Air Compressor made from PVC - is this be taken Seriously - Page 1
Forum section: electronics / general

author: jonovid
author_rank: Super Contributor
timestamp: April 17, 2025, 10:00:34 am
content: I am most impressed by the effort put into the making of the video.even if the PVC air compressor has a limited useful life. as air compressors do get hot.is that CA glue? super glue.-if anyone is interested.PVC maybe how to make a one of a kind odd shaped prototype electronics enclosure that is too large for the 3D printer.if the glue used holds up over time.

author: jpanhalt
author_rank: Super Contributor
timestamp: April 17, 2025, 12:03:16 pm
content: That really is a clever video. Particularly nice was the lack of overly detailed talk.As a practical use for home and maybe small shop (regulations may need to be considered for commercial uses), PVC pipe makes excellent compressed air supply lines. Pressure rating of SCH 40 1/2" and 3/4" lines well exceed any typical supply. At outlets, you will need an NPT threaded piece (typically 3/8" or 1/2") for whatever couplers you use for your flexible lines. I prefer the one-hand push-on type.

author: coromonadalix
author_rank: Super Contributor
timestamp: April 17, 2025, 12:06:10 pm
content: dont know if its the same guy who build machinery, vehicules etc ... well done indeed

author: MadTux
author_rank: Frequent Contributor
timestamp: April 17, 2025, 12:22:57 pm
content: Stupid trash for youtube money...

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 17, 2025, 01:11:26 pm
content: Quote from: MadTux on April 17, 2025, 12:22:57 pmThis isn't trash. But yes, it's content creation and with 4.6M views, yes, that's for "YT money".It's not a job that's much worse than any other.To get an idea of how much this video probably makes (of course that's just an average) considering that the guy appears to be from Vietnam, and the category of videos, about $2.5/thousand views. So for 4.6M views, that's about $11500. Just for this video.I don't see a problem with this, this is well done, this may not have a lot of practical use, but it has "tech entertainment" value and may get many young people to consider an engineering career. Just my 2 cents.

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: April 17, 2025, 01:24:56 pm
content: For sure, the guy is really skilled in plastic/PVC model construction.

author: bdunham7
author_rank: Super Contributor
timestamp: April 17, 2025, 02:02:49 pm
content: Quote from: jpanhalt on April 17, 2025, 12:03:16 pmActually they don't. They're unsafe and specifically prohibited in commercial installations in those areas that have gotten around to it. A few decades ago PVC looked like a good option until the embrittlement and explosive rupture problems started happening.

author: jpanhalt
author_rank: Super Contributor
timestamp: April 17, 2025, 04:35:38 pm
content: Thank you for that information. Use of PVC was quite common in my area in barns and sheds as of 2015 at least. It seems the issue is shattering. OSHA does say a shatter resistant sleeve is required for PVC/CPVC but not for ABS if installed above ground:https://www.osha.gov/laws-regs/standardinterpretations/1988-11-08QuoteIn the US, ABS and PVC/CPVC compete for household water and sanitary systems. What's code and isn't code in various areas seems illogical. In my area, both are code, and ABS is readily available (i.e., available at home supply stores). Where ABS is not code (an adjacent county) you can't find it in those stores. I don't mind working with ABS. I suspect small diameter ABS will be solid and not foam core for lightness.

author: thm_w
author_rank: Super Contributor
timestamp: April 17, 2025, 11:23:37 pm
content: Even hard locates the belts without any tension adjustment, impressive.Quote from: jonovid on April 17, 2025, 10:00:34 amYeah seems so, super thin CA glue. When he did the inner fittings for the tank he reinforced the edges with baking soda.

author: temperance
author_rank: Super Contributor
timestamp: April 18, 2025, 12:26:50 am
content: He didn't show how the connecting rod was made. It seems to be some of the shelf part because you can't really make that with some simple tools.

author: amyk
author_rank: Super Contributor
timestamp: April 18, 2025, 12:33:06 am
content: Quote from: temperance on April 18, 2025, 12:26:50 am2:30Quote from: thm_w on April 17, 2025, 11:23:37 pmIt's a toothed belt, not something that needs much adjustment in my experience (especially for the short period of time that this model has to work).Quote from: thm_w on April 17, 2025, 11:23:37 pmPVC cement (solvent) would've been a much better (stronger) choice, but once again I doubt the product needed to last much beyond the video.

author: fzabkar
author_rank: Super Contributor
timestamp: April 18, 2025, 12:59:08 am
content: OceanGate might be interested ...

author: wraper
author_rank: Unknown
timestamp: April 18, 2025, 01:09:03 am
content: Pressure vessel held by a super glue. What could possibly go wrong? Don't look on that pressure gauge, its trajectory may end into your eye. BTW cylinder cooling ribs made of PVC must work really well.

author: Stray Electron
author_rank: Super Contributor
timestamp: April 18, 2025, 01:54:04 am
content: Quote from: jpanhalt on April 17, 2025, 04:35:38 pmNo, it's not illogical. Compressed air can expand so a plastic compressed air line can break and will shatter and it will explode and send shrapnel in all directions. Water however doesn't expand or contract significantly with pressure so a rapture in a pressurized water line will simply vent a minute amount of water and thatinstantlyrelieves the pressure so the line won't explode or shatter.Also the standard pressure in most compressed air systems is 125 PSIG and household water systems only run about 40 PSIG.

author: bill_c
author_rank: Regular Contributor
timestamp: April 18, 2025, 03:34:04 am
content: Please do not use PVC for compressed air or vacuum, I have seen it fail in both situations and I am glad I was not very close to it when it went boom. PVC shards traveling about 10m and causing deep dents (nearly pierced) in the side of a steel building. Use steel, stainless, galvanized pipe,or in some cases even special aluminum pipe. I have used PEX and it may fail when the temperature-pressure curve is exceeded, but it usually just splits open without sending deadly plastic spikes in all directions.But that is a neat example of what can be done with basic materials and good crafting ability.

author: Analog Kid
author_rank: Super Contributor
timestamp: April 18, 2025, 04:17:03 am
content: Quote from: bill_c on April 18, 2025, 03:34:04 amPretty sure the stuff he used is ABS, not PVC. Is ABS less likely to shatter like that?QuoteIndeed it is. Very impressive.Funny thing is, I have a little Harbor Freight tire inflator pump that's very close to what this guy built (except no tank), and it sounds exactly like his!I bought it to inflate my car's tires, even though the package said "Do not use to inflate automobile tires".Welll, the one I had before this one, that I bought for $5 at a garage sale, was identical, and I used it for about 5 years for just that purpose before it crapped out. Sure, it take a while: about 15 minutes to completely inflate a flat tire, but it does work, and pretty reliably as well. Gets a bit hot.

author: jpanhalt
author_rank: Super Contributor
timestamp: April 18, 2025, 04:54:08 am
content: Quote from: Stray Electron on April 18, 2025, 01:54:04 amPlease explain the logic of starkly different codes for ABS vs. PVC for domestic water and sanitary systems in adjacent counties.

author: pcprogrammer
author_rank: Super Contributor
timestamp: April 18, 2025, 07:06:03 am
content: I assume this guy is making a bit of money of of his HOBBY, and as a hobby it is nice. I love the excavator he build.And when SiliconWizard is right not a bad deal, but is it enough to make a living out of it, taking into account the time and materials it takes to make such a model.

author: nctnico
author_rank: Super Contributor
timestamp: April 18, 2025, 09:19:04 am
content: And that excavator actually works...Crazy amount of details.Regarding PVC and pressure: last time I looked for compressed air piping, I found plastic piping as well. And for water you can also buy high pressure PVC piping. So PVC should be OK for as long as it doesn't get compromised by exposure to heat and chemicals. But the compressor the Youtuber madegoes up to 0.5 bar or so. Edit: 3 bar indeed as wraper noted below.

author: wraper
author_rank: Unknown
timestamp: April 18, 2025, 09:59:40 am
content: Quote from: nctnico on April 18, 2025, 09:19:04 amThere was almost 3bar on the pressure gauge. Watch at 13:05.QuoteThose pipes are not rated for any pressure. Not to say danger of gas pressure is way more higher, especially when any significant diameter/volume is involved. Water will just leak if the vessel cracks. With air very likely it will explode.

author: elektryk
author_rank: Regular Contributor
timestamp: April 18, 2025, 10:25:42 am
content: QuoteThat's why pressure vessels are tested with water (usually at 150% of rated pressure).

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 18, 2025, 12:30:21 pm
content: There is PVC that is rated for compressed air use. The stuff I am aware of has something other than PVC incorporated to deal with the fracture mode. But I don't trust it.There is lots of info on what happens when PVC pipe fails on compressed air applications. Read and watch them before deciding to use PVC in your home shop. Changed my mind completely and caused me to do a much more difficult and expensive installation.

author: coppercone2
author_rank: Super Contributor
timestamp: April 18, 2025, 01:21:49 pm
content: Lol if you ever work with a old CPVC pipe you will just say no to this. There was was a stuck old valve. I gently with one hand tried to turn it before I gave up. Gently. A year later that pipe blew up and flooded the crapper. I saw other PVC pipes (the ones that are supposed to be good) explode too in workplace for reasons unknown.The mini air compressor inside of blood pressure monitors is also plastic, but its much smaller.

author: IanB
author_rank: Super Contributor
timestamp: April 18, 2025, 04:36:37 pm
content: The item in this video is a model, which serves to explain how a compressor works. It is not an actually useful compressor, and most likely cannot be run for more than a few seconds at a time without risk of melting.The cylinder of a compressor gets hot, really really hot, and at minimum needs cooling fins to carry the heat away. The cylinder and cooling fins need to be made of a thermally conductive material like aluminum. In this model, the "cooling fins" are made of plastic, and are purely decorative in function.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 18, 2025, 05:11:49 pm
content: Quote from: IanB on April 18, 2025, 04:36:37 pmIn the video he runs it for more than a few seconds. And demonstrates inflating a moped tire with the compressor. But he only demonstrates about 40 psi max pressure. I suspect it will go for quite a while before heating exceeds PVC limits. My biggest concern is the pressure tank. Very rough calculations show that there are about 400 lbf (about 1600 Newtons) pushing the end plugs out. And the stored energy in that volume of air could be very exciting if released suddenly.One of the things that most interests me is his assembly methods. He appear to put the parts in place and then wick CA in. How does he get the parts to stay in place prior to the wicking. See for example where he puts the legs on the tank.

author: coppercone2
author_rank: Super Contributor
timestamp: April 18, 2025, 05:24:34 pm
content: use water in video then carefully glue it together in a fixture off camera?

author: IanB
author_rank: Super Contributor
timestamp: April 18, 2025, 06:05:22 pm
content: Quote from: CatalinaWOW on April 18, 2025, 05:11:49 pmI guess I didn't watch it right to the end.However, room temperature air will reach about 150°C if compressed to 40 psi. I think that is hot enough to exceed the thermal tolerance of PVC. It will probably soften and may release nasty smells. I dare say you could run the compressor for a short while before the PVC itself reached that temperature, but it's not a long term proposition, in my opinion.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 18, 2025, 10:00:23 pm
content: Quote from: IanB on April 18, 2025, 06:05:22 pmTotally agree that it can't run steady state at 40 psi. But think you might be surprised how long it might run. There are several mitigating factors. Peak temperature only occurs at peak compression and much of that hot air immediately escapes to the tank where there is both a much larger thermal sink and better heat paths ( not good, just better) to the environment. In each cycle a fresh charge of cool air is brought into the cylinder doing some cooling. 40 psi is a generous reading of the pressure gauge, it could easily be a few pounds less. And because he incorporates a pressure switch in the design it will be difficult to achieve an operating condition that involves continuous operation at max pressure. Most output flows will result in either a duty cycle or a pressure drop.None of that constitutes a recommendation to build and use this as a daily driver. It is like one of those bibles engraved on the head of a pin. A masterwork of building that fundamentally has no real use.

author: Analog Kid
author_rank: Super Contributor
timestamp: April 18, 2025, 10:21:18 pm
content: Quote from: CatalinaWOW on April 18, 2025, 05:11:49 pmPretty sure it's not cyanoacrylate (CA) but solvent cement, which actually melts the two pieces of ABS together.Very strong bond.Dunno how he gets things to stay together before adhering. Magic, I guess, or really good fits.

author: wraper
author_rank: Unknown
timestamp: April 19, 2025, 12:56:24 am
content: Quote from: Analog Kid on April 18, 2025, 10:21:18 pmNobody adds baking soda to that.

author: Analog Kid
author_rank: Super Contributor
timestamp: April 19, 2025, 03:38:52 am
content: Quote from: wraper on April 19, 2025, 12:56:24 amYep, you're right.Maybe he used both solvent cement and CA in different places.

author: Stray Electron
author_rank: Super Contributor
timestamp: April 19, 2025, 01:29:18 pm
content: Quote from: jpanhalt on April 18, 2025, 04:54:08 amI'm sure that you can look that up in any decent supply catalog. Or better yet, just use what your building code requires and that will keep you out of legal trouble. My explanation was about why you shouldn't use any plastic pipe that designed for low pressure water use for high pressure air lines.Not directed at you but just for general conversation, when I was in my early teens and first started playing with air compressors and such we didn't have access so any decent industrial supplies so we used the plastic tubing from cheap kid's jump ropes as air line. The id is small in comparison to the wall thickness and we found that it would hold up to about 90 PSIG. The tubing from a jump rope was about 11 foot long and at the time a jump rope only cost about 15 cents U.S.

author: tooki
author_rank: Super Contributor
timestamp: April 19, 2025, 05:26:32 pm
content: Quote from: Analog Kid on April 18, 2025, 04:17:03 amI don’t think it is ABS. That looks like (in both appearance and behavior) exactly like the hard PVC we use at work (in the machine shop, for making things). PVC is easily solvent-welded, too. Not sure whether this guy actually did that or if it’s just CA glue.Not to mention the video expressly stating that it’s PVC.

author: nctnico
author_rank: Super Contributor
timestamp: April 19, 2025, 08:09:49 pm
content: Quote from: CatalinaWOW on April 18, 2025, 10:00:23 pmI agree with the above but want to add that (IMHO) the amount and effect of hot air is not to be underestimated. I have a low cost compressor (2.5kW power rating) and you can feel a warm spot on the tank opposite of the side where the air get blown into the tank (20 liter) after it ran for a couple of minutes. All in all I don't think you can model the air in the tank as being mixed quickly. Unfortunately I have to been able to find some kind of cooler (finned pipe) that is easy to retrofit.

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 20, 2025, 01:54:39 pm
content: It 100% looks like PVC.PVC is widely used for plumbing and can widthstand relatively high liquid pressure. Less sure about gas in terms of porosity, but again I don't think the guy showed something that is meant to be ultra reliable or durable.

author: Refrigerator
author_rank: Super Contributor
timestamp: April 25, 2025, 08:37:09 pm
content: I don't get people who look at someone's hobby creation and try argue how it's not practical for real world use, as if it's ever meant to be.The guy did it because he can and that's it. It's pretty much the same reason kids make sand castles and i don't see you guys arguing how they're not going to hold up to the weather and are way too small for anyone to live in.I see this as a simple display of skill and an impressive one at that.

author: Analog Kid
author_rank: Super Contributor
timestamp: April 25, 2025, 08:43:04 pm
content: Quote from: SiliconWizard on April 20, 2025, 01:54:39 pmOK. I thought®™ that PVC was white and ABS was gray. (Used to work in a hardware store, and those were the colors of pipe we sold.)

author: coppercone2
author_rank: Super Contributor
timestamp: April 26, 2025, 03:26:58 am
content: Just beware of the scammers that substitute parts and stuff like that during construction to make it look better then it is, or those things like the vietnam 'mud palace houses' that are built with heavy machinery but they make you think its possible to make it in the woods with your hands, and fake repair videos (where they throw mud on a stereo to try to convince you it was found in a swamp sumerged for 20 years)..they could lead you to waste exorbitant amounts of time if you try to mimic it and its been faked or make you believe in impossible processesbut at least its not a fake refrigerator video (now they make quite nice copper 'things' where they pump butane into it off camera to make people think its possible to build a refrigerator out of a computer fan and a aquarium pump.. the construction looks nice but its a total sham, I guess a derivative of free energy machines. But instead of free energy its 0 parts cost machines. I am waiting for the video where they show tool steel being hogged by a mill powered by a battery fan motor and some impressive wooden gears lolI can see how a PVC compressor might make someone feel like its the refrigerator scam all over again (this one is low quality, I have seen the similar things with 'convicing' worksmanship.

author: tooki
author_rank: Super Contributor
timestamp: April 26, 2025, 12:58:53 pm
content: Quote from: Analog Kid on April 25, 2025, 08:43:04 pmRaw PVC is transparent, while raw ABS is translucent-to-opaque off-white.So in both cases, you were just seeing the colors that the plastic had been colored to. (There’s probably some industry standard in the plumbing world for plastic pipe colors.)

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 26, 2025, 01:06:14 pm
content: For PVC pipes, I've only ever seen this gray shade.People who haven't must have never been in a hardware store, or they avoided the plumbing hardware area carefully.

author: pcprogrammer
author_rank: Super Contributor
timestamp: April 26, 2025, 03:11:04 pm
content: Quote from: SiliconWizard on April 26, 2025, 01:06:14 pmThere are white pipes that are mostly used for bathroom or kitchen sinks.https://www.google.com/search?client=firefox-b-lm&channel=entpr&q=40mm+white+pvc+bathroom+sink+drain

author: nctnico
author_rank: Super Contributor
timestamp: April 26, 2025, 03:32:39 pm
content: Quote from: pcprogrammer on April 26, 2025, 03:11:04 pmYou can buy PVC piping in different colors depending on the purpose. Green, white, brown are typical colors besides grey. White pipes for bathroom / kitchen sinks can also be made from PPE which you can't glue together.

author: IanB
author_rank: Super Contributor
timestamp: April 26, 2025, 05:06:34 pm
content: A common grey colour for PVC:

author: ejeffrey
author_rank: Super Contributor
timestamp: April 26, 2025, 08:10:43 pm
content: Quote from: SiliconWizard on April 26, 2025, 01:06:14 pmIn the US, most of the PVC for domestic water use (schedule 40) is white/beige not grey. Schedule 80 is usually grey, but that's normally used in industrial/commercial environments. PVC electrical conduit is also usually grey, but again less common in residential settings. ABS used for drain / sewage piping is often black. I'm not sure if this is an official standard or if it's just a convention, None of these are the natural color, it's all pigment, so it's not surprising that different regions have different standards. But for most people in the US what they see as PVC pipe is whitish.

author: Analog Kid
author_rank: Super Contributor
timestamp: April 26, 2025, 08:25:15 pm
content: Quote from: ejeffrey on April 26, 2025, 08:10:43 pmOK, so at least I know I'm not (that) crazy.And I remember now that all the white PVC we sold was schedule 40.I'm puzzled by that pic posted by @IanB above: how could a piece of plumbing be rated "for outdoor use only"? I thought outdoor applications were always more demanding than indoor, like the use of UF (underground feeder) cables which can be directly buried as opposed to indoor NM cables (and couldn't you use UF indoor legally in place of NM?).

author: IanB
author_rank: Super Contributor
timestamp: April 26, 2025, 10:14:06 pm
content: Quote from: Analog Kid on April 26, 2025, 08:25:15 pmThis mainly means it is not approved for potable water supplies. It (potentially) might leach harmful contaminants into water passing through it that would render it unsafe to drink. In reality, who knows, but it does not satisfy the regulations for that use.In addition, the white shade of PVC used for drinking water is not UV safe, and if used outdoors must be buried or painted to protect it from sunlight.

author: Analog Kid
author_rank: Super Contributor
timestamp: April 26, 2025, 10:27:21 pm
content: Quote from: IanB on April 26, 2025, 10:14:06 pmHeh; that brings to mind an interesting conundrum:What if a guy built an outbuilding next to his house and plumbed it with PVC? The pipes between house and building would have to be certified for outdoor use, but also for potable water.Meh. I'd go with copper. (If I could afford it!)

author: IanB
author_rank: Super Contributor
timestamp: April 26, 2025, 11:09:59 pm
content: Quote from: Analog Kid on April 26, 2025, 10:27:21 pmYeah, that fitting is for irrigation systems. But there isn't room on the label to write "For outdoor irrigation use only".

author: nctnico
author_rank: Super Contributor
timestamp: April 27, 2025, 12:24:07 am
content: Quote from: Analog Kid on April 26, 2025, 10:27:21 pmCopper isn't healthy either. Nowadays plastic tubing seems to be the norm over here although I have not used plastic tubing for drinking water myself -yet-. The suitability for indoor / outdoor use is probably printed on the piping or the package. Still, I would put pipes sitting outdoors in protective sleeving. UV from the sun destroys everything.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 27, 2025, 03:56:11 am
content: All of these warnings need to be evaluated for applicability to you.Just as an example - White PVC is not UV resistant. True. And when I lived in southern Arizona which has relatively high UV exposure I discovered that used in an irrigation it could fail in around five years. But similar pipe used in the swimming pool plumbing was still going strong after 20+ years. Someone living in high altitude Colorado might see even faster degradation. In my current southern Oregon location I have seen only minor evidence of UV degradation after more than a decade. I still usually paint my pipes, but here freezing is a threat, and if I am late on winterizing the system cleaning the paint off is a significant additional step in the repair. There is a tradeoff and I am still not sure which approach is better.Similar logic applies to the leaching situation. The regulations are based on worst case situations with error margin. If you have the wrong water chemistry, in a hot region, regularly let the water sit in pipes for weeks and then drink the first thing that comes out of the taps and are in the most sensitive tail of the population distribution to the leachates you will be at some noticeable risk. If you don't check all of those boxes your risk will be much lower.