Piston valves explained visually [Update 3]

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Postby MonkeyDoo » Tue Dec 28, 2004 2:11 pm

I had a visual.....

Inlet at top
__| |__
________Outlet here
^
This end capped.

The piston moves from the outlet towards the cappped end.
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Postby BillyBobJoe » Tue Dec 28, 2004 3:08 pm

<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by MonkeyDoo
[br]I had a visual.....

Inlet at top
__| |__
________Outlet here
^
This end capped.

The piston moves from the outlet towards the cappped end.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Why? Theres no pressure acting on it from there. Unless you mean the inlet is the barrel and the outlet is the chamber?
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Postby MonkeyDoo » Tue Dec 28, 2004 3:26 pm

Inlet is a connection to chamber and outlet is a connection to barrel. Let's assume I have something that triggers the piston's movement(I do, but I don't want to explain it). Would that design work?
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Postby BillyBobJoe » Tue Dec 28, 2004 3:51 pm

<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by MonkeyDoo
[br]Inlet is a connection to chamber and outlet is a connection to barrel. Let's assume I have something that triggers the piston's movement(I do, but I don't want to explain it). Would that design work?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

You mean theres a pilot valve? Even if there is, there are no forces acting on the piston, so it won't move.
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Postby MonkeyDoo » Tue Dec 28, 2004 5:02 pm

<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by MonkeyDoo
[br]Inlet is a connection to chamber and outlet is a connection to barrel. Let's assume I have something that triggers the piston's movement <b>(I do, but I don't want to explain it)</b>. Would that design work?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

I'm asking whether if the piston moved the way I said it does, would the design work?
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Postby BillyBobJoe » Tue Dec 28, 2004 5:32 pm

<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by MonkeyDoo
[br]<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by MonkeyDoo
[br]Inlet is a connection to chamber and outlet is a connection to barrel. Let's assume I have something that triggers the piston's movement <b>(I do, but I don't want to explain it)</b>. Would that design work?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

I'm asking whether if the piston moved the way I said it does, would the design work?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

NO, I've been trying to tell you that - WHY in the hell would it move!!! Theres no pressure pushing on it!!! If you switched the inlet and outlet ports it would work.

But if it moved the way YOU said it would (though it isn't possible) it would work, but the piston would have to be forced by something, and fight the pressur ein the chamber.
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Postby MonkeyDoo » Tue Dec 28, 2004 6:59 pm

I'm designing/making an auto-pneumatic. I was planning to combine the bolt and valve sine I had eliminated the other types of valves since I had no idea how to hook them up properly. I was going to use a pneumatic actuator to move the bolt, and I thought about doing the same thing to move the piston.
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Postby chewy » Tue Dec 28, 2004 11:46 pm

M.D., You would need a ram with a diameter bigger than your piston to move it. Even a 1.5 air cylinder is going to be to big to really be practical. It would be far essayer to let air pressure do the work.
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Postby MonkeyDoo » Wed Dec 29, 2004 1:12 am

Wait, chewy, why would the ram with a bigger diameter than the piston be nessecary? Assuming that

<img src="http://img72.exs.cx/img72/9135/piston13wo.png" width="449" height="355" alt="Image Hosted by ImageShack.us" />

is drawn correctly, why wouldn't the 40 PSI pushing the piston backwards move it?
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Postby chewy » Wed Dec 29, 2004 9:41 am

I misunderstood the first time. I thought you were going to pull the piston off of the barrel to fire. I have the refresh syndrome bad and keep missing posts. :(
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