Everyday uses for PVC water pipe
tomtilley.net
tomtilley.net
This working excavator is rather extraordinary.
https://m.youtube.com/watch?v=qam0DmWq_No&pp=ygUTcHZjIHBpcGU...
At the end of the day, these things are entertainment for us to consume and they don't have to show us all the effort happening off-camera.
I say this generally for these kinds of channels, not this one specifically.
He also seems to be working with several tools he made himself.
This is not how engineers work.
The video is an hour long, but the fast scene cuts, and focusing on the actual assembly actions makes the video somehow more compelling and "can't-look-away".
this is fucking amazing. stencil a photo from a screen and trace it on to an object.
i am generally hateful towards 5 minute crafts but this is serious engineering.
I would guess he would have used some CAD tool to design this excavator? It had to have been very carefully thought out to ensure proper access to put the pieces together and take them back apart all along the way. Does he say in other videos what he uses?
What a mad man
CPVC has much better hot water performance, isn’t terribly hard to find, and glues just like PVC as long as you use the right glue.
(Very confusingly, CPVC pipe is usually sold in “copper tube size” instead of Schedule 40/80. But this means that many push-to-connect fittings work on CPVC pipe.)
Most indoor water pipes are still copper but PEX is becoming more popular. Outdoor is now nearly always MDPE.
Indoors, fancy contractors seem to prefer copper and less fancy contractors seem to prefer PEX. Those fancy copper-using contractors seem to mostly mess up and use non-water-soluble flux, which is against code and is very much a mistake on cold water pipes.
Residential fire sprinkler pipes are almost always CPVC. PEX is permitted in most jurisdictions if the pressure is regulated, but almost no one uses it despite being much less fiddly than CPVC. (Commercial fire sprinkler pipes seem to be mostly steel (!). I don’t know why. It always seems like a dubious idea to me.)
Because steel can withstand much higher temperatures than CPVC, PVC, or Pex, by at least an order of magnitude, not to mention withstand much higher water pressure too.
Domestic fire sprinklers are also, sadly, quite uncommon. They've started to become more common in flats, particularly since Grenfell, but still, I've never had cause to touch the pipework for one. Fire safety in the UK is pretty poor compared to the USA.
Copper has has been the dominant form of indoor plumbing for ages here, so every plumber knows how to work with it. It's still seen as the preferred option, and most people, myself included, consider PEX as a cheap alternative. As far as joints go, compression fit seems to maybe be more popular now than soldering for domestic plumbers due to speed of installation, but I personally prefer soldering as I've had bad luck with compression fittings developing weeps after years. Push fit has been making some inroads - but I wouldn't trust it myself!
John Guest also has some very nice “ProLock” build-your-own-manifold fittings.
For what it’s worth, there are a couple of applications for which plastic or stainless steel are the only credible choices. Carbonated water is dangerous when in contact with copper or brass, and boiler condensate (which is basically carbonated water) will rapidly destroy copper or brass. So your boiler condensate drainage system generally ought to be made entirely of plastic.
I’ve personally had some rather impressive failures of copper pipe due, I think, to aggressive water at excessive velocity. Copper’s ability to resist corrosion is finicky.
The tighter fire regulations in the US are a result of building everything from far more combustible materials. Even so, the fire death rate in the US is more than double that of the UK, 11/million vs 5/million annually.
Living in California it's probably a good thing my home is made of wood rather than bricks if there is ever an earthquake, but coming from the UK it all seems a bit flimsy!
Copper is not without its disadvantages: it's outrageous expensive as of late, soldering can be dangerous (banned in some cases due to fire risk), it takes longer to install than most other options, and some water supplies have a composition that leads to premature failures.
PEX is a universe of options: PEX-A, PEX-B, crimp rings, clamps, plastic/brass fittings, etc. It also needs to be properly installed - PEX B has very specific locations for the crimp/clamp rings on the fitting, and the difference between a proper crimp/clamp and a failure waiting to happen is very subtle.
Just my personal opinion, that's the problem with US housing. We build stuff to last 20-30 years(if properly installed) , instead of 100s of years.
Well obviously, if we don't build houses to last longer than a few decades. You're describing a symptom not a reason.
My house is typical for a house its age. I have no idea what people will want from a house in 2073, but it will be at least somewhat different from today. Some of that will be style of course, but some will be real functional differences.
My point is that it's possible to build a house with with a lasting structure that can be updated for new technologies as they arise relatively easily, but we don't do that because the home building industry is overrun with corner cutting.
If you visit old houses (pre-war) you can see that the general quality of the construction is just considerably higher than the crackerjack boxes we've been erecting since the '50s. Sure, there is an element of survivorship bias, and some of the legacy stuff is ugly to deal with (lead paint, asbestos, horsehair, and knob and tube, I'm looking at you), but overall they were built to last in a way that new construction today just isn't.
Sure the old houses looked stronger, and and often were in places where strength is not needed. However they often are lacking in critical areas.
Floods generally will not destory a house structure but it will destory the drywall, carpet, and the like so the cleanup is expensive.
No need to worry about incorrect crimps and it just works.
If you consider push-to-connect fittings acceptable, something like this could be very nice for connecting tubing to shower valves:
https://www.johnguest.com/us/en/cts-fittings/prolock/threade...
(3/8” is permitted by code, but not by the tables in the UPC - actual math is required.)
[0] PEX, unlike copper, tolerates fairly high velocity hot water. Copper has a delicate passive layer on the inside, and scrubbing it off will erode the pipe. The interior of a PEX pipe, is, drumroll please, just PEX, which is a rather tough polymer that is not going to be easily eroded away.
For domestic hot water, for the connection from whatever part of the system stays hot (the header, the recirc loop, etc) to the fixture, the amount of time and wasted water needed to get hot water to the fixture is directly proportional to the volume of the interior of the pipe, and for a fixed length of pipe, it’s inversely proportional to velocity. So you want the narrowest pipe you can get away with. 3/8” PEX has about half the interior cross-sectional area as 1/2”. This means you get hot water about twice as fast. 3/8” PEX loses about 26 psi/100 ft at 2 gpm and much less at lower flow. If you have 40 psi water and you have a short-ish pipe, that’s usually fine. Or if you have higher pressure and a longer pipe, you’re still fine.
The issue here has that, while the 3/8” PEX is near-perfect for this application, the rest of the system is not amazing. Your sink is likely (sigh) “3/8 female compression”, aka non-standard 9/16 UNEF or so, but the flow rate is well under 2 gpm, so this isn’t a big deal - use whatever adapter you like.
But your shower likely has 1/2” NPT brass female threads. To get the benefit of 3/8” PEX, you need to adapt it at the shower.
> If needed anything that required the 3/8 in, I would just use copper because it’s likely a very small and isolated case.
No, don’t do that. From the horse’s mouth (this particular horse very much wanting you to use copper):
https://copper.org/applications/plumbing/cth/design-installa...
> [Copper Pipe] Water Velocity Limitations
> To avoid excessive system noise and the possibility of erosion-corrosion, the designer should not exceed flow velocities of 8 feet per second for cold water and 5 feet per second in hot water up to approximately 140°F. In systems where water temperatures routinely exceed 140°F, lower flow velocities such as 2 to 3 feet per second should not be exceeded. In addition, where 1/2-inch and smaller tube sizes are used, to guard against localized high velocity turbulence due to possibly faulty workmanship (e.g. burrs at tube ends which were not properly reamed/deburred) or unusually numerous, abrupt changes in flow direction, lower velocities should be considered. Locally aggressive water conditions can combine with these two considerations to cause erosion-corrosion if system velocities are too high.
A 2.2 gpm shower head fed by 3/8” copper is out of spec.
I have personally seen copper tube fail when used with plain water at excessive velocity. It’s not pretty. Fortunately it was outdoors. Don’t do this inside your walls. Most vendors seem to think 8 ft/sec in PEX at 140F is fine, though.
Can you elaborate on this please?
It takes 90 seconds for hot water to flow from my water heater to my kitchen in the winter. I’m not sure if I have 1/2 or 3/8 pex (I’d have to crawl under the house to check). I’ve been thinking of adding a small Bosch water heater under the sink or a recirculation like, but maybe I should reduce the size of the pipe too
But they don't list all possible pipes, or all lengths. And the argument is that 3/8 PEX will flow to requirements and have a smaller amount of water sitting in it.
Back in the day all us kids knew to get the ABS stuff when building our potato cannons. I was terrified of the combustion chamber shattering right next to my face.
I guess the pro move is to either (1) fully characterize the amount of pressure made from a random shot of hairspray, then choose a PVC pipe to accommodate, or (2) put a larger ABS sleeve over the inner PVC combustion chamber to contain the shrapnel.
This should be repeated every year.
PVC is common in sewage, drainage, and as conduit.
Those dinky 1” pipes in your house develop quite modest tension at 100psi. 8” underground pipes are a whole different story.
But public infrastructure that wants to move is always scary conceptually
Relevant for salmonella for example. This alone would be reason for me to just use copper.
Heated water is kept in a different reservoir and the piping uses heat resistant PVC.
In Brazil, most times the water has a smell of chlorine so I guess the chances of it having deadly/lethal microbia there are next to null?
Drank water from the tap (where plumbing is done properly) for all my life, never had any problems so far.
Water heaters are pretty clever, in a low-tech sort of way. Technology Connections did a good video about them recently. [1]
0: https://livefreehc.com/blog/heat-pump-water-heater-vs-tankle...
I'm not sure what would work as a good general-purpose replacement for PVC for making things out of though. I'm not sure if ABS is available in the narrow diameters that PVC is. Pex is more bendy. Bamboo is strong, but not uniform. Wooden dowels or aluminum tube could work for some things, but it'd be more expensive.
AFAIK the health scare is mainly around the plasticisers used to make PVC (very) flexible, but rigid PVC pipe does not contain any plasticiser.
The East Palestine train wreck recently was carrying a big load of vinyl chloride among other things.
https://en.wikipedia.org/wiki/2023_Ohio_train_derailment
https://en.wikipedia.org/wiki/Vinyl_chloride
Maybe other plastics are just as bad, but it seems like not making stuff out of vinyl chloride if we can possibly help it might be a good move generally.
> "This colorless compound is an important industrial chemical chiefly used to produce the polymer, poly(vinyl chloride) (PVC)"
So rather than go down this path, the way to go is to lobby hardware stores to carry "better" (by whatever metrics your judging PVC). It's not like we, as average humans, have unlimited choices in building materials. We choose from what's available at the store. PVC is at the store now.
Generally, if there were a better solution we would be using it. If you know of one, you should share it with us.
If you don't, maybe work on finding one.
Your comment comes across a bit off-tenor.
Also keen to hear if folks on here have other ideas (before you ask: I don’t have any).
> Generally, if there were a better solution we would be using it.
If this were actually the attitude people adopted, literally nothing would improve ever.
There is a saying, "everyone is a mechanical engineer". As one, we consistently have to field this kind of question in design reviews, etc.
The question, in general, is why don't you invent a new material to solve that problem, the answer generally is we don't have the budget on this $100k project to ask DOW chemical or 3M or BASF to spend 10 years designing a new plastic for us.
So while I agree in concept, in practice it's not really a helpful question/suggestion.
The way we MEs have learned to answer this question is to say we made from the most appropriate material given the requirements and operating conditions, if anyone is aware of a material that we should also try then please speak up.
Almost never is there someone that speaks up.
The other thing is there is a huge difference between "material exists " and material is mass produced and available to the general public.
In this case, to compete with PVC pipe by making some new better resin, extruding it into pipe, then making it readily available on the general market so that it's available enough to write a guidebook on how to use it to make stuff. That's a billion dollar investment.
I think they were asking whether there’s an alternative that hobbyist could use for these types of projects.
For example, there might be a material that’s significantly greener and a bit more expensive — enough so that a large scale project couldn’t justify the economic costs (i.e. it wouldn’t be a general purpose replacement for PVC), but such that a small project hobbyist would prefer to have that melting in their garage shop instead of PVC.
I dont think there is.
Does anyone have any suggestions?
Wood Bamboo
https://www.pvcfittingsonline.com/resource-center/diy-musica...
These are fun:
Just realized that no one mentioned potato guns. I used sch 80 for those. That quickly leads to using iron pipe with a sparkplug and a propane fitting threaded in though.
Makes you wonder why the stuff gets dyed at all really.
You can do without unions altogether by just heating one end enough to flare it, then slide the other pipe into the flare while heating more to let it conform and produce a union lap joint in-situ.
Mastering heating is key to avoiding wasting money on tons of adapters which rarely even produce exactly what you want.
This has absolutely nothing to do with "pros", we're not talking about plumbing - we're talking about alternative applications for PVC. PVC hacks if you will.
The amount of time you waste trying to find fittings that match your weird ass project in the disorganized and poorly stocked shelves of the local Home Depot you probably already could have had the thing done with just some careful application of heat. You often end up with a more streamlined end result too.
It tends to not produce very nice looking results because it's mostly right angles, but that's doesn't matter as much if you're using it as a frame and keeping it hidden.
3D printing also greatly expands the possibilities of pipe.
I bought a ratcheting PVC cutter and honestly am not sure if I would have been able to complete the project without it.
One note: most instructions suggested doing a “dry fit” but I found that the pipes slid into the connectors much farther once they had PVC glue on them. Not a big deal, but everything ended up smaller than planned as a result.
I like to be able to disassemble my creations so I dry fit and then bury a self tapping stainless screw through adjoining pieces instead of using glue.
I don't see that listed but I used 3 PVC pipes and two 45-degree PVC couplings for about 5 years as a curtain rod above a bay window in my breakfast nook.
I painted them black and glued a finial on each end to disguise it. Nobody ever noticed, which is quite disappointing.
If you do want to paint it spray paint gives great results, but make sure to use plastic primer. To make it even sturdier apply a clear coat spray paint over the colored spray paint you use (so 3 layers: primer, paint, clear coat).
And more dangerous!
Can also store balls in pressurised pipe to keep them bouncy for longer.
<https://www.country-reiten.de/magazin/tipps-tricks/112-klein...>
Hope someone else remembers who that was too
The spatially adjacent classrooms never failed to detect when someone was dozing.
Edit: also mentioned by user "nomel" in this same thread https://news.ycombinator.com/item?id=37530235
An awful lot of things I see people doing with PVC pipe, and it's not very good at it, would be much better done with wood, which nature already understands how to process when you're done with it.