Slag

Non-metallic solid material entrapped in weld metal or between weld metal and base metal.

Water tube boiler

A multiple tube circuit heat exchanger within a gas-containing casing in which steam is generated inside the tubes by heat transferred from a hot gas flowing over the tubes.

Water tube pipe coil HRSG in a pressure vessel

A tube or pipe coil circuit within a pressure vessel in which steam is generated inside the tubes by heat transferred from a high-temperature fluid or fluidized solids surrounding the tube circuits.

Target wall

A vertical refractory firebrick wall which is exposed to direct flame impingement on one or both sides.

Radiant section of a Heater/ Boiler

Portion of the heater in which heat is transferred to the tubes, primarily by radiation.

Integrity operating window

A set of operating parameters for the equipment that define the range of operating variables for the materials of construction .  If exceeded for some critical time interval, the likelihood of failure to an unacceptable level.