Check Valve Modification?

Build a homemade water gun or water balloon launcher and tell us about it.
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martianshark
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Check Valve Modification?

Post by martianshark » Sun Mar 21, 2010 6:26 pm

Would it be possible to modify a check valve to make a pull valve? This would allow you to add a trigger to your homemade. The flow be so probably wouldn't be very strait, but a laminator should solve this.

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C-A_99
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Re: Check Valve Modification?

Post by C-A_99 » Sun Mar 21, 2010 8:38 pm

It'd be tricky to do with a regular check valve that you buy but I could see it happening with a homemade check valve here:

http://www.sscentral.org/homemade/check_valves.html

That actually gave me an idea worth looking into: I got some parts and was looking to do a homemade check valve to save on costs for a later project (since I already have the tire valve around as well as two springs) but I could try making a pull valve out of what I have.

I still prefer ball valves for water though. The huge, linear flow coupled with a good nozzle (that's only about 7mm - it's actually a water balloon filler but works excellently as a nozzle) produces a very clean stream that gets ranges very close to a CPS 2000. (coming from a bladder that's about as powerful as the CPS 1000's, that's very impressive.)

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JuchTurtles
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Re: Check Valve Modification?

Post by JuchTurtles » Sun Mar 21, 2010 10:15 pm

You might be able to, but like what C-A_99 said, it would be tricky. I actually don't suggest it; ball valves are cheaper and easier to operate (plus no mod). Another thing is that ball valves are usually better for water; just harder to make a trigger with. So interesting thought, but just not that sensible and say convienent plus more expensive.
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C-A_99
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Re: Check Valve Modification?

Post by C-A_99 » Sun Mar 21, 2010 11:28 pm

Pull valves are good for Nerf guns and WBL's, cheaper than modified sprinkler valves.

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soakernerd
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Re: Check Valve Modification?

Post by soakernerd » Mon Mar 22, 2010 5:49 pm

It has been done. Granted, air is much less viscous than water, and you don't need high flow for nerf, but it is possible. It is similar to a horizontal mauler valve. (I think). because of the design of this type of trigger, you need an elbow or tee right after the valve. it also gets very bulky when you are using pipes larger than 3/4". Combined with how expensive check valves become in larger pipes, I just don't think it is practical or worthwhile.

Also, what would this be used for? for a WBL, it may be possible, but WBLs are so bulky that a trigger wouldn't be worthwhile.

If you try it, tell us about it.

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C-A_99
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Re: Check Valve Modification?

Post by C-A_99 » Mon Mar 22, 2010 6:25 pm

What I had in mind was to pull the check valve open instead of push, but they both accomplish the same thing and for a traditional check valve where the shut end is blocked, pushing is far easier than pulling.

Most WBL's already have "triggers" if they use a blowgun activated sprinkler valve. These are far easier and better to operate than trying to flip a torque arm as fast as possible. For WBL's however, a check valve as a firing valve may or may not work. At higher pressures the check valve may be shut tight and require tons of force to open, thus another kind of piston valve may be needed.

http://forums.sscentral.org/t4819/1.html#post38525

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martianshark
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Re: Check Valve Modification?

Post by martianshark » Mon Mar 22, 2010 7:15 pm

Heh, that looks more like what might be called a "push valve." It is probably easier to do than making a pull valve. :D

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C-A_99
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Re: Check Valve Modification?

Post by C-A_99 » Tue Mar 23, 2010 12:51 am

Martian, I addressed the push/pull valve idea in my post; please check previous posts before posting in the future. Thanks.

For the check valve pull valve, I posted a link earlier to a homemade check valve. (this was created to save costs) The valve that WaterWolf built in the link can be easily converted to a pull valve. I say easily because there's nothing that blocks the rubber seal from being accessed unlike a traditional check valve you buy in the store.

I may be able to come up with a paper design for a pull-check valve based system, but another concern is sealing between the rod and pipe system. I'd have to see how SS and garden hoses seal first. But the piston valve is probably a better idea for reasons mentioned above. (unless we're talking about using this for an easy trigger in a water gun but I still prefer ball valves)

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