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The world of pipe fittings

naich.net

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Re: The world of pipe fittings

#231

Post by fuzzfactor »

agsamek wrote: post #66

This article doesn't touch much about why plumbing is hard. I'm from Poland so I'm not only IT but also a plumber ;) Plumbing is hard because it is not forgiving. It's as binary as IT except you can learn the outcome with some delay, once you learnt about a damage caused by a leak. Either you do a pressure tests right or repair can be expensive. And bugfixing is always tricky. Water also goes down whether you like it…

>It's as binary as IT

Yup, it either leaks or it doesn't.

IOW in the case of helium leak testing, it either leaks an unacceptable amount or it leaks an acceptable amount.

For higher pressures or stronger vacuums there's always this:

https://products.swagelok.com/en/all-products/fittings/c/100?

https://products.swagelok.com/en/all-products/valves/c/200?

For things like aerospace or energy.

Re: The world of pipe fittings

#232

Post by quietbritishjim »

aidos wrote: post #116
jkqwzsoo wrote: post #9

In case anyone from the US reads this, BSPP and BSPT fittings are rare and incredibly frustrating here, as our NPT (National Pipe Taper) threads are different and the selection of BSP(P/T) fittings is extremely poor in comparison. Also, I work with NPT fittings quite a lot: > For what it’s worth, I tightly wrap the tape 10 times round the male thread and get an enraged mountain gorilla to tighten it up. This is a WTF…

I think there’s cultural difference where the tongue in cheek context has been lost a bit. They probably use neither 10 full wraps, nor an enraged mountain gorilla, but then I’ve seen stranger things in plumbing.

Except in the next sentence he says that he doesn't really use a gorilla (and that's the bit that's obviously a joke). But he doesn't say he doesn't use 10 wraps.

Re: The world of pipe fittings

#233

Post by rsync »

couchand wrote: post #169
rsync wrote: post #121

Earlier quoted context omitted.

"My roommate had a "unlimited BTU" gas fitter license (Canada Class "A") and this for a living and preferred "pipe dope"" I do this kind of thing a lot as we own and maintain our own water plant. My preferred sealant is the yellow PTFE tape that is used for natural gas. It is quite a bit thicker than the white tape, it sticks to threads better and it is easier to work with, in terms of manual dexterity. I never use t…

I've seen people suggest that white tape should only be 1.5-2 but yellow should be 5 or more, do you have thoughts on that? Is there a difference in usage or is it the same overuse pattern on both?

I have no idea.

I don't think you can use too much tape. Suggestions that you can break fittings with too much tape are almost certainly incorrect - with either plastic or metal.

I usually do 5-ish wraps with the thick yellow tape - and that is true with schedule 40 PVC, plain old galvy, or with small stainless fittings.

I am wasting tape, and I know it, and I have no problem with that - and neither do the fittings.

Re: The world of pipe fittings

#234

Post by ropable »

thedanbob wrote: post #6

I had a major plumbing problem some time ago (leak in the house’s main line) and paid a plumber way too much to dig a hole and fix it. I of course wasn’t about to pay him to fill the hole back up, and while it was open I took a good look. That’s when I discovered PEX. PEX is wonderful: easy to work with, inexpensive, simple to fix if you screw something up. I wish all plumbing was PEX. I briefly installed an NPT flow…

PEX is great until rats start chewing through it in random places. Then copper pipe starts looking pretty good again.

Re: The world of pipe fittings

#235

Post by hilbert42 »

bombela wrote: post #221
hilbert42 wrote: post #213

Earlier quoted context omitted.

I know, 12" rules are bad enough at disappearing but 6" ones seem as fleeting and ephemeral as the wind. At least it's nice that one can now purchase them in packs of a dozen or so.

I am glad to be using metric. 150mm and 30cm rulers don't seems to run as fast as theirs us customary unit counterparts ;)

Mine are mainly metric or dual Imperial/metric too. I usually convert to Imperial because most readers are in the US.

If you were to read some of my old HN comments you'll realize defending the metric system in a US environment is pretty much a waste of time.

I recall one debate where some US commentators didn't have a clue about what a comfortable room temperature in Celsius would be. 68F=20C was meaningless to them even though 20C is a standard calibration temperature in lab and scientific work.

Not worth raising the issue.

Re: The world of pipe fittings

#236

Post by johnwalkr »

ethbr0 wrote: post #204
johnwalkr wrote: post #164

Earlier quoted context omitted.

I don’t think it’s acceptable. Maybe works in pinch to get through a weekend but I would always replace it with a proper fitting. Plus if you damage the female threads or o-ring seat, you’ve made a much worse problem for yourself.

It's probably a commentary on the idea that the tapered male diameter is its max diameter(?), versus straight is throughout. Consequently, a tapered male will fully screw into a straight female, albeit with gaps between the threads at the deep end of the socket. Whereas a straight male will at most only screw the first few threads into a tapered female, leaving most of the male hanging out.

Tapered pipe threads are actually much larger than you’d expect given the nominal diameter. 1/4 inch tapered pipe threads have a maximum outer diameter of more than 1/2 inch and 18 threads per inch. They will sort of work with a 1/4 inch straight thread but not by fully screwing in.

Re: The world of pipe fittings

#237

Post by naich »

lazide wrote: post #219
aidos wrote: post #116

Earlier quoted context omitted.

I think there’s cultural difference where the tongue in cheek context has been lost a bit. They probably use neither 10 full wraps, nor an enraged mountain gorilla, but then I’ve seen stranger things in plumbing.

It’s hard to tell the difference between a frustrated home owner/part time plumber and an enraged silver back I guess. At least one of them is vegetarian?

In this case, both. Sorry.

Re: The world of pipe fittings

#238

Post by naich »

throwawayacc4 wrote: post #82

This article sucks. Lots of bad info from an inexperienced plumber. How the US military, nuclear power plants, and plumbers worth their weight in salt do fittings: 3-4 times around the (male) fitting with PTFE tape, then a light amount of pipe dope on top of the PTFE tape. Also, DO NOT buy the cheap PTFE tape as suggest. Buy the milspec tape. Your big box store will have both and you'll know where that money (a coupl…

Mate, I'm not a plumber and it's 100% written from the perspective of someone who is not a plumber. This article is not an instruction manual for plumbers, but a blog of what a non-plumber found to work for him.

Re: The world of pipe fittings

#239

Post by naich »

Blog updated and the following added:

Thanks to all the good people on Hacker News for their input, from which I've learned a lot. I should stress that any following advice is not from a professional plumber and is purely from my own experience as an idiot making a low pressure beer handling system. It should not be read as the proper way to do anything, especially if you are working on pressurised systems and definitely totally 100% not with gas fittings. Get someone in to do that, you lunatic. Seriously. Don't mess with gas.

Re: The world of pipe fittings

#240

Post by jaggederest »

TEP_Kim_Il_Sung wrote: post #141
jaggederest wrote: post #129

Earlier quoted context omitted.

Yes I've found it's very frustrating looking for "genuinely zero lead" brass and bronze. Almost all scrap has lead in it to some degree, and even new metal often has a trace.

Remove about 82% of lead from bronze using this one weird trick! https://www.researchgate.net/publication/250155103_Removal_o...

Neat, this dovetails with another interest of mine, pottery. NaF is "sodium feldspar" and Ca-Si compounds are "wollastonite" among others. Both useful as fluxes in metal casting, in addition to their pottery uses.
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