Abstract: A refractory system of the type having a refractory material attached to a wall by anchoring studs has a plurality of improved anchoring studs. These studs have grooves extending from the top toward the bottom of the stud and refractory material in at least some of the grooves. Preferably the grooves are parallel to one another and to a longitudinal centerline through the stud. The studs may have a smooth section on the side wall adjacent the bottom. The bottom may be conical. Spikes may be provided on the top of the stud.

Abstract: A studded wall in, or replacement panel for, a boiler or furnace has a plurality of substantially parallel tubes, each pair of adjacent tubes being connected. Separate regions of studs are attached to the wall. In each region every pair of adjacent studs is a selected distance apart, typically from one-eighth to one-half inch. The regions are configured and positioned to define a line between the regions. That line has a width different from the selected distance between the studs in the regions adjacent the line. Corrosion testing is done at selected points on the lines. The lines enable each successive test to be performed at the same locations.

Abstract: A stud of the type attached to a furnace wall or boiler tube has a plurality of projections extending from the top of the stud which act as a heat sink. The projections also have a corrosion or erosion resistant coating such as a chromium diffusion layer. The stud as well as the furnace wall or boiler tube to which they are attached will have a longer service life.