Diaphragm expansion tanks are widely used in hot and cold water supply and heating systems. Their main purpose is to compensate for the excess volume of the coolant resulting from thermal expansion.
Instructions
Step 1
The membrane tank consists of two parts. The first half contains the coolant, and the second is occupied by air or gas pumped into it under pressure. The compartments are separated by a diaphragm fitted with a nipple. The main difference between membrane tanks for water supply and heating tanks is that the water inside them should not come into contact with the walls of the case. The technical passport of the tank indicates the pressure parameters when it is not yet connected and is filled only with air.
Step 2
On the eve of starting the heating system, the gas pressure is adjusted to the statistical pressure - 1 bar x 10 meters of water column above the membrane expansion tank, but not more than 4 bar. When the coolant in the system heats up, it expands and enters the water chamber, which naturally leads to an increase in pressure inside the tank until it equals the pressure level of the entire system.
Step 3
The volume of the tank is calculated in such a way that when a certain pressure is reached, the pump turns on, or turns on a certain number of times during an hour at a certain intensity of water intake. For stable operation of the pump motor, a diaphragm expansion vessel should be selected in which the volume exceeds the minimum allowable.
Step 4
It is allowed to install several diaphragm expansion tanks in one system, provided that the pressure in them is the same. The expansion tank should be connected to the system next to the boiler, together with a safety device that will work as soon as the pressure inside the system exceeds the permissible value. Disassembly and dismantling of the tank, as well as drilling holes in it and applying great force is prohibited. Take care that the coolant does not contain oxygen and other corrosive gases.
