Resideo by Honeywell TK300-30 Expansion Tank 4.4 Gallon 1/2 in NPT

The Resideo by Honeywell TK300-30 is a 4.4-gallon thermal expansion tank designed to protect closed-loop potable water systems from excessive pressure buildup. When water heaters heat water, thermal expansion occurs and can cause dangerous pressure increases in systems with check valves, backflow preventers, or pressure-reducing valves that prevent water from flowing back into the municipal supply.

Key Features:

• 4.4-gallon capacity suitable for residential water heating systems
• 1/2 inch NPT male connection for standard plumbing installation
• Pre-pressurized butyl diaphragm separates air and water to prevent waterlogging
• Durable steel construction with protective coating
• Complies with thermal expansion requirements in most plumbing codes
• Helps prevent relief valve discharge, pipe stress, and fixture damage

This expansion tank is typically installed on the cold water supply line near the water heater. The Sparco-Trol design provides reliable performance and easy maintenance. Proper sizing and installation of an expansion tank helps extend the life of water heaters, plumbing fixtures, and appliances while ensuring safe system operation.