We have in ours Delayed Coker unit, installed filtrate system, whose function is to eliminate particules greater of 25 microns (as much Pall as RP systems), I indicate to you that during the change of drums they are themselves affected one by the volume that increases and another one by amount of solid (this depend of as operates the washing section), we have had that desinged from 33 to 50% over the necessary filtrate area that the manufacturers indicated in almost all of them, and in some until the 100%, this have depending what system were installed (pall or RP also the model), all these are filters with backwashing system
I´m sorry for my english