Needs to be atleast a 10-12 foot length. Would prefer steel, but can be made of something else as long as it is strong. The pipe will be for a couple of 24'" fireworks shells being constructed. Just as a reference, most shells available to the public are 1-2" and the average fireworks show might have shells up to 6-8". My buddy is a member of the pyrotechnics organization meeting in October. The pipe will be buried on end about 8 feet in the ground, then the shell loaded inside. This is all 100% legal too in case you are wondering. Most mortars built specifically for fireworks are made of a very thick and strong PVC it feels like. But anything over 16" is hard to come by from those suppliers. Anybody have a recommendation on where to get one or what it should be made of?
This is something I know absolutely nothing about, which of course compels me to add my 2 cents... Wouldn't the force in an increasingly larger shell grow, not in a linear fashion, but geometrically? Wouldn't that take a proportionally stronger piece of material to contain? Just asking, cause if your buddy is used to working with 6-8" shells, 24" would be a whole different animal, wouldn't it? Or am I barking up the wrong tree?
He makes much bigger than 6-8". I used those as an example of what you might see at your local town or fairgrounds 4th of July Fireworks show. He usually makes shells 10-12" for recreational shooting but has made as big as a 16". He wont be making this shell alone. It can take several days to construct a shell like this. Not sure what you mean about growing in a geometrical fashion. He has mentioned that if it is steel, we will have to weld a piece of steel on the end in the ground. Usually the bigger mortars are buried in concrete since a lot of force is directed under the shell. The shell won't be a perfect 24 inches. You want it to be able to easily drop down in the mortar. The mortar ofcourse is just there to guide it on the initial lift charge. The shell itself doesn't blow for about 500 feet.
Id try to find a piece of 24" DICL pipe (water Pipe)
I wanna Watch!!!!!!!!!!!!:cool2:drinkup
Digger might have meant exponential growth. I don't think that would be the case though. Pressurre would be determined by LaPlace's law for a cylinder: Wall tension= pressure X radius So doubling the radius would double the wall tension even if the pressure stayed the same. If one of the values was squared or cubed then exponential growth would occur. I don't know anything about these fireworks or what that wall tension of various pipes are. I would guess that a bigger shell would make more pressure and if you need a bigger pipe to launch it that will also affect how much tension is placed on the pipe's wall. Doubling both values or whatever it would be would take a serious piece of pipe. And would be similar to exponential grown. 2x2=4 baseline for example 2x4=8 doubling one value either the pressure or radius and leaving the other the same 4x4=16 doubling both
All I can say is you better video it when it goes off!!!
And stand Back, Way Back
well, since you mentioned it, I can give you some names of contractors specializing in laying large gas lines. they would have .375 & .500 wall steel pipe in various diameters... And I wanna see the video too.
Thank you. That's the term I was thinking of. I wasn't thinking in terms of radius and wall tension though. I was thinking in terms of a 24" charge being substantially more powerful than an 8" charge. Remember that the area of a circle is Pi times the square of the radius. So, a 24" round object has an area of 452.16 square inches, while an 8" round object only has an area of 50.24". That's about a nine times difference. Much bigger boom to contain, meaning much stronger pipe. Personally, I think it would be more apropriate to figure out what thickness and type of material would provided the needed strength, and then go looking for that, rather than starting by looking for something that comes in a 24" diameter. Just my opinion.
Piledriving companies might have some 24" cutoffs they would sell cheap.
blow dat up real good.lol
Your from Raleigh, There's plenty of jobsites around here. Just ride around and offer someone some cash, I'm sure you'll get something. Can you use something like some 24" corrigated metal pipe or do you need something like ductile iron? I know a fellow that has acres and acres of pipe laying all in the woods that's for sale off of old millbernie Road between Hwy 64 and I-540. Send me a pm if you want some more info. Oh By the way, When you set that off, call me so some friends and I can come watch! Might even be able to see them from my house:drinkup
If anybody is bored. Here are some shells my buddy has made. The videos unfortunately do them ZERO justice as the size and sound of these things just can't be felt. It is an awesome sight though. Turn your speakers up. Here is a single 12" shell that releases 12 smaller shells along the way. Just for reference. A 12" shell is a little bigger than a basketball. I got to push the button to launch it. Thats me counting down at the beginning. Notice the never ending echo. http://www.youtube.com/watch?v=Kn-IkZxYd0A An assortment of 8" and 10" shells. http://www.youtube.com/watch?v=LohVC3pwF6M Just a big loud shell... http://www.youtube.com/watch?v=6H17a-kCzNQ
Did you try the closest scrap yard or Ebay?