Upper and lower manually operated valves illustrated at 24 and 25, respectively, are illustrated for supplying air through the lines {HEAD ~ 24a} and {TAIL ~ 25a} to the air jet devices 
Upper and lower manually operated valves illustrated at 24 and 25 , respectively , are illustrated for supplying air through the lines { HEAD ~ 24a } and { TAIL ~ 25a } to the air jet devices
OTH OTH 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 OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH