Pipe thread connections - what's the trick to getting it right?

[b-body-bob]

I've got a reno under way and put a ball valve in the water supply where the underground supply line enters the house. There is a 3/4" male threaded connector there, so the ball valve threads on.

When I had the handle where I wanted it, it didn't feel tight so I turned it more and I ended up with the handle about 45 degrees around from the top. There was no way I could turn it any further because then the handle would've run into the water line and no chance it was going to turn all the way around again to get the handle where I wanted it anyway.

Making it worse, when we turned the meter on, there was a small leak right at the threads on the ball valve.

It seems like I'm always having this problem. The ball valves on my compressor are also turned around and it drives me crazy. If I stop when vthe handle is where I want it, there's a leak, and if I keep going I end up with the handle in an awkward position. Is there a secret to knowing when to stop turning, and how to keep things from leaking?

In this case I put teflon tape on the inlet pipe before adding the ball valve. Do I need to add some other kind of sealant too, so I can position the handle where I want it without it leaking? I bought some rectorseal but I'm not sure that's the right stuff or not.

Any help in understanding how to get it right is greatly appreciated.

 

[kams1973]

Can you take the handle off the ball valve? I do this all the time. Simply remove the handle and position the valve where I need it. When all is tight, reinstall the handle.

 

[LG63]

I don't have any tricks to offer for that specific situation but when alignment is important I "design in" an extra pipe bushing or close ****** to give me an extra joint to improve the odds of landing the valve where I want it.

 

[b-body-bob]

Can you take the handle off the ball valve? I do this all the time. Simply remove the handle and position the valve where I need it. When all is tight, reinstall the handle.

I wish it was that simple. I've taken handles off, and even bent a 90 in the handle on a compressor valve to get clearance. Those kinds of things I can generally hillbilly my way out of.

The water line comes out of the north wall of the house, with the ball valve then a 90 that turns horizontal and to the west. The line runs through a notch in a stud so if the handle isn't on the top, bottom or right sides, the handle will hit it.

Another complication that I neglected to mention is that I have a problem holding the male fitting out of the wall while I tighten the valve. It doesn't protrude far enough for me to get a wrench on it, which makes me a little bit skeered of twisting that off so I don't wanna go crazy tightening on it trying to stop the leak.

It's snugged up now and if a thread sealant is all I need, then that would solve a lot of problems for me.

The stuff I have is Rectorseal Tru-Blu, that I bought for my compressor since it's formulated for a vibrating environment. The leak isn't a spraying leak, I guess I'd describe it as a seeping leak. Will the Tru-Blu help with that so I don't have to resort to overtightening things to get it to work?

FWIW, I guess the worst case is I re-run the line after the valve. It's PEX and I ran it to match the copper that used to be there. So I'm not married to the design, but I sure like the fact that it's already done.

 

[b-body-bob]

I don't have any tricks to offer for that specific situation but when alignment is important I "design in" an extra pipe bushing or close ****** to give me an extra joint to improve the odds of landing the valve where I want it.

Yes that would be good but I'm close to the wall and want to keep it there.

But as I mentioned above, the ability to just re-run the PEX may end up being my extra joint if I end up with it turned further around to stop the seeping.

 

[mobiledynamics]

Remove the tape. Tape is considered a lube when threading. Any decent PTFE should do the job.

As far as tight, I'd day wrench tight andy then a 1/2. It's all about the feel. You could go tighter so it close to bottoms out, but again, it's all about the feel of the threads...

 

[Durka]

Remove the tape. Tape is considered a lube when threading. Any decent PTFE should do the job.

As far as tight, I'd day wrench tight andy then a 1/2. It's all about the feel. You could go tighter so it close to bottoms out, but again, it's all about the feel of the threads...

Did you mean to say,-Tape isn't considered a lube ?

I agree with the tightening procedure mobiledynamics...same here. - you should be able to get one more turn...specially w/3/4".
Actually 3/4 NPT = 9T - 3/3/3 Tightening sequence. - That's 3 loose, 3 engagement, 3 threads left.

b-body-bob - Rectorseal should be fine with water, - it's definitely not the best for air though. No matter what the label says lol.

Loctite 561 Quickstix paste ( its similar to a large stick of chapstick) or 567 for those larger jobs. It's the BEST IMO. Use the 561 for small stuff or quick fixes, quick clean and easy to work with. The stuff is great with dissimilar metals as well.

Both products resist squalling and give yuh that extra nudge easier when needed.

You can find both products on Ebay and Amazon. What you have to watch for is the age of the product. Some resellers on those sites try to sell out dated stuff. So far I haven't had any problems with outdated Loctite sealers. Just be aware. Hell, I've seen LT 545 for sale on ebay and they quit making that formulation more than 8 years ago lol.

 

[mobiledynamics]

nope. AFAIK, in a plumbers perspective, tape is more a lube.
Use a PTFE compound whenever you want a good seal. I use BlueMonster PTFE compound on almost everything just short of gas. For Black pipe, I prefer Gasiola stuff.

I have tape in my stash and very hardly use it these days....DOPE is better anyday

 

[Jswain]

What size pipe wrench are you using on it? We use tape on everything and never have a problem on 5000psi hydraulic lines, steam lines, water lines, air lines, or diesel lines. If it is leaking its either ****** threads/cross threaded/ or just not tight enough.

As for getting everything lined up start with a small pipe wrench and when you can't turn it any further go the next size up.(24" range)

 

[b-body-bob]

OK, seems like I just need to take it back apart and use dope instead of tape.

Durka I'd seen you post that 3-3-3 deal before and tried to stick with that. I did a search and found a spec sheet recommending from 1-1/2 to 3 turns past hand tight.

I don't remember how many turns I got on it but it was about as tight as I dared to go since I had nothing to hold the male fitting behind it. Plus I knew it wasn't going to go a whole turn more from where it was so I just stopped because I don't want to dig up the line outside the house.

 

[b-body-bob]

What size pipe wrench are you using on it?

I think the technical term for the tool I used is "big-ole crescent wrench".

I probably oughta get a cheap wrench to fit that male fitting and grind it thin until it fits in the gap there so I don't have to be worried about twisting the fitting off the underground line or worse.

 

[Jswain]

It would take some serious torque to twist off a 3/4 pipe, but it would be a wise choice to put a backup wrench on it anyways. Sorry assumed you would be using a pipe wrench didn't clue in with the valve...so what size crescent wrench are you using?

 

[b-body-bob]

I don't have it handy but it's at least a 10" wrench.

I'm less worried about twisting off the pipe than I am about finding the weak spot in the solder joint between the pipe and the male fitting.

 

[mobiledynamics]

You're using 1 wrench.

Any chance you can dig around the pipe some more and fit 1 proper plumbers wrench.
Plumbers wrench on the pipe, adjustable on the valve and snug it up proper....

Maybe just taking the time to dig around to get the proper wrenches in there should solve all your issues..

 

[b-body-bob]

There's no digging around the pipe, it comes through a block wall. You're right though, I need to hold the back side of it because that's probably the root of my problem - I'm too skittish to get it tight enough. I'll search and see what a proper plumber's wrench is and see about getting one before messing with it.

 

[A_Pmech]

Bob,

An old plumber told me the trick to preventing leaks is to use 3-6 wraps of teflon tape followed by "Great White" or similar teflon pipe dope on top of the tape. After I took his advice I've never had a leak when making up threaded pipe connections for air or water, even at much less than the standard wrench make-up distance.

 

[b-body-bob]

An old plumber told me the trick to preventing leaks is to use 3-6 wraps of teflon tape followed by "Great White" or similar teflon pipe dope on top of the tape.

You're talking 3-6 wraps right on top each other to build up the thickness, right?

 

[A_Pmech]

You're talking 3-6 wraps right on top each other to build up the thickness, right?

Yes. Wrap it around the male pipe a thread or two up from the end. This prevents teflon from extruding into the pipe. Then brush some dope on top of the tape and make up the joint.

The purpose of the tape and dope is to seal the helical leak path between the truncated male thread crest and the female thread root.

 

[Durka]

Durka I'd seen you post that 3-3-3 deal before and tried to stick with that. I did a search and found a spec sheet recommending from 1-1/2 to 3 turns past hand tight.

That's about right. It is a torque by feel thing towards the end there, -as mobiledynamics referred too above. 3 threads left over is an "on average" number for 9 thread BI or Stainless. That can vary either way about a 3/4 turn,- as you most likely know.

 

[R6 Racer]

FWIW I have always used both teflon tape & pipe dope (1 or 2 layers of tape [at most] & then pipe dope) . An old plumber taught me that years ago & I have used that method ever since. I have never had a problem using that method unless there was another problem present.

I would also second what mobiledynamics said about doing whatever you can to get a wrench on the other part of your connection. I might even go as far as taking a cheap pipe wrench & grinding it thinner to try to get some amount of hold on the pipe itself.

Good luck!
Steve

 

[G_P]

I use a bit of pipe dope, a few wraps of tape, and then a bit more pipe dope. No leaks unless you get a POS Chinese female fitting that splits when tightened.

 

[coljar]

What size pipe wrench are you using on it? We use tape on everything and never have a problem on 5000psi hydraulic lines, steam lines, water lines, air lines, or diesel lines. If it is leaking its either ****** threads/cross threaded/ or just not tight enough.

As for getting everything lined up start with a small pipe wrench and when you can't turn it any further go the next size up.(24" range)

^^^This, but I'll use Teflon pipe dope in addition to the tape on important stuff.

 

[Partsman2012]

I have become a fan of Jomar "Green Stuff" thread sealant. I can't recall that I've had any leaks when using this product. The mechanics here at work love it. It's great for fuel nozzles (diesel).

 

[mobiledynamics]

How much access you got on the other end ? A helper can just hold a wrench from the opposite end....if you dig to get to it.

I never intermingle between the 2 - either use dope or tape. But that is subjective, just like sweating versus quick connectors.

A helper on the other end holding the pipe, while you give it the final turn should do the trick...

 

[Durka]

Yea, either dope or tape here as well. I prefer good dope.
Allot of people mix the two. That's an older way that's been around for a long time. Hey whatever works right ? There's more reliable methods today. Why take the chance..uknow.

b-body-bob, - For 3/4 NPT and for the seal your looking for, -tape wise would be 3 wraps of yellow gas tape mill. MOST other mills readily available in white would be for 1/2" down. Personally, I despise re-work and having something leak after a repair lol. Cut through the trial and error **** and use one the top products used in the industry for tapered thread contact.

This, -

http://www.henkelna.com/product-search-1554.htm?nodeid=8797960863745

567.

It's like no other.

561 works just as well. (Quikstix), -

http://www.henkelna.com/adhesives/product-search-1554.htm?nodeid=8797961945089

____________________________________________________

For high pressure air (150 psi +) @ 3/4 NPT, - Same stuff, but use the aerosol primer/promoter before hand.

Here's that stuff, -

http://www.henkelna.com/product-search-1554.htm?nodeid=8797888086017

or

http://www.henkelna.com/adhesives/product-search-1554.htm?nodeid=8797888413697

Either or.

 

[b-body-bob]

How much access you got on the other end ? A helper can just hold a wrench from the opposite end....if you dig to get to it.

The pipe is at least 16" under ground and hopefully more. I haven't tried to measure it though but 16" is code for the frost line here. It'd be easier to grind a thin wrench to hold it with if I can't find anything else to fit. I did a quick search for a plumber's wrench and some special gadget turned up at Home Depot but I'm not sure it's big enough to fit the hex (max 15/16) or thin enough for the gap. More post-workday research and measuring is needed.

 

[mobiledynamics]

Surely, you can't have that *little* pipe exposed coming in.
You make it sound like literally, it just the male thread protruding out.

If it's that thin, a usable thin plier would be a set of adjustable pliers. Not as nice as a plumbers wrench....but if you need it thin.

Otherwise, I'd **** it up and dig outside to get a hold...
Do it once and forget about it ....

 

[C96]

Hi bob,

Glad to here things are coming along on the new place.

Without actually seeing the situation and if the tape / dope trick doesn’t work, how about unsoldering the male fitting, then make up the joint in a vise and re-solder the assembled ball valve in any position you want it.

You could also get a solder ball valve or even a 90 degree if it would help

 

[b-body-bob]

For 3/4 NPT and for the seal your looking for, -tape wise would be 3 wraps of yellow gas tape mill. MOST other mills readily available in white would be for 1/2" down.

Yellow tape - will pick up a roll of that while I'm out trying to find a thin wrench, or a cheap one to grind.

Personally, I despise re-work and having something leak after a repair lol.

Yep, that's two (million) of us. I left the PEX loose at the valve just in case this happened so at least I don't necessarily have to rework that.

Looks like the only place near here that stocks the full Loctite line is Fastenal and that's stretching the limits of what I can get to on my lunch break.

 

[PelicanPines]

Whenever I do a ball valve with threads... I put short threaded pipes on both ends then i use a compression connection on each end. Doing it this way... you can get the value exactly how you want it. The ball valve with the "ends" can spin until you tighten the compression connections. Hope i explained it well.

}{==//ball valve//==}{

 

[b-body-bob]

Yes I understood that. It's similar to the reason there are unions all over our pool plumbing.

It may come down to that yet, but since it would a) put an additional point of failure inside the house on the wrong side of the valve and b) push the ball valve and plumbing out into the living space, I'm trying to work with what I've got.

I'll definitely keep the idea in mind.

 

[JamieK]

How do the threads look? Where did you get the pipe cut and threaded? If you are using "off the shelf" lengths of a name brand pipe, then the threads should be okay. But if you had it cut and threaded at the big box store, then the threading job could be causing the leak. Depending on who was operating the threader, and how badly the dies were worn, the threads may not be fitting together properly. I've also heard of this on cheap Chinese pipe.

 

[JamieK]

Also, would there be any avantage to changing from a ball valve to a gate/screw valve? THat might allow you more clearance around the handle.

 

[b-body-bob]

The male fitting and incoming service line has been there since 1971 AFAIK. I'm not sure who made the ball valve, maybe Apollo, but it came from Home Depot. So that's probably imported.

The house had a screw valve on it to start with, but it was stuck. I've got the same deal in this house, so I'm leery of those things. The last thing I want to deal with when turning the water off due to a leak is a valve that doesn't work.

I've had screw stops snap off internally before when they were stuck. The last time it happened we were flushing a drain using a line off a stop (bathroom remodel), and things got a little stressful before we got to the meter to turn it off.

 

[Techie1961]

Get a bigger wrench and crank on it. I have to do close fit stuff all the time and have never had any difficulty getting another turn on 3/4" pipe. Even with stainless steel pipe, you can get another turn. The only time that you might not be able to get a turn is with solid steel fittings for hydraulics, etc. Until you bottom out the threads in the valve and interfere with the ball, you will be okay.

You would be shocked at how many more turns on the valve you can get. We buy machines built in Italy for dry cleaning and these have a lot of piping that has multiple close fit ups all over the place. They don't make ******* in 1/4" increments so it is very common to see fittings that are bottomed out to get the fitment correct.

 

[mobiledynamics]

How did you manage to remove the previous fitting on it. The same torque to properly seal it - is the same torque you would have needed to unbreak the connection ?

 

[Scott r c]

Any more than two wraps of Teflon tape and you are just wasting it, it will get pushed out Coming from a plumber, I use two wraps of Teflon, then blue monster. Of all the combinations I have tried over the years, this has been the best.

 

[b-body-bob]

Get a bigger wrench and crank on it.

THat's what I'm going to do, once I get something to hold the backside.

How did you manage to remove the previous fitting on it. The same torque to properly seal it - is the same torque you would have needed to unbreak the connection ?

The previous fitting was hand tight. Some goons working for the developer who had the property before us had cut the copper off with a bolt cutter, so I hammered a socket over that to try and get the fitting out. While I was fighting with that I noticed the whole thing was loose. No way to know if the guys taking the copper popped it loose or if it had been that way for a while.

It's not the only place I've found where the missing copper has kinda sorta worked in my favor because I've noticed places that would've leaked while taking out what little bit they left.

For one example there was two 3/4" sticks coupled together over the garage door that had just pulled out of the coupler. It had newish copper on the side that pulled out so it had been repaired before, just not very well. That would've been a disaster if it had come apart with pressure on it and nobody home.

 

[mobiledynamics]

Cement block or poured block

Either way, I would consider chipping it out from the inside to get more area to put a secondary wrench

Add Coupler
Add some length to the exisiting stub
Then use whatever shutogg of choice you prefer...

This would be a better permanent fix...

 

[b-body-bob]

<strike>Cement</strike> Cinder block

I'm waiting on my wife to leave for work then I'm heading over to take it apart and see what I can come up with so I can hold it.