11 Things You Need to Know About Hot Spots in Pressure Equipment

What are hot spots?  

Hot spots are regions on the pressure boundary of process equipment where the surface temperature exceeds the surrounding material temperature. These localized areas of overheating in pressure equipment can lead to deformation, or even loss of process containment, because when overheated, metals lose strength and may become susceptible to damage mechanisms.

Refineries and petrochemical facilities process fluids at temperatures in excess of 600 F. Elevated temperature equipment is often refractory lined internally to keep the pressure retaining wall temperature sufficiently low to permit less alloyed material to be used safely. Refractory degradation or failure exposes the pressure retaining wall to temperature above design and causes hot spots.  In addition, equipment may experience higher than design maximum temperatures and form hot spots during runaway reactions, process stream decompositions, and other operational issues.

When a hot spot occurs, it is therefore important to understand the effects of elevated temperature have on the mechanical integrity of the equipment.