Pipe threading help.

[Dave Shepard]

I have to install unions between my new oil tank and the fill and vent piping. Anyone have any suggestions for figuring out the length to cut the nipples? I've tried YouTube, but no luck, surprisingly. I have one 1 1/2" and one 1 1/4" to install. Thanks.

 

[Cobleskill]

Can you slide the tank to close a gap?

 

[Treeaddict]

What is the proper thread engagement for NPT (National Tapered Pipe Threads) to ASME B.1.20.1 Standard?

ANSI B1.20.1 Standard provides both “Hand Tight” engagement (L1) and “Wrench Make-Up” (L3) dimensions. The L-1 basic hand tight engagement applies to NPTF threads. It is the theoretical length of asse

support.boshart.com

So if I understand correctly, you need the measurements from the tank taps to the unions above? Measuring from edge of union outlet to edge of tank inlet and adding about 1-1/4” should get you there

 

[Cobleskill]

I got the pipe to turn going through the wall and didn't use a union.

 

[Dave Shepard]

This is what I'm up against. I'd have to take everything apart starting outside.

 

[Treeaddict]

Unions are good in a system like that. They enable tank removal. Just like a union at all gas appliances facilities appliance removal.

 

[Tree09]

The pipes will screw in with a wrench just over a half inch into the fittings if everything is done right, so that'll help you figure out the lengths. Or you can post your measurements here and I'll figure them out real quick for you. Screwed pipe is a kind of wierd compared to other types in that it requires a bunch of different variables to come together, so the tolerance is often up to 1/4" or more depending on what you're working with. Are you cutting the threads?

 

[BlackSmith]

 

[Kaveman]

Ahh, plumbing. Nobody pays me enough to think of that shit anymore.

Check out sharkbite unions, maybe they're the easy answer. I've never worked with heating oil systems, so don't know much about common issues, but it looks like you could scooch the tank around where you need it? Is there more plumbing inside the house or does your diagram end at the furnace?

 

[Tree09]

I wouldn't use sharkbite stuff, especially with oil!

 

[Dave Shepard]

I will be threading the parts I cut out to remove the old tank. My plumber gave me his Oster pipe threader when he retired. Plenty of room to move the tank around. Definitely sticking with iron, already have the unions. Thanks. Going to see how far I get later. It's raining, so an inside job is welcome.

 

[Kaveman]

I wouldn't use sharkbite stuff, especially with oil!

Hey, I did residential and utility plumbing, in Arizona, not much oil heat here.

Also, I love sharkbite, ive never had a callback on an installation or repair in more than a decade. Can't say the same for lickumstickum (PVC) or hot glue (copper soldering).

 

[Tree09]

That's cool, but I'm not a fan. I'm a union steamfitter, i install piping systems for a living (not much residential, we do mainly commercial and industrial), trees were my side hustle. I remember when they first came out, we did a job at a college dorm and the contractor decided to run a bunch of copper water lines with the sharkbite stuff, he thought he was gonna save a ton of labor on the job. And he did, until a few lines blew apart and he had to buy a bunch of computers and stuff for the flooded kids rooms. One guy even took a pipe to the face when one line blew apart, thankfully it wasn't a kid. I would be astonished to see a sharkbite fitting on a job, most have gone to pro press which is a similar product but is crimped onto the copper, i guess they even have another crimp style for steel pipe but i haven't seen it yet. Still at the end of the day it's often cheaper to simply solder it because of the fitting costs, correctly done it'll last as long as the pipe will.

Threaded and flanged connections work great on steel pipe, and are the correct application on an oil line. Sharkbite fittings rely on an oring and teeth to sink into the pipe wall, they won't work on steel pipe, only plastic and copper. If i was running that at my house i would have also chosen steel pipe, and likely threaded it too.

 

[cory]

trees were my side hustle.

"Were"?????

Still are, no?

 

[Tree09]

Not really since cancer, haven't been feeling good enough to do them, working 40 plus a week as a fitter is enough physical work for me at the moment, when the weekend rolls around I'm ready to relax a bit. If i was laid off it might be different, but I did my stem cell collection and have been working steady ever since. Doing my day job is much less strenuous than climbing is, I'm not sure I'll ever climb again like i used to (dying sloth), being a bucket baby is more my speed anymore. And of course not owning a lift isn't helping, and getting a loan is out of the question because if i relapse the last thing the wife needs next to a dead husband is an equipment payment. The other option is to hit the road and go to the big paying overtime jobs to money up, but that's not in the cards at the moment either since she really wants me around for the family life and memories. So for now I'm not doing trees, I'll get there again, just taking longer than I expected it to.

 

[stig]

We'll let you hang with us real treeguys anyway, Kyle.

 

[Burnham]

Yeah, we need your expertise in many other activities.

 

[cory]

Well dang! But all good any which way.

 

[Dave Shepard]

I got the tank in position this evening. Specs say it's 320 pounds. Not fun, to say the least. I think I need a 2" to 1 1/2" bushing, which I might have up at the farm. Otherwise, I just need to get the threader in the basement. It might weigh as much as the tank.

 

[Tree09]

I would cut and thread where the machine is and then carry the pieces down, much easier. A bit of walking is better than humping that thing around. Get your measurement, calculate the pipe length, then go cut your threads. I'm sure you know how to check and see if it's cutting right, spin a fitting on and you should get roughly 3.5 turns by hand, dry, that's how you set the dies (3 to 4 turns is usually close enough). And i would use both pipe tape and dope on them, that makes them seal better but they will be more likely to move around more, so make sure they are well supported. And a ton of never sieze on the union faces and threads, otherwise they will rust together and you'll fight like hell to get them apart again, and the faces might leak without it. Buy any shorter nipples you need 6" and under, if you don't have (or know how to make) a nipple chuck you'll fight them because you'll mess the threads up with the vise trying to hold them when threading. I prefer to cut my own because I'm particular like that, but for most that's too far for most applications.

 

[Dave Shepard]

I want the threader in the basement permanently anyway. I don't think the threader will damage the threads. It has a chuck, not a vise.

 

[Tree09]

I meant chuck. Cut some short nipples and you'll see what i mean.

 

[Kaveman]

I would cut and thread where the machine is and then carry the pieces down, much easier. A bit of walking is better than humping that thing around. Get your measurement, calculate the pipe length, then go cut your threads. I'm sure you know how to check and see if it's cutting right, spin a fitting on and you should get roughly 3.5 turns by hand, dry, that's how you set the dies (3 to 4 turns is usually close enough). And i would use both pipe tape and dope on them, that makes them seal better but they will be more likely to move around more, so make sure they are well supported. And a ton of never sieze on the union faces and threads, otherwise they will rust together and you'll fight like hell to get them apart again, and the faces might leak without it. Buy any shorter nipples you need 6" and under, if you don't have (or know how to make) a nipple chuck you'll fight them because you'll mess the threads up with the vise trying to hold them when threading. I prefer to cut my own because I'm particular like that, but for most that's too far for most applications.

Curiosity has the best of me...

Why tape and dope? I was taught to use one or t'other.

 

[Tree09]

It'll seal better, the tape goes on first and a thin coat of dope goes second. It's super rare to have a leak if you use both, dunno why exactly but it works wonderfully. I'll use just dope if i need a fitting to stay put tho, the tape and dope makes it very lubricated so it'll spin really easily.

 

[CurSedVoyce]

I remember feeling like tolerances changed somewhere in time.
Rarely a gas pipe ( iron) or water pipe (galv) or copper where threaded leak. Little bit of dope, good to go. In the 90s, had to use the better dope (almost like glue) on gas pipe, or teflon tape and dope on water. Air it up for the inspector. Always a leak at the threads if not.