Locking fitting for a fluid coupling

A locking nipple fitting assembly for selective removable coupling with a housing having a mounting location for receiving the nipple fitting assembly, the assembly comprising:

• a base having first engagement structure configured to engage structure adjacent the mounting location such that the base is secured against rotation relative to the housing;
• a nipple fitting received on the base and having first and second oppositely disposed coupling features, the first coupling feature configured to mate with a complementary coupling feature of the housing at the mounting location whereby the nipple fitting may be secured to the housing;
• locking structure between the base and the nipple fitting, the locking structure configured to resist relative rotation between the base and the nipple fitting until a torque applied to rotate the nipple fitting exceeds a predefined threshold;
• and
• a cover received on the base and capturing the nipple fitting to the base for relative rotation with respect thereto.

A method of securing a removable nipple fitting assembly to a housing having a mounting location for receiving the nipple fitting assembly, the method comprising:

• mounting the nipple fitting assembly onto the housing such that a base of the nipple fitting assembly engages complementary structure proximate the mounting location and prevents relative rotation between the base and the housing;
• rotating a nipple fitting of the assembly relative to the base such that the nipple fitting is operatively coupled with the housing in a fluid-tight manner;
• resisting rotation of the nipple fitting relative to the base with a locking structure between the base and the nipple fitting when a torque applied to rotate the nipple fitting is below a threshold torque;
• and
• enabling relative rotation between the nipple fitting and the base when a torque applied to rotate the nipple fitting in a loosening direction exceeds the threshold torque.