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