Stuffing box calculation for multistage pumps

[shreyas007]

thread819-59312

My query is regarding stuffing box pressure for multistage centrifugal pump for following cases:

case a) BB2 (double suction pump) - Pressurized dual seal - Seal plan : 11-53B-61
case b) BB5 pump with balancing line - Pressurized dual seal - Seal plan : 11-53B-61

For above cases,
1) what will be the stuffing box pressure on DE/NDE mechanical seals?
2) Will Stuffing box pressure be equal to suction pressure or it will be more than suction pressure as plan 11 is provided for inboard seal ?

Thanks.