StorageLocation purge for DICOM production

I'll paste the answer received by @Aya Heshmat 

Assuming the client is using a file stream and created a message header, we would expect the stream stored in the MGR/\stream folder to get cleaned with a purge. Because you can add custom code, the associated stream may not be getting deleted so they need to look at their code. If file sizes are large, global streams are preferrable over file streams since any failover would remove the reference and the stream which might be causing these items to not purge. Assuming the file path is potentially different on each failover member. if the resource is shared, I would still expect it to get purged.