What should be done before furnace fittings for tube replacements are ground?

• A. The outside of the fitting should be cleaned
• B. The inside of the fitting should be inspected
• C. The surface of the fitting should be polished
• D. New gaskets should be installed

Answer: (B)

Before grinding furnace fittings for tube replacements, you need to inspect the inside of the fitting. The interior is where issues like cracks, corrosion, pitting, burrs, or scale can hide and directly impact whether the tube will seat properly and seal reliably. By checking inside first, you can detect defects that grinding could either reveal too late or worsen, and you can address any internal damage before you alter the surface that actually contacts the tube and gasket. This helps ensure the joint will be leak-tight and fit correctly once ground.

Cleaning the outside or polishing the surface won’t catch interior problems that can compromise the joint, and installing new gaskets is part of reassembly, not a pre-grind inspection.