In the online shop www.pexuniverse.com You can buy expansion tank for heating (for example: Extrol 60 or Extrol 30) may from a reputable manufacturer Amtrol (Canada).
expansion tank tanks for radiant heating systems are intended to compensate for the expansion of water when changing the coolant temperature in heating systems. Structurally the coolant does not contact with air, which keeps the performance and durability of the heating installation. Diaphragm expansion tank has housing made of stainless steel, replaceable expansion tank divided into two chambers: a water and air. In the air chamber is pre-uploaded the air. Entry and exit from the expansion tank water through a threaded pipe. When heated, the system is enhanced water flows into a water chamber, and as cooling is squeezed back into the system.