It looks to be a galvanized threaded plug.
No purpose at all. Perhaps it was a hosebib at one point there.
I have a leak below the PRV which I'm planning to fix/replace. Since I'm there I'd also like to replace the valve with a ball valve. I have a couple of questions.
1) What is this rusted fitting and do I need it?
2) Are there any suggestions before I dive in?
If it were ahead of the water meter, it would have been someone's attempt to "steal" water. If it is not in your way, just remove the steel plug and install a brass one.
Licensed residential and commercial plumber
I vote for future sprinkler system connection (assuming there is meter at street).
Given exposed exterior supply I guess warm weather climate where sprinkler systems are very popular so "tee" is part of normal install when house was built allowing easy addition of sprinkler system.
Just looked up Rowland Heights, CA. May thru Sep has average high near 90 with less than 0.25" of rain per MONTH. I bet sprinkler systems are quite popular among the green thumb crowd...
Last edited by wraujr; 11-29-2012 at 03:32 PM.