piston valve question not explained in flash

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Postby jdp204 » Tue Mar 15, 2005 11:38 pm

what is it that lets the air into the chamber after the piston engages with the barrell? is it just a hole in the piston? does the piston only let air through one way? please help me out. thanks
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Postby clide » Wed Mar 16, 2005 12:30 am

Usually it is just the fact that the piston does not seal perfectly with the wall of the pipe. Air is able to leak around the piston, but if for some reason the piston has o-rings and seals perfectly with the pipe then it is just a hole through the piston (equalization hole).

In some cases the hole is made so air can only get through one way, but most of the time it just doesn't leak as fast as the exhaust valve can exhaust. So the pressure still falls in the pilot area, it just takes some of the chamber pressure with it. Usually it is not enough to matter.

Hope that makes sense.
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Postby jdp204 » Wed Mar 16, 2005 7:25 am

thanks, makes perfect sense
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