The AXI Pre-Filter System is designed to provide large-capacity, heavy duty pre-filtering when used as an accessory to AXI MTC Mobile Tank Cleaning Systems, or as a stand alone pre-filter unit. AXI Pre-Filter Systems facilitate the tank cleaning process by trapping extraordinary amounts of sludge, rust, scale, and other contaminants upstream. Utilizing an AXI Pre-Filter assembly provides a substantial reduction in the cost of consumables during a tank cleaning operation because pre-filter bags are inexpensive compared to fine filtration methods. AXI Pre-Filter assemblies can include a hose-kit to connect the pre-filter to the MTC System. Optional pre-filter assemblies include ball valves for the inflow and outflow lines, a drain valve, and a vacuum gauge to indicate the need to change the filter bag. The PF-30 HD is able to be mounted on a heavy-duty aluminum two-wheel cart for ease of mobility and setup.