Constant Water Pressure/Flow Concept

Threads about how water guns work and other miscellaneous water gun technology threads.
Locked
dizzyd
Posts: 6
Joined: Mon Nov 26, 2007 4:07 pm

Constant Water Pressure/Flow Concept

Post by dizzyd » Mon Nov 26, 2007 5:00 pm

Ok, this is my first post and my first attempt at designing and building a water cannon - or more accurately in this case a water machine gun.

I got the idea while playing with water guns while driving in a http://www.polarisindustries.com/en-us/Ranger/2008Navigation/700Series/XP/ Polaris Ranger. We would chase each other around the ranch in these rangers and shoot water guns at one another. Nice harmless fun but you do have to get pretty close and learn to shoot a moving object while on the move yourself and dealing with distance and wind velocities. Anyway....

Since the Ranger is a mobile platform we use a 55gal drum to refill the water guns - but why not turn the 55 gal (plastic, very heavy duty) drum into a water gun!

Basic concept: Utilize an EWP (electric water pump) that is made for high performance cars. and pump the water to a gun mechanism with an electric trigger (poppit valve or other valve system) see stcvalve.com and/or jeffersonvalves.com.

The result: a very high pressure/high flow water gun that can deliver steady streams or constant pulsed water shots via the programmable electric switch.

I estimate the cost of this project to be around $600 to $700 and probably 160 man hours of work and testing.

I'd like to get any feedback possible.

So far I have the following questions that i have yet to figure out.

1. The EWP produces between 80 gal per min to 110 gal per min flow. That is through the typical 1 1/8 to 1 1/2 inch fitting. Reduced down to 3/8inch what will the PSI be? Will it be enough to shoot water a distance of say 35 to 50 feet?

2. Any electric valve requires the water to take a different path and reduces the diameter then expands the diameter again. This will play havoc on the pressures and the turbulence in the water stream so I'm looking for a way around this but I still want an electric valve/trigger to activate the water gun.

I've learned a lot already from readying the physics portion of this forum so any tools you can suggest on resolving my problems will be greatly appreciated. Obviously the fluid dynamics and the multiple complexities of using high pressure hoses and reduction valves will complicate matters quickly.

Anyway - this newbie is looking for advice and help.

David

User avatar
Silence
Posts: 3825
Joined: Sun Apr 09, 2006 9:01 pm

Re: Constant Water Pressure/Flow Concept

Post by Silence » Mon Nov 26, 2007 10:37 pm

Welcome to the forums! :)

Such a water gun is certainly feasible. Here are some threads in which a turret or mounted water gun was discussed:
Lada artillery advice
Advice on Building Truck-Mounted Water Cannon
Pirate ship water cannons?

And here are a few more technical threads, which are probably more useful:
SuperCAP
MOARC

Yes, the electric switch would be the main killer. I'm not sure what specific type of valve you're looking for, but solenoid sprinkler valves at the most common. They're definitely bad choices because they will constrict flow (smaller internal diameters, along with lots of twists).

A better choice if you still want electric would be a motor-powered ball valve. McMaster-Carr sells them, but I've forgotten what the largest sizes are.

But if you turn on the pump only when firing, you may not need a valve. I'm not sure. The problem with that method is the stream may not have entirely constant pressure, and there may be a good deal of turbulence.

Nevertheless, I would avoid focusing on the 55-gallon tanks. Since you're dealing with heavy-duty pumps and perhaps metal or large PVC tubing, you might as well use metal or PVC pressure chambers. At lower pressures you could even use rubber tubing, although it might wear down quickly.

Good luck! (Oh, and a system that pumps air instead of water might work, like with SuperCAP. Then you'd have to deal with refilling and pressurization, though.)

User avatar
Drenchenator
Posts: 807
Joined: Fri Jun 18, 2004 12:00 pm

Re: Constant Water Pressure/Flow Concept

Post by Drenchenator » Mon Nov 26, 2007 10:48 pm

A good valve would be the actuated ball valves on McMaster. They have electric ones, but they only work with AC.

Electrically Actuated— Actuators are permanently lubricated and have a manual override. They have a 1/2" electrical conduit connection; operate on 115 VAC, 50/60 Hz; and mount in any position. 90° rotation cycle time is 6 seconds. Actuator temp. range is 40° to 150° F.

The prices are very steep though (at least 400 USD). The largest size is 2" at at least 900 USD.

In short, ball valves are really the only good valves for water guns. The rest just disrupt the stream horribly.
The Drenchenator, also known as Lt. Col. Drench.

User avatar
SSCBen
Posts: 6449
Joined: Sat Mar 22, 2003 1:00 pm

Re: Constant Water Pressure/Flow Concept

Post by SSCBen » Tue Nov 27, 2007 3:07 am

Welcome to SSC!

To answer #1, you'll easily get greater than 35 feet of range with 80gpm. 80gpm is about 5 liters/s. That's very high water output, equivalent to about 166X on the Super Soaker scale. I wouldn't be surprised if you could get over 70 feet of range with that sort of water flow. Water flow is what matters for water gun performance, not pressure.

What you're proposing isn't completely clear to me. Are you suggesting using the pump to pressurize a 55 gallon drum and then release the water from there with a trigger? Or are you pumping water from the tank straight to a nozzle with some sort of intermediate trigger. It seems you're doing the first idea. I would suggest the second idea because the 55 gallon drum doesn't have to be under pressure and you don't need a second valve. You can actuate the electric pump instead. I'm pretty sure that's how the engine powered water gun posted before works.

;)

ben@sscentral.org / Please read this before emailing or PMing me

Do not ask me water gun questions by email or PM. Please post the question at the forum. Private questions and suggestions are welcome by PM and email. Also, I do not sell or buy water guns online.

dizzyd
Posts: 6
Joined: Mon Nov 26, 2007 4:07 pm

Re: Constant Water Pressure/Flow Concept

Post by dizzyd » Wed Nov 28, 2007 1:58 pm

Ben wrote:Welcome to SSC!

To answer #1, you'll easily get greater than 35 feet of range with 80gpm. 80gpm is about 5 liters/s. That's very high water output, equivalent to about 166X on the Super Soaker scale. I wouldn't be surprised if you could get over 70 feet of range with that sort of water flow. Water flow is what matters for water gun performance, not pressure.

What you're proposing isn't completely clear to me. Are you suggesting using the pump to pressurize a 55 gallon drum and then release the water from there with a trigger? Or are you pumping water from the tank straight to a nozzle with some sort of intermediate trigger. It seems you're doing the first idea. I would suggest the second idea because the 55 gallon drum doesn't have to be under pressure and you don't need a second valve. You can actuate the electric pump instead. I'm pretty sure that's how the engine powered water gun posted before works.

;)


70 Feet would be awesome! (ooops its 80 to 100 LITERS Per Min)

The drum is not pressurized it is just the reservoir for the water. The Polaris Rangers have a little truck bed in the back so strapping down a barrel is no problem. The EWP (Electric Water Pump) will be mounted on the outside of the barrel and used to draw water OUT of the barrel. The EWP I plan to use is for use in high performance street/race cars. http://www.hrpworld.com/index.cfm?form_prod_id=747,587_3529&action=product

They run on 12V naturally so hooking into the Rangers Power system is no problem. I'll have to manufacture the hose hookup from the barrel to the pump (2inch). The H2O out side of the pump will start out as a 2inch pipe/hose but quickly reduced to a quarter (1/4) inch high performance hose that will connect to the trigger housing and mechanism.
Dizzy D
The tree of liberty must be refreshed from time to time, with the blood of patriots and tyrants.

User avatar
SSCBen
Posts: 6449
Joined: Sat Mar 22, 2003 1:00 pm

Re: Constant Water Pressure/Flow Concept

Post by SSCBen » Wed Nov 28, 2007 3:55 pm

80 to 100 liters per minute is very different than 80 to 100 gpm. You could easily get over 45 feet of range with that, and depending on the efficiency of the system, you could easily go into the 50s in range. Not bad at all.

Don't use a trigger actuated valve. Make a small housing that could hold a nozzle and a push button. The push button actuates the water pump. This method is a lot cheaper and probably will work better. ;)

ben@sscentral.org / Please read this before emailing or PMing me

Do not ask me water gun questions by email or PM. Please post the question at the forum. Private questions and suggestions are welcome by PM and email. Also, I do not sell or buy water guns online.

dizzyd
Posts: 6
Joined: Mon Nov 26, 2007 4:07 pm

Re: Constant Water Pressure/Flow Concept

Post by dizzyd » Wed Nov 28, 2007 4:39 pm

Ben wrote:80 to 100 liters per minute is very different than 80 to 100 gpm. You could easily get over 45 feet of range with that, and depending on the efficiency of the system, you could easily go into the 50s in range. Not bad at all.

Don't use a trigger actuated valve. Make a small housing that could hold a nozzle and a push button. The push button actuates the water pump. This method is a lot cheaper and probably will work better. ;)


Yep, I didn't notice the unit of measure the first time I looked at the pumps. Higher volumes are available but they get into the $600 range. ouch.

For a base model you are correct a simple on off switch for the pump would work well. The reason I'm going with an electric ball valve is so that I can later add a DL05 from AutomatedDirect.com. It is a PLC direct logic unit that will allow me to program different trigger reactions and include various gauges and on/off switches.

This will allow me to switch from a single burst (as long as I'm holding the trigger) to 3 2second bursts, or 5 1 second bursts or whatever we come up with and I could select fire between each mode.

The DL05 also will allow be incorporate water full level and cut power when the water is to low so the pump will not burn up. As well as pressure indicators on the 2in line as well as the just after the reduction valve. This will allow monitoring of the complete system. The DL05 is only about $100 but with the accessories I'm talking about will quickly jump up to about $500.

All in all this whole project is looking to be around $2100. I know this is alot but what the hell. It could be really cool! My original est was $600 so each day it gets more expensive and complicated. :D

Thanks for your help/advice!
Dizzy D
The tree of liberty must be refreshed from time to time, with the blood of patriots and tyrants.

User avatar
SSCBen
Posts: 6449
Joined: Sat Mar 22, 2003 1:00 pm

Re: Constant Water Pressure/Flow Concept

Post by SSCBen » Thu Nov 29, 2007 3:02 am

Sounds interesting, but I think the simpler solution of a push button would work fine. Taping the button is always a possibility if you want burst shots. You can add an indicator to the water tank to let you know when it's running low. KISS (Keep it simple, stupid) is a good rule, so I'd alway suggest the simplest method. When you add complication, you're just adding more chances for the system to go wrong. When I could do something in a way that would be simpler, cheaper, easier to set up, and just as good, I'd do it that way.

I'll admit I don't know anything about PLCs, but that seems to be overkill for a simple water gun project. Just my opinion. :p

ben@sscentral.org / Please read this before emailing or PMing me

Do not ask me water gun questions by email or PM. Please post the question at the forum. Private questions and suggestions are welcome by PM and email. Also, I do not sell or buy water guns online.

Locked