Threading pipe for slope

steamydeeds

I recently bought a 1900 home with steam. A pipe servicing a second floor rad had been cut in the basement, and sure enough when I tested the section going up the wall it had a leak. I ended up cutting it out and now need to replace it. I noticed that the old verticle pipe is threaded at a slight angle on the ends, so that the pipes coming off of it have the correct slope. Is this the way it's still done to get proper slope? Can pipe be threaded at an angle with a regular pipe threader? If not who can I get to do this for me?
Thanks

JUGHNE

Is this a 1 or 2 pipe system? Is it possible to get the correct slope/angle by using swing 90 ells from the horizontal transition to the vertical pipe? Pictures are always good.

steamydeeds

It's a 1 pipe system. By "swing 90 ells" I take it you mean 2 ells put together at the transition of the verticle and horizontal so that the horizontal can be sloped? I could do this on the second floor but in the basement there's very limited access and I don't think I would want to notch the rim joist to the point where I could fit all that back there. I'll take some pics next time I'm over there.

Larry_52

Are you meaning the concentric taper on the threads? NPT is 3/4" per foot taper threads.

If you actually mean an of center thread...
A standard pipe threader cannot cut eccentric or off center threads as it uses the pipe outside diameter as its reference. You could cut pipe threads on a lathe off center with a 4 jaw chuck but never heard of such a thing. Pipe would probably need to be schedule 80 to get a decent off center angle on threads.

The only practical way of getting off center threads is to tap the female end to the angle you want. Would have to be custom fitting as you can't tap over previous cut threads. The diametrical swing on the free end length of pipe will magnify over its distance as you tighten. How can you not use ell's but a pipe that is going to dance around at the end to accomplish what you are asking for?

If this is a transition from vertical to horizontal why not use a long sweep elbow.

If fitting this is as crazy as it sounds why not hydraulically bend pipe to what you need then thread the ends and union it in.

nicholas bonham-carter

Ice Sailor has described such a process, so maybe he will chime in.--NBC

steamydeeds

I do mean an off center thread, that's sure what it looks like was there originally, which sounds difficult to replicate. Maybe I can just use an ell and the pipe will have enough play to get to where I need it. Would a long sweep be better for any reason? I'll give that a try and report back.

EBEBRATT-Ed

The correct answer for this is what the old timers called "cutting a drip thread" No one I know does this anymore. Your going to have to make it up with 90s, 45s and swing joints etc They used to cut a crooked thread on a pipe to get the slope or pitch they wanted

I've been doing this 42 years and never cut a drip thread (don't know how) I've only read about it. You would need a threader like a Ridgid 65R where you can set the gide collar on the back "off center". They also make a 65R -TC which you cannot use for this. the tc stands for "true center"

JUGHNE

What size of pipe on the basement end; the one that was off center threads?

TonyS

EBEBRATT-Ed you have been doing this a long time. Most guys today dont even know how to use those threaders much less know the difference between the two.

steamydeeds

Its 1-1/4" pipe, and was "drip threaded" at both the top and bottom (basement and 2nd floor). Thanks for the explanation of the cutting a drip thread.

AlCorelliNY

Never heard "drip threaded", but cut many a crooked thread with my 65 RIGID.

Larry_52

Yep, learn something new all the time here. Had no idea intentional off center threads were a practice.

ChrisJ

I'm 90% sure you can do this using a Ridgid 65R-C

When I bought my 65R-TC icesailor told me it was a mistake because it was the true-centering version that couldn't do drip threads.

I believe Ridgid even has instructions for it, but not for my version.

https://www.ridgid.com/us/en/65rc-manual-receding-threader

Luckily, I don't need to do drip threads, but perhaps this is the answer you need? It does 1" 1 1/4" 1 1/2" and 2".

EBEBRATT-Ed

Well, Al has at least done it.. by accident maybe haha. I think I have too. I like the 65 R threaders..have two of them. I like them because they cut 4 sizes of pipe 1", 1 1/4", 1 1/2"-2" with the same dies because 1"-2" all have the same threads per inch. The 65R-TC true center has a centering guide that spins around and as it spins it opens and closes for different size pipe. The regular 65 R has a centering guide with two posts and a set screw to lock it on the pipe. I am the only one in our shop that will use it everyone says there too heavy so they don't like them.

I like them for two reasons, the dies last a long time because they only have to cut threads the threader pulls the dies on the pipe and they cut easier which puts less strain on the 300 machine or whatever your using.
They are really designed like the 141 threader used on 2 1/2"-4" wihtout the gear reduction ...maybe that's a clearer way to explain it. Ridgid still makes them.

EBEBRATT-Ed

Yeah. Here's the instructions and they do talk about a drip thread so the "DEAD MEN" must have done it

billtwocase

I think my old 65 would make those threads

ChrisJ

Don't let the new retail price scare you.

There are many good units on Ebay and new dies are affordable as well. Remember to buy a a handle, though I suspect a piece of 3/4" pipe may work, but I'm not sure.

http://www.ebay.com/itm/RIDGID-NO-65-R-1-2-PIPE-THREADER-RATCHET-RECEDING-65R-JAM-PROOF-/261782722019?pt=LH_DefaultDomain_0&hash=item3cf37755e3

For drip threads make sure you buy the standard 65R-C unit not the "TC". you can easily tell because the standard unit has a large screw for tightening it to the pipe. The TC has a large paddle lever you flip.

Here are pictures showing both, first the one you want.






And now, the TC version like mine that cannot do drip threads.

EBEBRATT-Ed

Yup. Bill & Chris you are both correct!!!! there is another trick that your supposed to be able to do with this threader and I never tried this one either.

One of the threader disadvantages is that you can't cut a nipple shorter than 7 or 8" I forgot the exact size. They say you can chuck a "thread protector" coupling in the rear guide with a short pc of pipe threaded into the coupling The other end is not threaded. they say you can use the coupling like a nipple chuck to thread a short nipple.

You can only do this with the TC--True center workholder. So I guess both styles have their use!!!!!!!!!!!
Ed

ChrisJ

EBEBRATT-Ed said:

Yup. Bill & Chris you are both correct!!!! there is another trick that your supposed to be able to do with this threader and I never tried this one either.

One of the threader disadvantages is that you can't cut a nipple shorter than 7 or 8" I forgot the exact size. They say you can chuck a "thread protector" coupling in the rear guide with a short pc of pipe threaded into the coupling The other end is not threaded. they say you can use the coupling like a nipple chuck to thread a short nipple.

You can only do this with the TC--True center workholder. So I guess both styles have their use!!!!!!!!!!!
Ed

I'd love to know exactly how to do this trick because it has been an issue for me and I'm sure will be again.

Wish there was a youtube video on it....

EBEBRATT-Ed

Yeah, I usually bring nipples up to 6" with me and try to plan the piping so I don't need a 6 1/2, 7, 7 1/2 etc. Then I bring a few extra couplings in case I have to make a 7" with two nips and a coupling. Ridgid makes a nipple chuck kit and you can cut close nipples with it but it only works on a 300 machine with the carriage and the quick opening dies

j a_2

An even easier way is to by couplings from the big box stores…Not much quality control there….they make a straight run look like a worm wiggling…..

Charlie from wmass

You can hire me to cut the thread.

icesailor

EBEBRATT-Ed said:

Yup. Bill & Chris you are both correct!!!! there is another trick that your supposed to be able to do with this threader and I never tried this one either.

One of the threader disadvantages is that you can't cut a nipple shorter than 7 or 8" I forgot the exact size. They say you can chuck a "thread protector" coupling in the rear guide with a short pc of pipe threaded into the coupling The other end is not threaded. they say you can use the coupling like a nipple chuck to thread a short nipple.

You can only do this with the TC--True center workholder. So I guess both styles have their use!!!!!!!!!!!
Ed

You make a nipple holder with a pipe coupling that comes on a length of T&C pipe. You put the appropriate pipe size pipe in the 65RC Diestock and start cutting the thread. After two revolutions, you release the back of the chuck and let the diestock turn freely. When you are done, the very end of the pipe inside the coupling will be 2 or three thread revolutions from the end face of the coupling. SO, you thread the required running thread on the nipple, then stop and engage the back of the diestock and finish the thread. Remove the diestock. Put the coupling on the threaded nipple and wind the coupling on the nipple/pipe. Stop 2 or 3 turns from the end. The piece you will want to make a nipple with screws up against the pipe nipple inside the coupling. The "nipple holder" goes into the power drive or vice stand. Flip the 65RC so the threaded jaws are down. Put the nipple to be cut into the 65RC and if the coupling hits, open the back jaws. If you are threading 1 1/4" pipe, open the jaws to 1 1/2 so the coupling sets inside the adjustable collar. Center the coupling in the collar and close the centering part so the pipe is centered. Tighten the wing nut. Thread. You can make any length you need. It is cheaper to buy nipples, but when you find you need a size that you don't have, make one.

Every pipe should have a thread on one end. No matter how short. For convenience, I always made them a minimum of 10". Excluding the coupling.

My old dead boss only called them "Crooked Threads".

EBEBRATT-Ed

Good description. Thanks!!

steamydeeds

Well I ended up just doing it with swing joints. I do have a 6" section or so with no slope. Is this a huge no no? Thanks for the insight.

KC_Jones

This is a picture of some original piping across my first floor ceiling going to a small radiator in a walk in closet on the second floor. Thought this was a good visual of how they did it. Yes that is a 90° elbow (checked it with a square) and it goes straight (plumb) up through the ceiling/floor.

JohnNY

My father used to say he/they used to make "off center" threads using a wedge of wood in the stock and die somehow.
I'm going to ask him.

icesailor

In the Photo, you need two crooked threads. One before the pipe comes out of the wall, and the other on the riser to the radiator. Or some combination.

If both ends of a pipe are threaded, and you cut off a piece to length to thread it, you will never have an orphaned piece of pipe that you can't thread.

Charlie from wmass

Da always made me thread both ends. Also never leave cutter closed or dies open.

ChrisJ

Charlie from wmass said:

Da always made me thread both ends. Also never leave cutter closed or dies open.

The cutter I can kind of understand, like if you keep a micrometer closed it mess up the calibration if it warms up because the steel expands. But why not keeping dies open? What's the difference?

icesailor

Charlie from wmass said:

Da always made me thread both ends. Also never leave cutter closed or dies open.

Sounds like my old dead boss. Always leave both ends threaded.

Charlie from wmass

Was he Scottish too?

Charlie from wmass

If the next guy sides the die forward thinking it closer he hit the pipe end with his wrist.

ChrisJ

Charlie from wmass said:

If the next guy sides the die forward thinking it closer he hit the pipe end with his wrist.

Ah,
I assume you meant thinking it's open.

I guess that makes sense.

Charlie from wmass

Thinking it is closed. I mean.

icesailor

Larry said:

Yep, learn something new all the time here. Had no idea intentional off center threads were a practice.

When you go to pipe off the top of a boiler in a vertical direction, and you can't get the pipe plumb in all planes, a crooked thread is a wonderful thing.

If you rise out of a boiler with the riser 1 or 2 degrees off, and every thing else is plumb and level, the end product will look like it came from the dump.

EBEBRATT-Ed

I have heated pipe with an oxy-act torch and bent it .The old timers bent a lot of pipe too.

Charlie from wmass

When you are bending iron pipe make sure you keep the seam neutral.

icesailor

Charlie from wmass said:

Da always made me thread both ends. Also never leave cutter closed or dies open.

When using a Power Drive, always shut off the power so that the diestock stops at the top. So you can loosen the chuck and flip the jaws closed. For the next thread. When you do that, you don't drip cutting oil all over your hands.

Always put a couple of 2" X *" pieces under the back leg(s) to pitch the diestock end forward and lower so that the oil runs out of the pipe and into the oil bucket. Not back down the pipe.

For the Steamheads, it might cut down on oil skimming. My old dead boss used to jump up and down if you left oil inside the pipe. Something about oil in the valves. He never explained the real reason.

Abracadabra

icesailor said:

Always put a couple of 2" X *" pieces under the back leg(s) to pitch the diestock end forward and lower so that the oil runs out of the pipe and into the oil bucket. Not back down the pipe.

And here I was thinking I was the only one that did that!

j a_2

Me too