What is Hydronic Expansion? Hydronic expansion tanks are diaphragm type tanks designed to keep system pressures below relief valve settings. Hydronic expansion tanks absorb the expansion of water in residential or commercial hydronic (forced hot water) heating and cooling systems. Without hydronic expansion tanks, the system will quickly over-pressurize resulting in added stress to the various system components. Hydronic expansion tanks protect safety valves from failing or wearing out quickly, avoids valve stem and ball seal leaks, prevents wasted BTU’s and vastly extends water heater life. Technical Features • Certified synthetic SBR rubber diaphragm • MIG welding eliminates interior rough spots and sharp edges • Each tank is factory leak tested to ensure tank integrity • All diaphragms designed to maximize drawdown • External baked epoxy-polyester coating provides a durable appliance finish • Welded side outlet allows easy and quick installation • Protected pre charge valve eliminates potential leak path • Low profile tank design with full membrane depth eliminates stretching of diaphragm, providing increased life cycle Additional Description • Shell: Carbon Steel • Connection: Carbon Steel • Diaphragm: SBR Synthetic Rubber • Color: Gray • 150 PSI Max pressure rating • External baked epoxy-polyester coating provides a durable appliance finish • Exclusive polypropylene liner eliminates internal corrosion • Protected precharge valve eliminates potential leak path Material Description • Shell: Carbon Steel • Connection: Stainless steel • Diaphragm: Butyl • Color: Almond Operating Conditions • Max. Operating Pressure: 150 PSI • Operating Temperature: 210 Degrees Fahrenheit • Factory Precharge: 40 PSI ” WARNING: Handling of this product will expose you to lead, a chemical known to the State of California to cause [cancer, and] birth defects or other reproductive harm. Wash hands after handling.