The upper portion of housing 4 contains {HEAD ~ the aforementioned impeller} 6 immersed in {TAIL ~ a viscous fluid} 18, the fluid completely fills the upper portion of housing 4 
The upper portion of housing 4 contains { HEAD ~ the aforementioned impeller } 6 immersed in { TAIL ~ a viscous fluid } 18 , the fluid completely fills the upper portion of housing 4
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH