ClimaVeneta chiller FOCS2/K 3902

Hi,
I have one chiller FOCS2/K 3902 with Bitzer compressors CSH2583 and one of compressors have - only for 1 second , un metallic sound when it stops normal.
All is OK with pressure , temperature , noises when compressor run .

I hope that this noise does not indicate a faulty compressor early.
If you've encountered the phenomenon , please , help me with information.

Many thanks

At start or stopping? Or during work?

At normal stopping , and not an every stop .
I recorded the sound but did not know how to attach registration .

Hi
This noise is probably the non return valve at the discharge port.
Good luck

Hi
I replace the non return valve .
The noise is same . Only at normal stopping .
Have you any ideas ?

Thanks