Conveniently, although not necessarily, this will be {HEAD ~ a position} in which the reservoir is at least partially inverted, with {TAIL ~ the outlet opening} thereof in a lowermost position 
Conveniently , although not necessarily , this will be { HEAD ~ a position } in which the reservoir is at least partially inverted , with { TAIL ~ the outlet opening } thereof in a lowermost position
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH