Pass Flow-Balancing – Symmetrical Piping
The piping that is used to split and recombine the flows should be symmetrical in both plan and elevation. This will make the flow splitting as self-regulating as possible.
If significant vaporization takes place in the passes, then additional balancing valves are needed to keep the flow split evenly among the passes. The extra pressure drop provided by the valves should be about the same as the pass pressure drop caused by vaporization at design flows.