A liquid drain withdraws {HEAD ~ the liquid constituent} from {TAIL ~ the vessel} at a rate determined by a level assembly 
from
A liquid drain withdraws { HEAD ~ the liquid constituent } from { TAIL ~ the vessel } at a rate determined by a level assembly
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH