Replacing the membrane in the hydraulic accumulator. DIY. Metabo

The membrane is an elastic balloon, which is made of a safe material suitable for interaction with drinking water. Its main task is to separate the air and water environments so that the water does not have direct contact with the walls of the tank and remains drinkable.
Membrane operating principle
In operating mode, air is under pressure between the walls of the accumulator and the membrane, and water is accumulated inside the membrane, which is pumped there using a pump. When the pump turns off, excess pressure arises between the walls of the hydraulic tank and the membrane, under the influence of which water is pushed into the water main. Thus, the membrane reduces the risk of water hammer and allows you to save energy resources of your pumping station or submersible pump.
Damage or wear of the rubber membrane inside the accumulator can allow water to enter the air chamber, which will affect the operation of the pump. The pump will start to start more often and may eventually fail.
What factors accelerate membrane wear?
Like any elastic product, the membrane has a limited resource for the number of cycles of stretching and compression; when the number of these cycles is exceeded, the membrane fails. But there are a number of factors that can speed up the process of natural wear and tear:
Low pressure, lack or absence of air inside the tank cavity.
The presence of mechanical impurities in water.
Sudden temperature changes inside the hydraulic tank.
Friction of the membrane against the walls of the accumulator.
How to check membrane integrity
In order to check the membrane for damage without disassembling the accumulator, you must remove the plastic cap from the air valve (nipple) and press on it.
If the membrane is intact, you will hear air hissing.
If, when pressed, air and water come out, the membrane is damaged.
If you don't hear any air hissing, but no water comes out either, this may mean there is no air in the air chamber.
How to determine that the membrane in the accumulator needs to be replaced
The pump started turning on more often than usual.
You notice a lack of air in the tank cavity.
The pressure gauge began to record strong pressure surges.
When you press the air valve, water flows out of it.
When draining, air comes out along with the water.
Condensation forms on the outer walls of the tank.
How to change the membrane in a hydraulic accumulator with your own hands
To bleed off all the air that might remain in the accumulator, to do this you need to press on the nipple.
Clean the surface of the flange and accumulator, and also inspect them for irregularities and dents - there should be none.
Make sure there is no damage to the bolts. If necessary, prepare new ones to replace them.
Unscrew the bolts that secure the flange to the counterflange.
Remove the old membrane.
Remove any remaining water from the housing. Wipe the hydraulic accumulator dry from the inside.
Install the new membrane so that it is located exactly in the center.
After replacing the membrane, install the flange and begin tightening the bolts. The bolts should be tightened evenly and in strict sequence: the first one, then the bolt located opposite, and then every other one in a circle. This approach will create a sealed flange connection.
Pump air into the accumulator using a car pump. It is important to remember that the pressure in the accumulator should be 0.1-0.2 bar lower than the starting settings of the automation that controls your pump.
Replace the plastic cap.

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You should keep the water away from the tank outside prevent the rust...