Dry Gas Seal Cleaning

[H_Eizan]

Dear Friends
We have Problem about Dry gas Seal (Tandem with intermediate labyrinth) in our Multi stage centrifugal Compressors.
Before Compressor Startup Dry gas seal purged with warm Nitrogen (from Primary Seal inlet)
But most of times this action don't work
Some Engineers Suggest nitrogen Injection from primary vent
My question is:
What is Difference between these methods?
Is there any procedure to in place cleaning of Dry gas seal?
Thanks in advance for your help

 

[Nicolas13]

What do you want to clean, the seal faces (internal or external) to avoid/reduce the process gas leakage? No chance by flushing wih N2.