Innards of a "European" QEV

[BeaverRat]

Well, I decided to take apart one of my 3/4" European QEV's to model it accurately in GGDT. Here are the specs:

-3/4" (pipe threads) input/pilot, chamber, and exhaust ports
-3/4" (actual) diameter diaphragm seat
-1.5" diameter diaphragm (extrememly light)

This particular model works very well, becuase it has no support struts in the pilot and exhaust ports.

[Gun Freak]

Wow, the internals look very nice! Is it a diaphragm or a piston? I want to get my hands on one of those, but I don't really have the need for one. Hell maybe 10 of them will show up at my doorstep

[BeaverRat]

Yeah, it's pretty beautiful construction... It is nickle plated brass.

Oh, and it is a piston design. Plus, it opens far enough to have no flow restriction too!

[inonickname]

Yeah, it's pretty beautiful construction... It is nickle plated brass.

Oh, and it is a piston design. Plus, it opens far enough to have no flow restriction too!

It will still have flow restriction. You can't take air through bends like that and not lose flow or efficiency.

Nice photos. I have a belpro (rectangular) QEV and the innards are similar. The pistons are practically identical except for color.

[BeaverRat]

It will still have flow restriction. You can't take air through bends like that and not lose flow or efficiency.

Of course, I am just refering to the fact that the distance the piston slides back is enough to theoretically provide no flow restriction.

[jhalek90]

i bought 7 of these off of ebay for 35 dollars.

one thing to watch out for, if you take it apart, there is an o ring that you dont want to mess up in the pilot section. It seals the removable pilot side "cap"

in my experience, they work very very well, and are powerful little valves.

mine have been to 500 psi.... no problems yet.

[jackssmirkingrevenge]

This particular model works very well, becuase it has no support struts in the pilot and exhaust ports.

What do you expect, it's European

[Insomniac]

What, so Europeans don't have support struts in their pilot or exhaust ports?

Yes, I'm aware that this joke does not even make sense.

[dewey-1]

Well, I decided to take apart one of my 3/4" European QEV's to model it accurately in GGDT.
This particular model works very well, becuase it has no support struts in the pilot and exhaust ports.

The title implies that this style of QEV is only European.
It is not true. They are available world wide!

Rewrite the title to Inside a Piston Style QEV.

http://www.mead-usa.com/products/media/ ... athers.pdf

The difference is in how the valves ares constructed that determines the diaphragm type. They both use diaphragms, the difference is the shape.
Cup style are the "piston" type diaphragm. Both styles of constructions are available world wide.

McMaster Carr sells this brand;
http://www.deltrolfluid.com/pdfin-line/in-line17.pdf

edit

[POLAND_SPUD]

well yeah but we refer to it using this term... that's due to the fact that it is the most popular QEV offered in europe, while in the USA those sold by mcmaster are more popular...

sure we can say something like 'that round QEV' but it doesn't make much sense

[Ragnarok]

The title implies that this style of QEV is only European.

It's just what they get called. Not all that long ago, simply seeing the style of the QEV meant you could tell with some reliability whether the launcher had been built in Europe or the US.

It's not the best naming system out there, but it's like "American muffins" and "English muffins". Both can be made, or indeed bought, pretty much worldwide, but the naming still persists - it's good enough to differentiate the two.

[dewey-1]

All I am saying is that both types are available world wide.

Edit content.

[Ragnarok]

Anyway, for the sake of doing something a bit more relevant to the thread's original purpose than worrying about naming, I disassembled my 1/2" QEV (Piston or European style, whichever you prefer) earlier, and took some measurements.

1/2" BSP threading.
35.1mm piston diameter.
14.2mm seat diameter.
4.4mm piston movement.
4.76 gram piston.
15.3 cc internal (chamber side) volume, not including volume in the threaded port.

Internally pretty much identical to the pictures above (save for the fact that a few years of use has introduced a light coating of muck to the internals).