Watts 212026 Hydronic Expansion Tank 3.5 Gallon

Product Description

The WATTS 212026 is an ASME-rated hydronic expansion tank with a 3.5-gallon total capacity and a 2.3-gallon acceptance volume. It is designed to absorb pressure fluctuations caused by thermal expansion in closed-loop hydronic heating systems. The ASME construction meets code requirements common in commercial and residential boiler installations. Licensed plumbers and hydronic heating technicians install this tank as part of a properly designed closed-loop system to protect boilers, piping, and system components from overpressure conditions.

This expansion tank is suited for residential and light commercial hydronic heating applications, including hot water boiler systems with closed-loop piping. It handles the volume changes that occur as water heats and expands within the system. The 2.3-gallon acceptance capacity makes it appropriate for small to mid-sized systems where precise pressure management is required. It is typically installed on the supply or return side of the boiler per system design specifications.

Key Features

• 3.5-gallon total capacity with 2.3-gallon acceptance volume
• ASME-rated construction for code-compliant hydronic installations
• Designed to control pressure buildup from thermal expansion in closed-loop systems
• Compact design suited for residential and light commercial boiler applications

Compatibility

Designed as an OEM-style replacement or new-installation expansion tank for closed-loop residential and light commercial hydronic heating systems.

Installation Notes

Installation should be performed by a licensed plumber or hydronic heating technician in accordance with local plumbing codes and ASME guidelines. Shut down and depressurize the boiler system completely before installing or replacing the expansion tank. Verify the pre-charge pressure of the tank matches the system fill pressure prior to connection. Do not install on open-loop or potable water systems unless the tank is specifically rated for that application.

Technical Specifications

• Total Capacity: 3.5 gallons
• Acceptance Volume: 2.3 gallons
• Standard: ASME

Standard Information

• Brand: WATTS
• Manufacturer Part Number: 212026