These openings 518 allow {HEAD ~ a cooling medium} to flow through {TAIL ~ the passage} 516, which assists in removing heat from the coils 306 a,b 
to flow through
These openings 518 allow { HEAD ~ a cooling medium } to flow through { TAIL ~ the passage } 516 , which assists in removing heat from the coils 306 a , b
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH