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