8" Tube Sources

Hey all,

I am new to the forum, so hello to everyone.

I have made a nozzle using 4" PVC, and just standard materials available to Home Depot, Lowes, ect. However, I would like to take it the next level, and step up to the 8" nozzle and make it awesome, like many of yours are!

I have been looking online for some 8" PVC, but I see that some of you have found a clear (acrylic?) 8" tube! I would love to know where you get this, as well as an approximate price. I think this wold be very helpful to the community as we can all have a basis of reference, and let others know when we find parts for a price less than the "average".

Thanks in advance!

Well, I guess I will answer my own question for anyone who is interested.

I was able to get some 8" pipe from McMaster-Carr (www.mcmaster.com). They are a great source for not only the pipe, but a lot of other parts too! They carry sheets of PVC for end caps. They also carry solenoids for your cutter.

Hope this helps!

Sorry for no answering your post, but check out your local sprinkler supply place. Sometimes they have large sections of pipe too. Also a great place for cheap solenoids are Electronics Goldmine, and Alltronics.com (http://www.alltronics.com/) for stepper motors!

hi to all, i use a smooth post sleeve of 8" diameter x 72" works perfects for $ 50.00 you can buy it for many supplies store on the net

Hi there Guitarman, I hope you are still making your laminar flow as i am keen for a few answers. The solenoid for the cutter, was it successful? was it easy or as complicated as some others are on here. Anything electrical or electronic and I am lost. Was the 8" the diameter" and how long did you make the pipe.

Hi all,

Want to start a project but looking for cheap alternatives for 4" and 6" PVC pipe. Sewer pipe in these dimmensions is cheap and easy to find but of course it is not meannt for pressure applications. Has anybody actually measured the pressure inside a typical set-up? I'm assumming that if you have a 4" pipe with a 1/2" nozzle (which obviously is always full open), there is actually not much pressure inside. (I once pressure tested a 2 liter plastic coke bottle (different project, long story) and the damn thing easily held 100 psi). Obviously, it is not easy to find any published pressure ratings for pipe that is not meant to hold pressure, but has annyone ever pressure tested it? Thanks

Hello!

@Kiwi girl : The 8" diameter pipe was great! I made mine about 24" long, which is much longer than you need. I would think 16"-18" would be sufficient, maybe less. As or the solenoid, it is not too complicated to get the cutter working. The most difficult part is designing it so that the solenoid does not get wet. For this reason, I am looking into other way to cut my stream.

@bbrio1 : I have never pressure tested my set up. Actually, on my second nozzle this spring, I plan to do exactly that. I would like to see the pressures in the lines before and after my "low pass filter", as well as in the nozzle. The pressures would greatly depend on the output and ratings of your pump. What material are you looking to use instead of PVC?

Hi G-man, many thanks for your interest. Actually, here in Brazil its dead easy to find "sewer" pipe in 6" and 8", but just like in other places, it is not designed for pressure appliications, that's why I'm asking. It would seem to me that I could possibly get away with it. I'm not worried about it bursting since pressurized water doesn't carry a lot of energy, a compressed gas would be a completely different story. But a ruptured sewer pipe full of water would just let a bunch of water out, no explosive release of energy. On the other hand, even with very low pressures, the pressure acting on the end caps will be trying to blow them off with quite a bit of force eg. 10 psi x area of 8" ID pipe (50 in2 area) = 500 pounds pushing on the end cap.

If I can manage to find normal PVC pipe for pressure applications I will go ahead and buy it, just worried I might have to shell out for a 3 meter section, increasing costs considerably.

As for low-pass filter, I'm toying with the idea of using an old propane bottle, the short stubby kind (about 10 gallons?) I'm sure I could find some guy to weld a couple of fittings on it. Or maybe an old fire extinguisher - easy to find ones that are too old to be certified. Same with the old Freon tanks for re-charging A/C's etc. (I think this could turn into kind of a MadMax sort of affair)

If I do any of that, I'm definitely goiing to include a little 1/4" fitting so I can actually geet an idea of what sort of pressure we're dealing with. With an open 1/2" nozzle on the vessel, I can't imagine anything near high pressure, I'm thinking maybe 20 psi max.

Ah, I understand now. Yes, there is a good amount of pressure pressing on the end caps! I agree with you about the PCV pipe, shouldn't be an issue.

For your filter, any of your ideas would be very cool! In mine, I am just using acrylic tube. I would really like to know the prssure of both the water and of the air in the filter. You seem to know a good amount about pressue, I have a question for you. If I want to measure the water pressure at the output of my pump, and output of my filter, does how I mount the pressure sensor make a difference? The easiest would be to just cut a hole in the PVC pipe and mount the pressure gauge, would this work?

I agree, I don't think the pressures are very high. I will try and help you look into this more!

You can mount a pressure gauge anywhere, all you need is the correcct fitting to tap into whereever you want to measure. Now, I know nothing about laminar fountains but I do know about pressure. The pressure you measure at the outlet of your pump will be the highest pressure in the system. As water (or any fluid flows through pipes to somewhere else (for example, the low-pass filter), you will lose some pressure in the pipe, so the pressure insiide the low-pass filter will be less than the pressure at pump outlet. If you have a big pipe between pump and filter the pressure loss will be small (for my project I think I will use 2" piping, to keep pressure losses small).

From the filter to the nozzle there will be more pressure loss, some of it due to the pipe connecting the two, some of it in the famous sponges and drinking straws. Basically, if velocities are high anywhere, pressure losses will be greater than for lower velocities.

Finally, there will be a pressure loss at the nozzle. The pressure outside will be basically atmospheric. On the inner side of the nozzle, you will see whatever pressure remains from the pump after passing through all the associated tubing, and the higher that pressure is, the further you can shoot water out of the nozzle. If you put a bigger diameter nozzle, the pressure will go down, because the flow rate increases.

If you want to measure the pressure at any given stage of your system, don't worry too much about the physical location of the pressure gauge (i.e, on the low pass filter, you could mount the gauge on the top or the bottom, the pressure will be virtually the same, only difference would be due to hydrostatic. In water, hydrostatic pressure is 0.433 psi/foot. So a pressure gauge mounted at the bottom would read 0.433 psi higher than one mounted 1 foot higher in the same vessel).

Hope this helps

I think I will weld some fittings on one of these for a low pass filter. 5 bucks in the scrap dealer, looks in good shape.

https://i.servimg.com/u/f10/18/10/37/44/r22_cy11.jpg

Its an old gas cylinder for Freon (R22) gas.

http://yadi.sk/d/wI7_F7T42vw7Q
http://yadi.sk/d/kmOVFhI82vwJA

Very nice mumis. I see it also comes with a hergebuikgarantie whatever that is.

I'm thinking about looking around for irrigation pipe. Its cheaper than regular pressure PVC pipe and available in 8" sizes. Worried about having to buy 6 meters of it though.

After more research, I'm pretty sure I'm going to go with sewer pipe. Some calculations show it to be good for about 40 psi. I'm basing that number on some calculations based on SDR (ratio of O.D. to wall thickness) which for my sewer pipe is about 42. It's probably even better than 40 psi, maybe someday I will test a piece with water until it bursts (but not today).

Another possible material source would be PVC electrical conduit. This stuff comes in big sizes (but you won't find the big stuff down at Home Depot). It seems to be very sturdy having big wall thicknesses.

For feedthroughs for fibre optics, acrylic rods, etc. I think electrical conduit adaptors (PVC) are the way to go.