In 1954, Amtrol invented the thermal expansion tank to control pressure build-up in closed, hot water systems. Today they are continuing to roll out efficient and reliable tanks to improve your system. The ST vertical thermal expansion tank is a perfect example of this. By accepting expanded water caused by thermal expansion, the ST is able to then return the water to the system when hot water is used. The ST also prevents pressure relief valve discharge, dripping faucets, and intermittent toilet fill. From the strong deep drawn steel domes with corrosion resistant liner to the welded air charge fitting, the ST is designed to prevent damaging pressure buildup and eliminate energy and water waste. The ST-25V is ideal for large residential and light commercial applications.
All ST thermal expansion tanks are made in the USA at facilities certified for maintaining high-quality standards.
Heavy Duty Tank
From the deep drawn steel dome with rigid polypropylene liner to the welded air charge fitting, this thermal expansion tank is constructed from top to bottom for maximum strength and corrosion resistance.
Eliminates Wasted Energy
Expanded water caused by thermal expansion is collected by the ST tank which returns the water back to your system which preventing faucet drips, intermittent toilet fill, and pressure relief valve discharge.
Protection for Your System
ST thermal expansion tanks are designed to protect your water heater, fixtures, and appliances by preventing dangerous pressure build up.
Multiple tanks can be installed to accommodate large systems.