When {HEAD ~ the flowing oil} meets {TAIL ~ the outlet} 132, the oil drops through the outlet 132 
When { HEAD ~ the flowing oil } meets { TAIL ~ the outlet } 132 , the oil drops through the outlet 132
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH