help! pipe thread nightmare!

[Livewire2076]

So I'm putting together my water feed and return mains for my in floor heat, and for the life of me I can not get these pipethreads to seal. I'm at my 4th stab at it, I've tried Teflon, Teflon pink,2 different pipe dopes, plus I've replaced some of the fittings with better brands. I've also tried tightening them at a reasonable torque and put extensions on my pipe wrenches and tightening the living hell out of the fitting. I've got 1 brass to copper leak, 1 black steel to black steel leak, and 2 copper to stainless leaks. Short of using jb weld as a compound I feel like I've tried everything. Can some please recommend a better fix? Will jb weld in the threads actually work? Or am I just going to waste more time doing that?

 

[Rock knocker]

So every thread type is leaking? Tighten them more

 

[Livewire2076]

A few of them are bottomed out in the fittings,others are @100 lbs plus. I had tried tightening them with conventional torque, extra torque, and finally with 2' extensions on my pipe wrenches. Still got the same results. Fitting are not out of round nor cracked, leaking from threads...

 

[404]

Hi,

In all cases the fittings should have no water on them which is going to be a pain if you have water in the system (instead of leak testing with air).

Pipe dope needs a generous, continuous, void free application pushed into the male threads with gloved finger and time to dry after assembly. Teflon taps needs generous application over all the male thread, mostly over lap the previous turn, applied so that screwing the male fitting into the female tightens the tape not unwinds it.

Rectorseal is a ok pipe dope if stirred up. Master mechanic leaks on every joint I ever tried it on. Not many after I wised up and threw it out. Am now using permatex with teflon and no problems.

No chance you are using/mixing up/confusing straight pipe that need o rings with taper pipe that needs tape or dope?

Regards,
404

 

[Livewire2076]

Hi,

In all cases the fittings should have no water on them which is going to be a pain if you have water in the system (instead of leak testing with air).

Pipe dope needs a generous, continuous, void free application pushed into the male threads with gloved finger and time to dry after assembly. Teflon taps needs generous application over all the male thread, mostly over lap the previous turn, applied so that screwing the male fitting into the female tightens the tape not unwinds it.

Rectorseal is a ok pipe dope if stirred up. Master mechanic leaks on every joint I ever tried it on. Not many after I wised up and threw it out. Am now using permatex with teflon and no problems.

No chance you are using/mixing up/confusing straight pipe that need o rings with taper pipe that needs tape or dope?

Regards,
404

Done all that, testing with air. A HVAC friend just dropped off some Megaloc thread sealant. Going to give this a try, wish me luck.

 

[Falcon67]

The method I use I got from a plumber - several wraps of Teflon tape, 4-6. Then pipe dope, then tighten. When you get tired of messing with it, then use JB Quick for pipe dope. When it comes time to R&R, just hack it out.

 

[gayler]

How much pressure are you putting on the system? Also wondered where your expansion tank is located?

 

[LS6 Tommy]

Not to insult, but is it possible you're overtighteneing them from the start? Ive seen it happen...

 

[404]

That is really strange then.

Regards,
404

 

[big.jim]

for awkward leaks /bad fittings i use gas ptfe tape , a lot thicker than normal tape but never leaked yet, yellow roll over here dont know what the spec will be over there

 

[tfinniii]

If they bottom out you have to trim end off especially if the die went up the pipe too far. I have found the threads pretty lousy on a lot of new fittings especially the iron ones.

 

[Falcon67]

for awkward leaks /bad fittings i use gas ptfe tape , a lot thicker than normal tape but never leaked yet, yellow roll over here dont know what the spec will be over there

Usually pink is what I see.

 

[Jackfre]

Not to insult, but is it possible you're overtighteneing them from the start? Ive seen it happen...

I'm with Tommy on this one. Threads should not bottom out, especially on the black iron. On IPS threads the purpose of pipe dope is to lubricate the joint so you can get proper make-in. The more modern pipe dopes help I guess, (I'm still using the yellow Rectorseal, but I lack imagination), but the joint is made metal to metal. I do agree that many iron fitting and ******* are really poorly done. I've gotten to the point I'll run them into my dies just to see if they are consistent and concentric.

 

[RECox286]

Where are you getting your fittings from ? Big box, or an honest

to goodness plumber's supply store ? Although the prices at big

box stores are attractive, and the fittings may look shiney and all,

they only stock stuff made in China, and the quality is less than it

should be. If this is your problem, turn those fittings in for scrap,

b/c that's what they are worth, and try some fittings from a

store where real plumbers shop for their stuff. And why are you

mixing materials in a water system ? Increases the chance of

electrolysis...more failures down the road.

Uncle Bob

 

[justind]

Your threads are probably too deep.

http://www.xpando.com/xpando.php

I have been told this stuff is good for problem joints.

 

[Techie1961]

Try hemp. It is great for tough to seal threads. There is a bit of technique needed but for water, there is nothing better. You use it along with pipe dope.

 

[geologist]

I agree that boxmart fittings are usually garbage-esque. Threads shouldn't be bottoming like that.

 

[brewchief]

The fittings I get from ferguson and other suppliers are made offshore just like the box store stuff.

Where on the system are the fittings that are leaking?

Your circulator should be rotated 90 degrees so the motor doesn't point down.

 

[jhelrey]

Pipe dope, thread tape, pipe dope, tighten but not over tighten

 

[EdT]

I'm not nearly as expert on pipe threads as many on this forum, but I have some experience. Pipe threads rely on interference between the two tapered thread sections(male and female) to create a seal. In a perfect world, they can actually seal w/o sealant, although I have never seen it happen. Since most of us don't live in a perfect world, pipe dope exists. You mentioned that the male pipes were bottoming out in the fittings. If that's the case, the interference between the threads can't happen and it's unlikely that the joint will ever seal. Since there is a wedging action that occurs when the two tapers are drawn together by the threads it is possible to stretch the fitting or collapse the pipe if you tighten it too tight. If that happens, it won't seal. Since you seem to be having similar problems across several kinds of fittings and pipe, I'd suspicious that you may be tightening things too much. If you do over tighten enough to distort stuff, both parts of the joint should be ditched and start over. New pipe fittings that are engineered to work have also been engineered to use as little metal as they can get away with so they are not very forgiving of abuse. Hope you figure it out.

 

[Livewire2076]

Thanks for all the suggestions. I ended up using the megaloc pipe sealant, it worked for all my copper, brass, and iron. The stainless ball valves I determined to be junk and the supplier is sending me some new ones, those were the only ones that actually bottomed out. They seemed to be in round, but would just not seal. I'm just curious, dose it matter that the motor faces down? I did it for clearance sake. All my products came from either plumbing suppliers or pex specialty shops. I don't think I overtightened anything... At least the first 3 trys, but every HVAC and plumber I talked to said "to tighten them more", well I'm sure that almost all of them have 100lbs on them at least, and don't leak. I don't like it but I did everything the pros told me. Including scraping some of the cheap hardware I had at first, had the same immediate results with the good stuff, til I put such torque on them.

 

[LS6 Tommy]

You shouldn't mix dissimilar metal fittings like stainless/iron & non ferrous metals unless you use a dielectric coupling in between. Yes, the pump needs to be rotated so the motor shaft is parallel to the floor.

Tommy

 

[wyo george]

You have an issue somewhere. I use Teflon tape and a craftsman 7/8 wrench to tighten fittings that hold 10,000 PSI on a daily basis with never a leak. All it should take is clean threads (in good condition) with 3 wraps of T tape and reasonable torque. I did have some 3" NPT plugs that took about 10 wraps of tape and a 48" pipe wrench to seal, but otherwise I've never needed extreme torque and our lowest tests are 2,000 psi