Discharge valve 12 can be moved by {HEAD ~ an adjustment mechanism} 15 in such a way that either of the apertures 13 or 14 is positioned in the flow passageway to {TAIL ~ the outlet} of exhaust line 11 
Discharge valve 12 can be moved by { HEAD ~ an adjustment mechanism } 15 in such a way that either of the apertures 13 or 14 is positioned in the flow passageway to { TAIL ~ the outlet } of exhaust line 11
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH