One of the main elements of the expansion tank is the membrane, is it largely determines the reliability and durability of the tank in general. Therefore dwell on this issue.
To date, there are some basic, frequently used by various manufacturers of materials membranes: natural butyl rubber and EPDM. The choice of material based on problems facing the tank when used in a system.
Thus, in systems of centralized heating under normal operating conditions the expansion of the liquid, and hence the loading of the membrane is slow, and during the entire period of the system varies slightly. However, the operating temperature can be quite high. Therefore, membrane for such a system must be made from temperature-resistant and durable material.
In cold water coolant temperature effect on the membrane is small, because the temperature of water in the system usually does not exceed 30 ° C. One of the main characteristics of the membrane for this system must be dynamic elasticity, because the system can be included several times an hour and fast loading.
In most models, expansion tanks Amtrol as the material of the membrane using high quality natural rubber (butyl rubber), at temperatures from -10 to +70 ° C (maximum percentage of 50% ethylene glycol) having a high resistance to water diffusion and has the highest elasticity in comparison with other materials. Such membranes possess all the modifications mentioned earlier model Amtrol: C, CE, Pro, M (V 2-12500 L, Roux 6.3.1910 bar). Scope of application: heating and cooling.
For membrane expansion tanks Amtrol Extrol A and DE (V 2-3000 l, PN 10/16 bar) uses natural food gum, through which the tank may be used in drinking water systems.
A new series of tanks Amtrol Extrol P (V 8-5000 l, PN 10 bar) is made of EPDM membrane for drinking water, thereby exploiting the data containers at a temperature of -10 to +100 ° C.
Expansion tank Amtrol has a certificate of conformity and the Sanitary-Epidemiological Conclusion, allowing their use in drinking water systems.
There are 3 types of mounting membrane:
1. replaceable membrane, which does not stretch and “rolled” on the tank walls, which increases its reliability, and the special design of the clamping ring provides durability and prevents drop in the initial pressure (achieved in models Amtrol C and Amtrol Extrol A);
2. replaceable membrane in the form of pear, which is attached to the upper flange, almost coinciding in length with a tank, so that when you receive a coolant, it relies on the tank wall and the load is distributed evenly over the area of “pear” and there is no tension of the neck that significantly increases the lifespan of the membrane (implemented in the model Amtrol CE);
3. replaceable membrane clamped between two flanges on opposite ends of the tank, that in addition to the benefits listed in the second paragraph, makes the membrane stationary (which is especially important when large volumes), thus at times increasing its reliability and durability (model: Amtrol M, on large volumes Amtrol Pro and Amtrol Extrol P).