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my pump caution

nuclear2@12

Registered User
Mar 5, 2013
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I have a 1.2cfm, is it ok to let this go constant for the whole filtration?

I thought the pump would hold the vacuum untill disconnected but it doesn't, once the pumps turned off after a couple seconds it drops the vacuum. So this pump is going to have to be operating the whole Time. My vacuum gauge shoots straight to its max at 30, I'm sire I raid my pump vacuums to 42. Will this not crack the glass flask?
 

tripletotal

Registered User
Mar 12, 2013
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Vacuum is not infinite...it can only be slightly less than atmospheric pressure (14psi at sea level, I believe).

A vacuum is simply the lack of atmospheric pressure on one side of a membrane.

So no, you cannot crush a glass flask with atmospheric pressure.

Your filter may not survive, though.
 

MDTS

Registered User
Oct 31, 2012
38
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Vacuum is not infinite...it can only be slightly less than atmospheric pressure (14psi at sea level, I believe).

A vacuum is simply the lack of atmospheric pressure on one side of a membrane.

So no, you cannot crush a glass flask with atmospheric pressure.

Your filter may not survive, though.

Exactly you will rip your filter have done twice myself. So i put a value to hold the pressure in the media bottle for a period of time at least.
 

nuclear2@12

Registered User
Mar 5, 2013
490
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0
Vacuum is not infinite...it can only be slightly less than atmospheric pressure (14psi at sea level, I believe).

A vacuum is simply the lack of atmospheric pressure on one side of a membrane.

So no, you cannot crush a glass flask with atmospheric pressure.

Your filter may not survive, though.


Ok cool so once the air is out the flask the reading on the vacuum gauge is meaningless when it goes over 14psi
 

nuclear2@12

Registered User
Mar 5, 2013
490
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The filters I am using are the fast caps from med lab and supplies the nylon membrane as its all they do filters upto 4litres.

There more expensive than the zap caps so I assume there stronger aswell? Anyone no the max psi for them?
 

tripletotal

Registered User
Mar 12, 2013
600
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The filters I am using are the fast caps from med lab and supplies the nylon membrane as its all they do filters upto 4litres.

There more expensive than the zap caps so I assume there stronger aswell? Anyone no the max psi for them?
What about putting a relief valve, essentially a controlled leak, into the system on the line between the flask and the vacuum pump?

Put a "T" in the line, add a small ball valve, and open it just enough so that you get the vacuum you desire, and not more, in the flask.
 

nuclear2@12

Registered User
Mar 5, 2013
490
0
0
What about putting a relief valve, essentially a controlled leak, into the system on the line between the flask and the vacuum pump?

Put a "T" in the line, add a small ball valve, and open it just enough so that you get the vacuum you desire, and not more, in the flask.


I like this idea, will give it ago, thanks :)
 

nuclear2@12

Registered User
Mar 5, 2013
490
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Iv made a home made release valve to drop the pressure, is it best put on the flask side of the vacuum gauge, not the pump side?
 

nuclear2@12

Registered User
Mar 5, 2013
490
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Iv have an image but it wont let me post off my phone I will need to when I'm next on a pc, but the diy valve does work great, pump is a little noisy but fuck it its doing its job. Basicly what I have is:



Pump

Horsetail x4 3/8- 1/4 tale

Vacuum gauge 1/4

Three way connector 3/8 x2

Ball valve connector 3/8 male to female.
 

nuclear2@12

Registered User
Mar 5, 2013
490
0
0
just running some veg oil to test
 

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