What is the burst pressure of 1/2" black poly tubing rated for 100psi. I want to bury it as an air line between my house and work building so it will have up to 125 psi in it. I have a lot of it for free that is why I want to use it.
that is polybutylene
Are you sure it's not polyethylene? Polybutylene is usually grey, PEX whitish or brightly colored.
Schedule-40 PVC is adequate for shop air, so long as the pipes are either buried, or far enough away from human contact so that bursting wouldn't endanger anyone.
LLoyd
On Mon, 03 Oct 2005 12:54:35 GMT, with neither quill nor qualm, "habbi" quickly quoth:
100psi. Bury it housed in PVC pipe so you can replace it easily when it bursts on you.A couple of thoughts, but not an answer to your question.
One is that plastic strength depends a lot on temperature. The part that is buried is less likely to burst that the bits that are exposed. So you might want to use stronger pipe where it would be exposed.
Also I think that plastic pipe tends to age and become more brittle with age. I am not sure that being pressurized accelerates the aging, but it might. So if you don't need an air line between your house and shop all the time, I would put in a ball valve so the pipe is pressurized only when needed.
If you have a lot of it, you might bury two runs so if one bursts, you already have another run buried. And if that happens, consider adding a regulator to keep the pressure lower the second time. Also think about what else you might want to run at the same time. Telephone line?
Dan
I used that stuff for some outdoor water faucets in the garden. All of it eventually failed (split) at the barb connections. I only run 40 psi water pressure.
Actually it depends on which stuff he has. The newer poly pipes are very good especially if he's got gas service rated. It's about all the gas companies are putting in the ground now days.
Wayne Cook Shamrock, TX
Habbi, a better choice would be to use inexpensive copper water pipe,
Then too, that's just my opinion.
Harry C.
How far is the house from the shop? Might want something larger than
1/2".dennis in nca
Sorry, but Sched. 40 PVC IS NOT NOW OR HAS EVER BEEN RATED FOR GASEOUS USAGE... Read the friggin spec before you spout off that it is acceptable for usage in air service. PVC an CPVC are rated for INCOMPRESSIBLE FLUID SERVICE ONLY. The pressure value thatis printed on the side fo the pipe that you are lookig at is ONLY FOR WATER. Take the time to use the pressure burst calculations for gaseous usage and plug in the allowable stress for PVC and it will tell you differently. If you run the calculations you will find that 1/2" PVC can SAFELY carry something around 4...YES FOUR PSI.
There are plastic pipe materials that are rated for gaseous usage, but PVC and CPVC are not and anyone that uses them for air service has basically installed a hair triggered bomb in their shop. When it goes, and it's not a question of will it go, but when it goes, it will do so violently and with all sorts of shrapnel that can do significant damage.
Do yourself a favor and Google the subject before you decide to plant a bomb in your shop. If you go ahead and use PVC, tell us where your shop is so that we can aviod coming anywhere close to it.
Craig C.
That would be HDPE, high density polyethylene, also used for the jacket on direct bury primary cable.
I just finished replacing the gray plastic supply tubes on the main bathroom sink after about 20 years. I originally installed them because of their flexibility (~2" radius) allowed for the builder's latitude in cabinetry. The cold line developed three lateral cracks, and being in a concealed location, the leak wasn't noticed for a couple days, so I have quite a mess downstairs, hopefully the carpet will dry. My point being, I don't trust bent plastic any longer. Gerry :-)} London, Canada
On 3 Oct 2005 17:43:17 -0700, with neither quill nor qualm, snipped-for-privacy@tigerbyte.net quickly quoth:
I's tremblin', I is.
Methinks you've taken this a wee bit OVERBOARD, C. Man, I'll bet you even ground your PVC dust collector lines, don't you?
Wuss! I worked around it for several years with no mishaps. Flynn's new body shop was built with 1.5" PVC pipe for air and had 25cfm going through it for most of the day. A few times, guys caught their hose on the cars they were backing out. The end of the pipe broke off with the air hose attached. Nobody ever got hit by any shrapnel nor were pieces found at the end of the day when they swept up. It was DAMNED noisy, though.
That said, I wouldn't plumb the shop with PVC now that I've seen the OSHA letters where the Plastic Pipe Industry recommends against it, but everyone should remember to wear goggles ALWAYS when using the air hose, but that's mainly from blown debris. (It's awfully hard to do good woodworking with only one eye.)
Read this and relax a bit, eh?
P.S: Do I translate "cvairwerks" to "Corvair Works" properly? I had a couple '62 convertibles and adored the little beasties. I took one on flying jumps with my dirt-bike-riding friends.
lots snipped here and there....
Don't have a dust collector system and if I did it wouldn't be in PVC anyway. I get a little freaky over this subjuct because since the last big discussion on this I had to take a fellow employee to the hospital for over 50 stiches to his face when a 1" PVC air line with less than
30 psig on it exploded in his face. The shop owner was like you and poo pooed the safety problem with air and PVC. By the time we got back from the hospital, the entire PVC air system had been torn out of the shop and a temp system with tons of hoses and pigs had been set up. I left the company before the OSHA fine came down, but I know it wsa pretty hefty.I get a little anal about certain safety controlled items. Where I work, even a minute mistake with the work procedures can at minimum cause huge hazmat cleanup bills all the way to killing numerous people. I've still got all my body parts and they all work and there are very few extral holes in me that shouldn't be there and I intend on keeping it that way for another few decades.
Don't have anyting to do with Corvairs...neat cars, but I play airplanes for a hobby and a living. The cv comes from my first name and my wife's.
Craig C.
Screen name has nothing to do with
On 4 Oct 2005 11:37:19 -0700, with neither quill nor qualm, snipped-for-privacy@tigerbyte.net quickly quoth:
(Sorry, I thought this message was over on the Wreck.) mea culpa
So it was -5° in the building and he smacked it with a big WHAT?
Condolences to your friend. That couldn't have been any fun. You're the first person I've ever talked to who has experienced anything negative with pvc air lines. But like I said, I wouldn't do it again. We all survived numerous breaks with no flak whatsoever, and that was at 125psig.
Yeah, I don't blame you, especially at a lethal workplace like that.
Gotcha. Ever fly a Corsair? They look like a lot of fun. After I finished the Basic Aviation course in high school, Dad (retired USAF pilot) let me take off in the rented Cherokee C, fly it from Oceanside, CA to Catalina Island and back, then line it up for landing. He took the controls then but I (at the ripe old age of 17) was sure I could have landed her safely.
-------------------------------------------------------- Murphy was an Optimist ----------------------------
The black poly pipe used for gas service is polyethylene, and it usually handles less than 100 PSI. Polybutylene is crap, and it cost the original manufacturers $hundreds of millions to settle lawsuits as it failed in water service lines all over the country. It is initially very strong and flexible, but with age it loses strength and develops stress cracks. Go ahead and use PB if you like the idea of digging trenches and re plumbing everything in a couple of years.
As others have mentioned, using rigid plastic pipes for air service is a really, really dumb idea born from desperation or ignorance. Spend a couple of bucks more and use metal tubing.
Actually it must be polyethylene, it is black with a blue strip and rated for 100psi, I have seen gold stripe which is rated for 160psi I think. It comes in rolls and is quite flexible. Anyway I also saw this on one of the websites for other uses and I read somewhere else that the burst strength is usually 3 times the working pressure. "Transportation of Natural/Coal/Gobar gas " I will try it and if it goes bang so what.
Only High Density Poly is good for natural gas. All of the HDPE I've seen used in New York is yellow. High pressure services here are around 60 psi, AFAIK from conversations with the gas utility. It is fairly thick walled and not quite as flexible as the type you are talking about, which sounds like the stuff we use to install sprinkler systems.
The black stuff is also available in higher pressure ratings and is often used in drilled wells with submersible pumps. I think the pump in our well hangs down about 250 feet on 1" 200 PSI black PE, which means it's been subject to about 150 PSI continuously for almost 20 yrs. Smaller polyethylene tubing, up to about 1/2" OD, is common in industrial pneumatic controls.
I wouldn't hesitate to use the higher rated polyethylene for a buried air line. I'd keep the transition to the indoor piping in a protected, but accessible, location.
Ned Simmons
On Wed, 05 Oct 2005 23:47:37 GMT, with neither quill nor qualm, "habbi" quickly quoth:
Call your local irrigation supply store and ask them to look it up. Most stock tens of thousands of feet of it and know all about it.
BUT, since it's chewable by gophers, I'd put in galvanized line (or wrapped black iron piping) and forget about it...unless you _like_ trenching every year or two. If you want to use that hose, hang it, don't bury it. Or perhaps bury it encloded in PVC pipe to keep the gophers away?
-------------------------------------------------------- Murphy was an Optimist ----------------------------
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.