In some embodiments {TAIL ~ the pedestal} also has {HEAD ~ a surrounding shroud} defining an annular pumping passage around the pedestal 
In some embodiments { TAIL ~ the pedestal } also has { HEAD ~ a surrounding shroud } defining an annular pumping passage around the pedestal
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH