# Popping Ghosts Help



## SavageEye

Need help...

Last year I did a "popping ghosts" prop. I had 3 ghosts positioned throughout the yard. I used 2 way valves and the air would push the ghosts up a post and come back down again.

My compressor line went to a 3-way manifold and then three separate lines to the solenoids. The solenoids were approximately 5', 15' and 25' from the manifold. The problem was that I could not get a lot of air to come out of the 25' line. It seems to me that if the line is pressurized, I should not have gotten loss of pressure no matter the length. Could it have been a bad solenoid? Or is my assumption wrong about the length of the run?

Here is video of my yard, you can see one of the popping ghosts at 53 seconds under the pirate flag.


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## corey872

Well, the simple answer is 'it depends'

On the 'pressure drop' - assuming a static pressure (ie the line is capped on both ends) then there should be no real drop. A gauge on one end should measure the same as a gauge on the other. 

Once you open the valve to pop the ghost, then there will absolutely be a pressure drop over the length of the line. The longer the length and/or the smaller the diameter, the lower the pressure will be on the output side. You don't mention the size of the line, but if it's 1/4 inch or smaller, then 25ft starts to become a pretty long run. 

I guess one quick way to narrow down the issue would be to swap only lines between ghosts and see if the issue follows the long line. If it does, then you have the culprit. If it stays an issue with the shorter line, then you might have a faulty valve.


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## Pumpkin5

:jol:I am zero help with your problem Will, but your haunt looks loverly! (ghosts will be ghosts....)


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## SavageEye

Thanks Corey. I will have to check the size hose that I used. It might well be 1/4". Everything you said makes sense. I will conduct the test and keep you posted.

Question though... They way I have it set up; Do the other two lines stay charged when the third line opens?

Thanks.



corey872 said:


> Well, the simple answer is 'it depends'
> 
> On the 'pressure drop' - assuming a static pressure (ie the line is capped on both ends) then there should be no real drop. A gauge on one end should measure the same as a gauge on the other.
> 
> Once you open the valve to pop the ghost, then there will absolutely be a pressure drop over the length of the line. The longer the length and/or the smaller the diameter, the lower the pressure will be on the output side. You don't mention the size of the line, but if it's 1/4 inch or smaller, then 25ft starts to become a pretty long run.
> 
> I guess one quick way to narrow down the issue would be to swap only lines between ghosts and see if the issue follows the long line. If it does, then you have the culprit. If it stays an issue with the shorter line, then you might have a faulty valve.


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## SavageEye

Thanks P5!! I will put your comment in the category of moral support! 



Pumpkin5 said:


> :jol:I am zero help with your problem Will, but your haunt looks loverly! (ghosts will be ghosts....)


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## bfjou812

Try this. It will give you the same pressure all the way around the loop, it won't have an end to it. I think it's pretty self explanatory, but if not PM me and I'll go into a full and more detailed explanation. This also will eliminate the need for auxiliary air tanks. If you need different pressures ,use full tank pressure then use a regulator before each solenoid. Hope this helps.

View attachment IMG_NEW.pdf


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## SavageEye

Thanks bfou812. That is self explanatory.

Question: What size tubing should I be using in this setup?



bfjou812 said:


> Try this. It will give you the same pressure all the way around the loop, it won't have an end to it. I think it's pretty self explanatory, but if not PM me and I'll go into a full and more detailed explanation. This also will eliminate the need for auxiliary air tanks. If you need different pressures ,use full tank pressure then use a regulator before each solenoid. Hope this helps.
> 
> View attachment 3652


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## bfjou812

The bigger the better , but what is most important is the loop.


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## SavageEye

I looked yesterday and it's 3/8" OD tubing.


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## spinman1949

ID is issue. 3/8 OD is likely 1/4. When it comes to any fluid dynamics, the ID is what is measured. 

I would offer that unless you want to provide supply tanks at the prop, you might consider installing pressure regulators at each prop. This way you can increase the supply pressure. 

Air is just like water. To get an idea. Open your water spigot with a short piece of hose attached. Notice how far the water jets. Now attach a 50 ft hose and you will see that the jet length is reduced. Just like electrical current, resistance reduces flow. The longer the hose the more resistance. Note. Do not do this test if you live in CA 

If you increase the supply pressure, the drop off will likely disappear. It will be like increasing your water pressure to maintain the same flow with a long hose.


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## Setarcos

I would suggest you try to find a location for one or more small storage tanks near your props that would be hooked up in-line with the hose from your compressor. In pneumatic systems design this is referred to as a "secondary air receiver" and serves a buffer that can deliver short bursts of high pressure when your props fire. Just google "pneumatic air receiver" and you can find some formulas for calculating air flow and the appropriate air receiver tank sizing.


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## Richie4540

The other way is to place an air tank at the prop end of the line, so that when the prop is not firing off the tank can fill and pressurise and when you fire the prop you have a large volume of air available for that prop. And when the prop has finished firing the tank will fill back up and be ready again, 

Richie


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## fontgeek

Also, test your lines and fittings for leakage.


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## halstaff

Did you get this worked out? If so, what did you end up doing to resolve the issue?


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## SavageEye

No, Haven't got it worked out yet. Have been working on my lighting project. Maybe I can bring them over and we can troubleshoot over some cold ones!


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