessary to unscrew the decorative cap on an ordinary automobile spool and check the pressure.

How to check it? Usually a manometer is used for this. It can be electronic, mechanical automotive (with a metal case) and plastic, which is supplied with some pump models. It is important that the pressure gauge has greater accuracy, since even 0.5 atm changes the quality of the hydraulic tank, so it is better not to use plastic pressure gauges, as they give a very large error in performance. These are usually Chinese models in a weak plastic case. The performance of electronic pressure gauges is affected by battery charge and temperature, and besides, they are very expensive. Therefore, the best option is an ordinary automobile pressure gauge that has been tested. The scale should be on a small number of divisions, in order to be able to more accurately measure pressure. If the scale is designed for 20 atm, and you need to measure only 1-2 atm, then high accuracy cannot be expected.

If there is less air in the tank, then there is a larger supply of water, but the difference in pressure between an empty and almost full tank will be very significant. It's all about preference. If it is necessary that the water supply constantly has a high pressure of water, then the pressure in the tank must be at least 1.5 atm. And for domestic needs, 1 atm may well be enough.

At a pressure of 1.5 atm, the hydraulic tank has a smaller supply of water, which will cause the pumping pump to turn on more often, and in the absence of light, the water supply in the tank may simply not be enough. In the second case, you will have to sacrifice pressure, because you can take a shower with a massage when the tank is full, and as it is empty, you can only take a bath.

When you decide what is more important for you, you can set the desired mode of operation, that is, either pump air into the tank or bleed the excess.

It is undesirable to reduce the pressure below the mark of 1 atm, as well as to exceed it excessively. A pear filled with water with insufficient pressure will touch the walls of the tank, and can quickly become unusable. And excess pressure will not allow a sufficient volume of water to be pumped in, since most of the tank will be occupied by air.

Setting the pressure switch

You also need to adjust the pressure switch. Opening the cover, you will see two nuts and two springs: a large one (P) and a small one (delta P). With their help, you can set the maximum and minimum pressure levels at which the pump turns on and off. A large spring is responsible for turning on the pump and pressure. By design, you can see that it kind of helps the water to close the contacts.

With the help of a small spring, the pressure difference is set, as specified in all instructions. But the instructions do not specify a starting point. It turns out that the reference point is the spring nut P, that is, the lower limit. The lower spring, which is responsible for the pressure difference, resists the water pressure and moves the movable plate away from the contacts.

When the correct air pressure is already set, you can connect the accumulator to the system. Having connected it, you need to carefully observe the pressure gauge. All hydraulic accumulators have the values of normal and limiting pressures, the excess of 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 head is reached. This happens when the pressure increase stops.

The pump power is usually not enough to pump the tank to the limit, but this is not even necessary, because when pumping, the life of both the pump and the pear is reduced. Most often, the pressure limit for turning off is set 1-2 atm higher than turning 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 triggered. After that, you need to open the tap and drain the water from the system. Watching the pressure gauge, it is necessary 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 indicator 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 is rotated, the lower limit is set. To do this, turn on the pump in the network and wait until the pressure reaches the desired level. After that, it is necessary to adjust the nut of the small delta P spring and complete the adjustment of the accumulator.

In the accumulator air chamber, the pressure must be 10% lower than the pressure when the pump was turned on.

An accurate indicator of air pressure can be measured only when the tank is disconnected from the water supply system, in the absence of water pressure. Air pressure must be constantly kept under control, if necessary, adjusted, which will add life to the membrane. Also, to continue the normal functioning of the membrane, a large pressure drop should not be allowed when the pump is turned on and off. Normal is a difference of 1.0-1.5 atm. Stronger pressure drops reduce the life of the membrane, greatly stretching it, moreover, such pressure drops do not allow comfortable use of water.

Hydraulic accumulators can be installed in places with low humidity, not subject to flooding, so that the flange of the device can successfully serve for many years.

When choosing a brand of a hydraulic accumulator, it is necessary to pay special attention to the quality of the material from which the membrane is made, check the certificates and sanitary and hygienic conclusions, making sure that the hydraulic tank is intended for systems with drinking water. You also need to make sure that you have spare flanges and diaphragms, which should be in the kit, so that in case of a problem you do not have to buy a new hydraulic tank.

The maximum pressure of the accumulator, for which it is designed, must not be less than the maximum pressure in the water supply system. Therefore, most devices can withstand a pressure of 10 atm.

To determine how much water can be used from the accumulator when the electricity is turned off, when the pump stops pumping water from the water supply system, you can use the diaphragm tank fill table. The water supply will depend on the setting of the pressure switch. The higher the pressure difference when turning the pump on and off, the greater the supply of water will be in the accumulator. But this difference is limited for the reasons stated above. Consider a table.

Here we see that in a 200 l membrane tank with pressure switch settings, when the pump on indicator is 1.5 bar, the pump off is 3.0 bar, the air pressure is 1.3 bar, the water supply will be only 69 l, which is equal to about a third of the total volume of the tank .

Calculation of the required volume of the accumulator

To calculate the accumulator, use the following formula:

Vt = K * A max * ((Pmax+1) * (Pmin +1)) / (Pmax- Pmin) * (Pair + 1),

Amax - maximum consumption of liters of water per minute;
K is a coefficient that depends on the power of the pump motor;
Pmax - pressure when the pump is turned off, bar;
Pmin is the pressure when the pump is turned on, bar;
Pair - air pressure in the accumulator, bar.

As an example, we select the required minimum volume of a hydraulic accumulator for a plumbing system, taking, for example, the Aquarius BTsPE 0.5-40 U pump with the following parameters:

Pmax (bar)	Pmin (bar)	Pair (bar)	A max (cubic meters/hour)	K (ratio)
3.0	1.8	1.6	2.1	0.25

Using the formula, we calculate the minimum volume of HA, which is 31.41 liters.

Therefore, we choose the next closest GA size, which is 35 liters.

The volume of the tank in the range of 25-50 liters is ideally consistent with all methods for calculating the volume of HA for domestic plumbing systems, as well as with empirical assignments from different manufacturers of pumping equipment.

With frequent power outages, it is advisable to choose a larger tank, but at the same time, it should be remembered that water can only fill the tank by 1/3 of the total volume. The more powerful the pump is installed in the system, the larger the volume of the accumulator should be. This sizing will reduce the number of short pump starts and extend the life of the pump motor.

If you bought a large-capacity hydraulic accumulator, you need to know that if water is not used regularly, it stagnates in the HA tank and its quality deteriorates. Therefore, when choosing a hydraulic tank in a store, you need to take into account the maximum amount of water used in the water supply system at home. Indeed, with a small water consumption, it is much more expedient to use a tank with a volume of 25-50 liters than 100-200 liters, the water in which will be wasted.

Repair and prevention of the hydraulic accumulator

Even the simplest hydraulic tanks require attention and care, like any device that works and benefits.

The reasons for repairing a hydraulic accumulator are different. This is corrosion, dents in the body, violation of the integrity of the membrane or violation of the tightness of the tank. There are also many other reasons that oblige the owner to repair the hydraulic tank. In order to prevent serious damage, it is necessary to regularly inspect the surface of the accumulator, monitor its operation in order to prevent possible problems. It is not enough to inspect the GA twice a year, as stipulated in the instructions. After all, one malfunction can be eliminated today, and tomorrow not to pay attention to another problem that has arisen, which over the course of six months will turn into an irreparable one and can lead to the failure of the hydraulic tank. Therefore, the accumulator must be inspected at every opportunity, so as not to miss the slightest malfunction, and to carry out their repair in time.

Causes of breakdowns and their elimination

The reason for the failure of the expansion tank may be too frequent switching on / off of the pump, water outlet through the valve, low water pressure, low air pressure (lower than calculated), low water pressure after the pump.

How to troubleshoot a hydraulic accumulator with your own hands? The reason for repairing the accumulator can be low air pressure or its absence in the membrane tank, damage to the membrane, damage to the housing, a large difference in pressure when the pump is turned on and off, or an incorrectly selected volume of the hydraulic tank.

Troubleshooting can be done as follows:

to increase the air pressure, it is necessary to force it through the tank nipple with a garage pump or compressor;
a damaged membrane can be repaired at a service center;
the damaged case and its tightness are also eliminated in the service center;
you can correct the difference in pressure by setting too large a differential in accordance with the frequency of switching on the pump;
The sufficiency of the tank volume must be determined before it is installed in the system.

And horizontal. The name fully characterizes the way they are installed. Which one to choose if the dimensions of your room allow you to use both types.

The choice of accumulator

The selection of a hydraulic accumulator depends on many factors. Here we would recommend to pay attention to the method of removing the accumulated air inside the rubber membrane. The fact is that in water supply systems there is always dissolved air in the water. Over time, during operation of the system, this air is released from the water and accumulates in various places, forming air pockets. One of these places is the cavity A of the accumulator. To remove this air, as well as air locks that occur during installation and repair of the system, an additional nipple is provided in the design of large accumulators (100 or more liters), through which the air accumulated in the system is periodically bled. When using a vertical accumulator with a capacity of more than 100 liters, air accumulates in the upper part and can be removed using this air release valve.

In hydraulic accumulators for horizontal water supply, air can be removed using an additional section of the pipeline, consisting of an outlet air nipple, a ball valve and a drain into the sewer. At the same time, the accumulated air should be bled periodically once a month. Small volume accumulators are not equipped with an air bleed nipple. Therefore, the choice of a hydraulic accumulator is carried out exclusively by the convenience of the layout in your room. The removal of accumulated air in them is carried out by periodic complete emptying. To do this, an additional ball valve can be provided in the pipeline scheme. In addition, it is possible to remove air from systems with a small accumulator simply by periodically (once a week) turning off the power supply to the installation and bleeding the accumulated air through a washbasin or shower tap or other draw-off point closest to the accumulator. However, for greater efficiency, this procedure should be repeated several times. That is, turn off the power to the pump, open the cold water tap, drain the water completely, close the tap and turn on the power to the pump. And so two or three times in a row.

How to choose the size of the water supply hydraulic accumulator?

The correct selection of accumulators for individual water supply systems is quite complicated. There is a large amount of input data that needs to be taken into account. In addition to the traditional shower and faucet in the kitchen, modern homes can be equipped with a bathtub, bidet, sewer, washing machine and other equipment that requires water to operate. In addition to equipment, the number of people in the house can be different. These are objective factors, but when choosing the size of a hydraulic accumulator, subjective factors also have to be taken into account. For example, how many times per hour can you turn on the pump and fill the accumulator? What happens if several people use water at once? What happens if the washing machine is running at this time?

It should be noted that up to now, in our opinion, there have been no methods for choosing the volume of hydraulic accumulators in Russia. Firstly, because in Russia there were no individual water supply systems. Secondly, people's requirements for such systems are too different. We offer you a method for selecting the volume of a hydraulic accumulator, which is based on the international calculation method UNI 9182.

Let's start with the fact that if you only have a water faucet, a shower and a watering faucet in your house, then you don't need to count anything. You need a standard water supply installation with a 24 liter hydraulic accumulator. Feel free to buy it. It is optimal in cases where the number of permanent residents in the house is up to four people. Even if you need to increase the number of water outlets in the future, you can simply buy separately and install another 24-liter hydraulic accumulator at any point in the system.

If you have a house without sewerage, but with more than three points of water analysis, then in any case, a hydraulic accumulator volume of 50 liters is enough for you.

The methodology for calculating the volume of a hydraulic accumulator is intended for individual houses equipped with a sewerage system (septic tank), with bathtubs and other equipment that consumes a significant amount of water.

1. Determine the total water consumption coefficient Su. To do this, make a list of points of analysis in your home and indicate the number of each type of equipment.

2. Fill in table 1. Its second column is a table of coefficients for the frequency of use of each type of equipment (Cx). In the third column, enter the number of devices of each type of equipment in your home (n). In the right column of the table, multiply the Cx value by n. Sum the values of this column. You will get the total water consumption coefficient of your house.

Table 1. Determination of the total consumption coefficient Su

Type of equipment	Utilization coefficient Сх	Number of each kind n	Product Cx x n



Faucet in the sink

Faucet in the kitchen
Washing machine
Dishwashing machine
Irrigation faucet
The total coefficient Su is = _______

3. Depending on the obtained value of the total coefficient Su, determine the value of the maximum water flow required for your home. These values are presented in table 2.

For example, if you have a toilet, a shower, a faucet in the sink, a faucet in the kitchen (one for each device), then your consumption coefficient is Su = 3+2+6+2=13. The nearest Su value in the table is 12, therefore, for the normal functioning of the water supply system at home, you need to ensure a maximum flow of about 36 liters per minute.

4. To determine the volume of the accumulator, it is necessary to decide how many times per hour (a) it is allowed to turn on the accumulator at maximum consumption intensity. Normal is 10-15 times per hour. It is also required to assign thresholds for the pressure switch of the water supply station (Рmin and Рmax). The lower threshold Pmin for two-story houses is usually 1.5 bar, and the upper threshold Pmax is 3 bar.

Calculation of air pressure in the accumulator

What initial air pressure should be in the accumulator? If you installed a hydraulic accumulator in the basement, then its minimum value is easy to calculate. You need to take the height in meters from the basement to the top point of your water supply system. For example, for a two-story house it is 6-7 meters, a three-story house is about 10 meters, then add 6 to this value and divide by 10. You will get the required value in atmospheres. For example, for a two-story house 7 + 6 = 13 / 10 = 1.3 atmospheres. This is the minimum air pressure in the accumulator. Otherwise, water from it will not flow to the second floor of your house. However, these values \u200b\u200bshould not be overestimated, otherwise there will simply be no water in the accumulator. Usually the manufacturer himself sets the air pressure in the amount of 1.5 atm., but it may happen that the air pressure in the accumulator you purchased will be different. You should initially check it with an ordinary pressure gauge, connecting it to the accumulator nipple and, if necessary, increase it using a car pump.

The difference between the operation thresholds Pmax - Pmin determines the amount of water produced by the accumulator. The greater this difference, the more efficient the operation of the accumulator, but in this case the membrane is loaded more heavily and may burst.

The Pmin value (pump start pressure) is determined based on the hydrostatic pressure (water height) in your home's water supply system. For example, if the height of the pipes in your system is 10 meters, then the pressure of the water column will be 10 meters, which is equal to a pressure of 1 bar.

What should be the minimum pressure Pmin? The air pressure in the counter pressure chamber of the accumulator must be equal to the hydrostatic pressure, that is, in our case 1 bar. The lower threshold Pmin should then be slightly higher (by 0.1 bar) than the air pressure in the accumulator.

However, we need the system to work stably. The most critical, in terms of stability, is the highest point of analysis (for example, a faucet or shower on the top floor). The valve works normally if the pressure drop in it is at least 0.5 bar.

Therefore, the pressure must be 0.5 bar plus the hydrostatic pressure of that point. Thus, the minimum value of the gas pressure in the accumulator is 0.5 bar plus the value of the reduced hydrostatic pressure at the location of the accumulator (height distance between the upper point of analysis and the location of the accumulator). In our case, if the accumulator is located at the lowest point of the water supply system, then the minimum gas value in it should be set to 1 bar + 0.5 bar = 1.5 bar, and the threshold for operating (turning on) the pump Pmin = 1.5 + 0.1 = 1.6 bar. If the accumulator is located at the upper point, and the pressure sensor is at the lower point of the system, then the gas pressure in the accumulator should be set to 0.5 bar, and the pump activation threshold Pmin = 1.6 bar.

When assigning an upper threshold for the operation of an automatic water supply system, several points must be taken into account, first of all, the pressure characteristic of the pump. The value of the pressure generated by the pump in meters of water column, divided by 10, will show the maximum pressure value. However, it is necessary to take into account:

The characteristics of the pump indicate the maximum parameters without taking into account the hydraulic resistance of pipelines;

The voltage in the electrical network often does not correspond to the nominal 220 V;

At maximum head values, the pump flow is minimal and your system will take a very long time to fill.

With prolonged use, the performance of the pump decreases.

Knowing how to choose a hydraulic accumulator for water supply systems, you can not only ensure pressure stability in an individual pipeline, but also extend the life of the pump and communications.

A hydraulic accumulator is a reservoir that contains pressurized water designed to compensate for changes in the system. Why is a hydraulic accumulator needed in a water supply system? Its presence can solve many common problems in the operation of individual water supply systems and provide:

maintaining the pressure required for normal operation of the consumption points at a time when the pump is not turned on,
prevention of frequent switching on of the pumping unit, which can lead to rapid wear,
protection against water hammer dangerous for pipes, fittings and gaskets,
availability of a supply of water in the event of a power outage or failure of the pump.

The right choice of a hydraulic accumulator for water supply systems allows you to install a reliable intermediate link between the pump and the consumer. Such equipment compensates for minor changes - a small flow and a decrease in pressure, allowing powerful equipment to replenish the volume only when it is significantly reduced.

Types of construction and their device

In order to know exactly how to choose the right accumulator for water supply systems, it is important to study the characteristic features of various models.

Location

There are on sale horizontal and vertical models of hydraulic accumulators, the type is chosen, first of all, guided by the availability of free space in the pump room. If the free space allows you to install any of the modifications, and the volume of the accumulator exceeds 100 liters, it would be more expedient to purchase a vertical model.

This choice is due to the fact that when the liquid flows in the tank, air bubbles appear, which always accumulate in the upper part of the tank. In a vertical accumulator, the area of the upper part is smaller, which facilitates the process of bleeding air. This is usually done with a special nipple. The location of bubbles in a horizontal tank with a large top area is more difficult to determine. A tap with a valve can be used for bleed. The presence of air in the accumulator is undesirable due to the likelihood of air locks.

For models less than 100 liters, the location does not matter, although when used in conjunction with pumping stations, the choice is usually given in favor of the horizontal option.

Device models

Choosing a battery for a water supply system includes deciding which device will be more efficient. In general, the device of all types of equipment in this category is similar - the capacity of the accumulator is divided into two parts. One part contains compressed air and the other contains water. The plasticity of the partition of materials separating water and air allows the latter to "push" the liquid into the system.

There are two main types of accumulators - membrane and balloon. The latter are often called "pears" in everyday life.

membrane models literally divide the reservoir into two parts,
balloons are arranged according to the “vessel in a vessel” principle, water is pumped into a container made of rubber rubber, which, in turn, is surrounded on all sides by air.

When choosing, it is usually doubtful that in membrane models water comes into contact with the walls of the accumulator, however, high-quality materials are used in models of reliable manufacturers, so the risk of corrosion is not high, and the water does not acquire an undesirable aftertaste.

To make it easier to understand the question of how to choose a hydraulic accumulator for water supply systems, we recommend watching this video.

Criterias of choice

Obviously, one of the main characteristics of the accumulator is its volume. It should be remembered that water usually occupies only half of the tank. In addition, the features of operation should be taken into account - this equipment can be a “reserve” in case of a power outage. The pump does not work at this time, but the water supply of the house will not stop due to the supply of fluid from the accumulator. In this case, a volume larger than the nominal one is selected.

The nominal volume is selected taking into account the fact that the accumulator during normal operation is switched on about 15 times per hour. Pump performance also matters. In this case, the basic parameter in the calculations is the volume of water consumption. It is not difficult to calculate it with a high degree of accuracy by counting the number of consumption points with water consumption coefficients according to the UNI 9182 system. At the same time, there is no need for such accuracy, since there are not many variations of such equipment.

Suffice it to calculate:

No more than three points of consumption and a pump with a capacity of about 2 cubic meters. m / hour correspond to a hydraulic accumulator of 20-24 liters.
Up to 8 consumers and a pump for 3.5 cubic meters. m / hour - 50-60 liters.
Over 10 flow points and a 5cc pump m / hour - 100 liters.

When calculating the air pressure in a hydraulic accumulator for water supply systems, the location of the accumulator is taken into account in relation to the highest point of water intake.

The accumulator must provide:

pressure is higher than in the system,
rise to a certain height (from the basement to the level of the dwelling, and sometimes to the 2nd, 3rd floor),
normal pressure in the tap (at least 0.5 bar).

When calculating the pressure for lifting, it is considered that for every 10 meters (approximately 3 floors) 1 bar of pressure is needed.

Thus, for private houses, accumulators are selected with a pressure in the range of 1.5-4.5 bar.

Important: The operating pressure of the accumulator must be at least 0.5 bar lower than the cut-in pressure of the water pump.

Sometimes it is recommended to take into account the mass of the filled accumulator when choosing, however, this characteristic is more important when installing equipment, prefer a tank with a pressure less than necessary just because it is lighter, wrong.

The hydraulic accumulator works in conjunction with the automation system, which acts as. Learn more about its device and how it works.

How to choose a pumping station, read the material.

You can find the hydraulic accumulator connection diagram at this address.

Possible malfunctions

A breakdown, which in any case requires an appeal to specialists, is hull damage. "Patch" it at home will not work.
Water in the air valve is a sign of membrane damage. Such a partition is not subject to repair. It must be replaced, and it is important to purchase an identical one, without trying to fit the first one that you managed to buy. Procedure:

Cut off the accumulator from the water supply system by closing the valve.
Drain water from the tank and from the section of the underwater pipe located after the valve.
Disconnect the tank and partially disassemble it (unscrew the bolts and remove the counterflange).
Remove the damaged membrane through the hole formed.
Prepare the membrane by treating its outer surface with talc.
Prepare the internal cavity of the accumulator by blowing it with air.
Install a new membrane in accordance with the instructions (ensure a snug fit of its apron to the flange).
Assemble the accumulator.
Restore the air pressure that has decreased due to loss of tightness.

Rapid reduction of air pressure- evidence of damage to the nipple. If purge does not change the situation, it will need to be replaced.

The right choice, competent installation and operation of the accumulator will stabilize the water supply in the house or in the country.

A hydraulic accumulator (hydraulic tank) is a metal container designed to be connected to water supply pumps, inside which a reserve amount of water is stored at a given pressure. By equipping the pump with a hydraulic accumulator, you will always have a small supply of drinking water in the house, even in the absence of electricity.

In this article we will consider a hydraulic accumulator for water supply systems, we will study its purpose, device and principle of operation. You will also learn about the varieties of such equipment, the features of its selection, calculation and connection.

1 Purpose, device and principle of operation

Initially, let's clarify the terms - a hydraulic tank and an expansion tank are not the same devices. The accumulator is used in water supply systems of a private house, arranged for water supply using a pump from an external source, while an expansion tank is installed in heating and hot water systems in order to stabilize their pressure and prevent the occurrence of water hammer.

Consider the main functions of a hydraulic tank in water supply systems:

the device prevents pump wear due to frequent switching on - since the tank constantly contains water, the pump will start only when it is empty, which will positively affect the durability of the unit;
the hydraulic accumulator reduces the likelihood of water hammer in the pipeline when the pump is turned on, it also maintains a stable pressure in the system, preventing pressure fluctuations when several taps are used simultaneously;
the tank provides a constant supply of water, which is especially important in country houses with problematic power supply.

The hydraulic tank device consists of a directly metal tank and a membrane located inside it, which divides the tank into two chambers - one for water, the second for air. The water chamber is made of butyl, a sanitary-safe variety of rubber, the liquid stored in it does not come into contact with the metal walls of the tank. Water is supplied and drained through two threaded pipes, to which pipelines are connected, the pipes have an identical diameter.

The pneumatic valve is responsible for regulating the pressure in the air chamber. Large volume accumulators (100 liters and above) are equipped with a check valve, which is needed to bleed air from the water chamber. A shut-off valve performs a similar function in small tanks. The standard air pressure in the accumulator is 1.5-2 Bar.

The principle of operation of the hydraulic tank is quite simple. Initially, the pump pumps water into the tank, and when the storage tank is full, the pressure switch detects this and turns off the pump, stopping the supply. Further, as the water reserve is used up, the relay detects a decrease in pressure, turns on the pump and the cycle repeats.

1.1 Varieties of hydraulic tanks and features of their calculation

Depending on the shape of the body, this equipment is divided into two types - horizontal and vertical hydraulic accumulator. There is only one design difference between them - vertical tanks with a volume of more than 50 liters are equipped with a tap to bleed air, which accumulates in the water chamber and reduces the efficiency of the device. In horizontal tanks with a volume of 50-100 liters, the valve is located in the end part on the side of the body.

In all hydraulic accumulators with a volume of less than 50 liters, air is bled from the water chamber by completely draining the water. The choice of the shape of the tank is based on the size of the room where it will be mounted. There are no tricks here - you need to take the tank that fits best into the space allotted for it.

More difficult is the choice of a tank according to the performance parameter. Here you need a calculation of the equipment, which will help determine its required volume.

The calculation is performed according to the formula: O \u003d K * Rmax * (Dmax + 1) * (Dmin + 1) / (Dmax-Dmin) - (P + 1), in which:

K is the power factor of the pump connected to the hydraulic tank;
Rmax - the largest planned flow of liters of water per minute;
Dmax - water pressure level in the tank to turn off the pump (Bar);
Dmin - water pressure limit to turn on the pump (Bar);
P - air pressure in the hydraulic tank (Bar).

The coefficient of the pump depends on the power of its engine:

power 0.55-1.5 kW - coefficient 0.2;
2-3 kW - 0.375;
4-5.5 kW - 0.625;
5-9 kW - 0.875.

The calculation of almost any hydraulic accumulator for domestic water supply stations will show that it is necessary to use a tank with a volume of 25-50 liters. This is the optimal volume for most pumps for wells and wells, which will be enough for a full-fledged water supply to a private house.

It makes sense to take a larger accumulator (75 and 100 liters) with frequent and prolonged power outages at home, when a serious supply of drinking water is needed. Under normal conditions, buying a tank "with a margin" is pointless, since unused water in it will stagnate and lose its taste.

1.2 How to choose a hydraulic accumulator? (video)

2 Wiring diagrams and installation features

The choice of the hydraulic tank connection scheme must be carried out based on the functions assigned to it. In total there are 3 connection schemes:

To connect the hydraulic tank and put it into operation, you do not need to call specialists, you can do everything yourself. The tank is attached to the floor or wall using anchors, and it is imperative to place a gasket made of vibration-proof material under the mounting plate. Connection of pipes to the branch pipe of the storage tank is carried out through special flexible adapters that come with it.

After the installation of the tank is completed, it is adjusted - initially you need to determine the pressure in the accumulator, which can be done using a conventional pressure gauge. On the body of the tank you will find a spool to which the measuring device is attached. The normal pressure level is 1.5 bar, if its actual value is different, then it is necessary to pump air with a pump.

As already mentioned, the water inside the container is in a rubber "pear", surrounded by air. The more air in the tank, the more the pear shrinks and loses its maximum size. And vice versa - the less air, the larger and more capacious the pear, but the less water supply pressure. You can adjust the pressure within 1-2 bar at your discretion, achieving the desired operating mode of the hydraulic tank.

It is also necessary to adjust the pressure switch. Under the cover of the relay housing there is a pair of springs (large and small). Changing their position allows you to set the minimum and maximum pressure levels at which the station will turn on the pump. A large spring is responsible for the minimum level at which the water supply begins. The required pressure difference is set with a small spring.

The most common failure of the accumulator is the loss of tightness between the working media - water and air, which occurs due to wear or damage to the rubber membrane (pear).

The reason for the depressurization of the membrane is the wear of rubber, which occurs due to its stretching with water at an insufficient level of air pressure in the tank. Also, accelerated wear provokes accelerated pumping of water from the tank - after complete emptying, the membrane folds into a flat sheet with strongly curved edges.

Trying to restore a worn-out membrane with your own hands is pointless, since no patches will return it to full tightness. You will need to buy a new membrane that matches the size of your tank and replace the damaged part.

The algorithm of actions is as follows:

The water is completely drained from the tank and the tank is disconnected from the pipeline.
The bolts fixing the flange on the back side of the tank are unscrewed, and the air pump spool nut is also dismantled.
The spool is pushed through the hole into the tank, after which the membrane is removed from the body.
The internal cavity of the tank, if necessary, is cleaned of corrosion and deposits using sandpaper or a metal brush.
A new membrane is being installed, the spool is threaded and fixed with a nut.
The edges of the membrane are leveled on the neck of the container, after which the flange is mounted with uniform tightening of the bolts.
After assembly, the calculated amount of air is pumped into the accumulator and waited for 12 hours, after which the tightness of the tank is checked. If there is no pressure loss, the device is connected to the supply pipeline.

It is also not uncommon to have problems with bleeding air from the tank, the cause of which is the deformation of the spool. Eliminating air loss is quite simple, you just need to buy a metal cap with a rubber gasket in the auto shop and screw it onto the spool.

A country estate, as a rule, does not have a central water supply. In this case, the source of water is a well or a well, from where, using a pump, liquid is pumped into the home plumbing system.

Water consumption is not constant. Sometimes you need to draw a glass of water from the tap, and in another case - fill the bathroom. In both cases, when the tap is opened, the water pressure in the system will drop and the pump will turn on, but if the pump runs for 10 minutes for the bathroom, then 5 seconds is enough for a glass of water. And if you need to collect several glasses of water with an interval of half a minute, then the pump will turn on for each of them - this mode of operation is unacceptable for the electric motor and it quickly fails. To prevent this from happening, a hydraulic accumulator for water supply systems is built into the pipeline.

A hydraulic accumulator in a private house will help to avoid problems with water supply Source novosibirsk.tiu.ru

Purpose and principle of operation

The main task that falls on hydraulic tanks for water supply systems is to accumulate a certain volume of liquid and give it to the water supply system when the pressure drops in the pipes. Thus, there is a supply of water in the system and when the taps are opened for a short time (to draw water into the kettle or rinse hands), the pump does not work, since the water comes from the hydraulic tank.

As a result, the main principle of operation of a hydraulic accumulator in a water supply system is to reduce the number of on / off of the water pump, which means to increase its service life.

Structurally, the hydraulic tank is a sealed hollow metal cylinder. Inside there is a membrane, which is also called a "pear", made of special rubber - butyl or synthetic ethylene-propylene rubber. These materials are durable, meet all sanitary and hygienic requirements and are resistant to bacteria. The membrane divides the cavity into two parts, one of which accumulates water. The second is occupied by compressed air, which pushes water from the hydraulic tank into the system when the tap is opened.

The device consists of a hollow cylinder and a flexible membrane inside Source homius.ru

The operation of the accumulator occurs cyclically:

When the water pressure in the system decreases (when water has already been selected from the hydraulic tank), the pressure sensor is triggered and the pump starts to supply water.
"Pear" is filled with water, its volume increases. The air is compressed, the pressure in the tank increases.
The pressure switch gives a signal and the pump stops working.
When water is consumed, the pressure switch is activated again and the cycle repeats.

The beginning and end of the working cycle of the accumulator Source nts-sk.ru

Benefits of installing a hydraulic tank

There are a number of reasons why a hydraulic accumulator is needed in a water supply system:

The main task is that thanks to the hydraulic accumulator, the pump starts and stops less frequently. The engine does not overheat and does not fail longer.
In addition to creating a supply of water, the drive softens hydraulic shocks in the water supply system. The air contained inside the cylinder reduces pressure drops in the pipeline due to its compressibility. As a result, all elements of the system wear out less.
During a power outage, a reserve supply of water remains in the hydraulic tank, which is important in case of frequent power outages.

Types of structures and their device

Depending on the pump used and the location of the pumping station, horizontal and vertical hydraulic accumulators are used in everyday life.

Such types of molding allow you to fit them into the space of any technical room. It is necessary to install the unit with the expectation of its convenient maintenance. It is necessary to provide access for repairs and, if necessary, draining water.

Vertical and horizontal accumulators will fit into any room Source remkasam.ru

It is most rational to connect horizontal hydraulic tanks to external pumps, and vertical ones to submersible ones, but in any case, the final decision must be made on site, depending on the parameters of the entire system.

There are no fundamental differences in the operation of the units. The difference is in the method of bleeding off excess air that accumulates during operation in the plumbing system. With large volumes of water passing through the storage tank, dissolved air is released from it. It can create air pockets and hinder system operation.

In designs with a vertically located cylinder, the opening with the valve is located in the upper part of the unit, because air collects at the top of the cylinder. In horizontal hydraulic tanks, there is usually no such device. Additional installation of the pipeline from the ball valve, drain pipe and nipple is required.

Storage tanks up to 100 liters do not have air venting devices. Excess gas is removed after the water is completely drained.

Water is drained by a standard tap at the inlet. Source makemone.ru

Why you need to be able to select a hydraulic tank

In order for the equipment to function well and provide water to the inhabitants of the house, you need not only to know what a hydraulic accumulator is for water supply systems, but also how to choose it correctly.

If the volume of the accumulator is insufficient, then the pump will work in an enhanced mode in order to provide the necessary pressure in the network.

With an excessive volume of the hydraulic tank, there will be no such problem, in addition, there will always be a certain volume of water in the tank, which can be used, for example, in the event of a power outage. But do not chase the size, because the main purpose of the equipment is to maintain pressure to distribute fluid in the network. And for the water supply, you can pick up another, less expensive tank, for example, made of plastic.

Each thing has its own purpose - an ordinary plastic container will do better with storing water "in reserve" Source gidrosnab.ru

Calculation of the optimal volume of the hydraulic tank

Properly selected volume of the hydraulic tank will allow:

ensure adequate water intake,
optimal use of pumping equipment,
extend the life of the drive and system elements.

There are several ways to choose a hydraulic accumulator for water supply systems and calculate the required volume of the drive.

Italian engineers have developed a calculation method UNI 8192. The selection is carried out according to three parameters: the maximum water flow, the number of permissible pump starts per hour and the height of the water supply.

With a small need for water supply, for example, for a family of 2-3 people living in a one-story house, the volume of the hydraulic tank can not be calculated. A 24-liter container will suffice.

For houses with a higher number of storeys and with a considerable number of points of water consumption, a calculation should be made.

The required size of the hydraulic tank can only be selected on the basis of calculations. Source pumpekhoob.com

It is carried out according to the scheme:

According to the tables, the total coefficients of water consumption are determined depending on the equipment used.
The maximum water flow is calculated. For example, when the shower, flush tank and faucet in the kitchen work together, this figure will be 30l / min (Qmax).
The estimated number of pump starts per hour (for comfortable operation) is taken as a = 15. With more intensive work, the hydraulic tank membrane oscillates too frequently, which leads to its premature destruction. In addition, the performance of the pump does not make it possible to completely fill the drive with water. The pump during continuous operation overheats and fails faster.
The next important value is the maximum and minimum pressure for the relay to operate. For two-story houses, these values are 3 bar and 1.5 bar, respectively (Pmax and Pmin). The calculation involves the initial gas pressure in the installation P0=1.3 bar.
The required volume is determined by the formula: V=16.5 x Qmax x Pmax x Pmin /(ax (Pmax-Pmin)x P0)=16.5x30x3x1.5/(15x(3-1.5)x1.3)=76 l.

The closest in value is a tank with a volume of 80 liters.

A hydraulic accumulator for water supply systems with such a capacity will make it possible to fulfill the water supply needs of residents of a 2-storey building with three water draw points operating simultaneously.

Video description

Do you need a reserve capacity

The additional volume of water stored in the hydraulic tank does not affect its operation. The main function of the unit is to maintain pressure in the water supply network.

If a significant supply of water is needed, it is easier and much cheaper to integrate a plastic reserve tank into the system. Therefore, when selecting equipment, it does not make sense to purchase a hydraulic accumulator with a margin.

With an increase in the need for water supply, for example, with an increase in the number of residents or the number of household appliances consuming water, you can additionally install another small-capacity hydraulic tank. Their performance is cumulative. The location of the additional hydraulic tank does not play an important role.

If necessary, several hydraulic tanks can be installed in the system. Source nts-sk.ru

Calculation of pressure in the accumulator

In order for the equipment to work efficiently and meet the needs of the residents of the house, the pressure in the hydraulic tank must be excessive.

In order for water to flow to the upper point of analysis, the air pressure in the cylinder must be greater than the hydrostatic pressure created by the liquid column from the lower to the upper point of water consumption. For example, for a two-story building, this value is P min \u003d 0.7 bar (10 m \u003d 1 bar). The height difference in this case is about 7 m.

For stable operation, a difference of 0.5-0.6 bar is required between the pressures at the lower and upper points.

Thus, the nominal pressure in the accumulator Рnom = 0.6 + 0.7 = 1.3 bar

The factory settings provide for the required pressure of 1.5-2 bar, which is optimal for the operation of the accumulator. To control it, a tonometer is built into the device.

A tonometer is needed to control the pressure in the hydraulic tank. Source armada52.ru

If the pressure parameter deviates downward, it can be corrected by pumping air with a car pump, for which a nipple is provided in the device body.

Installation, testing, connection

Simply mounting a hydraulic tank is not a difficult task - a more pressing problem is usually a competent choice of volume and working pressure, so it is better if all the work in the complex is carried out by specialists.

First of all, a place for installation is selected, which must meet the following requirements:

vibration and noise from operating equipment do not interfere with residents,
there is sufficient space for maintenance and repair of the hydraulic tank,
reliable support on a flat and strictly horizontal base is provided.

During installation, shock-absorbing rubber pads are used, which partially dampen vibration.

A solid foundation is required to install the hydraulic tank Source decorexpro.com

Connecting the accumulator to the water supply system is carried out in the following order:

A level area is being prepared on a solid base, such as a concrete basement floor.
The hydraulic tank is installed on the base using special gaskets.
Control measurements of pressure in the cylinder are carried out in a non-working state. It must be at least 1.5 bar (atm). This is the factory setting. With insufficient pressure, you can use a car pump.
A fitting with five outlets is installed on the accumulator branch pipe.
A water pump, a water pipe, a pressure gauge and a pressure switch are connected in turn to the outlets of the fitting.

Flexible adapters are used to reduce vibration. They are installed at the site of connection of the unit to the water supply. Make sure that the clearance of the adapter is not less than the diameter of the pipe to be connected.

Video description

Connecting the pump to the hydraulic tank is shown in the video:

The hydraulic tank is filled with water and checked for leaks. If necessary, additional sealing of threaded connections is carried out.

Water must be poured into the tank very slowly to avoid rupture of the membrane. With long-term storage, sticking of the “pear” is possible; with gradual filling, the flexible form will smoothly straighten out.

The power supply is connected and the pressure switch is configured according to the instructions for the equipment.

When using a submersible pump, a check valve must be installed. It prevents the backflow of water into the well.

Scheme of connecting the accumulator to the elements of the water supply network Source gkyzyl.ru

Popular Models

The buyer, when purchasing a hydraulic accumulator, focuses on the volume of the cylinder. To date, models with a capacity of 10 liters to 200 liters are produced and used in everyday life.

According to a survey of the Russian Internet audience, the most popular are hydraulic tanks with a volume of 76-100 liters, 11-25 liters and 26-50. For summer cottages, drives up to 10 liters are often bought. Vertical installation is a priority.

Usually, which accumulator to buy for water supply systems is chosen simply by the price-quality ratio. Manufacturers offer models that combine different equipment and decent quality at a reasonable price. The manufacturer rating is as follows: Reflex, Jeelex, Wester, UNIPUMP, CIMM.

Conclusion

A hydraulic accumulator is a necessary element for the water supply system of a private house, which will ensure the long-term operation of the pump and uninterrupted water supply. In order for the device to serve for a long time and not require frequent repairs, it must be correctly selected and correctly installed, for which it is recommended to use the services of competent specialists. Having figured out what a hydraulic accumulator is for, you can plan its installation and look for good specialists who will do everything at the highest level.