Best practice for NPT?

[AlexKay]

I have a new boil kettle with a 1/2” NPT ball valve, and I have a 1/2” NPT to hose barb adaptor.

Do I Teflon tape the connection so it doesn’t leak, or skip the tape so it doesn’t harbor bugs? Do I put new tape on each time? Please advise.

 

[kiwipen]

Wouldn't the threads harbor bugs even without the tape?
I think tape is needed to avoid leaks, especially if it's stainless on stainless. Disclaimer: I don't use NPT fittings on my system.

My impression is that @Bobby_M knows this stuff.

 

[tracer bullet]

Tape is PTFE, aka Teflon. It's almost like a lubricant to get the threads to slide on each other for tightening. It tends to seal but that's not the main job. The liquid versions are better for that. But, anyhow, PTFE itself is super inert and won't harbor anything on its own.

As far as trapping bugs, unless you do a terrible job I can't imagine it being any worse than just the threads, as kiwipen mentioned. Interested in Bobby's take as well.

 

[hotbeer]

You are boiling in this kettle aren't you? Bugs shouldn't be an issue unless you never clean it and there is a thick layer of crud to keep them insulated from the heat of the boil.

If I was threading a brass or bronze valve into a stainless vessel, I wouldn't use plumbers tape or anything at all if it sealed up without leaking. If I was threading stainless valves into stainless vessels, then I'd use something. Probably the tape in this case. SS threaded into SS can gall and be almost impossible to tighten or loosen when it does gall.

While I probably wouldn't worry too much about removing the valve and cleaning between every boil, I would remove, clean, sanitize and redo everything past the valve.

 

[AlexKay]

It's all stainless, so I'll break out the Teflon tape.

How does this sound: I'll leave the fitting threaded into the valve, but before each batch I'll remove the valve from the kettle and let it sit in boiling water for a few minutes, followed by running PBW and StarSan through everything. Does that seem sufficient, or should I remove the fitting (or, for that matter, take apart the entire valve) each time?

I know I'm boiling in the kettle, but I doubt the output side of the valve gets hot enough to sterilize it. That will touch unpitched wort, so I worry about it from an infection standpoint.

 

[hotbeer]

I know I'm boiling in the kettle, but I doubt the output side of the valve gets hot enough to sterilize it. That will touch unhitched wort, so I worry about it from an infection standpoint.

Well after you have it all put together, do a boil in it with just water. Then you can see just how hot the other side of the ball valve gets. You'll also be able to find out what your boil off rate is if you leave it for the length of time you normally boil.

 

[kiwipen]

Remember that ball valves shouldn't be cleaned fully opened, then the cleaner wont reach all the parts. I pump cleaning solution through it and cycle it open and closed a few times and leave it about 45° open for a while. The same goes for drying it out, I don't want moisture trapped in there if I'm not brewing for a while.

 

[day_trippr]

One runs the risk of galling stainless steel threaded fittings if assembling without some kind of lubrication.
Classically, that's either teflon tape or teflon-heavy pipe dope...

Cheers!

 

[Deadalus]

Put a quick disconnect on instead of the NPT to barb and the hose. 1/2" NPT x QD(male) and then QD(female x barb). Or a camlock if you want.

I pump PBW through the system after each brew, rinse then starsan. I also use a smaller bottle brush on the valve. I only take apart the valves periodically. If you take apart threaded fittings, then you want to put new teflon tape. I take all the old tape off.

 

[tracer bullet]

I think you'll find that your regimen depends on your comfort level. I clean valves after each use with normal water. For my kettle that's good enough, for my fermenter I'll later soak it in Iodophor. and do the open / close things a few times.

My metal valves get an annual disassembly and thorough cleaning. My plastic valves get replaced even if they look OK.

So far, so good. I find far more gunk inside them than I do on any threads.

 

[slayer021175666]

Just keep in mind, anything on the hot side is fine. Not, that I don't recommend periodic cleanings of EVERYTHING but, it's the cold side that you should make sure is really clean and sanitized well.

 

[Bobby_M]

I don't advocate taking everything apart after each brew. It's overkill. Yes teflon tape or you'll have leaks. Stainless is too hard for the threads to deform enough to seal on its own, and you can actually weld the fittings together by accident without the lubricating function of the tape (technical term "galling").

Hot water, scoop of PBW, let it flow through the fittings and valve open at 45 degrees. Rinse with hot water.