What is installed to accommodate the expansion of refractories without exerting pressure on linings?

The correct answer is the option related to expansion joints. Expansion joints are specifically designed to accommodate the thermal expansion of materials, such as refractories, without placing stress on the lining systems.

As refractories heat and cool, they expand and contract. If these movements are restricted, it can lead to cracking or failure of the lining. Expansion joints are installed to provide a flexible connection that allows for this movement, accommodating the thermal expansion as it occurs. This ensures the integrity and longevity of the refractory lining, which is critical in environments exposed to high temperatures.

The other options, while related to the maintenance and functionality of thermal systems, do not serve the specific purpose of managing the thermal expansion of refractories. Insulation barriers are designed primarily to reduce heat loss or protect personnel from heat, support brackets are used for structural stability, and access panels facilitate maintenance but do not directly address the issues of thermal expansion in refractories.