Vapor Barrier

A metallic foil placed between layers of refractory as a barrier to flue gas flow.

Riser (Boiler)

Boiler tubes where the fluid flow is toward the steam drum.

Stack

A vertical conduit used to discharge flue gas to the atmosphere.

Protective coating

A corrosion-resistant material applied to a metal surface; for example, on casing plates behind porous refractory materials to protect against sulfur in the flue gases.

Fire Tube Boiler

A shell and tube heat exchanger in which steam is generated on the shell side by heat transferred from hot gas/fluid flowing through the tubes.

Heat Recovery Steam Generator (HRSG)

A system in which steam is generated and may be superheated or water heated by the transfer of heat from gaseous products of combustion or other hot process fluids.