How should the fit-up for a bottom mounted drain nozzle on a vessel be fit-up?

How should the fit-up for a bottom mounted drain nozzle on a vessel be fit-up?

• A. Flush to the inside
• B. Aligned to the center
• C. Flush to the outside
• D. Floating position

Answer: (A)

For a bottom-mounted drain nozzle, the fit-up should be flush to the inside. This keeps the interior surface continuous and smooth, ensuring the bore remains unobstructed for efficient drainage and thorough cleaning. A flush interior avoids internal steps or pockets where sediment, corrosion products, or cleaning solutions could accumulate, which can compromise flow and the integrity of the weld around the nozzle. It also helps the interior weld meet cleanable, inspection-friendly standards. If the fit-up were flush to the outside, a protruding inside edge would create an obstacle in the flow path and docking the drain, making cleaning and drainage less effective. A floating position would risk misalignment and leaks, while simply aligning to a center reference doesn’t address the need for a seamless interior surface.

For a bottom-mounted drain nozzle, the fit-up should be flush to the inside. This keeps the interior surface continuous and smooth, ensuring the bore remains unobstructed for efficient drainage and thorough cleaning. A flush interior avoids internal steps or pockets where sediment, corrosion products, or cleaning solutions could accumulate, which can compromise flow and the integrity of the weld around the nozzle. It also helps the interior weld meet cleanable, inspection-friendly standards.

If the fit-up were flush to the outside, a protruding inside edge would create an obstacle in the flow path and docking the drain, making cleaning and drainage less effective. A floating position would risk misalignment and leaks, while simply aligning to a center reference doesn’t address the need for a seamless interior surface.