XT-30 - Diaphragm Hydronic Expansion Tank - 5 GallonElbi XT 30 Diaphragm Hydronic Expansion Tank 5 Gallon Designed and manufactured by Elbi since 1975, the XTXTV Series expansion tanks are solid and have proven reliable in millions of installations worldwide. The two shell welded construction allows the tank to withstand high pressure ratings and therefore adds safety to your system. The BUTYL diaphragm separates the air from the water and prevents waterlogging while saving space and energy. Product is