What type of boiler tube rupture resembles a burst bubble with tapered edges?

The choice highlighting "thin-lipped" accurately describes a type of boiler tube rupture that appears similar to a burst bubble, characterized by its tapered edges. In this context, "thin-lipped" refers to the nature of the rupture where the edges of the break are sharp and steep, resembling a bubble that has just popped, hence the tapered appearance. This type of rupture typically occurs due to a combination of high pressure and temperature, leading to the failure of the tube material in a clean and defined manner.

Conversely, other types of ruptures have distinctly different features. Circular ruptures tend to have more uniform, round edges, which do not fit the description of a tapered appearance. Irregular ruptures are marked by jagged and uneven edges, lacking the smooth contour associated with a thin-lipped rupture. Fat-lipped ruptures would display wider and more pronounced edges, differing from the subtle tapering seen in thin-lipped scenarios. Understanding these differences is crucial when diagnosing the condition of boiler tubes and addressing issues related to their integrity.