Catalysts beds are used through out the refining process and can be negatively impacted by particulate contamination in two main ways. Fine particles can plug the flow pathways within the catalyst bed and general particulate contamination can cause deactivation of the catalyst. The use of either polypropylene filters such as SupaPleat II or SupaSpun II or nylon filters such as VisClear rated at 5-10 µm are an effective method to reduce the occurrence of these problems. We also offer SupaMesh sintered metal and woven mesh elements for high temperature and aggressive gas processes. Often these filters are also used downstream of the catalyst bed to retain any catalyst particles that may be shed into the process stream.