THE EXTROL EX-30 EXPANSION TANK IS PRE-PRESSURIZED AND FEATURES A DIAPHRAGM DESIGN. FOR USE IN CLOSED NON-POTABLE HYDRONIC HEATING SYSTEMS. ACCEPTS EXPANDED WATER AS SYSTEM TEMPERATURE RISES TO REDUCE PRESSURE BUILD-UP. HELPS REDUCE ENERGY CONSUMPTION AND REDUCES SYSTEM WEAR. FEATURES UL STYLE""MARGIN-TOP0PX;PADDING-TOP 5PX; PADDING-BOTTOM 5PX;"" FACTORY PRE-CHARGE 12 PSIG MAXIMUM WORKING PRESSURE 100 PSI MAXIMUM OPERATING TEMPERATURE 240 DEGREE F WATER TIGHT RESERVOIR FOR EXPANDED WATER