Water Fountains

[kingfisher1]

hate to say buddy but i think i just heard a bubble pop.

 

[jwl868]

PVC should not be used for compressed air.

The PVC piping that is typically used in the white or grey, pressure-rated, small diameter piping used for water plumbing American Society for Testing and Materials (ASTM 1784) Schedule 40 or Schedule 80. There is other non-pressure-rated plumbing under ASTM 2665 and 3311. Electrical conduit meets a different set of standards and is not meant for plumbing.

It is not a question of pressure; it is a question of chemical resistance. The oils and high temperatures typically associated with compressed air systems weakens PVC. Over time, the system that could easily handle 250 psi will fail at 150 psi or whatever the compressor is putting out. As an analogy, consider a steel pipe carrying sulfuric acid. The pipe can handle the pressure initially, but eventually the acid will weaken the pipe and the pipe will fail.

Rigid PVC (polyvinyl chloride) pipe should not be used with compressed air. Chemtrol, a major PVC products manufacturer (owned by NIBCO), puts this warning at the bottom of each page of their PVC products catalog. "Explosive Fragmentation" is a term I've seen used in one manufacturer's warning. I found at least one Australian pipe vendor's website that includes the admonishment against the use of PVC for compressed air (although the Australian warning allows it to be buried or "protected").

A few PVC pipe manufacturers also produce ABS (acrylonitrile-butadiene-styrene) piping which can be used for compressed air. The ABS is often marketed with the rigid PVC product, but it is not PVC. There are other plastic piping material including polyethylene and polypropylene.

Nibco and Chemtrol links:
http://www.nibco.com/cms.do

http://www.nibco.com/assets/plasticfit.pdf

An Australian source (thermoplastic pipe systems)
http://www.vinidex.com.au/vinidex/l...4PVCPipesandFittingsforCompressedGaslines.pdf

Joe

 

[chieftfac]

I think the only way you can get water to stay in the column that high is to use something called "lamminar flow" It's a way of spinning the water around inside the pipe before it gets shot into the air. They use it both at Disney and at that olympic park down in Atlanta. Shoot water that high and it's going to come down eveywhere. As a former basketball player I would kill the person who got the floor wet before a game. Though as a stage tech I can't wait to see the pics!!!!

 

[jwl868]

One other follow up:

Water hammer is the result of a sudden change in the velocity of the fluid in the pipe. (The physical properties of the pipe affects the magnitude of water hammer as does the velocity of the fluid). The source of the power on the fluid (whether a pump, reservoir, or compressed air vessel) does not directly affect the water hammer. The sudden change in velocity can be caused by quickly closing (or opening) a valve (you may hear this in your household plumbing with a quick opening bathroom sink faucet), pumping at full rate into an empty pipeline that has a vertical, upward segment, and a pipeline bursting (often when an old municipal water line suddenly bursts, other weak points may begin to leak or burst too.)



Joe

 

[soundman1024]

Perhaps the best thing you can do is use gravity.

 

[ricc0luke]

Perhaps the best thing you can do is use gravity.

Water hammer is a sudden change when there is nothing to absorb the force... Thats why when you run a water pipe it runs about a foot above where the lead to the focuet is... in this foot of pipe air gets trapped and absorbs the sudden change in velocity...

There shouldn't be a problem with water hammer in this set up.

 

[Mayhem]

PVC should not be used for compressed air.

The PVC piping that is typically used in the white or grey, pressure-rated, small diameter piping used for water plumbing American Society for Testing and Materials (ASTM 1784) Schedule 40 or Schedule 80. There is other non-pressure-rated plumbing under ASTM 2665 and 3311. Electrical conduit meets a different set of standards and is not meant for plumbing.

It is not a question of pressure; it is a question of chemical resistance. The oils and high temperatures typically associated with compressed air systems weakens PVC. Over time, the system that could easily handle 250 psi will fail at 150 psi or whatever the compressor is putting out. As an analogy, consider a steel pipe carrying sulfuric acid. The pipe can handle the pressure initially, but eventually the acid will weaken the pipe and the pipe will fail.

Rigid PVC (polyvinyl chloride) pipe should not be used with compressed air. Chemtrol, a major PVC products manufacturer (owned by NIBCO), puts this warning at the bottom of each page of their PVC products catalog. "Explosive Fragmentation" is a term I've seen used in one manufacturer's warning. I found at least one Australian pipe vendor's website that includes the admonishment against the use of PVC for compressed air (although the Australian warning allows it to be buried or "protected").

A few PVC pipe manufacturers also produce ABS (acrylonitrile-butadiene-styrene) piping which can be used for compressed air. The ABS is often marketed with the rigid PVC product, but it is not PVC. There are other plastic piping material including polyethylene and polypropylene.

Nibco and Chemtrol links:
http://www.nibco.com/cms.do

http://www.nibco.com/assets/plasticfit.pdf

An Australian source (thermoplastic pipe systems)
http://www.vinidex.com.au/vinidex/l...4PVCPipesandFittingsforCompressedGaslines.pdf

Joe

Thanks for the clarification Joe – there is obviously a mix up the description of the materials, as the pipe I have seen and heard about was touted as being PVC. Obviously it is different. You are also correct in saying that the stock is generally kept in with other types of PVC pipe. I'll have to see if I can find some more info on it.

With the comment on the oils in compressed air – I would expect this to only be an issue if an automated oiling system was in place. If not, the only issue with liquids getting into compressed air is water, which should not pose any problem as PVC pipe is designed to carry water.

 

[kingfisher1]

Other questions
Have we thought about how this is giong to be operated? just some random pearson flipping a valve?

just anouther idea....
provided that the fountain works...maybe, to minimize splatter, you should pad the trough with a softer material that would act as and absorbant airbag to the water and minimize splater. maybe sand or something?

 

[jonhirsh]

I have to say this might not be coherant because i just finished drafting a show and its 230am but here i go.

I work on a kids tv show called the doodlebops where one of the leads gets dumped with a bucket of water every show, its a 5 gallon bucket. now i cant tell you how we do (disney sigh...) but i can tell you that even with a 5 foot diameter trough filled with towels the splash from this bucket goes about 10' to 14' in every which concivable direction. now of course its hitting a person and being droped from 12' up but i think you might have the same issue. water does not do what we want it to we like to think if the diameter of the jet strem is 4" then the water that falls should fall in lets even be generous and say a 4 foot radius. well it doesnt because it will hit your pipe on the way down, wind will change its path. and so on and so on if i were you i would just step back and say hey its a basket ball game lets save our production buget for things that we really need and besides the fans are going to come weither you do the effect or not , its not like you will increse your fan base by doing it.

whats the benifit to you? to your team? to the school?

are you doing it so you can add somthing to your resume?

if you are thats not a great way to make choices. pyro, water, fire there cool but if the show or sporting event in this case doesnt call for it why do it, its not wwe raw its a high school game.


again its 240am now so i hope i wasnt to offensive i didnt mean to be just tired and trying to help.

JH

 

[saxman0317]

Ive seen a hydrolic like efect used before. Imagine that you have a big plunger on one end filled with water and the tubing primed as well. Have someone puch down hard and fast on the plunger and youll get that effect at the other end. Cheap, easy to build and silent. (less things to go wrong than with air, etc. to)

 

[kingfisher1]

that'd be one massive plunger, but really like the thinking here

 

[saxman0317]

that'd be one massive plunger, but really like the thinking here

not really though. When you think about hydrolic effects, for a effective say 1/4" stream at the end, you shouldnt need more than a 7-10"coloum at the other end, and not even more than say 3-5" deep depending on how long you want to squirt the water.

 

[mbandgeek]

you can also use baking soda and vinegar. in a two bottle device (vinegar in the top and baking soda in the bottom) that had a couple of valves that close to build up pressure (you want to do this when the vinegar entered the baking soda bottle). Easily shot over 30 feet. with the right combination of vinegar and baking soda.

 

[MHSTech]

I'd like to create a water effect where water is shot in a straight column around 20 feet in the air and then falls back into a trough.

So, in other words, you want to creat a high powered complex squirt gun.

Personally, I would use a high-pressure water pump that goes either straight to the nozzel or to the nozzel through a short piece of hose. Why? There's no place that will hold pressure, and the only kind of pressure that will happen during this is backpressure from the nozzel. Also, there's going to be less places for the thing to leak or fail. Only problem I see with this is that the pump might not prime right away. In which case you would want the pump downhill from the water supply as that the water will be at the pump and no air in the line.

 

[mbandgeek]

So, in other words, you want to creat a high powered complex squirt gun.

Personally, I would use a high-pressure water pump that goes either straight to the nozzel or to the nozzel through a short piece of hose. Why? There's no place that will hold pressure, and the only kind of pressure that will happen during this is backpressure from the nozzel. Also, there's going to be less places for the thing to leak or fail. Only problem I see with this is that the pump might not prime right away. In which case you would want the pump downhill from the water supply as that the water will be at the pump and no air in the line.

that is a very interesting way how to put it. why can't you just hook up something to a hose, somehow limiting the amount of space that water can flow throughsmaller hole increases the shooting distance.

 

[Radman]

So, in other words, you want to creat a high powered complex squirt gun.

Personally, I would use a high-pressure water pump that goes either straight to the nozzel or to the nozzel through a short piece of hose. Why? There's no place that will hold pressure, and the only kind of pressure that will happen during this is backpressure from the nozzel. Also, there's going to be less places for the thing to leak or fail. Only problem I see with this is that the pump might not prime right away. In which case you would want the pump downhill from the water supply as that the water will be at the pump and no air in the line.

Only downside being noise. If that's not an issue, this may be the best idea, as they make fairly small (smaller than your tank would be) electric pumps. They use simple garden hose, heck you could have the whole setup be garden hose, run from a spout even. No tank required.