A slide valve 3 including a groove in {HEAD ~ said guide member} for receiving an end of {TAIL ~ said support column} 
A slide valve 3 including a groove in { HEAD ~ said guide member } for receiving an end of { TAIL ~ said support column }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL