6.3 Gal. Hydronic Heating Expansion Tank

Zilmet ZHT24-60 – 6.3 Gallon Hydronic Heating Expansion Tank

The Zilmet ZHT24-60 is a 6.3-gallon diaphragm expansion tank designed for closed-loop hydronic heating systems. Its purpose is to accommodate thermal expansion as water is heated, stabilizing pressure fluctuations and reducing stress on system components. This model is suitable for both residential and light commercial applications requiring stable, long-term performance under variable temperature conditions.

Manufactured with a carbon steel outer shell, this tank is internally lined with a synthetic rubber diaphragm that separates system water from the air pre-charge. The diaphragm maintains consistent pressure retention and resists degradation under elevated temperature and glycol-based system fluid conditions.

Key Performance Features

• Factory Pressure Tested – Every unit is hydrostatically tested to confirm structural integrity and seal reliability.
• Carbon Steel Shell – Designed for hydronic applications; resists fatigue and deformation from repeated pressure cycling.
• Diaphragm Construction – Heat-resistant synthetic rubber ensures durability under high-temperature operating conditions.
• Compact Profile – Low-profile vertical design allows installation in mechanical rooms and wall-mounted applications with space constraints.
• External Finish – Epoxy-polyester powder coating provides resistance to external corrosion and mechanical abrasion.

Construction and Connection Details

• Tank Volume: 6.3 gallons
• Maximum Operating Pressure: 60 psi
• Tank Height: 16.3 inches
• Tank Diameter: 12.8 inches
• Connection Size: 1/2″ NPT (welded side outlet)

Installation Considerations

The ZHT24-60 is intended for vertical mounting and should be installed on the system return line, upstream of the circulator and isolated from direct boiler output. Proper installation requires verification of system fill pressure and adjustment of the tank’s air charge to match static conditions. All installations should comply with applicable hydronic design standards and local mechanical codes.

Additional Technical Features

• Welded Side Outlet Connection – Facilitates simplified piping layout in wall-mount and compact systems.
• Stainless Steel Nipple – Provides corrosion resistance at connection point to maintain integrity over time.
• MIG Welded Construction – Produces smooth interior and exterior seams, minimizing weak points and enhancing safety during handling.
• Protected Schrader Valve – Allows for field adjustment of pre-charge and reduces risk of valve damage or leakage.