Roy E. Hanson Jr. Mfg. hot water tanks are used in many projects. 

The tanks are ASME Code Section IV, stamped HLW. 
Both potable and non-potable water storage tanks are needed in numerous buildings. The tanks can be insulated.Many energy saving comes from properly designing, installing and maintaining of the hot water tanks. With epoxy or glass lining the tanks can last many years if sufficient maintenance is present.