Economizer arrangement for steam generator

A method of modifying a steam generator, comprising:

• replacing an existing, mechanically supported economizer located in a convection pass of the steam generator with a completely water cooled stringer supported economizer, wherein the water cooled stringer supported economizer comprises:
• at least one bank of economizer sections having at least one flow path;
• a water cooled stringer support system having at least one flow path;
• header means for providing fluid to both the economizer sections and the water cooled stringer support system;
• header means for receiving fluid from both the economizer sections and the water cooled stringer support system;
• and
• means for transferring the weight of the economizer section to the water cooled stringer support system.