<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by markfh11q
[br]OKAY, I deleted my last post. I thought we were talking about chamber sealing valves for a second...<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">
Please Mark, I'd be interested in your comments on chamber sealing valves!
I like both species!
[quote]All of these simulations are run at 100 PSI.
With design #1...
Force pushing piston against barrel: 706 net pounds
Force pushing piston away from barrel: ... need barrel outside diamter. I'm gonna go with 2-3/8", though, so: 263.2 net pounds
Sealing force: 442.8 net pounds
With this design, you would need a drop of 62.72 PSI for the piston to fire, (sealing force to equal zero). NOTE: these are in ideal conditions with equalization flow area and pilot venting flow area not taken into consideration.
This means that there will still be 37.28 PSI in the pilot volume for the piston to compress against, (once again, pilot venting flow area not taken into consideration).
~Mark<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
This reads like you are taking the information from some calculator? GDDT?
I'm missing some key knowledge on how you arrived at the 62.72 PSI drop for the piston to fire.
Can you explain?
I'd also like your ideas on variations of what you just suggested.
For example.....Let's say you had the ability to control the dump pressure behind the piston? (Throwing out pilot flow, drag, piston leakage etc)
What would happen if you brought the pilot pressure just below the firing point...say 1 lB less ...as opposed to total evacuation of the pilot area.
Does the piston dump equally well at any pressure below the firing point?
There is probably a relation between equalization flow, pilot venting flow, piston diamter, and sealing area, (area in front of piston around O.D. of barrel exposed to the 100 PSI used in these tests as an example), that can allow you to make a ratio or equation to calculate the effectiveness of a barrel sealing coaxial valve.
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I agree. I think it is a subject worth much discussion for two reasons: