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