VACUUM FILTERS FOR USE IN INDUSTRIAL PROCESS MACHINES, NAMELY, PRE-COAT FILTERS, BELT FILTERS, OLIVER FILTERS, AND PRESSURE FILTERS IN THE NATURE OF FILTER PRESSES; PNEUMATIC MACHINES, NAMELY, SUBMERGIBLE PUMPS, MIXED FLOW PUMPS, AXIAL FLOW PUMPS, VOLUTE TYPE PUMPS, TURBINE PUMPS, SCREW PUMPS, AND VACUUM PUMPS