Pipe threading

[Heyseed]

I have to cap a galvanized pipe in an old building. The end will have no threads and I'm looking for ideas. I see that Harbor Freight has a threading tool. Anyone know about the quality? This may be the only time I use it so spending a lot doesn't make sense.
Will the size be the same for Galvanized and black pipe?
Any thoughts on using a Dresser Compression Coupling instead. This is a water line with maybe 50 PSI max.
Thanks.

 

[kcm.MN]

Galvanized and black pipe are interchangeable. As for the threader, I haven't a clue.

 

[Janicholson]

A threading tool like that will be fine. I suggest looking into renting one if it will not be used after the job. If nothing else giving it to a handy plumber friend might be an idea. smashing the end and welding it shut is easier!! Jim

 

[Tony in SD]

I bought a used Rigid set at a pawn shop for the same money.

 

[Charles in Aus.]

How long does this work have to last ?

My SIL lives in an old mansion that had a broken gal pipe , so bad that I wouldn't dare even try to thread it . I bought a pipe joiner that was a stainless sleeve with a rubber insert . I cut the end of the broken pipe square then used the joiner to couple it to a short piece of new pipe with an end cap on. This was six odd years ago and it is still holding with not a hint of a leak .

 

[Heyseed]

Hey Charles, that is a Dresser compression fitting. I had the same idea for a fix. This pipe is under the floor and threading it would be a tricky option. Thanks

 

[RedMF40]

Possibly put a flexible coupler to pvc and cap the plastic?

 

[JF in MI]

I have one that I have used numerous times. They are "so so". Not great but not too bad either.

 

[showcrop]

Any chance of removing the stub length back to the last coupling or elbow?

 

[Logan in S.E. Texas]

There are places that rent tools also. Being it's possible that you will not need it in the future.

 

[Stephen Newell]

If all you are going to do is cap one pipe you have nothing to loose in buying that pipe threader. It will either work or they will take it back. More than likely it's a good tool but the dies won't last as long as a better brand.

 

[Russ from MN]

Unless you have other use for the threader I would use a compression fitting, they are widely used in industry and reliable if properly installed.

 

[rustyfarmall]

(quoted from post at 22:41:22 01/10/18) I bought a used Rigid set at a pawn shop for the same money.

I bought the Ridgid set at an auction. 1/2" up to 2" dies. It works very well, but a pipe wrench is also needed to keep the pipe from turning.

 

[Steve@Advance]

I would suggest a dresser coupling.

Then plug the other end of the coupling with a threaded nipple and cap.

To be safe, nail a block across the capped end. Sometimes if there is water hammer, or the rubber seals relax over time, they can come off if not trapped.
Dresser Coupling

 

[Steve@Advance]

PS, another reason for the coupling, the pipe may be too corroded to take a thread. Threading is a pretty forceful operation, could break something, start another leak down stream.

 

[kevinj54]

(quoted from post at 08:53:49 01/11/18)
Any chance of removing the stub length back to the last coupling or elbow?

That is generally how our plumbers would do it.

Today you can rent a crimp tool and put a valve on it with a plug.

 

[Stan in Oly, WA]

Heyseed; I have that Harbor Freight pipe threading set and it has served me well for many years---so many years in fact, like almost 40, that the odds of it being the same as the ones they are selling now would be very low. Before I owned that set I once rented a Rigid brand pipe threader and cutting dies from a rental shop in the poor end of Seattle. (BTW, Seattle doesn't have a poor end any more.) The young man who ran the rental place for his parents was a no nonsense person who had seen customers try to pull every possible trick. I doubt that anybody managed to put one over on him by then. Anyway, I started cutting some 1" galvanized steel pipe and some teeth broke off the cutting die. I knew I had used it correctly, but the young man didn't know me, so I expected quite an argument from him. Instead, what he said was that he would normally make me pay for the damage, but a regular customer of his who he knew to be experienced and careful had brought the tool back with the same problem, so he assumed that Rigid had released a bad batch of dies. I tell this as a warning that a high quality brand doesn't necessarily guarantee a trouble free product---it only gives you better odds.

You've gotten some very good suggestions here about how to deal with your problem without trying to thread the pipe end you've got to work with. I'd strongly advise you to use the best alternative you can find that doesn't involve threading your pipe. My extensive experience dealing with old plumbing is that trying to correct a problem leads to one or more other problems more often than not. The things that could go wrong with your situation are the stuff of nightmares.

Stan

 

[Heyseed]

Thanks for all the suggestions, I used a Dresser Compression Fitting and a capped off nipple. It did the job, I added a bit of safety wire which felt like overkill, but why not.

 

[Fred Werring]

Huh...never even heard of a Dresser coupling before.

Learn something every day

Fred