The 4.5 Gallon Thermal Expansion Tank with a 3/4" MPT Connection from Braxton Harris is essential for managing water pressure in closed plumbing systems. This tank is designed to absorb excess pressure caused by thermal expansion, protecting your plumbing fixtures and appliances. With a capacity of 4.5 gallons, it is suitable for residential and light commercial applications. The 3/4" MPT connection ensures compatibility with standard plumbing systems. This product meets industry standards for performance and reliability, making it a crucial component for efficient water heating systems.