I have a pipe in which I need to replace the gate valve (already have it on hand) the issue with the current one is with it fully closed it still allows water to flow.. Now the issue with the pipe is that it's too close to the wall for me to use a pipe cutter, and I have the mini type.. the angle of the picture is not the greatest..

This is my first run at replacing a copper pipe (it runs to a dishwasher) so assuming I need a mini hacksaw I will also need to extend the pipe in order to replace what I cut off.. I do have flux and soldering for pipe and a torch.

 

If you can shut the water off and drain that line.... maybe you could use a torch to break a coupling or that 45 loose.

 

Maybe.. another thing was at first I picked up some small 3/4 stop couplers but then I noticed it was just a butt piece.. so I picked up some 3/4" Type M pipe in a foot and it slips over and in my gate valve.

Another question is say you had some section of pipe that was not connected but had a gauge on one end and all the twisting trying to removed it caused a section of pipe to come undone, how should I go about fixing that section back up?

 

That valve is in a 3/4" line..... it looks like 1/2".

I'm not following your second question...... if you had a section of pipe that wasn't connected.... how could it come undone ??

 

Ok assuming I need to go out and get another valve then? I know they have 3/4 to 1/2" but will it fit on the 3/4" so I can sweat it?

 

Since you are trying to replace the valve in the picture you need to determine what size pipe that is there. It looks like 1/2" but it isn't always easy to tell in a picture.

You should use a brass ball valve as replacement. They are more reliable and rarely have leak problems.

Both valves come in 1/2" and 3/4" threaded or direct sweat on.

 

Looks like an angle valve coming through the wall. Concrete? Will need to get into that wall to replace it.

 

I already have the new gate valve I ordered from the internet so I will just stick with this what I have, what's on the other side of the wall leads into the broiler room area and it's just another gate valve in-line which is how I was able to fully shut off the water for now.

I will grab another view of the valve the fitting today I picked up may or may not be the right stuff.. I picked up a 3/4 to 1/2" C X FTG I'm not too sure the ends on the current pipe are cupped.

 

Here we go this should help some

 

Hi Mike –

I’m not a plumber, just a newbie, but I’ve done some plumbing work. I think you have to determine what pipe size you really have there. Using the pic in post #1, if you measure the outer diameter of that short piece of pipe between the valve and the 45 elbow, and if it measures 7/8, then you have a ¾ pipe and your valve is 3/4. But if the OD measures 5/8, then you have a ½ pipe and your valve is ½.

That’s because the OD on copper pipe is 1/8 inch larger than the nominal pipe size.

Also, you can’t reuse copper fittings because you can’t clean (with any degree of certainty) the old solder out of the cup into which the pipe is soldered, and you must have a clean cup to do a proper solder job.

But you can remove a fitting from a pipe, and clean the solder off the outside of the pipe, get it really clean and nice and shiny, and solder it into a new coupling. (I do that, and as far as I know that’s OK to do. The plumbers will weigh in I’m sure if that’s wrong.)

I just mention that because you have to take that into account when you remove and replace things.

If you have to return that gate valve because it’s the wrong size, I would do what PJmax suggests. I think everyone uses the ball valves today. (I think as PJ says they are much more reliable.)

The FTG side of a fitting is made to slip into the cup of another fitting. So you just solder the FTG side of the fitting INTO another fitting, For example, if you have a 90 degree ½ C x FTG elbow, then on the C (cup) side, a ½ pipe gets soldered into that cup just like any other ½ fitting. But on the FTG side, that side gets soldered INTO a ½ inch fitting. In other words that side (FTG side) acts like a ½ pipe and thus can be soldered directly into another fitting. (But maybe you know all that already and this is boring. LOL)

I can’t see what kind of elbow that is going into the wall but it seems you are saying that there is a reduction from ¾ to ½ somewhere. (You certainly could be correct, I’m no expert.)

 

The last picture is the one you should have posted first. I see a pressure reducing valve there. That would lead me to believe that it is not the shutoff for the dishwasher we are looking at.

 

Willing to bet on it? On the backside of the wall is just another gate valve like I said before I turned that one off because the one under the sink failed to close all the way.

 

Its going into a pressure reducing valve.