Control valves are located at the inlet ports to control {HEAD ~ the supply} of chemical concentrates into {TAIL ~ the manifold}, and the concentrates are drawn into the manifold by the operation of a positive displacement pump 
Control valves are located at the inlet ports to control { HEAD ~ the supply } of chemical concentrates into { TAIL ~ the manifold } , and the concentrates are drawn into the manifold by the operation of a positive displacement pump
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH