The accumulator plays an important role in the water supply system. It serves to maintain a constant pressure, allows you to automate the water supply process, protects the electric motor from premature wear and breakdown, and protects pipelines from water hammer.
One of the most important characteristics of this device is the pressure in the receiver, which is the air cavity of the storage water tank, which is separated from the water by a sealed rubber membrane. If the pressure in the pipes is incorrectly set, when water is supplied, it begins to "jump", and unwanted frequent actuation of the water pump relay occurs. As a result - the impossibility of normal operation of the water supply system and premature failure of the electric hydraulic pump.
To ensure the normal operation of the water supply system, the optimal value of the pressure in the accumulator is calculated, its correct adjustment is carried out, and subsequent control is provided with a frequency of 1 - 2 times a year.
All this can be done independently, without having any special tools and special skills at hand. More on this below.
When carrying out maintenance work, do not forget to check the system for leaks. In the presence of undetected leaks, the efforts to set up the equipment can simply be nullified!
Why you need to create pressure in the accumulator
A decrease in pressure below normal will lead to the fact that the pumping station will turn on too often. With a significant decrease in pressure, the pump starts almost immediately after opening the water tap. Accordingly, when the valve is closed, the hydraulic pump turns off almost instantly. In addition, frequent relay actuation cycles lead to failure of the electric pump.
- Competent calculation of the maximum and minimum pressure values at which the pump should be turned on (off).
- Correct adjustment of the pressure in the receiver.
The air pre-injection pressure is 1.5 - 2 bar (depending on the volume of the tank). The determination of the value of air pressure for operation in tandem with a specific pumping station is based on the factory parameters of the pressure switch. The average pressure at which the pump is switched on is between 1.4 and 1.8 bar. The shutdown threshold is usually in the range of 2.5 - 3 bar. The optimum air pressure should be 10-12% less than the pump activation pressure.
Calculation example. The pressure switch is set to start the pump at 2 bar. The air pressure in the receiver is 2-0.2 = 1.8 atm.
If these requirements are met, after turning off the hydraulic pump, a certain amount of water is guaranteed in the accumulation tank, sufficient to create a stable pressure until the next start of the pump.
How to check the pressure in the accumulator
To measure pressure, you must:
- unscrew the cap that closes the union with a spool located on the tank body;
- connect the pressure gauge to the spool (you can use an electronic or automotive pressure gauge), take a reading and compare with the calculated value;
- in case of a decrease in the pressure level, pump up the compressor to the optimal value;
- bleed air to reduce pressure.
If the adjustment is carried out before turning on the hydraulic tank in the system, it must be left for a day. After this time, after the control measurement, the device is installed.
How to adjust pressure
The correct operation of the pumping station is determined by three main parameters:
- Start pressure;
- Shutdown pressure;
- Air pressure in the hydraulic tank.
The first two parameters determine the operating mode of the pressure switch. The adjustment is carried out empirically, and in order to increase the measurement accuracy, the check can be performed several times.
The electrical relay consists of two vertically arranged springs. They are located on the axles and tightened with nuts. One of the springs (larger diameter) is used to adjust the closing pressure, the smaller spring is used to regulate the required difference between the starting pressure and the shutdown pressure of the pump. The springs abut against the diaphragm, which closes and opens the contacts of the control circuit.
The adjustment process is carried out in the following sequence:
- Measurement of air pressure in the receiver using an external pressure gauge (for example, automobile), if necessary - pumping with a hand pump or compressor to the calculated value. It is carried out when the pump is off after a complete release of pressure.
- Measurement of pump activation pressure. With the pump turned on, but not running, open the pressure relief valve and take the system manometer reading at the moment the relay is triggered (when the pumping station is started).
- Adjusting the starting pressure. If the obtained pressure value does not coincide with the required value, turn the nut of the large spring in the direction of increase or decrease. After completion of the control measurement, if necessary, repeat the operation (possibly several times).
- Measurement of the cut-off pressure of the pump. Close all drain taps and wait until the pump is turned off.
- Adjustment of the difference between the pressure levels of starting and stopping the pump. If the calculated value of the shutdown threshold of the pumping station does not match, turn the spring nut of the smaller diameter in the corresponding direction. The spring is very sensitive: turn it by a maximum of 1/4 - 1/2 turn. After making a control measurement, repeat the steps if necessary.
- Repetition of the cycle described in points 1 - 5. If necessary, repeat the procedure several times until the desired parameters are reached.
The required start-up and shutdown parameters are indicated in the relay passport. Operating pressure air in the receiver indicated in the battery passport. It should be 10-12% less than the starting pressure.
Depending on the number of storeys of the building and the number of water consumers, it becomes necessary to change the factory parameters when adjusting the relay. After that, be sure to check the air pressure and adjust it in accordance with the new settings.
It should be noted that the described technology for monitoring and adjusting the battery parameters is the same for all types of this product, regardless of the configuration (vertical or horizontal design), volume and design features. The same is true for heating and hot water supply systems.
It is not necessary to be an expert in order to, having a minimum of simple tools, carry out simple operations to check and adjust the pressure in the accumulator.Simple actions that do not require any skills will take a minimum of time, while they will pay off with reliable uninterrupted operation of the water supply system for a long time.