An arrangement for and a method of horizontally supporting a side wall of a top-supported flue gas pass. The side wall includes evaporative water tubes at a first temperature, and the flue gas pass includes a superheating tube at a temperature higher than the first temperature and having rigid, horizontal tube legs extending across the flue gas pass between the side wall and a second side wall of the flue gas pass and being supported from above by a hanger, which is in operation at a temperature higher than the first temperature. Rigidity of the side wall is increased by horizontally supporting the side wall by the horizontal tube legs including end sections attached to the side walls by attaching means allowing relative movements of the end sections with respect to the side wall to which the end section is attached, only in a direction of their relative thermal movement.

Apparatus and methods are described for novel radiant tube coil support designs that are insertable through holes in the casing walls of fired heaters from the outside of the heater.

Apparatus and methods are described for novel radiant tube coil support designs that are insertable through holes in the casing walls of fired heaters from the outside of the heater.

An arrangement for and a method of horizontally supporting a side wall of a top-supported flue gas pass. The side wall includes evaporative water tubes at a first temperature, and the flue gas pass includes a superheating tube at a temperature higher than the first temperature and having rigid, horizontal tube legs extending across the flue gas pass between the side wall and a second side wall of the flue gas pass and being supported from above by a hanger, which is in operation at a temperature higher than the first temperature. Rigidity of the side wall is increased by horizontally supporting the side wall by the horizontal tube legs including end sections attached to the side walls by attaching means allowing relative movements of the end sections with respect to the side wall to which the end section is attached, only in a direction of their relative thermal movement.