R.F. MacDonald Co. Performs Boiler Door Repairs

Boiler Door Refractory

R.F. MacDonald Co. Refractory Dept. has instructed boilermakers how to repair boiler doors both in the shop and in the field for over 10 years.

Knowing how to properly rebuild a boiler door is a boilermaker growth requirement at RFM. Our in-house Refractory Dept. provides training for boilermakers during level three of a five-level growth program. In March 2019, three boilermakers attended door-building training at our Central Repair Facility in Fresno, CA. The instructor focused on rebuilding the upper and lower half of a 96″ boiler door, emphasizing a step-by-step process to proper insulation.

The upper half requires Kaowool insulation, a ceramic fiber blanket that traps heat. The lower half requires refractory (cement) to ensure heat from the burner will not reach the metal of the boiler door. Heat on a boiler door will cause hot spots. Hot spots are signs of refractory damage and inefficient heat circulation.

Upper-Half Door Building
1. Install Kaowool within the boiler door joints.

Lower-Half Door Building
1. Insulate with green ceramic inboard. Properly place the green ceramic inboard within the boiler door joints. The objective is to make sure the joints are tight and eliminate any link paths that could allow the cement refractory to seep in. This is how hot spots occur.
2. Fill the boiler door with refractory.
3. Insulate 3.5”.
4. Install mold.

Special thank you to the RFM Refractory Dept.