6U - DIU Series Round Hub Positive Displacement Pumps

6U - DIU Series, Round Hub, Internal Gear, Positive Displacement, PumpsThe Universal Pump Design combines the innovation of our UniverSeal shaft seal, the rugged simplicity of Haight's proven "gear within a gear" internal gear configuration, with the flexibility of a bolt-on, integral Relief Valve assembly. This combination of pump features offers pump users unsurpassed flexibility to adapt their pumps to changing system requirements.

Universal Relief Valve - the relief valve assembly can be added at any time, in the field, with no special tools. The valve can function in either the return to suction mode, or return to tank mode. Available with three different tension springs, the relief valve operates smoothly and effectively over a broad range of setting values.

"Gear within a gear" Internal gear design - For nearly seventy years, this design has demonstrated it's effectiveness in handling a broad range of applications while operating at standard motor speeds, and reducing wear. Both of these operating characteristics play an important role in minimizing overall capital investment, and operating expenses.

Our UniverSeal shaft seal configuration represents a significant advance in gear pump design. The UniverSeal incorporates standard, easily available seal components with a readily adaptable pump geometry. The pump can be easily converted in the field from Lip to Mechanical to Packed Gland shaft seal type without even disconnecting the piping. Flow direction in the pump can also be changed without disrupting the attached piping, or special tools.

All UniverSeal Shaft Seal Pumps Features:

  • reduce maintenance expenses - simple, quick seal changes
  • less production disruption and downtime - perform maintenance in place rather than in the shop
  • reduce maintenance inventory - one pump can be adapted to meet many application requirements
  • provide future adaptability - easily change the pump as your needs change
  • reduce replacement parts costs, no special custom design parts
  • interchangeable with existing Haight pumps without modification
  • pumps specified with an integral relief valve can be quickly and easily changed to perform in either suction return, or tank return mode. The relief valve can be readily changed to operate in either clockwise or counterclockwise flow direction.


  • Capacity range is: Not Available
  • Gear Design: Involute Gear
  • Construction Material: Ductile Iron
  • Capacity (max): 6 gpm
  • Discharge Pressure (max): 250 psi
  • Temperature: 620 ºF

Haight Internal Gear Pumps