The first and second stages of {TAIL ~ the compressor} are used to provide {HEAD ~ the combined compressed low and medium pressure} off gas stream 
The first and second stages of { TAIL ~ the compressor } are used to provide { HEAD ~ the combined compressed low and medium pressure } off gas stream
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH