BYPASS LINE B044
A bypass line is commonly used to connect the pump’s discharge to a lower pressure point in the system to allow the pump to operate closer to its best efficiency point (BEP).
You should try to avoid connecting a discharge bypass line to the pump suction because it will add additional heat to the incoming fluid and could cause a cavitation problem. You’ll be better off going from the discharge side of the pump to the source tank on the suction side.
A bypass line can used to re-circulate fluid from the pump discharge to the stuffing box and increase stuffing box pressure and prevent vaporization in the stuffing box. This is called discharge recirculation
Many times you can connect the stuffing box to the pump suction and clean up the stuffing box fluid if there are solids in the pumpage. This is called suction recirculation.