Plumbing advice requested - How do I know if I soldered a copper fitting correctly? (Sounds like a dumb question, I know)

I have just finished replacing some valves under the sink. The existing copper pipe was too short, so I added a coupling and an extension piece.

I have no fear of grabbing a torch and trying something new, but I'm not sure if I've done this correctly. I used flux and heated the pipe with a propane torch. The joint is not leaking under full pressure.

If the pipe isn't leaking, can I assume the joint is going to be fine? It ain't pretty, but I'm just an amateur. Unfortunately, now I'm second guessing myself.

Submitted November 27, 2014 at 01:45AM by Nate67 http://ift.tt/1yYMpJa