Amtrol 390603 Thermal Expansion Tank 8 Gal 150 Psi

Product Description

The AMTROL 390603 is a thermal expansion tank from the Therm-X-Trol line, designed to absorb the increased water volume that results from thermal expansion in closed domestic hot water systems. When a water heater heats cold water, the expanded volume has nowhere to go in a closed system — this tank provides that relief capacity, protecting the system from pressure spikes and premature component failure. With an 8-gallon capacity and a 150 psi working pressure rating, the 390603 suits residential and light commercial potable water plumbing installations. Licensed plumbers are the primary installers of this component.

This expansion tank is used in closed-loop domestic hot water systems where a backflow preventer, check valve, or pressure-reducing valve creates a closed condition on the supply side. Typical installations pair this tank with a storage-type water heater in residential construction or light commercial buildings. It is designed for potable water service and mounts on the cold water supply line near the water heater. Local plumbing codes in many jurisdictions require thermal expansion tanks in closed systems, making this a standard installation component for service plumbers and new-construction crews alike.

Key Features

• 8-gallon capacity handles thermal expansion in residential and light commercial closed hot water systems
• 150 psi maximum working pressure suits standard potable water supply pressures
• Therm-X-Trol series design intended for potable water compatibility
• Diaphragm-style construction separates the air charge from system water to maintain pre-charge pressure
• Vertical or horizontal installation flexibility for varied mechanical room layouts

Compatibility

Designed as an OEM-style replacement or new-installation thermal expansion tank for closed domestic hot water systems operating at or below 150 psi working pressure.

Installation Notes

Installation is performed by a licensed plumber in accordance with the applicable edition of the International Plumbing Code and local amendments. Shut off the water supply and relieve system pressure before connecting or replacing the tank. Verify the tank pre-charge air pressure matches the cold-water supply pressure at the installation point before placing the system back in service. Do not install on open or non-pressurized systems.

Technical Specifications

• Capacity: 8 gallons
• Maximum Working Pressure: 150 psi
• UPC: 642031689863

Standard Information

• Brand: AMTROL
• Manufacturer Part Number: 390603