Pneumatic questions, sorry!

**Max** · 23rd July 2011, 20:13

why do you need a buffertank in an fp system because surley (due to the lack of a regulator) the pressure between the main tank and the buffertank would equalize meaning the co2 would condense in the buffer tank filling it up with liquid co2 and then it would just become a second main tank ? also, will the tank ice up/ freeze more or less in a fp system than a lp system and is there any way of reducing/stopping this?

**woody** · 23rd July 2011, 20:37

You should not get much ...if any ..condensate from F.P. gas transfer.

**woody** · 23rd July 2011, 20:44

The freezing is caused by the liquid co2 turning to gas.... it boils ...to do this it requires energy ...the energy to boil is taken either from the liquid itself ...making it colder and possibly even turning the liquid to ice ... and the surroundings such as the bottle and the atmosphere immediately around the bottle.

A fire extinguisher bottle doesn't freeze when used because a vast majority of the liquid expansion to gas occurs outside the bottle... the liquid is ejected and becomes gas / snow after exiting the nozzle and the atmosphere supplies all the heat energy for the liquid expansion to gas.

So it's heat transfer to the liquid...if you can improve it then you can derive some benefit.

**Max** · 24th July 2011, 08:42

Sorry but i still can't see the point in a buffertank in a hp system, I have a vague understanding of why you need one in a lp system (because it takes some time for the regulator to start and you want the ram to start extending instantly) but there is no regulator in a fp system so why bother with the buffertank?

**maddox10** · 24th July 2011, 09:15

Originally Posted by Max

Sorry but I still can't see the point in a buffertank in a hp system,

I do.

but there is no regulator in a fp system so why bother with the buffertank?

The valve in a paintball botle has a 2mmÂ² hole, a Burkert valve has a hole of 126mmÂ².

I have a vague understanding of why you need one in a lp system (because it takes some time for the regulator to start and you want the ram to start extending instantly)

A tiny wrong idea if you ask me. A regulator starts regulating from the moment the pressure drops below the set pressure.
But has a certain capacity in let trough. (CV)
A small regulator has small holes to let the gas flow, you just can't fit a 16mm hole in a 15mm diameter body.

**woody** · 24th July 2011, 11:03

The valve in a paintball botle has a 2mmÂ² hole

and often even smaller ....the internal hole that the tapered needle seats into on two of my paintball valves is around 1mm dia ( approx 0.8mmÂ² ).... and this hole also takes the gas direction thru a right angle thus reducing the flow even further.

**maddox10** · 24th July 2011, 14:21

A different type then from mine, the ones I had (and leaked, therefor could be disassembled) used a teflon washer on a seat that is part of the burst disk assemby. And messuring that hole ain't easy. And the right angles don't help the flow.

I hope Max sees the reasoning for a buffertank now.

**Max** · 24th July 2011, 14:55

Ok, deffinitly going to use a buffertank! Are you allowed to make your own bottle to give it a bigger opening and also an internal and external heatsink to reduce freezing?

**maddox10** · 24th July 2011, 17:55

If your storage bottle has all the needed paperwork concerning pressure testing and such, you can.

Heatsink in the bottle. Can you give me a drawing or scetch about that?

External heatsink. Good plan,if you have the roomand weight to spare.