Hello,
my name is Arnost, I'm working for CSRC company (www.csrc.cz). We are looking for some degassing equipment and I really like this arragment: Complete Vacuum Degassing System (https://www.easycomposites.co.uk/ds26-s-complete-starter-vacuum-degassing-system But maybe I will need bigger vacuum. Could you please tell us maximal allowable pressure applied at these products:

Professional Resin Infusion Catch-Pot

https://www.easycomposites.co.uk/cp1-resin-infusion-catch-pot-small

Vacuum Degassing Chamber 26L

https://www.easycomposites.co.uk/dc26-vacuum-degassing-chamber-26l

Thank you in Advance,
Arnost Pavlik

Slightly below 1 Bar i assume ...

They will hold almost full vacuum .. which in turn means 1 Bar/Atm on the outside ..

Most oil-filled Single-stage vacuum pumps typically produce vacuum to 35 Torr (mm Hg) or 0.047 bar

Handling vacuum for composites purposes is not like using it for scientific experiments or devices that need an internal vacuum to function (Bulbs / vacuum tubes for electronics)


In short: You do not need higher vacuum than the EC "containers" can hold ..   At least not for ordinary degassing of resins e.t.c


"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

We prefer two-stages vacuum pumps. Because at previous projects we had requirement for 10^-3 Torr, for adhesive degassing.

Ok, I can see that you are dealing with Aero-Space requirements, and with the specs you are referring to, with regards to vacuum levels, you will need more specialized equipment than the semi-professional Easy-composites degassing system.

With the price levels on such equipment, you could probably afford to test the EC degassing chamber to destruction, with a sub 10^3 Torr two-stage pump- that would probably just be a fraction of the cost of a specialized Aerospace high vacuum chamber-

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

Do you have some tips for a specialized Aerospace high vacuum chamber or vacuum system?

No, sorry, not really -- most of my work have been with standard composite vac systems.

I can see that when the components you want to make has to endure hard vacuum (as i space vehicles/sats) you need to degas to a very low residual pressure.

If I had that sort of need for hard vacuum, I would probably have the chambers purpose built by a mechanical engineering company with experience in Aerospace components.

But, as I stated, first I would hook up a two-stage hard vac pump to the (in this setting) very affordable EC degassing chamber or catch-pot, and see how it copes with hard vac ..
If it works, then you are on a roll .. chances are that the only problem you will have is that it may leak very slightly, and so put a load on the high vac pump.




"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

Thanks for you tips

I don't see why the chambers couldn't hold far more pressure than absolute vacuum. Perhaps this is where my knowledge of the physics fails me, but I don't see the difference between a vacuum chamber and a pressure chamber. Ie, if a chamber can hold 100+ psi on the inside, then surely it can handle it from the outside. There is very little difference between these degassing chambers and a pressure pot in terms of structure, so I don't see why these couldn't handle 100psi? 

Hi Arnost,

Our pumps can go down to 25 micron/0.025 Torr which is not as close as you need.  The chambers themselves have been tested and routinely operated at 25 micron as is typical from dual stage rotary vane pumps.  We have not tested them down to 0.001 Torr although structurally I can see no reason why the chamber would not hold such a level of vacuum assuming the seal is in place properly. 

At that level of vacuum, even the tiniest hair or piece of dirt might be enough to breach the seal to a detectable level, although this depends on the ability of the pump you have and the measuring equipment you have. You would also need to ensure all the connection joints are perfectly sealed. You may choose to fit higher grade fittings and almost certainly will need a better gauge or sensor to monitor the vacuum level as our gauge simply cannot read at that resolution.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Not so...
An experiment I did as a school kid (many, many moons ago) was to boil a small amount of water in a tin can over a flame. The lid of the can was then put on and as the water and air in the can cooled the internal pressure reduced, resulting in the atmospheric air pressure on the outside crushing the can.