In normal operation, an inner oblique surface 46 of {HEAD ~ the seal cover} 24 meets a corresponding inner oblique surface 47 on the lip 37 of {TAIL ~ the vessel} 31 
In normal operation , an inner oblique surface 46 of { HEAD ~ the seal cover } 24 meets a corresponding inner oblique surface 47 on the lip 37 of { TAIL ~ the vessel } 31
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH