In article 6,
DerbyBorn wrote:


The whole system is under pressure either from gravity or from a filling
loop. There is not really a "suck" side to the pump - it is a
"circulator rather than a positive displacement pump

Then air could never find its way in?

--
*Gaffer tape - The Force, light and dark sides - holds the universe together*

Dave Plowman London SW
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