What is the typical procedure to install tubes in a steam drum?

• A. TIG welding
• B. Stick welding
• C. MIG welding
• D. Flux-core welding

Answer: (B)

When installing tubes into a steam drum, you’re working with thick, heavy sections in often field conditions, and you need a robust, dependable weld that can be done with simple equipment. Stick welding, or SMAW, fits this need well. It uses flux-coated electrodes that help maintain a stable arc and provide good penetration, which is important for fusing the tube into the tube sheet and sealing against boiler pressure and heat. The method is versatile for long runs, can be performed in tight or awkward positions around the tube sheet, and the equipment is portable and readily available on site. With careful root and fill passes, you can build a strong, gap-bridging weld that stands up to boiler service.

Tungsten inert gas welding is excellent for precision and thin-walled or corrosion-resistant work, but it’s slower and less practical for the heavy, field-based work of boiler tube installation. MIG welding requires shielding gas and is less forgiving in outdoor or windy conditions and with very thick sections. Flux-core welding can be productive but tends to produce more slag and cleaning work, which is not ideal for the tube-to-tube-sheet joints in steam drums. These reasons make stick welding the typical procedure for this task.