All Springer/NP/PCP Air Gun Discussion General > Machine Shop Talk & AG Parts Machining

Understanding valves [beginner]

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I have a 1322 valve that I have taken apart to understand it.  Also am modeling it in FreeCAD.  My apologies, I don't even know the correct terminology yet.  Is there a write up of valves and terminology?  Some kind of primer?  Eventually I want to get to the point of making valves, but one has to start somewhere...  My model doesn't have the Crosman sealing cone, it is a flat top valve.  I really don't know much about this stuff, so please pardon my trivial questions.  I only used calipers to measure things, I will end up using a micrometer to confirm some values, although it is tough to get good readings inside the bore.

First silly question, is the intake air sealing done on the conical part or the flat part?  Does anyone know the valve angle?  I'm guessing 60 degrees, but that is eyeballing it, at the moment, I don't have any way to measure it.

The plastic pieces are delrin or something like that?  I have seen where advanced users use peek.  For the poppet, it appears the seal is on a knife edge.  I have yet to model that side of the valve.  Is this angle critical?  For the poppet shaft, what are typical clearances?  Through the housing and for the air path?

Does anyone have a section view of this or other valves?  Dimensions or drawings?  I'm plodding along with this drawing, sort of to understand things better, and getting a little bit of CAD practice.

Moderators, if this is the wrong place for this post, please move it (and let me know where it went :) ).

A PCP valve might be an eaiser starting point since they don't (usually) have a check valve on them.

Probably, but, I don't have a spare one to take apart, yet.  I'm just starting out, trying to understand the terminology and basic aspects.  So I'm roughly attempting to draw what I have, with looking at how it is made/machined.  I have machining capability, but have yet to figure out the order of operations to make something like this.  I'd make any valve at this point, just to get some experience at it.  I'd have to grind my tooling, so it's best to figure out most of the operations and then proceed to mess it up  ;D

Don't have an idea of the tolerances, just yet, nor the inner dimensions to any degree of precision.  If I practice some, I will remember how to use the half ball hole gauges again.  The bores are too small to use a standard telescoping bore gauge.  No gauge pins or inside micrometer here either, so it's tough to get the inside measurements right.  I do know that it all has to fit, so there is some sort of bound - like a slip fit.

Here's some more of the valve, the other half.  Need to do the poppet and the knife edge seal.  Sort of subtracting it out of the body, kind of like one might machine it.  Those are pseudo threads, real helical threads make the poor computer work hard for little benefit.  Was a little tricky to line them up.  Still need to enlarge the area around the poppet shaft, got to measure that first.

Rob M:
very good cad work, this in the modern era may be a more important skill than machining.. As far as understanding the valve , i think your animation pretty much explains it. theres good youtube resources explaining it well

the plastic parts in a 1377 are nylon. The taper does the sealing on the check valve as I recall.
Something you overlooked in the rear drawing was the thrroat. the throat is a larger diameter section below the transfer port section , as you have it drawn , air could not passs the valve stem,


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