{HEAD ~ Fluid flow} through the return side filter may be accomplished using {TAIL ~ any} of three described alternative embodiments, including upflow, downflow, and direct feed 
accomplished using
{ HEAD ~ Fluid flow } through the return side filter may be accomplished using { TAIL ~ any } of three described alternative embodiments , including upflow , downflow , and direct feed
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH