2004 Copper Water Service - Am I seeing what I think I see?

Please see photos of the copper water service below. There is a button shaped object on the tubing just below the valve with lots of calcification around it. Looks like a nail head to me though I don’t see any rust. It wasn’t leaking at the time so there was no way I was going to scrape or touch it to try to determine what kind of material it was.

What say you?

Large pics follow

http://www.nachi.org/forum/attachment.php?attachmentid=64017&d=1365559012

http://www.nachi.org/forum/attachment.php?attachmentid=64018&d=1365559034

http://www.nachi.org/forum/attachment.php?attachmentid=64019&d=1365559049

http://www.nachi.org/forum/attachment.php?attachmentid=64020&d=1365559068

Is it possible that the valve is installed backwards and that is a drain fitting? I am assuming that the water flow is going up through the valve.

Copper sweated to gate valve, right? Looks like plain ole copper tube, don’t get it. If so, I don’t understand what protrusion is there. Weird. Also, what is the discoloration / small dot at area opposite where gate valve would seat when closed? Almost appears that moisture may have started from there, as it’s the high point. Good news is, a gate valve and section of copper are inexpensive and it looks like it’s worth a look at to repair.

I’d be tempted to scrape it, but would have tried to remember that curiosity killed the cat and may have to pay for the plumber too :smiley:

Yea, that was my take. Absent the weird appendage on the copper tubing, I would have just attributed the calcium buildup to a bad valve body casting, but I’m kind of baffled.

It did take some willpower not to mess with it.

I punted and described it as below with some detailed photos.

Still open to theories.