Pre-assembled coupling assembly with cap

A pre-assembled coupling assembly, comprising:

• a domed cap having a domed portion at a first end of the domed cap and a cylindrical portion between the domed portion and a second end of the domed cap, wherein the cylindrical portion comprises a sealing surface, a secondary key, and a groove between the sealing surface and the secondary key, wherein the secondary key extends radially outward from the cylindrical portion;
• and
• a coupling, comprising:
• a housing having a first segment and a second segment, each of the first segment and the second segment comprising:
• a first ridge configured to engage with the groove;
• and
• a secondary shoulder attached to the first ridge, a secondary groove being defined between the secondary shoulder and the first ridge, wherein the secondary key is received within the secondary groove to retain the coupling on the domed cap.