Generic Propellant Transfer Unit (GPTU)
GPTUs are multipurpose portable tanks. They are pressure loaded/offloaded using either helium or nitrogen as a pressurant gas. They can be used to directly load spacecraft when connected to a propellant control panel. GPTUs are made of 304L Stainless Steel and are insulated by virtue of there double-tank design (tank-in-a-tank like a cryogenic dewar). There are ten GPTUs and they are routinely available in MMH, MPH, HPH, and N2O4 low iron MON-3 service. GPTUs are available to commercial and DOD programs on a non-interference basis.
| Equipment | Generic Propellant Transfer Unit (GPTU) |
| Dimensions | 7′ 10-3/4″ X 5’4″ Diameter |
| Weight | 5720 lb tare, 11770 lb w/N204, 9920 lb w/Hydrazine, 9370 lb w/MMH |
| Capacity | 500 gallons with 10% ullage |
| Quantity | 10 tanks |
| Connections | Fill/Drain 1.5″ KC male or reduced to 0.5″ KC (typical) |
| Pressure/Vent | 3/4″ KC male or reduced to 0.5″ KC (typical) |
| DOT Code | DOT 51 portable tank with DOT-E-10887 for N2O4 service. |
| MOP | 240 psig |
| Operating Pressure | Full vacuum to 50 psig |
| PRV Setting | 286 psig |
| Approved Fluids | Hydrazine family fuels, N2O4, and related solutions. Helium or Nitrogen gas used for pressurant. |
| Other Features | Lift with crane or forklift. Built-in load cell weighing system. Transport on special trailer. Separate work platform available. |