teflon tape

eleft(retired)_3

Do you believe oil dissolves Teflon?

al

gehring

teflon tape


Can teflon tape be used on black iron steam pipe joints instead of traditional pipe thread compound? What are the pros and cons of either? Thank you.

[Deleted User]

we use both

teflon ribbon tape then a thin layer of dope.

Big Ed

Steam Pipe

Yes teflon could be used on steam pipes .The pro's on teflon is easy removal later on and not messy. Con's more chance of leaks and less rigid pipe work.. Pipe dope ...Con's ,Can't use a oil base pipedope with steam , messy... I feel the best is pipedope and lampwick.. No leaks and rigid pipe work. Con's,messy and time consuming....

Boilerpro_3

Ed, but with steam do you really want rigid pipework?

Those screw joints are supposed to move...that's partially why copper is a no no. Swing joints for headers,risers, etc., wouldn't be swing joints unless things move. Just wondering?

Boilerpro

KellyM

Please do not use teflon tape only. This is especially true if you are working with larger pipe sizes 2" and above. I can almost guarantee that you will get at least one leak and you'll have to redo your work. At the very least use tape and pipe dope sounds like over kill, but its not. The pipe dope will also help assure that you can get these pipes seperated in the future if necessary. Teflon tape alone will shred and the pipes will rust together. Also, make sure you get teflon tape that is larger than the standard 1/2" you get at your local hardware store. The quality is usually way below average and the size only works with pipe under 1" in size. I like to use 1" tape width myself.

Earthfire

Ditto

Teflon tape in the appropriate width and a good pipe dope make the pipes go together easily and seal. Also easier to take apart a couple of years down the line for alterations and additions. One place that NEVER gets teflon is oil pipe, tank supplies or burner feed lines, PIPE DOPE ONLY. JMHO

Steve Miller

pipe dope/teflon tape

I usually use teflon tape and pipe dope on all my joints except on a gas valve where I just use dope. With tape and dope you can screw the pipe in too far and split the aluminum cast of the valve. Just my .02

Steve M

kevin coppinger_4

What would be an example of...

an oil based pipe dope? I have been usuing whitlams blue magic...kpc

tombig

Swing Joints

Hey BP! Swing joints have way more to do with expansion of metal than actual rotation of thread joints. If thread joints moved with every heat/cool cycle they would surely leak. Pipe expansion is allowed by the 'give' of the pipes, not movement of the threads. Thus, "tight is right".

Unknown

Yes , it happened on a few of my jobs

We used Teflon tape and Rectorseal on 4 inch fittings for a steam boiler last year . For some insurance , we doped the inner threads of the fittings too . Had 4 joints leak on me . I think it was because it was extremely cold during the install , and when the system heated up , everything got loose . One elbow was hand tight when I took it apart - and I know I did not wrench it in like that .

I think I'm gonna try Scott Milne and JCAs trick next time -Rectorseal 1st , Teflon next , then Rectorseal again .

Boilerpro_3

Nice to hear from you Tom

I imagine you've been rather busy too. Working about a month out right now, myself. Funny some people don't want to wait for the busy contractor, and end up getting a contractor that can come out right away. I wonder if they ever think about why one contractor is so busy and the other has enough time to be there right away. Curious, isn't it.

Boilerpro

Jack_23

The purpose of ALL pipe dope is...

to lubricate the joint so you can make it up with reduced friction and therefore be able to get the tapered threads to get more and deeper metal to metal contact, thereby making the joint. Any sealing of the joint is secondary to that purpose. Bombs away!

Tony Conner

Pipe Thread

Here's the word on threaded pipe joints, from the guys who deal with pressures that routinely run into the thousands of PSI - the industrial hydraulics guys:

"Due to the clearance between the root of the internal thread and the crest of the mating external thread, there may be a spiral clearance along the length of the thread; therefore a sealant must be used on NPT threads. The sealant should be applied to the external threads only, avoiding the first one or two threads, to reduce the possibility of system contamination. The sealant will also act as a lubricant to reduce the possibility of galling.

A variation of the NPT thread is that used for hydraulic purposes is the Dryseal ANSI Standard Taper Pipe Thread (NPTF). This thread has the same form and dimensions as the NPT thread, except that the truncation of the crests and roots is changed to ensure that the spiral clearance around the thread is eliminated.

Note: The Joint Industrial Council (JIC) recommends the use of NPTF threads when taper pipe threads are used for pipe joints. This thread may also be referred to as the National Pipe Tapered Thread For Fuels.

The interference at the crest and root of the mating parts of this thread eliminates the need for sealant to seal any clearances. Be aware that assembling any thread without lubrication can lead to galling, especially with materials such as stainless steel or other nickel alloys. A thread sealant should be used with this thread for anti-galling purposes.

Note: Special taps and dies are required for making this type (NPTF) of thread. Unless specially marked, NPTF threads are not easily distinguishable from NPT threads."

This is from the "IPT's Industrial Hydraulics Handbook".

I find it very, very rare to get a leak on 150# steam, condensate, compressed air, etc when using the heavy orange Teflon tape (alone) for screwed joints. Wrap the tape in the same direction as the fitting will screw on, use the edge of the spool to chase the thread (push the tape into the bottom of the male pipe thread) then crank it together.

Earthfire

teflon &fueloil

Teflon is not a good sealant for fuel oil lines,and not recommended by the tech guys at suntec,webter,or any fuel injection repair/rebuild facility. Teflon can make its way into the pump and injectors and screw them up.Ever open a fuel pump for service and find stringy looking stuff on the strainer or in the pump. I've even found stuff on nozzle strainers.That ain't no spider in the oil.

eleft(retired)_3

Do you believe oil dissolves Teflon?

Leon in NJ

the FINAL teflon tape answer

OK boys here it is. I don't care what the engineers say because I've taken apart my perfect work too many times on their theories. (I still love them though) DON'T use teflon tape on steam pipes unless it's the center joint of a union or a radiator valve. Also you can do vents with it but that's it. PIPE DOPE is the way my friends! but you have to do it right. 1st take a spoon and take 2 scoops off the top of a new bottle to get all that creamy, oily stuff that settled to the top. That's a leaky joint waiting to happen, and don't try to mix it back in either. 2nd don't use that brush on the cap! You are wiping the dope OUT of the threads and don't know it. The more you wipe "on" the more you wipe "out".Get a medical "tongue depressor" or similiar thin wooden craft stick to apply the dope. I'm serious. When you get good at that, the dope on the pipe will LOOK like it's a bead of teflon tape. It fills the threads up flat and is almost to pretty to screw in. And 3rd, fill both threads! male and female boys. On 1 inch or 1 1/4 you don't need to but 1 1/2 on up it's a MUST. Wiping a little extra off with your finger is better that taking IT back off. Now for my favorite brand of dope - It's not rector seal or MEGA lock (too creamy,lacks solids and boiled out on me too many times) Its Real-Tuff with teflon from hercules. And you can even get it at the god forsaken HOME DEPOT. It's a heavy dope that sets up thick and I have not had one leaky joint since I've use my methods above. Just screw in the pipes right and if you measured wrong don't back it out a few turns and leave "em loose. Don't be lazy,get the right length pipe or you'll be taking it back apart since the threads won't compress right and don't blame the dope. My advice is geared for steam only, I hope it helps you on your quest. Pipe dope is your friend, have fun with it, doping pipe is half the job.

Leon in NJ

leaky joints suddenly OK?

Hey guys, no advice just a short,strange war story. Years back when I didn't know any better I slapped dope on a few new risers quick fixing my sisters radiators or free. 2 of them leaked, bad, dripping and hissing. Since I did it for free I said I'd get back to it but never did, and it stayed like that for the rest of the year, my sister nagging all the way untill summer. Now get this. These joints were leaking for almost half the heating season. I'm talking months and months.I was convinced that all the dope had boiled out and was getting ready to do it over at the beginning of the NEW winter when my sister said the heat had already come on a few times and it DIDN"T LEAK ANYMORE!!?? I had to see so I fired up the boiler, sat and watched, no leak, nothing, perfect joint. Now think about this. Can it be that we don't have to take apart our work anymore if there's a leaking joint? We could just put one of those stretch tight compressable wrap products to hold the leak over and remove it later. How much later I don't know, I'll tell you this though,I'm going to experiment with the next leaky joint I come across. Maybe I'll even make one leak on purpose just to see what happens when I "unwrap" it after 3 months, 1 month, 2 weeks? maybe we are all killing ourselves for nothing re-doing our hard work over?

Earthfire

I didn't say jello

no it doesn't dissolve but it does seem to migrate(on occassion) from the joint to the screen or pump. I think it is just too dang slippery with oil.In my younger days did use teflon on tank fill lines .They are all slimey at the thread. since I switched to straight dope on oil lines no wet threads. Same 24" wrenches, twenty year older muscles,for me it is dope, no teflon on oil.

kevin coppinger_4

What would..........

be an example of a oil based pipe dope dope????? kpc

clammy

whitlams blue magic

1 year ago i hassled a supply house for sending some blk pipe to a job that looked liked they pulled it up from the hudson aftyer rainting and bitchin they threw me some of that stuff about a case a salemen gave them samples i used it worked great on water boilers gas lines sets up and washes off your hands and as for steam i usally like double wick on2 1/2 and above and grip lite or grip but it's tough on clean up grip or grip lite or leaklock on oil.ps if your grip get to thick rubbing alchol thins it down and also cleans it

Mr. Smith

have you ever

heard of Loc-Tite #55???

this is some of the best stuff I have used. it is a thread sealing rope - teflon based.

I have yet to have a leak with it! unlike teflon tape and pipe dope wich has caused some major headaches over the years!

Great Stuff!!!

Chris

eleft(retired)_3

teflon on oil

Seems like a product used in so many other industrial areas gets a bad rap here because it does not get applied properly.

al

David Sutton_3

this works great for me

on the big steam fittings i like to wick it first then teflon then dope, i found that the new locktite 55 in stead of regular wicking works real good, the 55 seems to expand when heated and make a great seal.... David

Tony Conner

Exactly...

...right, Al.

I suspect that a lot of people aren't setting their dies right. They need to cut threads that let them get 3 - 4 turns to make fittings hand-tight, with no dope or tape. And it's not just the adjustable dies used in Ridgid 300's and 535's etc. (Don't just assume that the increments marked on the die head will automatically put the dies in the right spot - lots of times, it won't.) The die heads like 12-R's and 00-R's also have an adjustment. Put the new dies in the head, and screw the retaining piece down tight to seat everything. Loosen the screws off that hold the ring down, and screw a factory pipe nipple into the die head. Back the nipple out carefully, so as not to move the cutters, and tighten the ring down. You should now be cutting a thread that's the same as factory nipple. (The instructions are on the back of the card that hold replacement dies, when they're bought.) For those that don't want to fool with this, Reed still sells "block" dies. One square piece, with all four dies as part of the single block. Put them in the matching ratchet handle, and get a factory thread every time.

Anybody using the 300 and a pipe wrench jammed in there to tighten the fittings onto pipe? Bad practice. The heat generated by the friction of tightening too quickly will often lead to leaks when the pipe is put into service. Don't do it.

Tony Conner

Slow Leaks Can Often...

... "take-up". Water slowly leaking can cause a little corrosion on the way out. Rust gradually plugs the leak, like carbuncles choking-off an old galvanized water line. Hard water helps a little too. As the water continually evaporates, scale is left behind, and stops the leak. Much of the time, very slow water leaks will stop on their own, especially on steel pipe. More often though, the slow leaks stay the same, or gradually get worse.