Two motor compressor units of {HEAD ~ the vertical shaft type} are housed in {TAIL ~ spaced parallel relation} in a common sealing housing 
Two motor compressor units of { HEAD ~ the vertical shaft type } are housed in { TAIL ~ spaced parallel relation } in a common sealing housing
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH