Mckenzie Corp: Boiler Refractory Care and Maintenance

According to the Refractory Institute, "Refractories are heat-resistant materials that constitute the linings for high-temperature furnaces and reactors and other processing units. In addition to being resistant to thermal stress and other physical phenomena induced by heat, refractories must also withstand physical wear and corrosion by chemical agents. Refractories are more heat resistant than metals and are required for heating applications above 1000°F (538°C)."

In a boiler the refractory protects the metal surfaces at critical points such as the rear door and in the furnace. This refractory should be inspected periodically to insure protection. Here is a list of what to look for and possible maintenance solutions:

***Visually inspect refractory. Look for large cracks or broken pieces. Small hairline cracks are to be expected.
***Wash coat the refractory with a high temperature bonding, air dry mortar.
***Face all cracks and joints with hi-temp bonding cement.
***If any bricks have fallen out or show signs of excessive wear, replace them.
***Remember, once the repair is complete it is important to follow the manufacturers recommendation for curing the refractory.

We also suggest that you inspect the refractory of your brand new boilers when they arrive on site. Check to be sure that the refractory has not been damaged in shipment. Report any defects to your boiler supplier immediately.