my centrifugal air compressor is not building pressure above 6.4bar although it is rated for 9bar.what would be the possible cause?

by Farrukh
(Pakistan)

Dear Sir,
my centrifugal air compressor is not building pressure above 6.4bar although it is rated for 9bar.what would be the possible cause?

please note that 1st and 2nd stage diffusers cleaned and sand blasted but no use.

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Bill says...

Hello Farrukh:

On the website TROUBLESHOOTING page, "Won't build pressure" there is quite a bit of information about why compressors don't build air pressure, yet continue to run.

However, I must confess I have zero experience with centrifugal air compressors, and throw this question out to all the super knowledgeable readers. What say? Anyone have ideas for Farrukh?

Thank you.

Bill