The pipes 19 contain pressurized water, e.g. at 2 4 bar, and {HEAD ~ the sprayers} 21 have {TAIL ~ respective nozzles} 21A directed downwards, i.e. in the opposite direction to the flow F1 
The pipes 19 contain pressurized water , e.g. at 2 4 bar , and { HEAD ~ the sprayers } 21 have { TAIL ~ respective nozzles } 21A directed downwards , i.e. in the opposite direction to the flow F1
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH