thread sealant

PDB2

In hydronic near boiler piping, is there a preferred type/brand to use when mating copper to black iron? Or for that matter, a certain type for all hydronic connections?

icesailor

Preference:

My preference for any threaded connection is quality Teflon pipe tape and a quality pipe joint compound like Rectorseal #100, Rectorseal #5 or MegLock.. But quality tale like Blue Monster first, always.

Gerry1

sealant.

I have noticed that screwing on th pipe pushes the sealant off to end. Is this where it seals. Whereas the tape over thread seems to be a better seal. Can some one explain the best thread sealing method. Thnx . Gerry

icesailor

Tape Seal:

You are supposed to use 1/2" tape on fittings smaller than 2" NPT. You are supposed to start the first wrap just back from the edge of the first thread and wrap it in a clockwise direction, no more than three wraps. The first two should be around the end of the thread with the last wrap slightly back from the end. Leaving two wraps around the base and three farther up. If the tape bunches up when tight, it may be a short fitting. It isn't important because the threads below will be filled with tape material. If you put it on in the wrong direction, it will just peel back like an orange.

There poor quality tapes and excellent quality tapes. Good quality tape is very pliable and easy breaks when you pull it apart when done. There are other tapes that seem to be some form of plastic tape and will cut your finger when trying to break the tape off.

On 1/2" fittings, two wraps may be all you need. If it is something very loose and something that you can't get another turn like a Tub Spout, use multiple wraps and leave it as close as you are comfortable with without over tightening the fitting. It won't leak. If you just use paste and its loose, it will leak behind the wall.

bob young

anything associated with water contact we use quick-wick & rectorseal. permatex is terrific & also blue block. using teflon w/ compound creats problems as the compound attacks the teflon & causes failure. proper torque with correct sized pipe wrenches completes the treatise.

RobG

That's funny, the question that has no answer (no offense intended Bob). what is the correct torque? I worked on helicopters in the Army for several years and everything was torqued to spec. I know what you are saying but one mans tight is another mans loose in this trade. When you are torqueing a straight thread bolt and safety wiring it, it is one thing. Correct me if I am wrong but I have never seen a Ridgid torque wrench. I think it's more common sense and experience personally. I'm a firm believer of "whatever works for you, stick with it" if you haven't been sued you must be doing something right.

Bob Bona_4

Blue monster tape and Megaloc thread sealant over it. Can't argue with success!

KC_Jones

RobG said:

That's funny, the question that has no answer (no offense intended Bob). what is the correct torque? I worked on helicopters in the Army for several years and everything was torqued to spec. I know what you are saying but one mans tight is another mans loose in this trade. When you are torqueing a straight thread bolt and safety wiring it, it is one thing. Correct me if I am wrong but I have never seen a Ridgid torque wrench. I think it's more common sense and experience personally. I'm a firm believer of "whatever works for you, stick with it" if you haven't been sued you must be doing something right.

Rob I agree 100% with you. What about the instructions that came with my water filter "do not over tighten" really? What does that mean exactly? I think what Bob might be saying (my interpretation) is use the correct size pipe wrench for each pipe size. This basically dictates a certain amount of torque or more likely a maximum amount of torque that can be exerted. I am not a pro, but my grandfather taught me that pipe wrenches are sized for different size pipe and you can see this by the jaw design and jaw opening. If I put a 36" pipe wrench on 1" pipe it can and will destroy the pipe from too much torque AND the jaw not fitting the pipe properly. Just another homeowner, but I have turned a pipe or 2 in my time.

Bob Bona_4

Used to be if you ended up with about 3 threads showing and it's feeling pretty tight, good to go. That gets blown out of the water with Asian fittings. Ugh.

j a_2

A properly threaded pipe should turn into a fitting approx 3.5 to 4 turns by hand…then tighten, with wrench….Gas pipe does have a specific torque per the nfpa codes…As well as each pipe size a specific number of threads per inch….I found it near impossible to fit pipe properly unless threads were equal…You end up with untrue end to end or ctr. to ctr. or end to ctr, measures….We all know what that ends up looking like...

KC_Jones

If you want to get really technical there are actually designed insertion dimensions, here is a link one chart listing the numbers. http://www.engineersedge.com/hardware/taper-pipe-threads.htm
I am a designer and we use these numbers daily to layout piping. I used these numbers to lay out the piping for my steam boiler and it came out perfect and I didn't check anything as I was assembling just screwed the pipe together. These numbers in general are pretty close, if the threads are made properly. The company I work for actually specs out that the mechanics follow these numbers and must use this insertion as a minimum spec to meet. It's not always a practical method, but if you dig enough there are specs for almost anything. JA I am curious do they actually make a pipe torque wrench? It wouldn't surprise me if they did I have never seen one though. When I did electrical work we had torque screw drivers to make sure terminal block screws were tight enough.

icesailor

Torque Tightness:

Torque Specs are designed around something that has no resistance until the nut or cap screw hits near a shoulder.

Thread lubricating compounds like "Never-Seize" are supposed to overcome the resistance of the bare threads and give you a true reading of torque. If you are bolting down a flange with more than 4 bolts, you are supposed to go around in a circular direction. If you have a bolt/fastener that requires 125 Ft./Lbs. of torque and you have 20# of resistance, and you tighten it with a torque wrench, to 125#, you only put 105# Ft./ Lbs. of torque on the fastener. If you use Never-Seize, you shouldn't get any friction resistance, and a true 125# tightening torque. If you work on small engines and need Inch/Pound Torque readings, it is very easy to over torque something with the wrong torque wrench. Especially when using a thread lubricant. Which OEM's require.

Any pipe fitting should only be made in no more than 1/2". That's what you allow when you are measuring and cutting pipe isn't it? My old boss always wanted us to go a thread longer by setting the collar on the diestock to cut a longer thread. We never figured out that you really need another 1/4" in overall length.

Try this. Take a machine threaded commercial nipple like a 1" one and the proper sized ell. Goop up the thread. Tighten it up. It will only make in 1/2". Any more and you are stretching the fitting. Take the same ell and nipple, Put Blue Monster, properly applied with three wraps and the first wrap not hanging over the end of the nipple. Tighten it up that same 1/2" depth with the Teflon tape and whatever paste you choose. It will not absolutely leak. There is so little thread friction that you can tighten it with a pair large water pump pliers.

I see Steamhead and others and their photo's using tape and paste. The threads aren't run into the shoulders. The tape is past the outside of the fitting. You don't need a 3' pipe wrench with pipe multipliers to tighten a 1" fitting. And I KNOW they aren't leaking.

RobG

Chinese fittings and old dies, I wouldn't try putting together a fitting in this day and age without both tape and dope.

Rob

icesailor

New dies don't help with modern Asian pipe.

j a_2

I can honestly say I have never seen a torque wrench for pipe….And have never used one….I do know never seize is used often as a protection against corrosion and assists in the removal process…Make up on pipe threads vary as to there size…If a tapered thread bottoms out you have issues…More often than not common sense prevails….Drawings are great but not always particle...

j a_2

Would never even consider a 1/2 make up on every size pipe...

KC_Jones

Well they do have torque wrenches for pipe, but doesn't seem worth the cost for any reason. lol
http://www.flexibleassembly.com/Products/Tohnichi-Product-Index/PHL280N?gclid=CKTJpqOThcECFa1m7AodKi8ANw

hot_rod

The newer thick tape works amazingly well even without pipe dope. I like the Blue Monster 3 wrap blue stuff.

It's really more about the crappy threads and fittings than the torque. The thick tape seems to better handle those issues than just pipe dope.

We use Loctite ™ 272 or 575 pipe thread product on many of the factory brass BSP straight thread assemblies. It allows you to stop after you have enough thread capture and it "glues" the connection solid.

It works well even on bad, steel pipe threads.

If you do need to disassemble a loctite joint, heat it slightly with a torch and the Loctite™ "gives up"

Too bad the installers need to find work arounds for the poor quality pipe and fittings. Seems even the well know US brands are sending out low quality import crap.

icesailor

j a said:

I can honestly say I have never seen a torque wrench for pipe….And have never used one….I do know never seize is used often as a protection against corrosion and assists in the removal process…Make up on pipe threads vary as to there size…If a tapered thread bottoms out you have issues…More often than not common sense prevails….

#1: You can bottom out any 3/4" or 1" pipe and fitting with a 24" pipe wrench.

#2: Common sense is not a monetary value.

icesailor

j a said:

Would never even consider a 1/2 make up on every size pipe...

That may be. If you measure between face to face between fittings up to 2" IPS. most add a 1/2" for make in for each fitting. Or add 1" to the measure. It always fits. If the measurement is short. each turn is worth 1/8". At least that is always how it worked for me.

When you're using The Square Root of 2 to find a 45 degree offset and you haven't made the fittings in, how much do you allow for the make in to hit your mark?

icesailor

hot rod said:

The newer thick tape works amazingly well even without pipe dope. I like the Blue Monster 3 wrap blue stuff.

Too bad the installers need to find work arounds for the poor quality pipe and fittings. Seems even the well know US brands are sending out low quality import crap.

Those Vulture capialists and the Wall Street Crime Syndicate need that ROI to pay their investors.

j a_2

I guess its up to the man on the threading machine…..Me, I would never use 1/2 make up on all fittings, don’t know what other people do because for almost all of my time working I was buy myself….I did teach for a bit at a local tech school, got laid off because not enough students were taking advantage of the great opportunity,we had a brand new state of the art facility... ,.
Those that took good advantage of it are doing great, as a matter of fact one of my students and former Marine has taken over my business...

icesailor

Code says 1/2" make-in. When I cut threads on my Rigid 1" to 2" TC die stock, I set the cam plate on the mark on the body. That gave you the proper length thread. My old dead boss wanted the mark half way down the marked space for a slightly longer thread. The beginning of the taper doesn't change no matter what. Once the end of the pipe leaves the end of the dies, it doesn't get any smaller. Just longer. There's no benefit.

I've made nipple holders with long running threads. Unless you looked inside to see where the threads stopped inside the coupling, you wouldn't know that the thread was at least 1 1/2" long.

AMGbolting

@RobG and @KC_Jones both make great points. When manually tightening a threaded fastener [pipe included] "one man's tight is another man's loose", however, over tightening can cause as much damage as under securing.

If you are using a Ridgid torque wrench or other controlled tightening / angle control tools there are typically torque conversion charts available to help you access the most accurate amount of applied force.

REFERENCE: amgboltingsolutions.com/6-ways-to-tighten-threaded-fasteners-for-various-industrial-applications/

@icesailor - the bolting pattern you refer to is only partial accurate. Some types of connections use a different formula, for example a CF flange.

See here: https://faebianbastiman.wordpress.com/2014/02/02/mbe-maintenance-how-to-tighten-a-cf-flange/

~AND~

amgboltingsolutions.com/how-to-tighten-a-cf-flange/