suckback

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Offline thegers91

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suckback
« on: 24/11/2007 11:56:38 »
What does the term 'suckback' mean?

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Offline techmind

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suckback
« Reply #1 on: 24/11/2007 13:37:46 »
What does the term 'suckback' mean?
You'll have to explain the context. Where have you seen/heard the word used. Perhaps car fuel systems, industrial/scientific vacuum pumps, other liquid-delivery systems...?

It usually refers to the tendancy for a liquid to be "sucked back" into somewhere you don't want it to go, due to the creation of a vacuum. You then have "anti-suckback" valves/devices which either block the liquid flow, or release the vacuum in such a way that it doesn't cause problems.
"It has been said that the primary function of schools is to impart enough facts to make children stop asking questions. Some, with whom the schools do not succeed, become scientists." - Schmidt-Nielsen "Memoirs of a curious scientist"

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Offline thegers91

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« Reply #2 on: 24/11/2007 14:35:17 »
"To avoid 'suckback', the mouth of the delivery tube must be removed from the water before heating is stopped"

From a school textbook

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Offline techmind

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suckback
« Reply #3 on: 24/11/2007 19:23:14 »
"To avoid 'suckback', the mouth of the delivery tube must be removed from the water before heating is stopped"

From a school textbook
Is this in some kind of distillation experiment then?

When you remove the heat from the apparatus, the air and gas vapours inside will contract when they cool, potentially creating a vacuum.
If the bottom-end of the delivery tube was below the liquid surface (in the container that's catching the drips - the distillate) then it could literally suck back some of that liquid into the apparatus. The "sucking" is much the same as when you suck up a drink using a drinking-straw.
« Last Edit: 24/11/2007 19:24:47 by techmind »
"It has been said that the primary function of schools is to impart enough facts to make children stop asking questions. Some, with whom the schools do not succeed, become scientists." - Schmidt-Nielsen "Memoirs of a curious scientist"

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Offline JimBob

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suckback
« Reply #4 on: 24/11/2007 20:49:52 »
"To avoid 'suckback', the mouth of the delivery tube must be removed from the water before heating is stopped"

From a school textbook


Ah! Distilling whiskey again?
The mind is like a parachute. It works best when open.  -- A. Einstein