Amtrol AMTR-ST-30V Thermal Expansion Tank 14 Gallon

Product Description

The AMTROL AMTR-ST-30V is a pre-charged thermal expansion tank designed to control pressure buildup in closed domestic water systems. When a backflow preventer, check valve, or pressure reducing valve is installed on the supply line, the system becomes closed and heated water has nowhere to expand. The AMTR-ST-30V absorbs that expanded volume using a pre-charged air cushion separated from system water, keeping maximum pressure well below the relief valve setting. Rated to 150 psi and 200 degrees F maximum, with a 14-gallon total volume and a maximum acceptance factor of 0.81, this tank is sized for residential and light commercial potable water applications. It installs on the cold-water supply line near the water heater.

The AMTR-ST-30V is used in closed-loop domestic hot water systems where a backflow preventer, check valve, or pressure reducing valve has been installed on the supply line. It is appropriate for residential and light commercial plumbing systems. Licensed plumbers install this tank during new construction or when retrofitting a closed system to bring it into compliance with modern plumbing codes that mandate backflow prevention on domestic water supplies. The 3/4-inch threaded connection fits standard supply line configurations.

Key Features

• 14-gallon total volume with a maximum acceptance factor of 0.81 handles significant thermal expansion loads
• Pre-charged air cushion is permanently separated from potable water, preventing waterlogging
• 150 psi maximum working pressure keeps system pressure safely below typical relief valve settings
• Rated to 200 degrees F maximum for compatibility with standard water heater temperature settings
• 3/4-inch threaded connection fits common supply line configurations
• Steel construction for durability in pressurized plumbing installations

Compatibility

Designed as an OEM-style replacement and new-installation expansion tank for closed domestic potable water systems requiring thermal expansion control per applicable plumbing codes.

Installation Notes

Installation should be performed by a licensed plumber in accordance with the International Plumbing Code (IPC) and applicable local codes. Shut off the water supply and relieve system pressure before making any connections. The tank connects to the cold-water supply line near the water heater using a 3/4-inch threaded fitting. Verify the tank pre-charge pressure matches the system supply pressure before installation, and do not exceed the 150 psi maximum working pressure rating.

Technical Specifications

• Tank Volume: 14 gallons
• Maximum Acceptance Factor: 0.81
• Maximum Pressure: 150 psi
• Maximum Temperature: 200 degrees F
• Connection Size: 3/4 inches
• Connection Type: Threaded
• Height: 23-7/8 inches
• Diameter: 15-3/8 inches
• Material: Steel
• Weight: 25 pounds
• Application: Plumbing
• Warranty: 1 Year

Standard Information

• Brand: AMTROL
• Manufacturer Part Number: AMTR-ST-30V