Preferably, a duct extends from {TAIL ~ the annular chamber} into {HEAD ~ the fluid tight volume} 
Preferably , a duct extends from { TAIL ~ the annular chamber } into { HEAD ~ the fluid tight volume }
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD