GP-340, 4-Passage Rotary Union, 3/8"-18 NPT Connections, Carbon Steel

GP-340, 4-Passage Rotary Union, 3/8"-18 NPT Connections, Carbon Steel
Product Code:
  • GP-340-R.A
General purpose, 4-flow passage rotary union with 3/8"-18 NPT connections, shaft O-ring face seal glands for flush mounting the union to an interface and carbon steel (black oxide) construction

Availability: 2

Additional Information

Additional Information

Downloads GP Series Catalog PDF Drawing DWG [2D] STEP [3D]
Number of Passages 4
Connection Type 3/8"-18 NPT
Max. Pressure 7,500 PSI [515 BAR]
Max. Speed 500 RPM
Media Type Air/Gas, Coolant, Oil/Hydraulic, Water/Glycol
Performance Charts Pressure vs. Speed Data
Material Type Carbon Steel
Diameter 3.875" [98.425 mm]
Length 6.980" [177.292 mm]
Min. Torque 9.5 ft-lbs [12.88 Nm]
Product Disclaimer Suitable Water/Glycol or Coolant media must have rust inhibitors present. Oil/Hydraulic media must be petroleum-based. Please consult with DSTI for approval.

Values listed are dependent on a combination of all application parameters. Please note operational life is dependent upon both rotational speed and duty cycle. Contact DSTI if your application requires operating close to the maximum rotational speed with a continuous duty cycle.

Applications with temperatures above 220° F (105° C) require alternative seal materials. Please consult with DSTI regarding your specific application requirements.

Value listed for the minimum torque required to rotate is based on zero pressure with oil/hydraulic media. Required torque to rotate may be greater when using other media types or dry running. For specific torque requirements, please contact DSTI to discuss your application.


The 4-passage, GP Series rotary unions for general-purpose use, feature a unique shaft configuration for easier installation by allowing the choice of mounting the shaft using the NPT thread connections or O-ring face seal glands for flush mounting the union to an interface.

They feature specialized sealing technology suitable for vacuum and bidirectional pressures and independent flow passages capable of transferring different media types simultaneously.

The carbon steel (black oxide) construction is suitable for air/gas and hydraulic service, in addition to water/glycol and coolant when rust inhibitors are present.

For more information, see GP Series 4-Passage Rotary Unions.