Hpa Dump valve ? Discussion points.

[Doc j]

Hi All ,

Not promoting anything so altered out names .

Product Description :

The ****** is a fixed volume system so only the air contained within the ******* cylinder is released down the barrel when fired. Therefore you use pressure to offset the need for more air volume to properly fill the barrel. As more pressure is put into the system, greater will be the air volume released down the barrell.


#1 Using a higher pressure doesn't necessarily translate into more air being used as it has to do with the volume of air that is being released at that pressure. Using a fixed volume system at 110psi will use no more air than an adjustable volume system at 80psi if the volume of air that both systems release is the same.

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#2 As an example, you can drop the dwell on an adjustable volume system to "under volume" the barrel at 80psi and thus reduce velocity. However, if you were to increase the pressure but not change the dwell, your velocity will increase due to the higher volume of air being released within that dwell since it is at a higher pressure. The same volume of air is being used, just at higher pressure the air expands in the barrel to fill it and propel the BB verses a slow flow of lower pressure air continuing to push the BB down the barrel.

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Those curious attached giff.
From patent drawing ,
Here's how the release system works .
Without the action of nozzle / back forward loads BB.
Assume done , inbetween trigger pull / sear , shots .
( Other attached giff / automag , seems design is sort of same working principal )

[Doc j]

Ran scenarios through GGDT.
Regards to point 1.
.30 gram BB @ 5.95 mm
.603cm I'd barrel @ 43 cm long
Assuming 1.52cm3 dead space.
Asummed Nozzle , 5 mm I'd . Same as seat ?

[Doc j]

As above .
But in relation to point 2.

[Doc j]

Hi

Maybe someone with more experience with the GGDT ,

Can explain why in the Dump ( 9999+ ms ) of valve .
In the results section : the pressure drop is not equal to the pressure in chamber .
( Train of thought if volume of chamber is completely dumped , it would equal the pressure
Drop .?)

Outside of what done above ,
To get dump valve and results of pressure drop higher ,is to reduce the volume of chamber by some 60% of the timed valve .

[jackssmirkingrevenge]

If I'm getting it right, the trigger simultaneously blocks the airflow from the main chamber and releases a blow-forward valve that dumps the firing chamber?