retrofitting a tee into an existing length of pipe

[Max]

I want to fit a new tee in a small section of pipe (about 8") between an elbow and an existing tee. When I cut the pipe I will need to somehow make the gap big enough to fit the new tee over the ends of now exposed pipe. Can I just pull the pipe apart or will this compromise existing joints? I can feel that there is some play in the pipe but I won't know the full extent until I make the cut. I would rather know the risks, if any, ahead of time. I obviously wouldn't want to force the pipe excessively but perhaps a little, gentle coersion is OK?

Cheers, Max

EDIT: the pipe configuration is something like this:


existing tee====x====elbow

where "x" is the planned cut point. I don't think there is any range of motion on the "existing tee" side of the system, it is connected to other pipes that are mechanically fastened to a joist and connected pipes pass through wood. The elbow side of the system drops 7' to the feed from the pressure tank and there is a connection to the water softener about 1/2 way down that vertical section.

LazyPup - what do you use to draw your pics with? Is it free because it sure looks useful.

[LazyPup]

When installing a tee on an existing line it is best to compute the insertion loss of the tee and make two cuts taking a piece of the pipe out equal to the fitting allowance of the tee.




Here is a trick,,pre-clean the whole section of the existing pipe before you cut it, the pipe is rigid and it makes it easier to clean the pipe with emery cloth. After you cut it you will need to go over it lightly again to clean any debris from the cutting process, but the worst of it is already done.



ILLUSTRATIONS: Some months ago Hazee made some very nice illustrations using the Microsoft "Paint" program. At his prompting I too began exploring the possibilities of that program. While I am still learning what it can do, I find Paint to be extremely user friendly and I am quite proud of some of the results to date.

MS Paint is a startup program that is prepacked on most computers...Look under "start - Programs - Accessories - MS Paint."

For best results in the forum on the paint top tool line hit "Image" then hit "Attributes" and set the height and width to 550 pixels, that will format it to fit the forum nicely.

After you create your image save the file as a JPEG file.

You then hit "Upload an Image" on the upper left side of the forum text box and a window will open.

Hit "Browse" to find your image file and open the file.

Then hit "Submit" and you will see it upload to the forum server. It will print an address in the window. Copy the complete address and paste it into your text message in the forum and the image appears when you open the thread in the forum.

[Max]

Thanks, LazyPup. I had no idea you drew them by hand using Paint. I use Paintshop Pro myself. I just assumed you had some package that had a library of images that you drag 'n' drop into a diagram - much like Visio for example.

Cheers, Max

[Max]

Well, got that done but it was a little freaky at times. I guess I didn't drain the system properly because I couldn't sweat the new tee into place. I thought I had drained the system but it wasn't until I opened up all the faucets that all the water came out. I was stressing out, I thought I would never get that fitting in place. Got it done now though and the wife can shower so all is well again. The hammer arrestor leaks a little but once my wife leaves the house I will switch off the water and refit it. It's a threaded type and I think I must have put too much ptfe tape so the hammer is not screwed in as far as it needs to be.

What doesn't kill you makes you stronger so I will be like the Hulk tomorrow.

Cheers, Max

[LazyPup]

Max,,It is doubtful that you applied too much PTFE tape. It is more likely that you applied the wrong tape.

The common white 1/2" x 50' rolls of PTFE (Teflon) tape which we find in most hardware stores is single density tape. It is only ANSI (American National Standards Institute) rated for fittings up to 3/8" in diameter.

Formerly we had a high density teflon tape that was 3/4" x 50 but only commonly sold in the Plumbing, HVAC or Electrical supply houses.

The ANSI has recently changed the standards on PTFE tape and instituted a color coding system to identify the different grades.

WHITE= Single density- for use on threads up to 3/8" when three or more wraps are applied.

YELLOW= Double Density- For use on NPT (National Pipe Taper) threads up to 3/4"-requires 3 full wraps. (before the standards changed yellow double density tape was designed to be used in place of the white single density on gas lines and it is commonly labelled or referred to as "Gas Tape")

RED- Triple density tape--for use on all NPT threads up to 2". Requires three full wraps.

GREEN- Oil Free teflon tape- for use on OXYGEN lines.

COPPER- Copper colored PTFE tape contains granules of copper and is only to be used as a thread lubricant, not listed as a thread sealer.

You can now find white, yellow and red teflon tape in most Lowes and Home Depot stores as well as many hardware stores. If you local hardware doesn't have the Red tape you may want to suggest they add it to their inventory.

The red tape sells for about $1.98 a roll as opposed to $.98 for the white, but since it is triple density you are actually getting three times as much tape on the roll,,,what a bargain..hehehehehhe.

I think you will find working with the thicker density is much easier.

Itis very important that teflon tape be applied correctly to insure proper tension on the threads..see illustration below.

[Max]

OK, I used white tape so I will replace it with the red tape. Thanks, Max