9 ms·

The world of pipe fittings

298 points by naich 4y ago

lisper 4y ago
Best. Conclusion. Ever.
naich 4y ago
Having just completed a small project involving plumbing, this post on my blog comes from the heart.
- typhonic 4y ago
  There are plenty of technical comments here, but I have to say I got a great laugh from this post. I have dealt with many of the absurdities state side, so I can relate to your experience. By the time I got to the words Windows XP Screensaver, I was laughing so hard I couldn't read anymore. After finishing, I bookmarked you. Looking forward to more. Thanks.
playingalong 4y ago
What would you call this writing style (which I like a lot). Ironic? Any more specific name?
- mongol 4y ago
  Gonzo-inspired?
- digitalsushi 4y ago
  conversational-familiar
- lelandfe 4y ago
  Disgruntled Brit? I read most of it in the tone of David Mitchell: https://www.youtube.com/watch?v=Bz2-49q6DOI https://www.youtube.com/watch?v=Bz2-49q6DOI
- OJFord 4y ago
  'Annoying', personally. Seriously though, sort of a monologue? Or I'd describe it (not a single word) as spoken English taken to paper, in an oral style, or something.
tehwebguy 4y ago
Probably because you only call them when building or solving a water or poop related emergency, so times when you really need a plumber. Interesting read about the pipe fittings too though!
jasonhansel 4y ago
Conveniently, of course, the US and Canada use NPT instead of BSP, the worldwide standard. Even if an NPT fitting and a BSP fitting are the same size, one won't screw into the other, since the threads have different shapes and are at different angles.
- djcapelis 4y ago
  This guy wrote a whole article outlining how bad and unusable the British pipe standards are and you’re surprised the two (ish) continents that don’t use them are actually pretty happy with their standard and don’t want the other? NPT has some flaws and complexities but generally while it’s comprehensive conventions and practices mean that for specific types of plumbing you’ll need some specific standard fittings and once you get used to them that’s pretty much that. From gases to liquids. None of this “whoa someone decided to use a tapered one here” you don’t get to chose what fitting you’re feeling like that day, we have building codes and if it’s a pipe in a wall carrying water than there’s a convention (and likely building code) that tells you your pipe, fitting, and which way the threads should turn! (Generally in the broadest strokes: Explosive gases are reverse threaded. Everything else isn’t.) Anyway we’ve been saying no to bad British ideas since 1776. Don’t blame us outside the Americas the rest of you (and ISO) fell for it.
jesusofnazarath 4y ago
thedanbob 4y ago
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 meter (that was probably actually BSP) in the line. I can confirm that the PEX-to-NPT fittings leaked until I used a whole roll of PTFE tape and a mountain gorilla. Eventually the cheap flow meter started leaking from the casing itself so I ripped it out and replaced it with beautiful PEX.
- toss1 4y ago
  Can confirm - also started using PEX recently, and it is fantastic - wouldn't go back for anything! Straightforward, solid, more resistant to freezing (tho I still drain/blow out the outside lines in winter). I've even had zero problems with the PEX-copper fittings; I generally just attach straight onto a cut pipe rather than an NPT fitting, so that may account for my different experience. I've run a few new lines in the house, and also new hose faucets outside. Looking at using it for both vacuum and compressed air lines in the shop.
  - VLM 4y ago
    There are two problems with PEX in the shop, one real one joke. The joke one is PVC + UV = shrapnel, and frankly given enough time and vibration PVC doesn't need UV to shatter, so old timers hearing you're using plastic in the shop will freak out. (edited for those who don't get the joke: Pex will definitely split or crack under UV but AFAIK never shatters, so using PVC is a major OSHA violation but using unprotected Pex is mostly safe although maybe economically unwise) The real problem is the melting point is unimpressive and you're like one lathe chip away from an air leak. Not catastrophic but annoying. Murphy's law is air leaks only happen when you don't have time to slap a new fitting on, or when your collection of fittings is empty/missing and the store closed five minutes ago.
    - toss1 4y ago
hirundo 4y ago
"When buying male fittings, it’s best to always get tapered ones so they fit in either." I tried that with a shop compressed air system and got lot of leaks, hissing, and the compressor turning on frequently. And I never did get the system not to hiss somewhere, so I can sympathize and ditto this rant. Even when using matching fittings, with gobs of tape and/or dope, and enough force to destroy multiple fittings, it leaks. I'd pay a plumber well to teach me some of those mystic arts, if I could find one in my plumber-free rural area.
- loeg 4y ago
  Air hose standards are also annoying and differ from plumbing. https://toolguyd.com/quick-guide-to-air-line-couplers-plugs/ https://toolguyd.com/quick-guide-to-air-line-couplers-plugs/
  - katmannthree 4y ago
    The quick connect side yes, the threaded side is a standard NPT (if you're in the US) which you treat the same way you would any other NPT connection.
- katmannthree 4y ago
  If you're talking about quick connects, they'll always leak a bit. The threaded fittings however are a different story. Assuming you didn't use stainless steel on stainless steel fittings [0]: * You can find the leaks by spraying soapy water on suspect connections and looking for bubbles (wash off and dry with clean water afterwards unless you want some serious corrosion). You can also buy a jar of noncorrosive propylene glycol based leak check fluid at your local hardware store for somewhere around $10, which is a strictly better option although it's a bit harder to clean off. * Undo the connection and throw away every fitting you can replace (you generally should not reuse NPT threaded connections unless you know what you're doing). Clean all fittings until they look brand new and with no visible debris on/in the threads. * Watch some videos [1] and remake the connection using the proper amount of tape and sealant and appropriate torque [2]. Only tighten the fitting. If you loosen it even a bit during the process, undo it completely. Clean both sides, reapply tape and dope, and try again. Let the sealant set ~24h and retest. [0]: Stainless steel pipe connections are a special case because they tend to cold weld before they're fully tightened. There are ways to mitigate that but the short answer is don't use them if you don't already know how. [1]: https://www.youtube.com/watch?v=whw9ApDJpJo https://www.youtube.com/watch?v=whw9ApDJpJo [2]: NPT connections really shouldn't be torqued (you instead use turns from hand-tight for properly cut threads) but if you're having trouble find a torque chart for your fitting material (copper, brass, steel, etc) and follow that.
jkqwzsoo 4y ago
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 NO!!! for NPT and I’ll assume a WTF NO!!! for BSPT as well. You need about 1.5 wraps of PTFE tape to seal a fitting. Any more is wasteful and asking for leaks (or damage, if you’re using plastic fittings). It helps if you use the correct tape width for the fittings (1/4”, 1/2”, and 1” for me) and develop a wrapping method that keeps the tape under tension at all time and in such a direction that threading it into the fitting doesn’t unwrap the tape. Also, in my experience, when someone inexperienced first learns what pipe tape is, they try to apply it to everything. 20 wraps around a tapered pipe? Wrap a Swagelok fitting? Try to make a butt joint or an adapter for two pieces of plastic tubing? I’ve seen it all.
- balls187 4y ago
  > Also, in my experience, when someone inexperienced first learns what pipe tape is, they try to apply it to everything. That’s me. Whoops.
  - rdl 4y ago
    Ugh, I applied it to PVC pipe, which made it leak, sigh.
    - deleted 4y ago
      [deleted]
    - VincentEvans 4y ago
      There’s no problem applying it to a threaded connection in PVC. Unless you mean that you’ve figured out a way to apply to a fitting that’s meant to be glued? In that case I commend your abundant creativity.
      - 4y ago
xyzelement 4y ago
Why "someone" gets paid a lot was a discussion topics this Thanksgiving. The answer is as always "law of supply and demand." Want to make money? Learn to do something people really need but not a lot of them can or want to do. Perhaps pipe fitting is one of the "things" for plummers.
blincoln 4y ago
I've helped out with some plumbing work in an older house, and it's pretty fascinating to see the progression of technologies. 100 years ago, most drain pipes in the US were massive cast-iron pieces with no threads at all. They were mated together, then the joint was filled with a compound called oakum. To really hold it together, the plumber would pour molten lead on top of the oakum. Just taking that stuff apart is a lot of work. I can't imagine putting it together as well, especially for 40 hours a week. I agree with the author's dismay about threaded fittings, but 100% disagree about PTFE tape versus thread sealant. PTFE tape is garbage. If you use thread sealer the way it's supposed to be used (put on a decent amount, then thread the pieces together with the "nudge and a grunt" technique instead of cranking down on it with a huge amount of force), it will seal perfectly almost every time, and any minor leaks can usually be fixed by tightening the joint slightly. If that's not enough, just take it apart and redo it. I've rarely had to try twice, and never three times. Not sure about British threaded pipe, but NPT threaded pipe actually doesn't benefit from being tightened beyond a certain point because of the way the threads are designed. I redid the seals and some of the fittings[1] on all the antique hot water radiators in a house because no contractor within a day's travel would work on antique hydronic heating systems. Good quality thread sealant, no garbagey PTFE tape, no leaks, even in constant use. That having been said, modern pipes and fittings make things dead simple. PVC (or ABS, but PVC is nicer IMO) for drains, push-to-connect fittings for water lines (I like PEX, but I know opinions vary). No lead, no torches. Easy to cut with hand tools. Lightweight. Anyone who's interested can probably do at least basic work with modern pipes. [1] https://youtube.com/watch?v=MeHiE-j1KuQ https://youtube.com/watch?v=MeHiE-j1KuQ
- blincoln 4y ago
  Just to be clear, I'm not trying to discount the skill and knowledge of professional plumbers. It's an incredibly complex field (especially since they need to be familiar with decades of different pipe technology), and usually involves working in filthy parts of the house no one else wants to go into. They deserve every penny.
  - MomoXenosaga 4y ago
    Normally the market is supposed to correct these things but sadly we've created a culture that looks down on physical labour. Now there is a small group that can charge whatever they want.
1970-01-01 4y ago
They're paid so much because you need to pay twice for the bad ones. My house's previous plumber threaded a copper line directly into the stainless steel DHW tank. That wasn't a problem, until it was.
- amluto 4y ago
  I’ve never encountered a DHW tank made of stainless steel with stainless steel fittings. The error that will destroy your pipes is to use anything copper in the condensate plumbing of a condensing boiler. Use PVC, CPVC or PEX (or stainless steel) with plastic fittings (PVC, CPVC, “engineered polymer”, or John Guest ProLock or similar). The high CO2 concentrations in the condensate will rapidly corrode copper.
  - zbrozek 4y ago
    https://www.chiltrix.com/heat-exchanger-tanks/DHW80.pdf https://www.chiltrix.com/heat-exchanger-tanks/DHW80.pdf
zabzonk 4y ago
i got worried at this point: "imagine putting a tapered male in a straight female"
mildchalupa 4y ago
The Teflon tape is only to be used as a friction modifier as NPT and other tapered threads seal on the threads. Reduced friction means that you can get enough load to deform the metal threads and create a seal. Be careful to not add tape to the first 2 threads as small pieces of Teflon tape can break off and get stuck into valves and things within appliances causing them to leak. There is nothing wrong with pipe dope and I find it to be superior though messy. Annoyance for those in the states: Big box stores used to advertise fittings as NPT (National pipe thread). NPT being an ANSI spec. They seem to have switched to MIP and FIP for Male Iron Pipe and Female Iron Pipe. These are NPT as well but with a new name? Perhaps they are looking to avoid holding themselves to the spec? Lead content in brass drinking water rated piping and fittings are being phazed out for obvious reasons. New low lead brass is stronger and does not deform as easily as the older leaded brass fittings. The result is that some fittings are now more difficult to tighten untill leak free. Pex and crimped copper fittings are not without there own issues. Relying on an o-ring with a 30 year shelf life is problematic when the pipe is behind drywall. Perhaps one day we will get laser welded copper fittings.
- digitalsushi 4y ago
  it's really easy to go crazy at a box store and get boiler fittings for a garden project. read the labels for lead content!
- imglorp 4y ago
  > Relying on an o-ring Another category is Shark Bite, a simple push-on tech that is almost homeowner proof. All you need for many jobs is a cutter, some sandpaper, and the fitting: no pro tools, no torch. There are tight joist spaces the new copper crimper won't fit and overhead soldering is fraught, which you can sharkbite in 2 minutes. Back to O-rings, I do wonder about the lifetime of the seals in there though.
  - belorn 4y ago
    Depend on size and material of the o-ring. A o-ring is a flexible material that under pressure will bend in order to fit a space. Under high pressure the material might intrude out slowly, if you repeatably bend it it might snap, and as with many flexible materials it may go brittle and crack if exposed to changes in temperature or moisture.
mindslight 4y ago
Cheap fittings from GENSYM sellers on Amazon/Ebay/Aliexpress will have crappy threads, which will cause you endless pain. I'm guessing this is what inspired the author's rant. I generally try to buy fittings from suppliers that have an incentive to do some quality control. If one thread in a joint isn't perfect you're probably fine, but when both are terribly out of spec, it will never seal. I see the author used the word "spanner" so I assume they're British which is why they have to earnestly deal with BSP. For fellow Americans, don't get anything BSP/BSPP/BSPT unless you have to (eg hydraulics commonly use BSPP/G-thread, and the bonded rubber washer is not optional). For pipe tape/dope, the important thing to know is their main purpose is to reduce friction so you can tighten a joint further, which deforms the threads more - packing the threads is a secondary effect. I generally do dope, then 2-3 wraps of tape (in the right direction, of course), then dope again. I generally use the thicker blue tape, but thinner white should be the same with a few more wraps. I learned this trick from an old timer at a hardware store, and it has definitely helped on some recalcitrant joints. I'd rather not find leaks after something is assembled, so I just take the time and do it on most every joint now. (For reference, I mostly deal with 1/4 - 1 inch NPT brass/stainless/copper threads). Also, not every type of connection takes dope/tape! For example, while US showers generally have NPT-M coming out of the wall, the showerhead generally has a rubber washer that makes the seal, and thus does not need tape. Similarly with flare/compression fittings. Also, plumbers get paid a lot because it's generally heavily regulated - water supply contamination is one of those things we've refined over centuries and now take for granted. The regulation means they get a middle class wage, which is prohibitively expensive for other individuals to pay owing to high taxes and other overhead. Imagine how much it would cost to hire yourself as a software engineer for half a day.
Kaibeezy 4y ago
All this plumbing talk got me remembering the time I redid a bunch of the copper in a fixer-upper. Reading up on solder joints, I got into the underlying metallurgy, and discovered solder isn’t “glue”. You have to abrade it to remove the oxide, quickly cover the raw copper with flux, and then let the boiling flux draw the molten solder into the joint. It doesn’t take much, and you end up with a metal-metal-metal bond. Once I understood the point, the joints were a breeze. Later, I had a pro plumber in to deal with some iron pipe, noticed my copper work and was impressed. Very satisfying.
- Scoundreller 4y ago
  > and discovered solder isn’t “glue”. I see you’ve never had the chance to observe some of my PCB work!
  - rzzzt 4y ago
    "The bigger the glob, the better the job". Some solder joints are structural.
- scotty79 4y ago
  I'm really not confident about copper pipes. Metals in solder are very different electrochemically than copper. There might be other electrically connected metals in the installation. There might be some impurities grains in the copper. I've seen videos of copper pipes developing pinhole leak from corrision. I always used aluPEX for doing the piping.
AlbertCory 4y ago
I had a doctor once who was quitting his solo practice and taking a regular job at a hospital, having become disillusioned with the biz. He said his house was bought by a plumber, who was trading up.
csours 4y ago
Because they are licensed, and the license requires the equivalent of apprenticeship.
agsamek 4y ago
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 or not. Think about all possible leaks inside the shower cabin. Or what is even more impressive that under a pressure the water goes everywhere possible. Plumbing is similar to electrical engineering, except it usually doesn't kill immidiately (though working with gas is tricky anyway) but requires similar strict mental model to do right. And when you see a plumber it seems like this person is just a physical worker. So work status misconception must be leveled with money...
- PaulHoule 4y ago
  My complaint is that plumbers frequently do poor work for the money. We had some come and install an instant water heater and they cut an ugly hole in the side of the house without much thought. At one office I worked in they called Roto-Rooter (a non-union franchise that is likely to wreck your pipes and require a call to the union plumbers afterwards) who claimed that we'd flushed a condom down the drain (very hard to believe) and wrecked the pipes so we had to call the union plumber. Another time the sink wasn't running so we called the union plumbers, they unscrewed the aerator from the faucet, saw some crud come out and the water run and left in triumph, sure of their ability to outthink a group of mere computer nerds. Us computer nerds were sitting at the faucet immediately after that, running it and talking about it. The now aerator free faucet clogged up again within 2 minutes of the plumbers leaving.
  - agsamek 4y ago
    > My complaint is that plumbers frequently do poor work for the money. Hehe - now you can feel like an IT customer. I think most people feel the same about IT but the domain is just more wide and prone to excuses.
    - pasquinelli 4y ago
PaulHoule 4y ago
When I had to do some plumbing I found that everything was undocumented. One source would tell you to refer to the documentation published by the manufacturer of the fitting, which is of course impossible to find.
luxuryballs 4y ago
I thought they were paid so much because plumbing is gross and often just a huge pain.
- iancmceachern 4y ago
  Exactly, I do the simple stuff myself and only call a plumber when it involves crawling around in a spider infested crawl space, working with poop, or similar things I am willing to oay someone to do.
weare138 4y ago
That's funny. I literally just finished installing a new kitchen sink and faucet at home. Holy crap was it a pain in the ass.
- victor9000 4y ago
  What was tricky about it? Having never done it, it seems somewhat straight forward in my mind.
  - blincoln 4y ago
    Sinks are one of the few areas that I don't think one can get out of using threaded connections on the supply lines (haven't seen push-to-connect for that last leg yet). A lot of them use NPT threads, and NPT is very easy to put together in a way that will have a slow leak. Even a single drop every few minutes can cause big problems if left unattended for long enough. Also, a lot of the connections are in locations that are a headache to reach, even with a basin wrench. Getting a good seal on a sink drain can be a little tricky the first time too.
    - sokoloff 4y ago
      The sink supply connections (usually from a shutoff valve) are compression threads (a parallel/straight thread). If the valve itself is threaded on, that inlet might be NPT (or might be compression), but the valve outlet will be compression, which uses a tapered ferrule to provide the seal and straight threads.
      - mindslight 4y ago
        The faucets I've seen are generally NPS where the supply lines attach to the faucet, often with the retaining nuts (or whatever they're called) using the same threads and going on first. To answer GGP's question, what's difficult about faucets is getting up behind the sink, with your back straddling the corner of the cabinet, reaching up with some sort of basin wrench that inevitably won't grip those bespoke retaining nuts well. Especially removing the old faucet where the retaining nuts are a bit seized.
everyone 4y ago
Programming is analogous to a trade like plumbing in many ways imo. * You both design and then build a thing. * No one else knows how it works or cares until it stops working. * Through work you build up your own set tools and methods that you like and can apply to various jobs.
turdherder 4y ago
Real life licensed and certified plumber here. Regarding the threads on common pipe fittings here in Cali: NPT threads are designed to be cut with a pitch and angle that are self sealing. Sealing compounds can assist in the lubrication of threads to easily tighten them up but should not be absolutely necessary. Imo it's an aid to assembly and disassembly and not always necessary depending upon the application. And in some applications it's forbidden
synecdoche 4y ago
In one of the larger companies in Sweden in the third largest city Malmö that sell to both other companies and consumers none of the staff knew what I was talking about when I mentioned that BSP and NPT are different. Neither people on the floor nor people answering the phone. These were what appeared to be experienced plumbers. It’s amazing.
throwawayacc4 4y ago
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 couple dollars at most) went.
- Severian 4y ago
  Milspec, lol. Doesn't that normally equal as cheap as they can get away with? There is a high-density thread sealing PTFE tape that works a bit better than the el' cheapo generic white stuff (although it's usually white too). Anything marked as such should be sufficient unless you are working on an oil rig or nuclear reactor. EDIT: Unless the package has MIL-T-27730 on the tape, labeling it milspec has no meaning.
  - kevin_thibedeau 4y ago
    > Milspec, lol. Doesn't that normally equal as cheap as they can get away with? It means a product meets stringent requirements that can't be cheated on.
  - throwawayacc4 4y ago
    >Milspec, lol. Yes, MilSpec [0]. >Doesn't that normally equal as cheap as they can get away with? No, wrong. You're thinking of "military grade", which is effectively meaningless as a term. >There is a high-density thread sealing PTFE tape that works a bit better than the el' cheapo generic white stuff This is what I was alluding to. It's thicker and denser. >EDIT: Unless the package has MIL-T-27730 on the tape, labeling it milspec has no meaning. This is where you're wrong. Milspec has a specific meaning [0]. The milspec in question is Military Spec # A-A-58092 [1]. [0] https://en.m.wikipedia.org/wiki/United_States_Military_Standard https://en.m.wikipedia.org/wiki/United_States_Military_Stand... [1] https://www.lowes.com/pd/Oatey-0-6-in-x-43-ft-Plumber-s-Tape/4751313 https://www.lowes.com/pd/Oatey-0-6-in-x-43-ft-Plumber-s-Tape...
bmalicoat 4y ago
I was hoping this was going to be written by Leslie Claret. https://www.lgclaret.com/ https://www.lgclaret.com/ "Hey, let me walk you through our Donnelly nut spacing and crack system rim-riding grip configuration. Using a field of half-C sprats, and brass-fitted nickel slits, our bracketed caps and splay-flexed brace columns vent dampers to dampening hatch depths of one-half meter from the damper crown to the spurve plinths. How? Well, we bolster twelve husked nuts to each girdle-jerry. While flex tandems press a task apparatus of ten vertically composited patch-hamplers. Then, pin flam-fastened pan traps at both maiden-apexes of the jim-joist."
- dtjohnnymonkey 4y ago
  This is what I came here looking for.
zackbloom 4y ago
I would personally recommend trying TFE paste, rather than Teflon tape. Easier to get a seal, less annoying to tighten.
VLM 4y ago
The story misses some points. The first issue is pipes are used for a lot more than pressurized drinking water, and for compressed gases there's various standards so you don't accidentally connect your acetylene tank to your argon regulator and vice versa. Depending on local building codes, you have to work really hard in the USA to cross connect your natgas to your water supply, etc. For a home handyman this seems laughable but for giant construction projects at industrial sites you will inevitably see insane stuff sooner or later where roughed in water lines get accidentally connected to compressed air and stuff like that. I personally saw a PVC convenience pipe roughed in for ethernet cable get connected to sewer vent. The second issue, related to the above, is NPT relies on thread deformation so the pros use pipe dope and the amateurs use teflon tape that contaminates everything, so you technically "can" use NPT for diesel or hydraulic but usually building codes and/or OSHA prevent such nonsense. Also thread deformation means every time you reuse a NPT its looser and leakier. Very slow leaking threads are not an issue for compressed air, so black iron pipe is common for industrial compressed air because who cares if 0.01% leaks out, but for flammable contamination sensitive stuff its a big issue. If 0.01% of your compressed air leaks out above a food prep assembly line nobody cares but if 0.01% of your hydraulic fluid leaks out into the food, then its a big food safety mess. The point is that most of this technology is being used outside its original use case, most NPT threads are not holding back compressed air, but crazy people are trying to use that tech to push natgas around or diesel or whatever and due to "tradition" and "codes" we are stuck with it. So the argument that NPT is shit so nobody should use it is pointless because its "really intended for" compressed air and is great for that, super cheap, easy to use, reliable enough, etc, so pointing out that its not optimal for car brakes is both true and also not useful "in practice". Another comedy about threads: You can buy pipe dope to professionally seal NPT threads for air, natgas, car brakes, and water, but those pipe dopes are not the same, and you can cause quite a bit of trouble if you use air dope on natgas for example.
- mildchalupa 4y ago
  There are a few pipe dopes that advertise a wide range of material comparability. I recently purchased some for a automotive racing fuel pump setup that was rated for gasoline, nat gas and water.
jsz0 4y ago
I had to do some plumbing work a few years ago and quite enjoyed solving the puzzle and completing the work myself. It did remind me a lot of my day job in tech. No individual part of the job is all that difficult but planning and executing everything properly, and all the cryptic/arcane knowledge required, was very similar. And just like when one of my networks or systems is down the work had to be completed quickly to resolve the outage.
swayvil 4y ago
Given the choice, I love pex and those compression-bands that you put on with the special pliers. Pex got flex. For drains, pvc of course. Given run-of-the-mill refurbby waterline junk with plain ol copper, I like that brass kind of compression with the little sleeve. Don't trust sharkbite. Am a mediocre sweater. For gas, threaded with that pipe goo works surprisingly well. Haven't fucked it up yet. I wonder if you can use pex with gas
- iancmceachern 4y ago
  Agreed on the compression fittings over the sharkbite stuff.
- ssl232 4y ago
  You do your own gas work? I'm in the UK and I'm pretty sure you basically cannot legally touch gas fittings unless you're a qualified plumber.
  - mildchalupa 4y ago
    Welcome to the states, we have no laws here. I helped my dad replace our gas lines as a child. I ran the rigid pipe lathe.
ok_computer 4y ago
Bsp, Npt, goop (yuck!), and teflon tape are all inferior to Swage. Cold weld and reuseable but it is a trade in itself to fit and bend to place. https://en.m.wikipedia.org/wiki/Compression_fitting https://en.m.wikipedia.org/wiki/Compression_fitting Working in labs on fluid and vacuum lines (<1in diameter) this is the way. If only it wouldn’t cost as much as the house in fittings + tube to hardpipe stainless fittings on our water supply lines. I stayed in a hostel hotel in Munich, DE with hard piped bathroom water lines. I was impressed and think they must have been in service for 30-50 years.
dhosek 4y ago
Of the three aspects of home maintenance that are most common¹: plumbing, electrical and carpentry, I feel most comfortable with plumbing. It seems nicely discrete in that you’re generally putting together existing components without having to do much if any measuring and cutting. That said, I’m moving into a new house where I’ve got a handful of carpentry projects that will definitely stretch my abilities in that arena. ⸻ 1. In my experience, I suppose, one could perhaps add concrete/masonry and may be something with dirt?
joshuaheard 4y ago
I had to learn the arcane world of pipe fitting sizes working with pneumatics for a scuba equipment project. It is extremely confusing. Unfortunately, it can have fatal consequences. In a recent story, a scuba store employee used the wrong size fitting on a 3,000 psi scuba tank which shot out and killed them. Seeing that American can't even adopt the metric system, I have little hope for a clear international standard for pipe fittings.
- noNothing 4y ago
  All Americans completely understand the metric system. We can convert anything to anything in our heads. By the way, we all speak a dozen foreign languages fluently, just choose not to. It is because we are so humble that you do not know this.
  - hansvm 4y ago
    I was with you till you asserted we only speak a dozen languages.
walrus01 4y ago
Of other industrial interest re: pipes, sch40 and sch80 hot dip galvanized pipes in various outer diameters are also a standard item for telecom construction projects. For when you want to have a pipe-to-pipe adapter to hang a radio on a tower, or wall mount it on top of a building mechanical penthouse or similar.
midhhhthrow 4y ago
One thing I’ve learned the hard way is that you need those little gasket seals on the inside to avoid a leak but if you over tighten the connection with a gasket inside you can actually get a leak just from over tightening it!
fijiaarone 4y ago
Nope. It’s the backbreaking work in tight places with a high probability of wallowing in shit.
naich 4y ago
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.

298 points by naich 4y ago

lisper 4y ago

Best. Conclusion. Ever.

naich 4y ago

Having just completed a small project involving plumbing, this post on my blog comes from the heart.

typhonic 4y ago
There are plenty of technical comments here, but I have to say I got a great laugh from this post. I have dealt with many of the absurdities state side, so I can relate to your experience. By the time I got to the words Windows XP Screensaver, I was laughing so hard I couldn't read anymore. After finishing, I bookmarked you. Looking forward to more. Thanks.

playingalong 4y ago

What would you call this writing style (which I like a lot). Ironic? Any more specific name?

mongol 4y ago
Gonzo-inspired?
digitalsushi 4y ago
conversational-familiar
lelandfe 4y ago
Disgruntled Brit? I read most of it in the tone of David Mitchell: https://www.youtube.com/watch?v=Bz2-49q6DOI https://www.youtube.com/watch?v=Bz2-49q6DOI
OJFord 4y ago
'Annoying', personally. Seriously though, sort of a monologue? Or I'd describe it (not a single word) as spoken English taken to paper, in an oral style, or something.

tehwebguy 4y ago

Probably because you only call them when building or solving a water or poop related emergency, so times when you really need a plumber. Interesting read about the pipe fittings too though!

jasonhansel 4y ago

Conveniently, of course, the US and Canada use NPT instead of BSP, the worldwide standard. Even if an NPT fitting and a BSP fitting are the same size, one won't screw into the other, since the threads have different shapes and are at different angles.

djcapelis 4y ago
This guy wrote a whole article outlining how bad and unusable the British pipe standards are and you’re surprised the two (ish) continents that don’t use them are actually pretty happy with their standard and don’t want the other? NPT has some flaws and complexities but generally while it’s comprehensive conventions and practices mean that for specific types of plumbing you’ll need some specific standard fittings and once you get used to them that’s pretty much that. From gases to liquids. None of this “whoa someone decided to use a tapered one here” you don’t get to chose what fitting you’re feeling like that day, we have building codes and if it’s a pipe in a wall carrying water than there’s a convention (and likely building code) that tells you your pipe, fitting, and which way the threads should turn! (Generally in the broadest strokes: Explosive gases are reverse threaded. Everything else isn’t.) Anyway we’ve been saying no to bad British ideas since 1776. Don’t blame us outside the Americas the rest of you (and ISO) fell for it.

jesusofnazarath 4y ago

thedanbob 4y ago

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 meter (that was probably actually BSP) in the line. I can confirm that the PEX-to-NPT fittings leaked until I used a whole roll of PTFE tape and a mountain gorilla. Eventually the cheap flow meter started leaking from the casing itself so I ripped it out and replaced it with beautiful PEX.

toss1 4y ago
Can confirm - also started using PEX recently, and it is fantastic - wouldn't go back for anything! Straightforward, solid, more resistant to freezing (tho I still drain/blow out the outside lines in winter). I've even had zero problems with the PEX-copper fittings; I generally just attach straight onto a cut pipe rather than an NPT fitting, so that may account for my different experience. I've run a few new lines in the house, and also new hose faucets outside. Looking at using it for both vacuum and compressed air lines in the shop.
- VLM 4y ago
  There are two problems with PEX in the shop, one real one joke. The joke one is PVC + UV = shrapnel, and frankly given enough time and vibration PVC doesn't need UV to shatter, so old timers hearing you're using plastic in the shop will freak out. (edited for those who don't get the joke: Pex will definitely split or crack under UV but AFAIK never shatters, so using PVC is a major OSHA violation but using unprotected Pex is mostly safe although maybe economically unwise) The real problem is the melting point is unimpressive and you're like one lathe chip away from an air leak. Not catastrophic but annoying. Murphy's law is air leaks only happen when you don't have time to slap a new fitting on, or when your collection of fittings is empty/missing and the store closed five minutes ago.
  - toss1 4y ago

hirundo 4y ago

"When buying male fittings, it’s best to always get tapered ones so they fit in either." I tried that with a shop compressed air system and got lot of leaks, hissing, and the compressor turning on frequently. And I never did get the system not to hiss somewhere, so I can sympathize and ditto this rant. Even when using matching fittings, with gobs of tape and/or dope, and enough force to destroy multiple fittings, it leaks. I'd pay a plumber well to teach me some of those mystic arts, if I could find one in my plumber-free rural area.

loeg 4y ago
Air hose standards are also annoying and differ from plumbing. https://toolguyd.com/quick-guide-to-air-line-couplers-plugs/ https://toolguyd.com/quick-guide-to-air-line-couplers-plugs/
- katmannthree 4y ago
  The quick connect side yes, the threaded side is a standard NPT (if you're in the US) which you treat the same way you would any other NPT connection.
katmannthree 4y ago
If you're talking about quick connects, they'll always leak a bit. The threaded fittings however are a different story. Assuming you didn't use stainless steel on stainless steel fittings [0]: * You can find the leaks by spraying soapy water on suspect connections and looking for bubbles (wash off and dry with clean water afterwards unless you want some serious corrosion). You can also buy a jar of noncorrosive propylene glycol based leak check fluid at your local hardware store for somewhere around $10, which is a strictly better option although it's a bit harder to clean off. * Undo the connection and throw away every fitting you can replace (you generally should not reuse NPT threaded connections unless you know what you're doing). Clean all fittings until they look brand new and with no visible debris on/in the threads. * Watch some videos [1] and remake the connection using the proper amount of tape and sealant and appropriate torque [2]. Only tighten the fitting. If you loosen it even a bit during the process, undo it completely. Clean both sides, reapply tape and dope, and try again. Let the sealant set ~24h and retest. [0]: Stainless steel pipe connections are a special case because they tend to cold weld before they're fully tightened. There are ways to mitigate that but the short answer is don't use them if you don't already know how. [1]: https://www.youtube.com/watch?v=whw9ApDJpJo https://www.youtube.com/watch?v=whw9ApDJpJo [2]: NPT connections really shouldn't be torqued (you instead use turns from hand-tight for properly cut threads) but if you're having trouble find a torque chart for your fitting material (copper, brass, steel, etc) and follow that.

jkqwzsoo 4y ago

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 NO!!! for NPT and I’ll assume a WTF NO!!! for BSPT as well. You need about 1.5 wraps of PTFE tape to seal a fitting. Any more is wasteful and asking for leaks (or damage, if you’re using plastic fittings). It helps if you use the correct tape width for the fittings (1/4”, 1/2”, and 1” for me) and develop a wrapping method that keeps the tape under tension at all time and in such a direction that threading it into the fitting doesn’t unwrap the tape. Also, in my experience, when someone inexperienced first learns what pipe tape is, they try to apply it to everything. 20 wraps around a tapered pipe? Wrap a Swagelok fitting? Try to make a butt joint or an adapter for two pieces of plastic tubing? I’ve seen it all.

balls187 4y ago
> Also, in my experience, when someone inexperienced first learns what pipe tape is, they try to apply it to everything. That’s me. Whoops.
- rdl 4y ago
  Ugh, I applied it to PVC pipe, which made it leak, sigh.
  - deleted 4y ago
    [deleted]
  - VincentEvans 4y ago
    There’s no problem applying it to a threaded connection in PVC. Unless you mean that you’ve figured out a way to apply to a fitting that’s meant to be glued? In that case I commend your abundant creativity.
    - 4y ago

xyzelement 4y ago

Why "someone" gets paid a lot was a discussion topics this Thanksgiving. The answer is as always "law of supply and demand." Want to make money? Learn to do something people really need but not a lot of them can or want to do. Perhaps pipe fitting is one of the "things" for plummers.

blincoln 4y ago

I've helped out with some plumbing work in an older house, and it's pretty fascinating to see the progression of technologies. 100 years ago, most drain pipes in the US were massive cast-iron pieces with no threads at all. They were mated together, then the joint was filled with a compound called oakum. To really hold it together, the plumber would pour molten lead on top of the oakum. Just taking that stuff apart is a lot of work. I can't imagine putting it together as well, especially for 40 hours a week. I agree with the author's dismay about threaded fittings, but 100% disagree about PTFE tape versus thread sealant. PTFE tape is garbage. If you use thread sealer the way it's supposed to be used (put on a decent amount, then thread the pieces together with the "nudge and a grunt" technique instead of cranking down on it with a huge amount of force), it will seal perfectly almost every time, and any minor leaks can usually be fixed by tightening the joint slightly. If that's not enough, just take it apart and redo it. I've rarely had to try twice, and never three times. Not sure about British threaded pipe, but NPT threaded pipe actually doesn't benefit from being tightened beyond a certain point because of the way the threads are designed. I redid the seals and some of the fittings[1] on all the antique hot water radiators in a house because no contractor within a day's travel would work on antique hydronic heating systems. Good quality thread sealant, no garbagey PTFE tape, no leaks, even in constant use. That having been said, modern pipes and fittings make things dead simple. PVC (or ABS, but PVC is nicer IMO) for drains, push-to-connect fittings for water lines (I like PEX, but I know opinions vary). No lead, no torches. Easy to cut with hand tools. Lightweight. Anyone who's interested can probably do at least basic work with modern pipes. [1] https://youtube.com/watch?v=MeHiE-j1KuQ https://youtube.com/watch?v=MeHiE-j1KuQ

blincoln 4y ago
Just to be clear, I'm not trying to discount the skill and knowledge of professional plumbers. It's an incredibly complex field (especially since they need to be familiar with decades of different pipe technology), and usually involves working in filthy parts of the house no one else wants to go into. They deserve every penny.
- MomoXenosaga 4y ago
  Normally the market is supposed to correct these things but sadly we've created a culture that looks down on physical labour. Now there is a small group that can charge whatever they want.

1970-01-01 4y ago

They're paid so much because you need to pay twice for the bad ones. My house's previous plumber threaded a copper line directly into the stainless steel DHW tank. That wasn't a problem, until it was.

amluto 4y ago
I’ve never encountered a DHW tank made of stainless steel with stainless steel fittings. The error that will destroy your pipes is to use anything copper in the condensate plumbing of a condensing boiler. Use PVC, CPVC or PEX (or stainless steel) with plastic fittings (PVC, CPVC, “engineered polymer”, or John Guest ProLock or similar). The high CO2 concentrations in the condensate will rapidly corrode copper.
- zbrozek 4y ago
  https://www.chiltrix.com/heat-exchanger-tanks/DHW80.pdf https://www.chiltrix.com/heat-exchanger-tanks/DHW80.pdf

zabzonk 4y ago

i got worried at this point: "imagine putting a tapered male in a straight female"

mildchalupa 4y ago

The Teflon tape is only to be used as a friction modifier as NPT and other tapered threads seal on the threads. Reduced friction means that you can get enough load to deform the metal threads and create a seal. Be careful to not add tape to the first 2 threads as small pieces of Teflon tape can break off and get stuck into valves and things within appliances causing them to leak. There is nothing wrong with pipe dope and I find it to be superior though messy. Annoyance for those in the states: Big box stores used to advertise fittings as NPT (National pipe thread). NPT being an ANSI spec. They seem to have switched to MIP and FIP for Male Iron Pipe and Female Iron Pipe. These are NPT as well but with a new name? Perhaps they are looking to avoid holding themselves to the spec? Lead content in brass drinking water rated piping and fittings are being phazed out for obvious reasons. New low lead brass is stronger and does not deform as easily as the older leaded brass fittings. The result is that some fittings are now more difficult to tighten untill leak free. Pex and crimped copper fittings are not without there own issues. Relying on an o-ring with a 30 year shelf life is problematic when the pipe is behind drywall. Perhaps one day we will get laser welded copper fittings.

digitalsushi 4y ago
it's really easy to go crazy at a box store and get boiler fittings for a garden project. read the labels for lead content!
imglorp 4y ago
> Relying on an o-ring Another category is Shark Bite, a simple push-on tech that is almost homeowner proof. All you need for many jobs is a cutter, some sandpaper, and the fitting: no pro tools, no torch. There are tight joist spaces the new copper crimper won't fit and overhead soldering is fraught, which you can sharkbite in 2 minutes. Back to O-rings, I do wonder about the lifetime of the seals in there though.
- belorn 4y ago
  Depend on size and material of the o-ring. A o-ring is a flexible material that under pressure will bend in order to fit a space. Under high pressure the material might intrude out slowly, if you repeatably bend it it might snap, and as with many flexible materials it may go brittle and crack if exposed to changes in temperature or moisture.

mindslight 4y ago

Cheap fittings from GENSYM sellers on Amazon/Ebay/Aliexpress will have crappy threads, which will cause you endless pain. I'm guessing this is what inspired the author's rant. I generally try to buy fittings from suppliers that have an incentive to do some quality control. If one thread in a joint isn't perfect you're probably fine, but when both are terribly out of spec, it will never seal. I see the author used the word "spanner" so I assume they're British which is why they have to earnestly deal with BSP. For fellow Americans, don't get anything BSP/BSPP/BSPT unless you have to (eg hydraulics commonly use BSPP/G-thread, and the bonded rubber washer is not optional). For pipe tape/dope, the important thing to know is their main purpose is to reduce friction so you can tighten a joint further, which deforms the threads more - packing the threads is a secondary effect. I generally do dope, then 2-3 wraps of tape (in the right direction, of course), then dope again. I generally use the thicker blue tape, but thinner white should be the same with a few more wraps. I learned this trick from an old timer at a hardware store, and it has definitely helped on some recalcitrant joints. I'd rather not find leaks after something is assembled, so I just take the time and do it on most every joint now. (For reference, I mostly deal with 1/4 - 1 inch NPT brass/stainless/copper threads). Also, not every type of connection takes dope/tape! For example, while US showers generally have NPT-M coming out of the wall, the showerhead generally has a rubber washer that makes the seal, and thus does not need tape. Similarly with flare/compression fittings. Also, plumbers get paid a lot because it's generally heavily regulated - water supply contamination is one of those things we've refined over centuries and now take for granted. The regulation means they get a middle class wage, which is prohibitively expensive for other individuals to pay owing to high taxes and other overhead. Imagine how much it would cost to hire yourself as a software engineer for half a day.

Kaibeezy 4y ago

All this plumbing talk got me remembering the time I redid a bunch of the copper in a fixer-upper. Reading up on solder joints, I got into the underlying metallurgy, and discovered solder isn’t “glue”. You have to abrade it to remove the oxide, quickly cover the raw copper with flux, and then let the boiling flux draw the molten solder into the joint. It doesn’t take much, and you end up with a metal-metal-metal bond. Once I understood the point, the joints were a breeze. Later, I had a pro plumber in to deal with some iron pipe, noticed my copper work and was impressed. Very satisfying.

Scoundreller 4y ago
> and discovered solder isn’t “glue”. I see you’ve never had the chance to observe some of my PCB work!
- rzzzt 4y ago
  "The bigger the glob, the better the job". Some solder joints are structural.
scotty79 4y ago
I'm really not confident about copper pipes. Metals in solder are very different electrochemically than copper. There might be other electrically connected metals in the installation. There might be some impurities grains in the copper. I've seen videos of copper pipes developing pinhole leak from corrision. I always used aluPEX for doing the piping.

AlbertCory 4y ago

I had a doctor once who was quitting his solo practice and taking a regular job at a hospital, having become disillusioned with the biz. He said his house was bought by a plumber, who was trading up.

csours 4y ago

Because they are licensed, and the license requires the equivalent of apprenticeship.

agsamek 4y ago

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 or not. Think about all possible leaks inside the shower cabin. Or what is even more impressive that under a pressure the water goes everywhere possible. Plumbing is similar to electrical engineering, except it usually doesn't kill immidiately (though working with gas is tricky anyway) but requires similar strict mental model to do right. And when you see a plumber it seems like this person is just a physical worker. So work status misconception must be leveled with money...

PaulHoule 4y ago
My complaint is that plumbers frequently do poor work for the money. We had some come and install an instant water heater and they cut an ugly hole in the side of the house without much thought. At one office I worked in they called Roto-Rooter (a non-union franchise that is likely to wreck your pipes and require a call to the union plumbers afterwards) who claimed that we'd flushed a condom down the drain (very hard to believe) and wrecked the pipes so we had to call the union plumber. Another time the sink wasn't running so we called the union plumbers, they unscrewed the aerator from the faucet, saw some crud come out and the water run and left in triumph, sure of their ability to outthink a group of mere computer nerds. Us computer nerds were sitting at the faucet immediately after that, running it and talking about it. The now aerator free faucet clogged up again within 2 minutes of the plumbers leaving.
- agsamek 4y ago
  > My complaint is that plumbers frequently do poor work for the money. Hehe - now you can feel like an IT customer. I think most people feel the same about IT but the domain is just more wide and prone to excuses.
  - pasquinelli 4y ago

PaulHoule 4y ago

When I had to do some plumbing I found that everything was undocumented. One source would tell you to refer to the documentation published by the manufacturer of the fitting, which is of course impossible to find.

luxuryballs 4y ago

I thought they were paid so much because plumbing is gross and often just a huge pain.

iancmceachern 4y ago
Exactly, I do the simple stuff myself and only call a plumber when it involves crawling around in a spider infested crawl space, working with poop, or similar things I am willing to oay someone to do.

weare138 4y ago

That's funny. I literally just finished installing a new kitchen sink and faucet at home. Holy crap was it a pain in the ass.

victor9000 4y ago
What was tricky about it? Having never done it, it seems somewhat straight forward in my mind.
- blincoln 4y ago
  Sinks are one of the few areas that I don't think one can get out of using threaded connections on the supply lines (haven't seen push-to-connect for that last leg yet). A lot of them use NPT threads, and NPT is very easy to put together in a way that will have a slow leak. Even a single drop every few minutes can cause big problems if left unattended for long enough. Also, a lot of the connections are in locations that are a headache to reach, even with a basin wrench. Getting a good seal on a sink drain can be a little tricky the first time too.
  - sokoloff 4y ago
    The sink supply connections (usually from a shutoff valve) are compression threads (a parallel/straight thread). If the valve itself is threaded on, that inlet might be NPT (or might be compression), but the valve outlet will be compression, which uses a tapered ferrule to provide the seal and straight threads.
    - mindslight 4y ago
      The faucets I've seen are generally NPS where the supply lines attach to the faucet, often with the retaining nuts (or whatever they're called) using the same threads and going on first. To answer GGP's question, what's difficult about faucets is getting up behind the sink, with your back straddling the corner of the cabinet, reaching up with some sort of basin wrench that inevitably won't grip those bespoke retaining nuts well. Especially removing the old faucet where the retaining nuts are a bit seized.

everyone 4y ago

Programming is analogous to a trade like plumbing in many ways imo. * You both design and then build a thing. * No one else knows how it works or cares until it stops working. * Through work you build up your own set tools and methods that you like and can apply to various jobs.

turdherder 4y ago

Real life licensed and certified plumber here. Regarding the threads on common pipe fittings here in Cali: NPT threads are designed to be cut with a pitch and angle that are self sealing. Sealing compounds can assist in the lubrication of threads to easily tighten them up but should not be absolutely necessary. Imo it's an aid to assembly and disassembly and not always necessary depending upon the application. And in some applications it's forbidden

synecdoche 4y ago

In one of the larger companies in Sweden in the third largest city Malmö that sell to both other companies and consumers none of the staff knew what I was talking about when I mentioned that BSP and NPT are different. Neither people on the floor nor people answering the phone. These were what appeared to be experienced plumbers. It’s amazing.

throwawayacc4 4y ago

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 couple dollars at most) went.

Severian 4y ago
Milspec, lol. Doesn't that normally equal as cheap as they can get away with? There is a high-density thread sealing PTFE tape that works a bit better than the el' cheapo generic white stuff (although it's usually white too). Anything marked as such should be sufficient unless you are working on an oil rig or nuclear reactor. EDIT: Unless the package has MIL-T-27730 on the tape, labeling it milspec has no meaning.
- kevin_thibedeau 4y ago
  > Milspec, lol. Doesn't that normally equal as cheap as they can get away with? It means a product meets stringent requirements that can't be cheated on.
- throwawayacc4 4y ago
  >Milspec, lol. Yes, MilSpec [0]. >Doesn't that normally equal as cheap as they can get away with? No, wrong. You're thinking of "military grade", which is effectively meaningless as a term. >There is a high-density thread sealing PTFE tape that works a bit better than the el' cheapo generic white stuff This is what I was alluding to. It's thicker and denser. >EDIT: Unless the package has MIL-T-27730 on the tape, labeling it milspec has no meaning. This is where you're wrong. Milspec has a specific meaning [0]. The milspec in question is Military Spec # A-A-58092 [1]. [0] https://en.m.wikipedia.org/wiki/United_States_Military_Standard https://en.m.wikipedia.org/wiki/United_States_Military_Stand... [1] https://www.lowes.com/pd/Oatey-0-6-in-x-43-ft-Plumber-s-Tape/4751313 https://www.lowes.com/pd/Oatey-0-6-in-x-43-ft-Plumber-s-Tape...

bmalicoat 4y ago

I was hoping this was going to be written by Leslie Claret. https://www.lgclaret.com/ https://www.lgclaret.com/ "Hey, let me walk you through our Donnelly nut spacing and crack system rim-riding grip configuration. Using a field of half-C sprats, and brass-fitted nickel slits, our bracketed caps and splay-flexed brace columns vent dampers to dampening hatch depths of one-half meter from the damper crown to the spurve plinths. How? Well, we bolster twelve husked nuts to each girdle-jerry. While flex tandems press a task apparatus of ten vertically composited patch-hamplers. Then, pin flam-fastened pan traps at both maiden-apexes of the jim-joist."

dtjohnnymonkey 4y ago
This is what I came here looking for.

zackbloom 4y ago

I would personally recommend trying TFE paste, rather than Teflon tape. Easier to get a seal, less annoying to tighten.

VLM 4y ago

The story misses some points. The first issue is pipes are used for a lot more than pressurized drinking water, and for compressed gases there's various standards so you don't accidentally connect your acetylene tank to your argon regulator and vice versa. Depending on local building codes, you have to work really hard in the USA to cross connect your natgas to your water supply, etc. For a home handyman this seems laughable but for giant construction projects at industrial sites you will inevitably see insane stuff sooner or later where roughed in water lines get accidentally connected to compressed air and stuff like that. I personally saw a PVC convenience pipe roughed in for ethernet cable get connected to sewer vent. The second issue, related to the above, is NPT relies on thread deformation so the pros use pipe dope and the amateurs use teflon tape that contaminates everything, so you technically "can" use NPT for diesel or hydraulic but usually building codes and/or OSHA prevent such nonsense. Also thread deformation means every time you reuse a NPT its looser and leakier. Very slow leaking threads are not an issue for compressed air, so black iron pipe is common for industrial compressed air because who cares if 0.01% leaks out, but for flammable contamination sensitive stuff its a big issue. If 0.01% of your compressed air leaks out above a food prep assembly line nobody cares but if 0.01% of your hydraulic fluid leaks out into the food, then its a big food safety mess. The point is that most of this technology is being used outside its original use case, most NPT threads are not holding back compressed air, but crazy people are trying to use that tech to push natgas around or diesel or whatever and due to "tradition" and "codes" we are stuck with it. So the argument that NPT is shit so nobody should use it is pointless because its "really intended for" compressed air and is great for that, super cheap, easy to use, reliable enough, etc, so pointing out that its not optimal for car brakes is both true and also not useful "in practice". Another comedy about threads: You can buy pipe dope to professionally seal NPT threads for air, natgas, car brakes, and water, but those pipe dopes are not the same, and you can cause quite a bit of trouble if you use air dope on natgas for example.

mildchalupa 4y ago
There are a few pipe dopes that advertise a wide range of material comparability. I recently purchased some for a automotive racing fuel pump setup that was rated for gasoline, nat gas and water.

jsz0 4y ago

I had to do some plumbing work a few years ago and quite enjoyed solving the puzzle and completing the work myself. It did remind me a lot of my day job in tech. No individual part of the job is all that difficult but planning and executing everything properly, and all the cryptic/arcane knowledge required, was very similar. And just like when one of my networks or systems is down the work had to be completed quickly to resolve the outage.

swayvil 4y ago

Given the choice, I love pex and those compression-bands that you put on with the special pliers. Pex got flex. For drains, pvc of course. Given run-of-the-mill refurbby waterline junk with plain ol copper, I like that brass kind of compression with the little sleeve. Don't trust sharkbite. Am a mediocre sweater. For gas, threaded with that pipe goo works surprisingly well. Haven't fucked it up yet. I wonder if you can use pex with gas

iancmceachern 4y ago
Agreed on the compression fittings over the sharkbite stuff.
ssl232 4y ago
You do your own gas work? I'm in the UK and I'm pretty sure you basically cannot legally touch gas fittings unless you're a qualified plumber.
- mildchalupa 4y ago
  Welcome to the states, we have no laws here. I helped my dad replace our gas lines as a child. I ran the rigid pipe lathe.

ok_computer 4y ago

Bsp, Npt, goop (yuck!), and teflon tape are all inferior to Swage. Cold weld and reuseable but it is a trade in itself to fit and bend to place. https://en.m.wikipedia.org/wiki/Compression_fitting https://en.m.wikipedia.org/wiki/Compression_fitting Working in labs on fluid and vacuum lines (<1in diameter) this is the way. If only it wouldn’t cost as much as the house in fittings + tube to hardpipe stainless fittings on our water supply lines. I stayed in a hostel hotel in Munich, DE with hard piped bathroom water lines. I was impressed and think they must have been in service for 30-50 years.

dhosek 4y ago

Of the three aspects of home maintenance that are most common¹: plumbing, electrical and carpentry, I feel most comfortable with plumbing. It seems nicely discrete in that you’re generally putting together existing components without having to do much if any measuring and cutting. That said, I’m moving into a new house where I’ve got a handful of carpentry projects that will definitely stretch my abilities in that arena. ⸻ 1. In my experience, I suppose, one could perhaps add concrete/masonry and may be something with dirt?

joshuaheard 4y ago

I had to learn the arcane world of pipe fitting sizes working with pneumatics for a scuba equipment project. It is extremely confusing. Unfortunately, it can have fatal consequences. In a recent story, a scuba store employee used the wrong size fitting on a 3,000 psi scuba tank which shot out and killed them. Seeing that American can't even adopt the metric system, I have little hope for a clear international standard for pipe fittings.

noNothing 4y ago
All Americans completely understand the metric system. We can convert anything to anything in our heads. By the way, we all speak a dozen foreign languages fluently, just choose not to. It is because we are so humble that you do not know this.
- hansvm 4y ago
  I was with you till you asserted we only speak a dozen languages.

walrus01 4y ago

Of other industrial interest re: pipes, sch40 and sch80 hot dip galvanized pipes in various outer diameters are also a standard item for telecom construction projects. For when you want to have a pipe-to-pipe adapter to hang a radio on a tower, or wall mount it on top of a building mechanical penthouse or similar.

midhhhthrow 4y ago

One thing I’ve learned the hard way is that you need those little gasket seals on the inside to avoid a leak but if you over tighten the connection with a gasket inside you can actually get a leak just from over tightening it!

fijiaarone 4y ago

Nope. It’s the backbreaking work in tight places with a high probability of wallowing in shit.

naich 4y ago

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.