The valve means 17 preferrably has {HEAD ~ the magnetically operated ball} 24 of {TAIL ~ a mass} sufficiently low to permit dispersion in the range 
of
The valve means 17 preferrably has { HEAD ~ the magnetically operated ball } 24 of { TAIL ~ a mass } sufficiently low to permit dispersion in the range
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH