We operate a process wherein Hydrogen is recycled to a hydrotreater via a diaphragm gas compressor. We run at 1100-1300 psi discharge. After changing hydrotreater catalyst, we're going through a lot of diaphragms, the likely cause seems to be attrition/fines from catalyst. We are already using a fine metal mesh witches hat conical filter. There is also a separator in the suction line to compressor. The equipment designer says there isn't really anything else that can be done to save multiple diaphragm failures/changeouts after reloading catalyst. I was wondering if anyone has come up with anything for this problem. This is a small hydrotreater, ~25 GPM feed rate on liquid side, I can provide gas flow rates but don't have any information on the fines particle size distribution. If anyone can point me towards design guidelines for what mesh size ought to be equipped for such an application that may be helpful also. I wasn't sure if sintered metal might work here but I'd need some guidance. Seems to me it would be acceptable to suffer a higher pressure drop the first week of operation if that didn't mean going through diaphragms.