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Pinch valves

Posted: Thu Feb 16, 2012 12:45 pm
by wetmonkey442
Has anyone ever tried using pinch valves in a full-size homemade? For my next project I'm going to try a clamp-and-tube style pinch valve. I think that the implementation of pinch valves has the potential to solve a lot of the ergonomic issues that most homemades suffer from.

Re: Pinch valves

Posted: Thu Feb 16, 2012 1:01 pm
by isoaker
I would suspect, though without any real experience, that pinch valves may not be able to keep in the sorts of pressures those who make homemades wish to achieve with their creations. Then again, it may hold, while not perfectly, good enough such that not too much pressure bleeds out prior to wanting to fire.

:cool:

Re: Pinch valves

Posted: Thu Feb 16, 2012 1:16 pm
by wetmonkey442
Yeah, I agree.

I was sort of inspired by my XP 75 which, despite being quite old, still shoots beautifully. I'm really excited about this project, but I'm going to wait to reveal the details until I have some good pictures to post. Soak on!

Re: Pinch valves

Posted: Thu Feb 16, 2012 2:07 pm
by HBWW
Aside from leaks and being unable to handle high pressure, flow is also a significant concern and will likely limit performance significantly. I don't see a tube larger than 1/4" working well for pinching, but with something that small, you might as well just buy a stock blaster.

Re: Pinch valves

Posted: Thu Feb 16, 2012 9:31 pm
by Nitro123PG
From what I've heard, pinch valves can't hold much pressure and leak very easily. It would be alright for a pistol, but anything larger should use a pull or ball valve.

Re: Pinch valves

Posted: Fri Feb 17, 2012 3:28 am
by marauder
The XP 75 is a fun blaster. I really love my mk3.

Image

Re: Pinch valves

Posted: Fri Feb 17, 2012 9:00 am
by wetmonkey442
CA99 wrote:Aside from leaks and being unable to handle high pressure, flow is also a significant concern and will likely limit performance significantly. I don't see a tube larger than 1/4" working well for pinching, but with something that small, you might as well just buy a stock blaster.
Well, I think that might be the problem with contemporary homemade design. Large diameter piping leading to nozzles decreases effective firing angle and reduce stream velocity. I'm actually planning on making a homemade with slightly smaller diameter piping on everything except the pump. Historically we used 1/2" PVC because it was the smallest easily available size. After a long time, people began to accept 1/2" as the default size for homemades, but why not smaller?

The hope is that a homemade CPH or APH will have superior range than a stock CPS, but in reality most end up falling short. I don't think the problem lies in the amount of power we can generate, but in the flow of the water through the system. We've thought a lot about nozzle design, but what about a simple reduction in pipe size? All stock CPS blasters use MUCH smaller diameter piping internally, just take a look at any internals picture.

1/4" and 3/8" PVC is easily available online, and might be worth checking out, if not for anything else but simple experimentation.