Gland seal Water System adjustement

[IGSAM]

Hi,
I have a question regarding adjustment of the gland seal water.
Online I can find a lot of information regarding adjustment of the stuffing box of the pump but nothing on the adjustment of the gland water itself.
My gland water is set-up so right before the pump I have a flow reading and a pressure reading. If the pump is not running my flow is at 0 and I have a pressure reading. Once the pump starts running: there is a pressure drop in the reading of the pressure gauge and evidently a flow. I do not understand fully why I have this pressure drop; is it due to the friction loss throughout the pipe during the flow, or it represent the differential pressure between the gland seal water and the slurry.
As you can see this will affect my gland water adjustment as I require gland water pressure to be 10psi higher than the discharge water of the pump.
Hoping there is an operator on this forum!
Thanks,

 

[ashtree]

Does the gland water feed system have a solenoid operated valve that opens when the pump starts and allows the water to flow to the gland? This would explain the pressure drop when the pump is running and no flow when the pump is stopped.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"