Hydraulic accumulator for water supply systems for hot water. Hydraulic accumulator for water supply systems: purpose, varieties, principle of operation and basic calculations. How water storage schemes work
To provide stable work plumbing, you should find out what a hydraulic accumulator is. This useful device is necessary to automate the operation of an independent plumbing system.
It also allows you to significantly extend the life of the pump and protect equipment from water hammer.
In this material, we will talk about the arrangement and principles of operation of hydraulic accumulators, as well as provide recommendations for installing equipment.
A hydraulic accumulator differs from a conventional drive by a more complex device that significantly expands its functionality.
It consists of:
- metal case;
- inner membrane;
- nipple;
- pipe for water.
The membrane divides the container into two parts, one is designed for water, and the second is pumped with air or an inert gas. As a result, the liquid inside the device is under a certain pressure. This allows you to regulate the pressure of water in the system.
Anyone who has encountered the problem of low pressure in the system at least once will be able to tell about why a hydraulic accumulator is needed. Sometimes the problem is solved with the help, but GA is a more effective option.
Inside the accumulator there is a membrane¸ that divides the device into two parts: for water and for air, therefore GA is also called a membrane tank
It is installed in the system after the pump on the external or internal water supply, the specific scheme depends on the characteristics of the system. Water enters the tank and accumulates there, while thanks to the membrane, the pressure necessary for the normal operation of autonomous water supply with trouble-free water supply to the taps is created inside.
A conventional accumulator does not guarantee suitable pressure characteristics for the water supply, since the pressure is only created due to the difference in the height of the water intake point and the water tank. But with a GA, you don’t need to raise the tank to the attic or overpass, since you can pump up air to create the desired pressure.
Modern technology, such as automatic machine, hydromassage, jacuzzi, Dishwasher, can only function when in the water supply network. Yes and regular shower it is more convenient to take when the flow of water is strong enough, and does not flow in a weak trickle.
A hydraulic accumulator must be used complete with a pressure switch that controls a pump that supplies water from a well, a well, etc., and a pressure gauge designed to control and monitor the operating parameters of an independent water supply.
Maintenance of the hydraulic tank is reduced to a careful inspection of the body and control of the pressure in the air compartment. Sometimes you need to pump air or bleed it to restore the correct performance. Usually the pressure should be about two atmospheres or a little less. In addition, the air that has accumulated behind the membrane in the compartment where water is stored should be removed.
Sometimes you can even install an automatic air vent here. If there is no hole for this procedure, you need to disconnect the GA from the water supply and completely empty it through the drain tap. The air will come out of the tank along with the water. Then it remains just to turn on the pump again so that water begins to flow into the tank again.
Speaking about how a membrane accumulator works, it is worth noting that the most frequent breakdown in HA - membrane rupture. This elastic element is subjected to constant tension and compression, and therefore fails over time.
Here are signs that the membrane has ruptured:
- water comes out of the tap with sharp jerks;
- the pressure gauge needle “jumps”;
- after the contents of the “air” compartment are completely bled, water flows out of the nipple.
The last point allows you to find out exactly whether the problem is really with the membrane. If water does not flow out of the nipple, and water enters the system weakly, most likely, the housing is depressurized. It is necessary to carefully examine it, find and repair cracks.
Replacing the membrane is not difficult, but you need to select exactly the same element as the damaged one, since it is designed specifically for this particular HA.
To carry out repairs, you need:
- Disconnect the device from the plumbing system.
- Drain water, bleed air.
- Loosen the fixing screws.
- Remove damaged membrane.
- Install the correct item.
- Fix it with screws.
- Install the GA in place and connect it to the system.
The most difficult part of this procedure is tightening the screws. It should be uniform, so it is recommended to twist them, making one turn alternately on each element. This tactic will allow you to properly fix the membrane on the body and prevent its edge from slipping inward.
Some inexperienced craftsmen, in an effort to improve the quality of the connection, apply a sealant to the edge of the membrane. This should not be done, as the composition can destroy the rubber and cause the opposite effect.
Conclusions and useful video on the topic
The device and principle of operation of the GA:
For an autonomous water supply system, a hydraulic accumulator is a useful equipment that provides automatic water intake, turning the pump on / off. Such a device will improve the quality of water supply and prevent breakdown of technical devices.
Do you have any questions after reading the material? You can ask them in the comment block, and we will try to give an extremely clear answer to them.
Expansion tanks closed type and hydraulic accumulators have approximately the same design: a strong metal shell, divided inside by a rubber membrane into two sections.
One section contains water, the other contains air. As the water pressure increases, the air compresses, the size of the air section decreases, and the membrane sags, the water displaces the air. On the one hand, the device has a connection to the water supply system, on the other, a spool for air pumping.
But the names of devices are assigned not because of design features, but according to their intended purpose.
purpose
- Expansion tanks are designed to compensate for the expansion of water due to heating in heating circuits, as well as hot water supply (DHW).
- Hydraulic accumulators are designed to accumulate volumes of water under pressure in water supply systems that have a pressure pump, to reduce the frequency of switching on this pump and to smooth out water hammer. Additional function- water supply food grade up to 1/3 of the total volume of the tank.
The nuance is that the same device is used for both hot and cold water supply, but it can be called differently, depending on what it does in a particular scheme - it either accumulates (accumulates) a supply of water, or takes its excess during thermal extension.
- The design feature of the accumulator is more often that there is not a membrane inside, but a pear made of food rubber, which is pumped with water. Water does not come into contact with the tank body.
- The expansion tank for the heating system is made with a membrane made of technical rubber, which divides the body into two compartments, and the coolant (not always water) also contacts directly with the body.
How to distinguish
In appearance, all membrane tanks are similar to each other. There is an opinion that for the heating system they are red, and for water supply they are blue. But it is not completely true, as individual manufacturers use other colors.
In fact, the devices can be distinguished from each other only by the technical characteristics that are indicated on the nameplates on the devices themselves:
- All devices for water supply, including for hot water supply - low temperature - up to 80 degrees C, but high blood pressure- up to 12 atm;
- expansion tanks for heating - elevated temperature - up to 120 degrees C, but low pressure up to 4 atm.
How water storage schemes work
The hydraulic accumulator in the water supply circuit smooths out pressure surges that occur when water is taken from the system, i.e. when the tap is opened, and reduce the number of pump starts, which should not be more than 50 times in 1 hour.
When water is taken in the volume of the cup, the accumulator will give this volume, the pressure in the system will decrease, but not so much that the pressure switch turns on the pump. When taking a larger volume (for example, in the volume of a bucket), the pressure will drop so much that the pump will turn on and fill the device. 
The expansion tank in hot water and heating systems receives an excess volume of water that occurs when it is heated.
If there were no such device, then in a heated closed circuit the pressure would very quickly rise above the critical one, since the liquid practically does not compress. This would lead to the release of water from the emergency pressure valve, which is usually set to a pressure of 3 atm.
In practice, if such a valve constantly passes water, then this indicates a malfunction of the storage device. If there is no emergency valve, then when heated, the destruction of the weak point systems.
When an expansion tank is needed in a hot water system
This is a natural question, because hot water supply can be performed in different ways. If there is a flow heater, for example, a gas double-circuit boiler that heats the water stream directly at its intake, then naturally an expansion tank is not needed.
If in the system the water is heated in a closed large capacity boiler (more than 100 liters), then installation is required. expansion tank in addition to the safety valve. Which is not right to hope for, since it is not at all designed for frequent operation and, with frequent switching on, it simply starts to flow.
How to choose the volume of the device for heating
The main question that arises for the user is how much volume of such a water-accumulating device is needed? At the same time, the user wants to purchase a smaller volume, since it is cheaper. But you need to purchase the one that fits the calculation.
The volume of the expansion tank for heating will depend on the volume of the coolant in the system, the pressures - limit and set.
The formula for calculating the volume is shown in the photo:
The volume of the coolant is indicated in the design data, or it can be calculated by adding up all the internal volumes of the system elements, and finally, in the finished system, it can be calculated when pouring buckets.
For home system- calculation of the volume "without unnecessary torment" - 1/10 of the filled coolant.
What pre-pressure should be set
At the factory, the air chamber is normally filled with nitrogen to a pressure of 1.5 bar. At the same time, the membrane bends and is visible through the connection fitting. The safety of the factory pressure indicates that the membrane is intact and the device is suitable for use.
But in the future, the membrane tank must be prepared for work in specific system. There are the following rules for determining pressure:
- In the cold water supply system, the accumulator is inflated with air at 0.2 atm. less than the lower setting of the pump pressure switch. More often, the lower value of the pressure switch is 1.4 atm. (pump start pressure) and the upper one - 2.8 atm. Accordingly, the initial pressure in the device is 1.2 atm. This setting will avoid water hammer when parsing water and rapid wear of the membrane.
- In a hot water supply system, the expansion tank is pumped with air to a pressure greater than the pressure at which the pump turns off (the upper limit of the pressure switch). In this case, the tank will not give cooled water to the water supply system. But you should not be afraid of stagnant water, the device is made in such a way that the pear is constantly washed by a stream of fresh water.
- In the heating system - the air chamber of the expansion tank is pumped up to a pressure of 0.2 atm. less than the pressure in cold system heating. Typically, the “idle” pressure in the system is 1.5 atm, respectively, it is pre-inflated to a pressure of 1.3 atm when the system is cold.
How to install
The general rule is that the connection to the system of any membrane tank should be at the bottom, and the air chamber at the top.
But it should be taken into account that the accumulator can be deployed as you like, the connection to the water supply can be both from above and from the side, there is nothing special about this, if there are no objections from the manufacturer.
And the connection to the heating should be only from the bottom of the device. If this is not observed, and the air chamber is located below, then if the membrane fails, if cracks appear in it, the air will immediately go into the heating system and air it. If the air chamber is on top, then nothing terrible will happen when the membrane cracks, the device will still be able to work for a very long time in normal mode.
The photo shows an example of a heating circuit with a closed-type expansion tank connected to it.
The hydraulic accumulator for water supply is designed not only to take on part of the pressure, it also performs some useful functions for heating. You should understand a little more about what the features of the accumulator are, as well as how it is installed.
Purpose
Before proceeding to the question of the purpose of the accumulator, it is necessary to understand what it is. The hydraulic accumulator is a metal tank, inside of which there is an elastic cavity. Subsequently, the cavity can be filled with water. Due to the air gap located between the metal walls of the tank and the elastic cavity, the water "bag" never comes into contact with the metal.
Such a device gives the accumulator many positive qualities.
First of all, the hydraulic accumulator allows you to partially remove the load from the pump. Before water is supplied directly by the pump, it is supplied from the accumulator. When the water level drops to a certain level, the pump turns on. Thus, the pumping unit is protected from water hammer.
Such measures can significantly increase the amount of time that the pump will last. Similar careful attitude it will protect it from premature breakdowns and wear, while the quality of the pressure will not suffer. Even if you use two taps connected to the selected pumping station at the same time, the pressure will remain at the set level.
Plumbing that works from the same source will also last longer because it will not be subjected to water pressure drops. For example, pipes washing machine won't wear out as quickly. And an additional supply of water will allow you not to be afraid of interruptions in its supply, which is convenient if you live in a private house and you always need water in the proper amount.
Functions
Summing it all up beneficial features, which are provided by the presence of a hydraulic tank, its functions can be determined:
- Pump protection. The presence of a hydraulic accumulator helps to protect the pumping system from undesirable influences, prolonging its service life. Due to the fact that the pump will turn on only as needed, it is guaranteed a certain number of unused starts. This refers to the deviation from the norm of inclusions per hour.
- Pressure support. Due to the fact that there is a hydraulic accumulator, you can not be afraid of constant drops in water pressure. For example, if with only a pump there is a chance that the water will go either stronger or slower, especially when several taps are turned on at once, then with a hydraulic accumulator, this problem disappears. After all, the load is divided into two technical devices, and not one.
- Leveling of water hammers. When you turn on the pump, you often encounter the fact that the water starts to flow too intensively. Such a sharp push is called water hammer. Using a hydraulic accumulator avoids such problems, since water is supplied smoothly from the hydraulic tank. Thus, the pipeline will also last much longer.
- Providing a supply of water. If you live in an area with water supply problems, you may find it useful to have a hydraulic accumulator. It provides some supply of water suitable for household needs.
Depending on the need, you can choose a hydraulic accumulator big size(up to 500 l) or very small (up to 5 l).
Device and principle of operation
The peculiarity of hydraulic tanks is that water does not come into direct contact with the metal body, but remains enclosed in an elastic cavity, also called a membrane. The membrane is made from butyl, a durable rubber material. Butyl provides the proper level of water protection from bacteria, which metal cannot boast of.
There is an air gap between the elastic membrane and the metal case. Nitrogen is pumped into it, but the chamber can also be filled with ordinary air. The chamber is equipped with a special pneumatic valve through which the pressure inside is regulated. You can fill the chamber through this valve or, conversely, bleed the air.
The hydroaccumulator installation can be disassembled and reassembled at any time. It has a simple device. This simplicity is ensured so that it is always possible to identify problems and carry out timely repairs. In this case, the device can be repaired without pouring all the water out of it.
Large volume accumulators have an additional valve in the membrane, which also allows you to bleed air, but here we are talking about air that is released from the water. In small hydraulic tanks, this function is not available, but the valve should then be on the pipeline.
The operation of the accumulator is carried out as follows.
- First, water is pumped into the elastic cavity by a pump, stretching and filling it. A special relay is attached to the cavity.
- After the pressure threshold is reached, the relay reacts to this and turns off the pump.
- Further, during the operation of the accumulator, the pressure drops again, and the relay, reacting to this, turns on the water again. The relay can be set to any level. This type of device is called an automatic hydraulic accumulator.
Now there are practically no such options, but there are still outdated hydraulic tanks, the degree of fullness of which needs to be monitored and filled independently as needed.
Types and selection criteria
There are many criteria based on which hydraulic tanks are divided. Each of them has its own characteristics that must be considered in the selection process. One of these criteria is the material. If the expansion tank itself is made of stainless steel, then the membrane can be made from various types of rubber:
- natural. It is a natural rubber designed for drinking water. It stretches well, but this property can lead to the fact that over time water will penetrate the walls of such a membrane. The cavity made of natural rubber can be filled with water at a temperature of -10 to +50 degrees.
- Butyl. This type of artificial rubber is also intended for drinking water. It fully complies with all safety requirements. It has less elasticity than natural, making it more durable. The temperature that butyl rubber can withstand is higher: from -10 to +99 degrees.
- EPDM. This type of rubber is also designed to store drinking water. Like butyl rubber, ethylene propylene rubber can withstand temperatures from -10 to +99 degrees, but fails somewhat faster than butyl rubber.
- SBR. The brand is intended for technical water. Such water cannot be used for household needs, but it has found application in heating systems. Such accumulators are used as expansion tanks for heating systems.
- Nitril. Perhaps the most unusual type, since it is designed to store oils and fuels.
When choosing, be sure to pay attention to what type of rubber is used, since the last two types do not match. sanitary standards and therefore not suitable for drinking water.
By configuration, accumulators are divided into vertical and horizontal.
- Vertical. Hydraulic tanks of vertical type are selected mainly for rooms with a small area. Since they are stretched upwards and take up almost no usable space, they are an excellent choice for small home boiler rooms. The pneumatic valve is located at the top.
- Horizontal. Horizontal accumulators are not so practical. In order to install them, you need to have a lot free space. There are no valves and such constructs, so you have to make a special valve to bleed air.
The horizontal unit has a mount, through which it is connected directly to the pump. Because of the possibility of fixing an external pump, they have gained such popularity.
According to the type of storage accumulators are divided into mechanical and pneumatic.
Mechanical
For the operation of this type of drive, the kinetic energy of the load or spring is required. These models have not been practically used recently, since they have more disadvantages than advantages. Among the shortcomings, the most significant are:
- Big size. Such units take up a lot of free space, which is by no means related to their volume.
- Inertia. This refers to the ability of such systems not to change their initial parameters, regardless of external factors.
Sometimes adaptability is needed. However, such accumulators are cheaper.
Pneumatic
Today, such accumulators are more common, since the operation due to the effect of gas is simpler. Such a device was described in the previous sections. Apparatuses from this category are divided into piston, pear or balloon and membrane.
- Piston. Apparatus of this type extremely rarely used in domestic conditions. They are more suitable for industrial use. Their capacity is extremely high and reaches 600 liters. It is clear that few people at home constantly need such a volume of water. However, the cost of such installations is quite small.
- With a pear or balloon. Such hydroaccumulator tanks are not used singly. Most often they are included in the hydraulic pumping system. In this case, a pear is fixed inside the metal tank. On one side there is a hole for filling it with water. It turns out that the pear is as if stretched inside a metal tank. The air pumped into the container around the pear further pushes out the water located there. When the pressure drops, the pear fills up again.
- Membrane. The principle of operation of a membrane accumulator is similar to that with a pear, however, in this case, a rubber silt membrane acts as an elastic cavity. The membrane is attached to the metal body with only one end. When empty, the membrane is pressed against the outlet by the gas inside. When filled with water, the membrane expands.
According to their purpose, accumulators can be divided into those suitable for heating, hot water and cold water systems.
- For heating systems. A hydraulic accumulator for heating is used to get rid of accumulated air in the pipes, as well as to prevent a decrease in water temperature.
- For hot water. Membrane expansion tanks are mainly used for hot water supply. They are designed to compensate for the expansion of water that occurs due to temperature changes. This expansion results in pressure drops.
- For cold water. For cold water, accumulators are mainly chosen, which are connected to an external source.
This solution is chosen mostly for private houses.
Tanks are divided into small and large sizes.
- Small. These units do not have a large volume, but they are ideal for the home. TO small devices include those whose volume is not more than 150 liters.
- Large. This includes industrial units that take up a lot of space and are rarely installed within private homes. Basically, they are made horizontal. Their volume can be up to 600 liters. They are designed to store process water.
Among other things, attention should be paid to those points that should fundamentally affect the choice of a particular unit. Summing up all of the above, we can highlight the following points that deserve special attention:
- Type. It is extremely important on what principle the accumulator works. For each of the needs you need a specific sample. So, for hot water, choose an expanding tank, and for cold water, choose an accumulator with the ability to supply water from a third-party source. When choosing a hydroaccumulator tank for drinking water, pay attention to the presence of a filter. It is best to buy a hydraulic accumulator with a pneumatic storage.
- Volume. It is better to choose the capacity of the tank so that it fully covers the needs. For example, if you track how much water you spend in one trip to the shower, you can focus on this indicator when choosing.
- Orientation. It is easiest to choose a tank configuration: if the room is small, then choose a vertical accumulator, but if the area allows, opt for a horizontal option.
Volume calculation
To make the volume calculation more accurate, it is recommended to use the following table. It shows the approximate amount of water that will be available after the pump stops pumping water due to power outages. Please note that this indicator cannot be determined exactly, since it all depends on how the relay is configured.
In order to make more accurate calculations, it is recommended to use a special formula: K (motor power factor) x Amax (limiting flow in liters per minute) x ((Pmax (pump off pressure in bar) + 1) x (Pmin (pump on pressure in bar) + 1)) / (Pmax – Pmin ) x (Pair (air pressure in the accumulator in bar) + 1).
For example, let's calculate according to the table, taking random values.
With coefficient K = 0.25, maximum flow Amax = 2.1, and pressures Pmax = 3, Pmin = 1.8 and Pair = 1.6, we get: 0.25 x 2.1 x ((3 + 1) x (1.8 + 1)) / (3 - 1.8) x (1.6 + 1) = 31.41 liters.
Installation steps
The installation of a hydraulic accumulator is carried out in several steps, completely different from those for an ordinary tank. . It should be borne in mind that the hydroaccumulator tank is practically never at rest. It is constantly working, the membrane or pear is involved all the time and is under pressure. Therefore, all installation and configuration steps must be carried out carefully and slowly.
First you need to fix the tank.
It must be securely fixed to the floor, not wobble. Under the legs you need to put rubber pads so that in case of vibrations, noises and other things, the tank is cushioned and does not stagger so much.
If this rule is neglected, during operation, the metal case can swing and rattle strongly, producing unpleasant sounds, and also being subjected to unnecessary influences.
The pipeline must also be connected using rubber pads, which in this case perform an insulating function. It is important that the rubber adapters must be flexible, otherwise they may crack and begin to leak water. In addition, flexible materials are easier to set up and operate.
It is optimal if the inlet of the accumulator and the connected pipeline have the same cross section. Then there will be no additional problems with the connection. It is impossible for the cross section of the wiring to the outlet to narrow: this will lead to an unreasonable increase in pressure in the accumulator tank, which can cause a strip, since tanks are often not designed for this.
The tank must be properly prepared before first use. First of all, the membrane or pear is checked for the presence of air. If there is air, it is bled off. Next, the tank is filled with water under very low pressure. This is due to the fact that the rubber, caking, sticks together, and if it is too sharply unsticked, it can be damaged or torn. To prevent this from happening, it is necessary to carry out the filling slowly and carefully.
When choosing a place for operation, it is necessary that free access to the mechanism be provided from any side. In general, it is best to entrust the connection of a hydroaccumulator tank in the water supply system to experienced specialists, since it is possible, due to inexperience, not to take into account some non-obvious, but important factors, such as a pressure drop or a mismatch in the cross-section of water pipes. Such risks are unacceptable, since the accumulator is a rather expensive unit, and the repair of the plumbing system will cost a pretty penny.
If you decide to take a chance and do everything yourself, use the following step-by-step instructions.
Adjustment
After the tank has been purchased and brought home, the first step is to check the pressure inside it. Usually it is equal to 1.5 bar, but often due to leaks due to long storage, the pressure drops. The pressure is checked with a manometer.
You can check it while in the store. Then, right at the time of purchase, ask the sales assistant to make the necessary measurements. The accuracy of the pressure gauge offered in the store is usually high enough that the error does not greatly affect the final result of the changes.
Usually, experts recommend setting a pressure that will be 10% lower than in the membrane when the pump is turned on. To adjust the level, pump up the air chamber or bleed off excess air. However, it should be borne in mind that pressure drops have an extremely negative effect on the life of the membrane. If the difference is more than 1.5 bar, then this will increase the load.
T Also, the pressure should be set with an eye to what exactly you need the tank for. For example, some people like to take a shower with strong water pressure or use a hydromassage. Then the pressure in air chamber should be slightly higher than if you only want to take a bath. However, the pressure in the air chamber should not be too high, otherwise you simply will not be able to pump water into the membrane. Too little pressure is also fatal: the membranes are not designed for an increased volume of water.
Relay setting
After the adjustment of the accumulator is made, they proceed to the adjustment of the relay responsible for turning the pumping station on and off.
To make the setting the right way, do the following:
- Open the cover of the compartment containing the relay.
- Take a look at what this relay consists of. You will see two springs and nuts. The large spring and nut will be denoted as P, and the small ones as delta P.
- First, deal with the components responsible for turning on the pump. This is group P. To make the spring more responsive to pressure, tighten the large nut a little.
- The delta P group is responsible for turning off the pump. By pulling it up, you will indicate the pump is turned off at the moment when the membrane is not yet completely filled with water.
After you have made the settings, test what happened. If you are not very happy with the result, tighten or loosen the nuts again.
During tests, it is not necessary to close the relay with a lid, but after setting all the settings, the lid must be closed.
Filling with water
After the pressure inside the accumulator is set and the relay is set, you can proceed directly to filling the hydraulic tank. Here again you will need a high-quality pressure gauge with a detailed scale of values and a small error. It is necessary to connect it to the tank and fill it with water, strictly observing the values.
Arm yourself with the specifications of your tank. They indicate which pressure can be considered normal, and which - the limit. If the pressure gauge is nearing limits, immediately stop the flow of water and try to equalize the pressure by bleeding or adding air to the air chamber.
When filling the accumulator tank, it is necessary to manually turn off the pump at the moment when the pressure becomes optimal. After that, the relay is adjusted according to the desired parameters, weakening or tightening the small spring. Keep in mind that a pressure of 3 bar is sufficient, although you can vary it to your liking. The difference between the pressure for turning the pump on and off should be about 1-1.5 bar. As practice shows, this is quite enough.
Having performed all of the above actions, you can safely proceed to the full operation of your accumulator. Once every couple of months, check the pressure in it, inspect the relay and joints with the plumbing system, and also monitor the operation of the pump.
The connection diagram shown here is not the only one. There are several other options that have found application in domestic conditions.
Scheme: options
First of all, the scheme for connecting a hydraulic accumulator to a pumping station depends on the functions that are imposed on it, as well as on the method of using the hydraulic tank itself. The most requested options include the following.
Booster pump station piping
Installing a hydraulic accumulator in this way is appropriate when there is a large amount of water consumption. At such pumping stations, there is always one pump running continuously, which can cause large pressure surges that need to be eliminated immediately.
Here, the hydraulic tank dampens pressure surges, thereby extending the life of all pumps. It also compensates for small pressure fluctuations that may occur due to the large volume of water consumed.
However, the scope of this type of connection is not limited to this.
It happens that power outages occur constantly, and the presence of water is vital. Similar situations may arise in agricultural facilities, for example. Here, a reserve of water helps to survive such periods of crisis, often lasting several days.
The accumulator here plays the role of a damper. The more powerful the pumping station, the larger the volume of the hydraulic tank and the greater the pressure it must cope with. Otherwise, the desired effect will not be achieved.
For submersible pump
In order for the submersible pump not to run idle, it is necessary that it make only 5 to 20 starts per hour, as detailed in its technical specifications. If in plumbing system pressure drops, the pump will turn on automatically. Such falls can occur much more often than 20 times per hour. To compensate for such differences, a hydraulic tank is needed.
In this case, the accumulator is designed to compensate for a small flow of water, which also leads to the pump turning on, thereby preventing the stupid start of the submersible unit. The accumulator relay is not as sensitive as submersible pump. In addition, the pump delivers water in sharp shocks and instantly, which is why the pressure jumps sharply. This negatively affects the pipes. Connecting a hydraulic tank eliminates this problem as well.
You don't need a big hydraulic tank. To choose the optimal volume, it is necessary to evaluate how much water is consumed per hour, how often the pump is turned on, and pumping power. An important role is played by where the tank will be installed relative to the pump and at what height the pump itself is fixed.
With storage water heater
If you connect a hydraulic tank to a water heater, it will be used as an expansion tank, not reacting to changes in water temperature. Since the water in the water heater rises under the effect of expansion, the water heater elements, not always designed for such loads contrary to their intended purpose, may be damaged, resulting in the need for a complete replacement of this expensive equipment.
The membrane in the hydraulic tank can easily withstand the expansion that the water is subjected to. The cavity is elastic and cannot be damaged by a small volume expansion.
In this regard, connecting the hydraulic tank to the water heater - good idea, allowing you to save the water heater itself safe and sound.
In front of the pumps in the direction of water flow
In this case, the accumulator is connected to the circuit in front of the imperious pump. It is needed so that the pressure does not drop so sharply immediately after turning on the water and the pressure remains at the same level. The volume of the hydraulic tank plays a special role here. So, the more water is consumed, the higher the capacity should be, otherwise all measures to install the accumulator will be useless and pressure compensation will not be achieved.
Connection
The hydraulic tank is included in the circuit in the place where it can provide the greatest return. The exact connection points are marked on the drawings above. Depending on the problem you are facing, the location of the accumulator and its volume will differ.
Examination
Checking the accumulator is carried out in order to identify malfunctions of the membrane and timely replacement of this important component. To date, there are many videos and instructions on how to conduct a test yourself at home. Below is the simplest of the instructions.
To begin with, there are several preventive measures designed to ensure the smooth operation of the membrane cavity. There are also signs that clearly indicate that something is wrong with the hydraulic tank. These include the following:
- Monthly pressure check. It is important that the existing parameter and those indicated in the technical data sheet of the accumulator match. If this is not the case, we can say that there is some kind of problem.
- The presence of rust on the body. If the membrane were intact, then water would not fall on the body and corrosion would not form on it. On the other hand, this may be due to the fact that water entered the body from the outside. For example, a hydraulic tank is located under a pipe with hot water, condensate from the pipe systematically drips into the same place on the surface.
- Moisture at joints. This may also indicate that the membrane has burst and allows water to pass through. Protruding drops cannot appear in a cavity, which is supposedly filled only with air or gas, just like that.
- Strange noises. Due to the running pump, it is almost impossible to hear any sound from the hydraulic tank. If there are sounds and quite distinct, then this can be a sign of a serious breakdown. If you have just connected the accumulator and it is still under warranty, it is recommended that you return it immediately.
- Visible damage. Armed with a flashlight, you should inspect the membrane in advance for visible damage to the eye: holes, cracks, cracks. They shouldn't be. If there are such shortcomings, replace the membrane.
Checking the initial pressure has already been covered in one of the previous sections, so it makes sense to briefly describe the order:
- the tank must be disconnected from the pumping station;
- further, the water in it is released from the hydraulic tank;
- by connecting a pressure gauge, the level of air pressure in the accumulator is checked.
Possible malfunctions
During the operation of the accumulator, many problems can arise, and it is necessary to know how to eliminate each of the malfunctions. To do this, it is necessary to take into account the reasons that can lead to such troubles.
- In case of malfunction pumping unit when it turns on and off frequently, it may be the membrane. In this case, it is recommended to test its integrity and, in which case, replace it with a new one, having previously dried the metal case of the tank well.
- The occurrence of a leak near the pneumatic valve, through which you can bleed air or fill the tank, is also associated with a violation of the integrity of the membrane. As in the previous case, the membrane must be replaced.
- For too low pressure there can be several causes in the valve. The simplest is insufficient thickness air gap. In this case, you only need to add a little air inside the hydraulic tank. The second reason is more serious. If the part through which the air escapes is broken, you will have to replace it. It may be necessary to carry out welding work.
- A leak in the pipe that comes from the pump may occur due to loss of tightness. In this case, try to tighten the flange a little tighter so that it fits snugly. If this does not help, it is recommended to completely replace the parts.
- If the pressure in the tap is uneven, despite the presence of a hydraulic tank, then the matter may be in the elastic cavity. Conduct a full inspection of it, test it several times. If you still have doubts about its tightness, then replace the existing part with a new one.
- Weak pressure is by no means connected with the membrane, but with the fact that your pump may not work properly or even be faulty. Be sure to check the pump for operation. Repair it if a problem is found. The second reason may be the wrong choice of the volume of the accumulator. In this case, there is only one way - replacing the hydraulic tank with a suitable one.
If fluid comes from the pneumatic valve or forms near it, it means that with one hundred percent probability the membrane will have to be replaced.
Expert opinion on the need
Below is a video in which a specialist clearly justifies the need to purchase a hydraulic accumulator. He claims that the hydraulic tank is one of best ways to level the excessive load on the pumps, thereby significantly extending their service life.
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 metal surfaces housing, as it is located in a water chamber-membrane, made of strong butyl rubber material, resistant to bacteria that meets all hygiene 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.
Diameters connecting pipeline and the discharge pipe should, if possible, coincide with 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.
This 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 most minimum flow water, 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 comes 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 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, verified. 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 normal pressure hydraulic accumulator, 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 there is not even a special need for this, 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 successfully serves for many years.
When choosing a brand of hydraulic accumulator, it is necessary to pay attention Special attention for 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 designed 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 tank volume .
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 - 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 appointments different manufacturers 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 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 (below the calculated one), low water pressure after the pump.
How to troubleshoot a hydraulic accumulator with your own hands? The reason for repairing the accumulator may 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.
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. He can create air locks and hinder the operation of the system.
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. Required additional installation pipeline from a ball valve, a drain pipe and a nipple.
Storage tanks up to 100 liters do not have air vent 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 amount 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 soul works together, flush tank and a faucet in the kitchen, this figure will be equal to 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. Pump at continuous work overheats and wears out faster.
- The next important value is the maximum and minimum pressure to operate the relay. For two-storey 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 /(a x (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.
When the need for water supply increases, for example, when the number of residents or the amount of water consuming increases household appliances, you can additionally install another small 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 challenging task- a more pressing problem is usually the correct choice of volume and working pressure, so it is better if all 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 flat area is being prepared on a solid foundation, for example, concrete floor basement.
- 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 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, you must install check valve. 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. Today, 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 often buy drives up to 10 liters. Vertical installation among the priorities.
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.
