When selecting parts for tanker trailers, you must prioritize material compatibility and pressure ratings. For fuel or chemical tankers, ensure valves and seals are made of Viton or PTFE to prevent chemical erosion. For pressure-related components like manhole covers and relief valves, verify they meet working pressure standards (e.g., 0.2 MPa for fuel tankers). Additionally, structural components like landing gear and axles should have a load capacity exceeding the trailer's Gross Vehicle Weight Rating (GVWR) to ensure safety under full load.