APH HELP

[illi]

Hello everyone. I am planning on making a new water gun. I have a few questions for you.

If my PC's are made from 3/4" pvc, will it be as good as 3" pvc? And about how long will they have to be to hold a good amount of water?

Also, which of the designs are better, the connected PCs or the disconnected?

[WaterWolf]

Unfortunately, 3/4 inch pipe will give you much less surface-area, resulting in a massive decrease in power. There is also the fact that 3/4 pvc can hold so little water, that you would either have terrible output, low shot-time or ridiculously tall pressure-chambers.

I'd also go for the connected PC design. Given a choice between the two ideas.

[Drenchenator]

The APH is pretty much maxed out where it is now. WaterWolf is correct; the decrease in surface area kills power. If you can, buy 4" pipe, as it provides much more power and capacity.

The connections won't do anything other than provide slightly more air to compress and an extra "handle" with structural stability. As I said, the APH is optimized where it is.

[Ben]

The decrease in surface area would provide less flow simply because the pipes are smaller. The lack of water also would be a problem. I'm just reiterating what has been said though.

There is no reason to use 3/4 inch PVC for a pressure chamber. The biggest reason you want to use larger pipe diameters is water capacity. You might want to use 3/4 inch pipe to save some money. You won't save any money with smaller pipe. You'll just get a water gun that doesn't work well.

I like the top connection idea though. It'd add cost, but having a handle there would be convenient.

[Silence]

I don't think surface area will make a noticeable difference - it doesn't change the pressure within. Wider tubing can have more flow, but the flow is restricted in the 3/4" tees anyway. Capacity is the reason you want larger PCs.

[WaterWolf]

Actually, it makes a big difference on power and range.
You will get a higher level of friction per unit of water from the sides of the pipe on a smaller diameter.
Also, (and I know Ben can explain this better) if the surface area available for the air to push against is smaller, this will lead to a massive decrease in power.
A very wide (6-inch) but short (4-inch) pressure chamber will have lots of range and power for an APH. Although getting the materiel for 6-inch pipe can be quite expensive, so I wouldn't suggest it.

[Ben]

There definitely is an increase in flow from larger pressure chambers. The potential for flow is more there and the other parts just slow it down. I have seen an increase in power over smaller pressure chambers. This is what I believe is going on in water guns such as the SS 300 and the CPS series. SilentGuy is right though in that the pressures are the same so they should all be at least somewhat similar. WaterWolf, I was wrong about much I said in that old thread as were several other arguments not made by myself, but larger pipes do have an advantage over smaller ones. Think of the flow starting off as higher and then being reduced. The flow for a 3/4 inch pipe starts off lower and doesn't get reduced.

With that being said, 3/4 inch reduces the water capacity to the point where achieving performance of any kind if hard simply due to the lack of water. It wouldn't even be comparable to an APH.