Plan 13 - Single seals - Flush through seal chamber to suction
Description: In a Plan 13, the flow exits the seal chamber through an orifice and is routed back to pump suction.
Advantages: With a Plan 13, it is possible to increase or decrease seal chamber pressure with proper sizing of the orifice and throat bushing clearance.
General: Typically Plan 13 is used on vertical turbine pumps since they have the discharge at the top of the pump where the seal is located. Because of the difference in flow patterns, Plan 13 is not as efficient in removing heat as a Plan 11 and thus requires a higher flow rate.