Assemblies including plug devices, and related plug devices and methods

A plug device for a milling application, comprising:

• a rigid body comprising:
• a base structure;
• and
• a male connection structure longitudinally protruding from the base structure and exhibiting an aperture longitudinally extending therethrough, the base structure extending outwardly beyond a lateral periphery of the male connection structure;
• a thread structure located within the aperture of the male connection structure and laterally protruding from surfaces of the male connection structure;
• and
• an adjustment device within the aperture and engaging the thread structure, the adjustment device configured to move longitudinally upward within the aperture upon being rotated in a first direction and to move longitudinally downward within the aperture upon being rotated in a second direction.

A method of plugging a component of an assembly, comprising:

• delivering a plug device into an opening extending through a shell of a vessel, the plug device comprising:
• a rigid body comprising:
• a male connection structure extending partially through the opening from an internal surface of the shell and exhibiting an aperture longitudinally extending therethrough, the male connection structure comprising:
• inner sidewalls defining lateral boundaries of the aperture;
• a threaded structure located within the aperture and laterally protruding from the inner sidewalls;
• and
• an upper surface completely contained within the opening and recessed relative to an external surface of the shell;
• and
• a base structure longitudinally adjacent the internal surface of the shell and extending outwardly beyond a lateral periphery of the male connection structure, the base structure coupled to the male connection structure through a weld joint, a braze joint, or a solder joint;
• and
• an adjustment device located within the aperture of the male connection structure of the rigid body and engaging the thread structure of the male connection structure;
• covering the internal surface of the shell with a structure, an external surface of the structure physically contacting at least one surface of the plug device;
• and
• coupling the structure to the shell using at least one retention device extending through the structure and the shell.