Build problem, need some advice!

Alright this is a little embarrassing but hopefully can be worked through. I recently had some fittings welded into my HLT, and pretty much as soon I left the keg with the welder I started to wonder how I would be able to install my herms coil with the nipple welded in place. Here is the way it looks:

This is my herms coil as I have it now:


Here is a picture of the fitting welded in (I know its the outside, but the inside looks the same):


Basicly they are both 1/2" male NPT fittings that have to be connected. This is usually done with a standard 1/2" coupling like the ones from bargainfittings (which are the ones I have). The problem is you cannot tighten down both at the same time without rotating one of the sides (as you tighten one side you losen the other). Since I cannot rotate the coil and the fitting is welded in place it seems impossible to use a coupler. Are there any other options available to connect the two sides? Mcmaster has what is called a pipe union:



This appears as though it would be able to do the trick, but I'd need two of them which means 65 or so more dollars after shipping plus it introduces a ton more areas for leaks. Another option is to disassemble the compression fittings, tighten them down to the nipple, then rescrew in the compression side, I am hesitant to do this cause I worried I will not be able to get them to seal again. I used a ton of force getting them into place the first time.

Anyways I am kind of bummed, if anybody has been in this pinch before or has any experience to offer please do.

Pipe union would be the easiest way. A union will have no more chance of leaking than a any other pipe fitting in the system. Also a union will allow for quick and easy removal of coil for cleaning. You should be able to get brass unions locally.

Looks like standard swagelok fittings. I'd break it at the tube and then reconnect after. Before breaking place a mark on the fitting and nut. When you reassemble you only need to go 1/32" past your marks to ensure you've got proper sealing.

How tight did you do it? For initial assembly you would have only needed to hand tighten it then go an additional 1-1/4 turns with a wrench.

Thirteen said:

Looks like standard swagelok fittings. I'd break it at the tube and then reconnect after. Before breaking place a mark on the fitting and nut. When you reassemble you only need to go 1/32" past your marks to ensure you've got proper sealing.

How tight did you do it? For initial assembly you would have only needed to hand tighten it then go an additional 1-1/4 turns with a wrench.

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Yea they are swagelok. And I tightened it down balls to the wall. I've found that my initial attempt at everything so far in this build has been a mistake lol. Cheapest solution would be to untighten the fitting, so long as I can get it to seal back up I'd be okay with it. Thanks for the feedback. I'd say this route is most likely at this point. I do like the idea of being able to disassemble a union for cleaning... but I've had so much trouble getting these npt threads to keep from leaking I would probably be scared to take it apart once I got it to seal.

On a union, you don't mess down the npt threads after install. The big "nut" is used to remove and install later. It is a machined surface that does the sealing and no thread tape or dope is needed.

MikeinAK said:

On a union, you don't mess down the npt threads after install. The big "nut" is used to remove and install later. It is a machined surface that does the sealing and no thread tape or dope is needed.

Click to expand...

That sweetens the deal. So as long as I can get the Npt threads sealed right I won't have to worry about the big one when I disassemble. It would be an added feature to be able to break down the inside to clean.

Yep, a pipe union is the best way to go IMO. NPT threads should present no problem with sealing. They will require some teflon tape. They always do. I'm not sure how much thread you have to work with on either side. NPT threads are normally tapered and will require at least several turns to seal properly. It appears that you will be hard pressed to have enough threads on the nipple exposed in order to do it. Using extra wraps of the teflon tape may help with this. The SS unions will set you back some, no doubt, but if you could live with some brass unions, it would save you a bunch.

Thanks for the feedback everyone. For now I am going to try to go with a pipe union. Turns out Bargainfittings has these for 6 dollars each and should work fine so it isn't too bad. If I can't make the union work I'll have to disassemble the compression fittings and jump through some hoops to get them to reseal, lets hope it doesn't come to that.