Hydrazine family fuels and Nitrogen Tetroxide are shipped in bulk quantities in Process Engineering Inc. tankers. The tankers are constructed of 304L SS and loaded and offloaded by pressurant gas via valves located on the top-aft-end of the tanker. Each tanker is actually a tank-in-a-tank which provides insulation for the contents. It also has other special crash protection features to prevent the lading vessel from failing in the event of a crash. The N2O4 and fuel versions are virtually identical with the exception of a remote valve closure device on the fuel tanker. NASA designed and built the prototype PEI tankers. DESC contract-carrier tankers deliver MMH, Aerozine-50 and N2O4 to Controlled Storage points. VAFB also has several PEI tankers for their on-base support.

PEI takers support Shuttle (MMH and N2O4 low-iron grade MON-3) operations and are used to load the Delta ELV 2nd state with Aerozine-50 and N2O4 low-iron grade MON-1 at Launch Complex 17. The vendor tankers also haul hydrazine and UDMH for blending into Aeroine-50 from the production facility to the storage facility.