A leak occurring in a pneumatic system operating with a nonvolatile gas such as nitrogen poses little danger, while {HEAD ~ a leak} occurring in a hydraulic system can result in {TAIL ~ contamination} of the oven or the workpiece or fire risks if a flammable hydraulic fluid is used 
result in
A leak occurring in a pneumatic system operating with a nonvolatile gas such as nitrogen poses little danger , while { HEAD ~ a leak } occurring in a hydraulic system can result in { TAIL ~ contamination } of the oven or the workpiece or fire risks if a flammable hydraulic fluid is used
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD 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 OTH OTH