"simon beer" wrote in message
...
Would someone be able to tell me please what a negative head pump does
over
a so called ordinary pump or I suppose what is negative head. Is it just
when the pump is positioned lower than where you are pumping to? many
thanks

I believe it means, in an open system, that the pump may be situated above
the level of the water in the header tank. It sucks, in other words, rather
than just circulating. The head referred to in "negative head" is that
presented to the pump at the inlet, not what it develops on the outlet.


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)