Help with leaking weld-less fittings

[blackheart]

We begun testing our weld less fittings for our 10 gallon brewing system and found most of the fittings leaked! Here is a picture of the final configuration that we found did not cause any leaks. (the washer is representing the Keg wall)

We got the parts from MoreBeer. It is what they use for their weld less fittings. Unfortunately, they do not fit into the grove in the lock nuts as I have seen others do. We tried several different combinations of washers, locknuts, and O-rings. It seems that with using the O-ring their is two places for failure. The outside of the O-ring tends to seal well. The inside that touches the threads however seems to be the failing point. When using a configuration of Outside female fitting - washer - O-ring - Keg - Nut, the washer does not seal up tightly against the female fitting on the outside, the water spirals around the threaded nipple and right past the inside of the O-Ring and leaks.

Still having trouble sealing the Temp probes from Brewers hardware but going to ask Derrin directly how he does that.

Since we have the washers and the extra room we may just use the washers on the inside to help ease the pressure from the nut. Looking at MoreBeer this is how they do it. A bit different from how we have seen things done by others here.

(more beer)

So I guess this is more of a, Does this look right to everyone else? kind of question?

 

[JVD_X]

You may try and smooth down the interior of your walls. What appears to be smooth to the naked eye is probably not. Be sure to use lots of teflon tape. In addition, try using the stainless steel locknuts from bargain fittings on the inside - they have grooves for the o-rings to seat and they work very well. The hole for the fittings needs to be exact... you should almost have to force the fitting through the hole.

If you put the o-rings on the outside they can overheat then dry out.

 

[jkarp]

My experience with weldless fittings is they rarely leak around the o-rings but through the NPT threads. As JVD_X says - use lots and LOTS of teflon tape.

 

[BargainFittings]

I agree. The threads will provide a path for water. I find the white teflon tape to be very thin and takes 6 or so wraps to provide enough material to provide a seal.

The gas (yellow) teflon tape is thicker and only take 3 or 4 wraps.

You can do what JVD_X said and flip the fitting around. Put the locknut inside and the washer on the outside with the valve.

The o ring pictured is too thick if used with the locknut. You need an 1/8" thick o-ring to fit the groove in the locknut.

 

[blackheart]

I see how your using the smaller O rings. We have the lock nuts with the grove but not the right O ring. we may have to order a bunch. Is the O ring on the inside necessary though? If you teflon tape the pipe nipple, then thread a locknut and O ring on to that it should stop all leaking.... I dont see what the O ring on the inside does... Also we drilled the holes to 7/8" but again I dont see how that is an issue as we are sealing the area around the hole not trying to plug it up with a fitting.

 

[BargainFittings]

Well the groove helps the o ring form a seal against the edge of the pot and the nipple.

I have installed sets without any locknut and had it work. I've used a male adapter, washer, o ring with nipple on inside and then put a valve on the outside and it sealed up fine.

Sometimes its a matter of finesse. Tightening up the fitting so the oring is just snug and not squashed.

 

[CodeRage]

I would hazard to guess that you tightened the nut way too tight with the oring on the inside. it just has to be hand tight and a quarter to half turn with a wrench will do you.

The best luck I have had is the oring on the inside against the keg wall with the nut behind it, tightened as described above.
Washers are only needed to take up space and should be placed on the outside between the valve and keg wall. This may be needed due to the tapered threads causing the nut to jam before it is sufficiently tight. The washers may need to be hogged out a bit to clear the thickest part of the nipple.

The reason why you dont want to place a washer between the oring and nut is because you have added an additional point that needs to be sealed. The nut will prevent fluid from leaking through the threads and the oring seals between the nut and the wall. With the washer in the mix fluids can weep between the nut and washer and out the wall via the threads.

 

[blackheart]

I think we have figured everything out... going to order a bunch of the right O rings and see if everything works.

 

[blackheart]

OK so here is what we came up with to solve our leaks.

Temp probe. -> locknut with small O ring on inside, washer on outside. Teflon tape seals nut to threads, O ring seals fitting to keg wall.

Normal fitting. Large O ring on outside seals fitting against outside of keg. Inside a washer and nut/fitting are used. This works most of the time.

Here is the best seal we have found so far. It took a few minutes to figure it out and its a bit more difficult to explain so here is a series of pictures showing how to assemble it.

The first think you will notice is the Close nipples are tapered so that they are wider in the middle. This means you can put a nut+O ring on the outside because you cant back the nut up far enough to leave room on the inside for the inside fitting. Instead you thread the nut from the opposite side of the close nipple giving you extra room on the end. Be sure to use plenty of Teflon tape to seal the nut to the Close Nipple.

wrap each end of close nipple separately so both thread well in correct direction.

Lock nut with grove for O ring

Thread the lock nut on so the O ring grove faces the center of the close nipple

Threaded on until it stops

Add the small O ring

Screw the back end into your fitting.

Now put that outside of you kettle, and on the inside put a washer and whatever female fitting you need. This seems to work well without requiring extra O rings or washers.

Thoughts?

 

[BargainFittings]

Looks fine. Generally the locknut can go inside or out with the o-ring forming the seal. With the teflon tape on the threads it should be leak free.

The biggest culprit for leaks is poorly drilled holes. Either too big or with rough edges. Next would be too much torque on the o ring.

The only reason for extra shim washers is if you have a very thin wall kettle.

 

[Bobby_M]

Hence my disdain for weldless setups that put the oring over threads. One solution is to silver solder a washer to the end of the coupling. You figured out the other way in your last series of pics where even if the liquid gets passed the vessel wall through the threads, you have sealing faces on the vessel wall and the female NPT device that threads on to the nipple. You can't have a washer touching the Oring in that configuration unless it's soldered to the female NPT device.

I mean, I get it. It's a cheap assembly and enough tape on the threads will fix almost anything but I'm not the type of guy who uses duct tape for things either.

 

[bigjoe]

The only problem I had with leaks was rough edges as BargainFittings mentions in his last post. My nipple would go throuigh the hole, but wouldn't slop around in it. I didn't even use teflon on my nipple.

 

[thisjrp4]

Get it welded in. I brought my weldless fitting and pot to a shop and the guy just about refused to only drill the pot out for me because he said the thing will leak. $40 later the nipple was welded in and I couldn't be happier.

 

[blackheart]

That would be great but we have about 11 fittings that need to be welded in. Thats not going to be cheap. Unless we can find someone who will work for beer then its going to be a while until we can upgrade to welded fittings...