1. Exit piping of tank 2 (T2); 2. Elbow of the upper
recirculation pipe of T2; 3. Left elbow of lower pipe, left of positive
displacement pump; 4. Right side of lower pipe, immediately
before positive displacement pump; 5. Lower pipe, immediately
after positive displacement pump; 6. Bottom exit of T2; and 7.
Bottom exit of tank 1 (T1)