PACK OF 2. Comet 1800.0012 Buna Diaphragms. Excellent replacements for worn or damaged diaphragms on the Comet APS101, APS121, APS145, IDS1000, IDS1401, IDS2001, IDS2200, and IDS2600 Diaphragm Pumps. Once you notice the oil in the sight glass is milky grey in color, stop running the pump and replace the diaphragms immediately. This is a good indication that the diaphragms are damaged. Running a diaphragm pump with damaged diaphragms can destroy your pump beyond repair.