A hydraulic accumulator is a special metal container that holds a certain volume of water under pressure. This device is used to maintain stable pressure in the hydraulic pipe, protects against drops and water hammer. If you have a hydraulic accumulator, you can keep the water supply for a while, even if there is no electricity.
The hydraulic tank does not create pressure in the water supply system. The last parameter is achieved by using a pump or depends on the retaining tower (in the case when the system is centralized). What should be the pressure in the accumulator depends on its volume, type and purpose.
Functions of a hydraulic tank in a water supply system
The main functions of the tank in the water supply system are:
- Protection of the pump and its working parts from premature wear. This parameter is achieved due to the constant filling of the tank with water. The pump only starts if the tank is empty. Also, each pump has a certain estimated number of working hours, and due to the stock of unused starts, the duration of operation increases.
- Maintain steady pressure in the system. What pressure should be in the accumulator depends on specific parameters (for example, the amount of interference in the form of elbows, cranes, etc.). Due to hydraulic obstructions leading to disruption of the flow of water, its temperature can also change. Installing a hydraulic accumulator will eliminate this drawback.
- The device softens water shocks that damage the pipeline and can damage it.
- Maintaining an acceptable supply of water. The hydraulic tank is able to maintain the maximum allowable amount of water during a lack of electricity. After fixing the problem, the device will automatically restore the necessary reserves and continue to work as usual.
Accumulator device
The main components of the hydraulic tank are:
- The tight case which is divided by a special membrane into two chambers - for water and for air.
- Membrane. Water is stored in this part of the tank. The membrane is made of a special material - butyl. The latter is resistant to biological substances and is safe to use.
- Pneumatic valve. This part is designed to control the air pressure in the system. In small tanks instead of a valve, a tee or crane is installed. What air pressure should be in the accumulator also depends on its volume (on average, 1.5-2 atm is normal).
Important! The device of the tank should be as simple as possible so that during disassembly a complete drainage of water from the membrane is not required.
In order to avoid water losses, it is necessary to select the diameter of the pipeline and pressure pipe with great accuracy.
Principle of operation
- When water is supplied under pressure into the membrane, pressure also increases.
- Upon reaching the required pressure level, the relay switches off the pump. Accordingly, the water supply is interrupted.
- When the set pressure drops, the pump resumes operation and water again enters the diaphragm.
Important! Efficiency depends on the volume of the tank: the larger it is, the more effective the result.
The frequency of the relay is adjustable. What should be the pressure in the accumulator, as well as the parameters for achieving smooth operation are indicated in the recommendations for use.
Types of hydraulic tanks
Tanks are made in vertical and horizontal layouts. Moreover, the principle of operation is the same for both types. A small difference in the tanks of vertical design is the presence of a special valve in the upper part of the structure. The use of this device is necessary for bleeding air that accumulates in the upper part of the vessel. The frequency of bleeding depends on what pressure should be in the accumulator of 50 or more liters.
In small devices, there are no special devices for pumping air. This process is carried out by completely draining the water.
In horizontal tanks with a volume of 50 liters or more, a special tap or drain is mounted for bleeding.
In the process of selecting a tank by type of execution, one should take into account the location, as well as its dimensions.
An example of selecting a hydraulic accumulator by volume
To select the most optimal device, determine its purpose:
- for water reservation;
- pump protection (with frequent start / stop);
- maintaining constant pressure in the accumulator. What constant pressure should be depends on the height of the tank.
It is best to install the tank closer to the pump. For normal operation of the system, a 24-liter hydraulic accumulator is sufficient.
If you select a device taking into account the frequency of turning on / off the pump, the percentage of water and air in the tank should be taken into account. The standard tank contains 50% liquid and the same amount of air. Also, when choosing a volume, the characteristics of household points, such as a shower, tap, type of toilet, should be taken into account. The approximate consumption for a 1-room apartment or a small house is 30-50 liters per minute. Therefore, for the most optimal operation, tanks are used that are 2-2.5 times the volume of water used.
The process of installing a hydraulic accumulator
Before installation, determine what pressure in the accumulator should be. The standard production pressure is 1.5 atm. In special cases (for example, during a leak), this parameter decreases. To determine the pressure in the system, a manometer and a spool are used.
Important! If the tank is installed for domestic use, a pressure of 1 atm will be quite normal. If the pressure gauge shows a mark of 1.5 atm, this is also the norm. It should be borne in mind that the greater the supply of air, the less water.
It is not recommended to set the pressure below or above critical values, since too low will cause the membrane to come into contact with the walls, which will entail rapid wear, and high will prevent the pear from filling up with water in the required volume.
Setting the tank and pressure switch
The maximum and minimum pressure threshold at which the pump starts and stops automatically is regulated by spring mechanisms.
On all devices, the manufacturer indicates what pressure should be in the accumulator. Most often, the parameter for switching off is 1-2 atm higher than switching on.
For example, to determine the lower critical value when the pressure gauge is 3 atm, you should rotate the smaller spring mechanism until the mechanism triggers. After this, drain the system.
Important! In the process of draining, it is necessary to monitor the pressure gauge. The moment at which the relay turns on will become the lower pressure limit. The fixed indicator should be slightly higher than in an empty tank.
When the large spring mechanism rotates, a lower limit is set. To determine it, you should connect the pump to the network and wait until the pressure reaches the desired level.
After that, the Delta parameter of the small spring mechanism should be adjusted and the process of setting up the hydraulic tank should be completed.
Hydraulic tank for station and heating system
The trouble-free operation of any system is ensured by a rubber bulb - a membrane. The latter is constantly exposed to air and water pressure. If any of the pressure drops, the membrane is deformed, and the service life is significantly reduced.
To prevent the formation of air jams in the structures, special devices are used. The technology for removing excess accumulations is used in the accumulator 100. What pressure should be in any of their tanks, the manufacturer determines.
To calculate the normal pressure in the pumping station, you can use the formula:
P atm = (h max + 6) / 10,
where P ATM - the minimum allowable pressure in the tank;
h max - the highest point of water intake, m.
The calculated indicator is compared with the natural one, after which adjustments are made.
What pressure should be in the heating accumulator depends on the length of the pipeline and the total pressure of the system. Also taken into account the technical characteristics of radiators (batteries, pipes). Given these parameters, the normal pressure in a closed expansion tank will be between 0.2 and 0.5 bar.
Malfunctions and their elimination
The main causes of failure and tank breakdowns are:
- frequent on / off pump;
- valve leakage;
- insufficient pressure of water at the inlet and outlet.
Before determining the causes of the pressure drop, it is necessary to find out what pressure should be in the accumulator of the station.
Faults include:
- incorrect pressure;
- rupture or deformation of the membrane, as well as the body;
- failure of the relay.
You can troubleshoot by:
- Pressure build-up when it falls.
- Recovering an unusable membrane.
- Recovering a damaged case.
- Differential control according to pump mode.
Important! The required tank volume should be calculated before it is installed in the system.
The hydraulic tank must be checked periodically, and the settings should also be adjusted. At least once every 2-3 months, the membrane should be completely cleaned of water. Particular attention is paid to air pressure - it must be pumped up or bleed when a malfunction is detected.
So, we found out what pressure should be in the accumulator of 100 l or another volume.