Question about vacuum degassing and danger of implosion

[BernardSmith]

If I use a vacuum pump to degas and use a 1 gallon carboy between the carboy I am degassing (3 or 6 gallons) and the pump should that 1 gallon carboy be filled with water or some other liquid to prevent potential implosion or is this really unnecessary? The maximum vacuum I am achieving is about 21 inches of mercury. Thanks

 

[vacuumpumpman]

If I use a vacuum pump to degas and use a 1 gallon carboy between the carboy I am degassing (3 or 6 gallons) and the pump should that 1 gallon carboy be filled with water or some other liquid to prevent potential implosion or is this really unnecessary? The maximum vacuum I am achieving is about 21 inches of mercury. Thanks

Is that 1 gallon carboy between the carboy being used as a vacuum reservoir ?
If so it should not have any liquid in it - if it is not being used as a reservoir than it is not necessary.
21'' of vacuum should not implode a known good carboy. If you are concerned -use the vacuum splash transfer method instead.

 

[BernardSmith]

Thanks Steve, Yes. I am using a 1 gallon carboy as a reservoir or trap to protect the pump in case wine from the target carboy is sucked back towards the pump. I guess my concern is whether a standard 1 gallon carboy is likely to be sufficiently robust enough to withstand the pressure of 25- 30 inches mercury (my pump typically achieves a vacuum of about 21 inches ) or whether an erlenmeyer flask is likely to be made with fewer flaws and so be stronger.
I know that there has been some discussion on this forum about how unlikely it is for the target carboy to implode but my question is about a carboy being used as a trap.

 

[vacuumpumpman]

I would assume that a 1 gallon carboy would be fine at those vacuum readings - if you are concerned - you can always purchase a medical grade vacuum reservoir. Or a single wine bottle should also be plenty strong as well.

 

[vacuumpumpman]

I did find this -
KIMAX® flask with side tubulation. Flasks are designed to take 1 atmosphere of vacuum or 29" of mercury. Sizes 25mL through 500mL have side hose connection designed to accept 5/16” I.D. flexible tubing. Sizes 1000mL and larger accept 3/8” I.D. tubing. Made with a heavier wall than a standard Erlenmeyer flask.

So it appears that the ones with the side hose connection is defintley heavier
wall glass - see this website
http://www.labsource.com/Catalog/Group.aspx?GroupID=110

 

[BernardSmith]

After chatting with Steve (Vacuumpumpman) I am convinced that a very effective and reliable way of removing the CO2 is to to transfer the wine under a vacuum from the source carboy to a clean sanitized target carboy allowing the wine to backsplash in the target carboy while under vacuum.