Coupling nut visible tightness indicator

A method for coupling a first component to a second component, the method comprising:

• coupling a fitting assembly to the first component, wherein the fitting assembly comprises:
• a nut comprising a threaded portion and a chamber portion, wherein the chamber portion comprises one or more through-holes,
• an indicator slidably disposed within the chamber portion,
• a retainer assembly disposed within the chamber portion and configured to interlock with an inner surface of the nut, and
• a spring disposed within the chamber portion between, and engaging, the indicator and the retainer assembly, wherein the retainer assembly is configured to interface with the spring to retain the spring within the chamber portion;
• coupling the nut to the second component such that the second component receives a portion of the first component;
• and
• rotating the nut such that the threaded portion threadably engages with the second component and until a visibility of the indicator through the one or more through-holes changes.

A system comprising:

• a first component;
• a second component;
• and
• a fitting assembly configured to visibly indicate nut tightness when coupling the first component to the second component, the fitting assembly comprising:
• a nut comprising a threaded portion and a chamber portion, wherein the chamber portion comprises one or more through-holes,
• an indicator slidably disposed within the chamber portion,
• a retainer assembly disposed within the chamber portion and configured to interlock with an inner surface of the nut, and
• a spring disposed within the chamber portion between, and engaging, the indicator and the retainer assembly,
• wherein the retainer assembly is configured to interface with the spring to retain the spring within the chamber portion, and
• wherein the fitting assembly is configured to receive the first component and the second component such that, when the nut is rotated, a visibility of the indicator through the one or more through-holes changes.